WebSVN – Kolibri OS – Path Comparison – / – /contrib/sdk/sources/Mesa/mesa-10.6.0/src/gallium/auxiliary/gallivm/lp_bld_arit.c Rev 5563 and /contrib/sdk/sources/Mesa/mesa-10.6.0/src/gallium/auxiliary/gallivm/lp_bld

Regard whitespace Rev 5563 → Rev 5564

 /contrib/sdk/sources/Mesa/mesa-10.6.0/src/gallium/auxiliary/gallivm/lp_bld_arit.c
 ,0 → 1,3587
+/**************************************************************************
+ *
+ * Copyright 2009-2010 VMware, Inc.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+/**
+ * @file
+ * Helper
+ *
+ * LLVM IR doesn't support all basic arithmetic operations we care about (most
+ * notably min/max and saturated operations), and it is often necessary to
+ * resort machine-specific intrinsics directly. The functions here hide all
+ * these implementation details from the other modules.
+ *
+ * We also do simple expressions simplification here. Reasons are:
+ * - it is very easy given we have all necessary information readily available
+ * - LLVM optimization passes fail to simplify several vector expressions
+ * - We often know value constraints which the optimization passes have no way
+ *   of knowing, such as when source arguments are known to be in [0, 1] range.
+ *
+ * @author Jose Fonseca <jfonseca@vmware.com>
+ */
+#include <float.h>
+#include "util/u_memory.h"
+#include "util/u_debug.h"
+#include "util/u_math.h"
+#include "util/u_string.h"
+#include "util/u_cpu_detect.h"
+#include "lp_bld_type.h"
+#include "lp_bld_const.h"
+#include "lp_bld_init.h"
+#include "lp_bld_intr.h"
+#include "lp_bld_logic.h"
+#include "lp_bld_pack.h"
+#include "lp_bld_debug.h"
+#include "lp_bld_bitarit.h"
+#include "lp_bld_arit.h"
+#include "lp_bld_flow.h"
+#if defined(PIPE_ARCH_SSE)
+#include <xmmintrin.h>
+#endif
+#ifndef _MM_DENORMALS_ZERO_MASK
+#define _MM_DENORMALS_ZERO_MASK 0x0040
+#endif
+#ifndef _MM_FLUSH_ZERO_MASK
+#define _MM_FLUSH_ZERO_MASK 0x8000
+#endif
+#define EXP_POLY_DEGREE 5
+#define LOG_POLY_DEGREE 4
+/**
+ * Generate min(a, b)
+ * No checks for special case values of a or b = 1 or 0 are done.
+ * NaN's are handled according to the behavior specified by the
+ * nan_behavior argument.
+ */
+static LLVMValueRef
+lp_build_min_simple(struct lp_build_context *bld,
+                    LLVMValueRef a,
+                    LLVMValueRef b,
+                    enum gallivm_nan_behavior nan_behavior)
+{
+   const struct lp_type type = bld->type;
+   const char *intrinsic = NULL;
+   unsigned intr_size = 0;
+   LLVMValueRef cond;
+   assert(lp_check_value(type, a));
+   assert(lp_check_value(type, b));
+   /* TODO: optimize the constant case */
+   if (type.floating && util_cpu_caps.has_sse) {
+      if (type.width == 32) {
+         if (type.length == 1) {
+            intrinsic = "llvm.x86.sse.min.ss";
+            intr_size = 128;
+         }
+         else if (type.length <= 4 || !util_cpu_caps.has_avx) {
+            intrinsic = "llvm.x86.sse.min.ps";
+            intr_size = 128;
+         }
+         else {
+            intrinsic = "llvm.x86.avx.min.ps.256";
+            intr_size = 256;
+         }
+      }
+      if (type.width == 64 && util_cpu_caps.has_sse2) {
+         if (type.length == 1) {
+            intrinsic = "llvm.x86.sse2.min.sd";
+            intr_size = 128;
+         }
+         else if (type.length == 2 || !util_cpu_caps.has_avx) {
+            intrinsic = "llvm.x86.sse2.min.pd";
+            intr_size = 128;
+         }
+         else {
+            intrinsic = "llvm.x86.avx.min.pd.256";
+            intr_size = 256;
+         }
+      }
+   }
+   else if (type.floating && util_cpu_caps.has_altivec) {
+      if (nan_behavior == GALLIVM_NAN_RETURN_NAN ||
+          nan_behavior == GALLIVM_NAN_RETURN_NAN_FIRST_NONNAN) {
+         debug_printf("%s: altivec doesn't support nan return nan behavior\n",
+                      __FUNCTION__);
+      }
+      if (type.width == 32 && type.length == 4) {
+         intrinsic = "llvm.ppc.altivec.vminfp";
+         intr_size = 128;
+      }
+   } else if (util_cpu_caps.has_sse2 && type.length >= 2) {
+      intr_size = 128;
+      if ((type.width == 8 || type.width == 16) &&
+          (type.width * type.length <= 64) &&
+          (gallivm_debug & GALLIVM_DEBUG_PERF)) {
+         debug_printf("%s: inefficient code, bogus shuffle due to packing\n",
+                      __FUNCTION__);
+      }
+      if (type.width == 8 && !type.sign) {
+         intrinsic = "llvm.x86.sse2.pminu.b";
+      }
+      else if (type.width == 16 && type.sign) {
+         intrinsic = "llvm.x86.sse2.pmins.w";
+      }
+      if (util_cpu_caps.has_sse4_1) {
+         if (type.width == 8 && type.sign) {
+            intrinsic = "llvm.x86.sse41.pminsb";
+         }
+         if (type.width == 16 && !type.sign) {
+            intrinsic = "llvm.x86.sse41.pminuw";
+         }
+         if (type.width == 32 && !type.sign) {
+            intrinsic = "llvm.x86.sse41.pminud";
+         }
+         if (type.width == 32 && type.sign) {
+            intrinsic = "llvm.x86.sse41.pminsd";
+         }
+      }
+   } else if (util_cpu_caps.has_altivec) {
+      intr_size = 128;
+      if (type.width == 8) {
+         if (!type.sign) {
+            intrinsic = "llvm.ppc.altivec.vminub";
+         } else {
+            intrinsic = "llvm.ppc.altivec.vminsb";
+         }
+      } else if (type.width == 16) {
+         if (!type.sign) {
+            intrinsic = "llvm.ppc.altivec.vminuh";
+         } else {
+            intrinsic = "llvm.ppc.altivec.vminsh";
+         }
+      } else if (type.width == 32) {
+         if (!type.sign) {
+            intrinsic = "llvm.ppc.altivec.vminuw";
+         } else {
+            intrinsic = "llvm.ppc.altivec.vminsw";
+         }
+      }
+   }
+   if(intrinsic) {
+      /* We need to handle nan's for floating point numbers. If one of the
+       * inputs is nan the other should be returned (required by both D3D10+
+       * and OpenCL).
+       * The sse intrinsics return the second operator in case of nan by
+       * default so we need to special code to handle those.
+       */
+      if (util_cpu_caps.has_sse && type.floating &&
+          nan_behavior != GALLIVM_NAN_BEHAVIOR_UNDEFINED &&
+          nan_behavior != GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN &&
+          nan_behavior != GALLIVM_NAN_RETURN_NAN_FIRST_NONNAN) {
+         LLVMValueRef isnan, min;
+         min = lp_build_intrinsic_binary_anylength(bld->gallivm, intrinsic,
+                                                   type,
+                                                   intr_size, a, b);
+         if (nan_behavior == GALLIVM_NAN_RETURN_OTHER) {
+            isnan = lp_build_isnan(bld, b);
+            return lp_build_select(bld, isnan, a, min);
+         } else {
+            assert(nan_behavior == GALLIVM_NAN_RETURN_NAN);
+            isnan = lp_build_isnan(bld, a);
+            return lp_build_select(bld, isnan, a, min);
+         }
+      } else {
+         return lp_build_intrinsic_binary_anylength(bld->gallivm, intrinsic,
+                                                    type,
+                                                    intr_size, a, b);
+      }
+   }
+   if (type.floating) {
+      switch (nan_behavior) {
+      case GALLIVM_NAN_RETURN_NAN: {
+         LLVMValueRef isnan = lp_build_isnan(bld, b);
+         cond = lp_build_cmp(bld, PIPE_FUNC_LESS, a, b);
+         cond = LLVMBuildXor(bld->gallivm->builder, cond, isnan, "");
+         return lp_build_select(bld, cond, a, b);
+      }
+         break;
+      case GALLIVM_NAN_RETURN_OTHER: {
+         LLVMValueRef isnan = lp_build_isnan(bld, a);
+         cond = lp_build_cmp(bld, PIPE_FUNC_LESS, a, b);
+         cond = LLVMBuildXor(bld->gallivm->builder, cond, isnan, "");
+         return lp_build_select(bld, cond, a, b);
+      }
+         break;
+      case GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN:
+         cond = lp_build_cmp_ordered(bld, PIPE_FUNC_LESS, a, b);
+         return lp_build_select(bld, cond, a, b);
+      case GALLIVM_NAN_RETURN_NAN_FIRST_NONNAN:
+         cond = lp_build_cmp(bld, PIPE_FUNC_LESS, b, a);
+         return lp_build_select(bld, cond, b, a);
+      case GALLIVM_NAN_BEHAVIOR_UNDEFINED:
+         cond = lp_build_cmp(bld, PIPE_FUNC_LESS, a, b);
+         return lp_build_select(bld, cond, a, b);
+         break;
+      default:
+         assert(0);
+         cond = lp_build_cmp(bld, PIPE_FUNC_LESS, a, b);
+         return lp_build_select(bld, cond, a, b);
+      }
+   } else {
+      cond = lp_build_cmp(bld, PIPE_FUNC_LESS, a, b);
+      return lp_build_select(bld, cond, a, b);
+   }
+}
+/**
+ * Generate max(a, b)
+ * No checks for special case values of a or b = 1 or 0 are done.
+ * NaN's are handled according to the behavior specified by the
+ * nan_behavior argument.
+ */
+static LLVMValueRef
+lp_build_max_simple(struct lp_build_context *bld,
+                    LLVMValueRef a,
+                    LLVMValueRef b,
+                    enum gallivm_nan_behavior nan_behavior)
+{
+   const struct lp_type type = bld->type;
+   const char *intrinsic = NULL;
+   unsigned intr_size = 0;
+   LLVMValueRef cond;
+   assert(lp_check_value(type, a));
+   assert(lp_check_value(type, b));
+   /* TODO: optimize the constant case */
+   if (type.floating && util_cpu_caps.has_sse) {
+      if (type.width == 32) {
+         if (type.length == 1) {
+            intrinsic = "llvm.x86.sse.max.ss";
+            intr_size = 128;
+         }
+         else if (type.length <= 4 || !util_cpu_caps.has_avx) {
+            intrinsic = "llvm.x86.sse.max.ps";
+            intr_size = 128;
+         }
+         else {
+            intrinsic = "llvm.x86.avx.max.ps.256";
+            intr_size = 256;
+         }
+      }
+      if (type.width == 64 && util_cpu_caps.has_sse2) {
+         if (type.length == 1) {
+            intrinsic = "llvm.x86.sse2.max.sd";
+            intr_size = 128;
+         }
+         else if (type.length == 2 || !util_cpu_caps.has_avx) {
+            intrinsic = "llvm.x86.sse2.max.pd";
+            intr_size = 128;
+         }
+         else {
+            intrinsic = "llvm.x86.avx.max.pd.256";
+            intr_size = 256;
+         }
+      }
+   }
+   else if (type.floating && util_cpu_caps.has_altivec) {
+      if (nan_behavior == GALLIVM_NAN_RETURN_NAN ||
+          nan_behavior == GALLIVM_NAN_RETURN_NAN_FIRST_NONNAN) {
+         debug_printf("%s: altivec doesn't support nan return nan behavior\n",
+                      __FUNCTION__);
+      }
+      if (type.width == 32 || type.length == 4) {
+         intrinsic = "llvm.ppc.altivec.vmaxfp";
+         intr_size = 128;
+      }
+   } else if (util_cpu_caps.has_sse2 && type.length >= 2) {
+      intr_size = 128;
+      if ((type.width == 8 || type.width == 16) &&
+          (type.width * type.length <= 64) &&
+          (gallivm_debug & GALLIVM_DEBUG_PERF)) {
+         debug_printf("%s: inefficient code, bogus shuffle due to packing\n",
+                      __FUNCTION__);
+         }
+      if (type.width == 8 && !type.sign) {
+         intrinsic = "llvm.x86.sse2.pmaxu.b";
+         intr_size = 128;
+      }
+      else if (type.width == 16 && type.sign) {
+         intrinsic = "llvm.x86.sse2.pmaxs.w";
+      }
+      if (util_cpu_caps.has_sse4_1) {
+         if (type.width == 8 && type.sign) {
+            intrinsic = "llvm.x86.sse41.pmaxsb";
+         }
+         if (type.width == 16 && !type.sign) {
+            intrinsic = "llvm.x86.sse41.pmaxuw";
+         }
+         if (type.width == 32 && !type.sign) {
+            intrinsic = "llvm.x86.sse41.pmaxud";
+        }
+         if (type.width == 32 && type.sign) {
+            intrinsic = "llvm.x86.sse41.pmaxsd";
+         }
+      }
+   } else if (util_cpu_caps.has_altivec) {
+     intr_size = 128;
+     if (type.width == 8) {
+       if (!type.sign) {
+         intrinsic = "llvm.ppc.altivec.vmaxub";
+       } else {
+         intrinsic = "llvm.ppc.altivec.vmaxsb";
+       }
+     } else if (type.width == 16) {
+       if (!type.sign) {
+         intrinsic = "llvm.ppc.altivec.vmaxuh";
+       } else {
+         intrinsic = "llvm.ppc.altivec.vmaxsh";
+       }
+     } else if (type.width == 32) {
+       if (!type.sign) {
+         intrinsic = "llvm.ppc.altivec.vmaxuw";
+       } else {
+         intrinsic = "llvm.ppc.altivec.vmaxsw";
+       }
+     }
+   }
+   if(intrinsic) {
+      if (util_cpu_caps.has_sse && type.floating &&
+          nan_behavior != GALLIVM_NAN_BEHAVIOR_UNDEFINED &&
+          nan_behavior != GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN &&
+          nan_behavior != GALLIVM_NAN_RETURN_NAN_FIRST_NONNAN) {
+         LLVMValueRef isnan, max;
+         max = lp_build_intrinsic_binary_anylength(bld->gallivm, intrinsic,
+                                                   type,
+                                                   intr_size, a, b);
+         if (nan_behavior == GALLIVM_NAN_RETURN_OTHER) {
+            isnan = lp_build_isnan(bld, b);
+            return lp_build_select(bld, isnan, a, max);
+         } else {
+            assert(nan_behavior == GALLIVM_NAN_RETURN_NAN);
+            isnan = lp_build_isnan(bld, a);
+            return lp_build_select(bld, isnan, a, max);
+         }
+      } else {
+         return lp_build_intrinsic_binary_anylength(bld->gallivm, intrinsic,
+                                                    type,
+                                                    intr_size, a, b);
+      }
+   }
+   if (type.floating) {
+      switch (nan_behavior) {
+      case GALLIVM_NAN_RETURN_NAN: {
+         LLVMValueRef isnan = lp_build_isnan(bld, b);
+         cond = lp_build_cmp(bld, PIPE_FUNC_GREATER, a, b);
+         cond = LLVMBuildXor(bld->gallivm->builder, cond, isnan, "");
+         return lp_build_select(bld, cond, a, b);
+      }
+         break;
+      case GALLIVM_NAN_RETURN_OTHER: {
+         LLVMValueRef isnan = lp_build_isnan(bld, a);
+         cond = lp_build_cmp(bld, PIPE_FUNC_GREATER, a, b);
+         cond = LLVMBuildXor(bld->gallivm->builder, cond, isnan, "");
+         return lp_build_select(bld, cond, a, b);
+      }
+         break;
+      case GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN:
+         cond = lp_build_cmp_ordered(bld, PIPE_FUNC_GREATER, a, b);
+         return lp_build_select(bld, cond, a, b);
+      case GALLIVM_NAN_RETURN_NAN_FIRST_NONNAN:
+         cond = lp_build_cmp(bld, PIPE_FUNC_GREATER, b, a);
+         return lp_build_select(bld, cond, b, a);
+      case GALLIVM_NAN_BEHAVIOR_UNDEFINED:
+         cond = lp_build_cmp(bld, PIPE_FUNC_GREATER, a, b);
+         return lp_build_select(bld, cond, a, b);
+         break;
+      default:
+         assert(0);
+         cond = lp_build_cmp(bld, PIPE_FUNC_GREATER, a, b);
+         return lp_build_select(bld, cond, a, b);
+      }
+   } else {
+      cond = lp_build_cmp(bld, PIPE_FUNC_GREATER, a, b);
+      return lp_build_select(bld, cond, a, b);
+   }
+}
+/**
+ * Generate 1 - a, or ~a depending on bld->type.
+ */
+LLVMValueRef
+lp_build_comp(struct lp_build_context *bld,
+              LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   assert(lp_check_value(type, a));
+   if(a == bld->one)
+      return bld->zero;
+   if(a == bld->zero)
+      return bld->one;
+   if(type.norm && !type.floating && !type.fixed && !type.sign) {
+      if(LLVMIsConstant(a))
+         return LLVMConstNot(a);
+      else
+         return LLVMBuildNot(builder, a, "");
+   }
+   if(LLVMIsConstant(a))
+      if (type.floating)
+          return LLVMConstFSub(bld->one, a);
+      else
+          return LLVMConstSub(bld->one, a);
+   else
+      if (type.floating)
+         return LLVMBuildFSub(builder, bld->one, a, "");
+      else
+         return LLVMBuildSub(builder, bld->one, a, "");
+}
+/**
+ * Generate a + b
+ */
+LLVMValueRef
+lp_build_add(struct lp_build_context *bld,
+             LLVMValueRef a,
+             LLVMValueRef b)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMValueRef res;
+   assert(lp_check_value(type, a));
+   assert(lp_check_value(type, b));
+   if(a == bld->zero)
+      return b;
+   if(b == bld->zero)
+      return a;
+   if(a == bld->undef || b == bld->undef)
+      return bld->undef;
+   if(bld->type.norm) {
+      const char *intrinsic = NULL;
+      if(a == bld->one || b == bld->one)
+        return bld->one;
+      if (type.width * type.length == 128 &&
+          !type.floating && !type.fixed) {
+         if(util_cpu_caps.has_sse2) {
+           if(type.width == 8)
+             intrinsic = type.sign ? "llvm.x86.sse2.padds.b" : "llvm.x86.sse2.paddus.b";
+           if(type.width == 16)
+             intrinsic = type.sign ? "llvm.x86.sse2.padds.w" : "llvm.x86.sse2.paddus.w";
+         } else if (util_cpu_caps.has_altivec) {
+           if(type.width == 8)
+              intrinsic = type.sign ? "llvm.ppc.altivec.vaddsbs" : "llvm.ppc.altivec.vaddubs";
+           if(type.width == 16)
+              intrinsic = type.sign ? "llvm.ppc.altivec.vaddshs" : "llvm.ppc.altivec.vadduhs";
+         }
+      }
+      if(intrinsic)
+         return lp_build_intrinsic_binary(builder, intrinsic, lp_build_vec_type(bld->gallivm, bld->type), a, b);
+   }
+   if(type.norm && !type.floating && !type.fixed) {
+      if (type.sign) {
+         uint64_t sign = (uint64_t)1 << (type.width - 1);
+         LLVMValueRef max_val = lp_build_const_int_vec(bld->gallivm, type, sign - 1);
+         LLVMValueRef min_val = lp_build_const_int_vec(bld->gallivm, type, sign);
+         /* a_clamp_max is the maximum a for positive b,
+            a_clamp_min is the minimum a for negative b. */
+         LLVMValueRef a_clamp_max = lp_build_min_simple(bld, a, LLVMBuildSub(builder, max_val, b, ""), GALLIVM_NAN_BEHAVIOR_UNDEFINED);
+         LLVMValueRef a_clamp_min = lp_build_max_simple(bld, a, LLVMBuildSub(builder, min_val, b, ""), GALLIVM_NAN_BEHAVIOR_UNDEFINED);
+         a = lp_build_select(bld, lp_build_cmp(bld, PIPE_FUNC_GREATER, b, bld->zero), a_clamp_max, a_clamp_min);
+      } else {
+         a = lp_build_min_simple(bld, a, lp_build_comp(bld, b), GALLIVM_NAN_BEHAVIOR_UNDEFINED);
+      }
+   }
+   if(LLVMIsConstant(a) && LLVMIsConstant(b))
+      if (type.floating)
+         res = LLVMConstFAdd(a, b);
+      else
+         res = LLVMConstAdd(a, b);
+   else
+      if (type.floating)
+         res = LLVMBuildFAdd(builder, a, b, "");
+      else
+         res = LLVMBuildAdd(builder, a, b, "");
+   /* clamp to ceiling of 1.0 */
+   if(bld->type.norm && (bld->type.floating || bld->type.fixed))
+      res = lp_build_min_simple(bld, res, bld->one, GALLIVM_NAN_BEHAVIOR_UNDEFINED);
+   /* XXX clamp to floor of -1 or 0??? */
+   return res;
+}
+/** Return the scalar sum of the elements of a.
+ * Should avoid this operation whenever possible.
+ */
+LLVMValueRef
+lp_build_horizontal_add(struct lp_build_context *bld,
+                        LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMValueRef index, res;
+   unsigned i, length;
+   LLVMValueRef shuffles1[LP_MAX_VECTOR_LENGTH / 2];
+   LLVMValueRef shuffles2[LP_MAX_VECTOR_LENGTH / 2];
+   LLVMValueRef vecres, elem2;
+   assert(lp_check_value(type, a));
+   if (type.length == 1) {
+      return a;
+   }
+   assert(!bld->type.norm);
+   /*
+    * for byte vectors can do much better with psadbw.
+    * Using repeated shuffle/adds here. Note with multiple vectors
+    * this can be done more efficiently as outlined in the intel
+    * optimization manual.
+    * Note: could cause data rearrangement if used with smaller element
+    * sizes.
+    */
+   vecres = a;
+   length = type.length / 2;
+   while (length > 1) {
+      LLVMValueRef vec1, vec2;
+      for (i = 0; i < length; i++) {
+         shuffles1[i] = lp_build_const_int32(bld->gallivm, i);
+         shuffles2[i] = lp_build_const_int32(bld->gallivm, i + length);
+      }
+      vec1 = LLVMBuildShuffleVector(builder, vecres, vecres,
+                                    LLVMConstVector(shuffles1, length), "");
+      vec2 = LLVMBuildShuffleVector(builder, vecres, vecres,
+                                    LLVMConstVector(shuffles2, length), "");
+      if (type.floating) {
+         vecres = LLVMBuildFAdd(builder, vec1, vec2, "");
+      }
+      else {
+         vecres = LLVMBuildAdd(builder, vec1, vec2, "");
+      }
+      length = length >> 1;
+   }
+   /* always have vector of size 2 here */
+   assert(length == 1);
+   index = lp_build_const_int32(bld->gallivm, 0);
+   res = LLVMBuildExtractElement(builder, vecres, index, "");
+   index = lp_build_const_int32(bld->gallivm, 1);
+   elem2 = LLVMBuildExtractElement(builder, vecres, index, "");
+   if (type.floating)
+      res = LLVMBuildFAdd(builder, res, elem2, "");
+    else
+      res = LLVMBuildAdd(builder, res, elem2, "");
+   return res;
+}
+/**
+ * Return the horizontal sums of 4 float vectors as a float4 vector.
+ * This uses the technique as outlined in Intel Optimization Manual.
+ */
+static LLVMValueRef
+lp_build_horizontal_add4x4f(struct lp_build_context *bld,
+                            LLVMValueRef src[4])
+{
+   struct gallivm_state *gallivm = bld->gallivm;
+   LLVMBuilderRef builder = gallivm->builder;
+   LLVMValueRef shuffles[4];
+   LLVMValueRef tmp[4];
+   LLVMValueRef sumtmp[2], shuftmp[2];
+   /* lower half of regs */
+   shuffles[0] = lp_build_const_int32(gallivm, 0);
+   shuffles[1] = lp_build_const_int32(gallivm, 1);
+   shuffles[2] = lp_build_const_int32(gallivm, 4);
+   shuffles[3] = lp_build_const_int32(gallivm, 5);
+   tmp[0] = LLVMBuildShuffleVector(builder, src[0], src[1],
+                                   LLVMConstVector(shuffles, 4), "");
+   tmp[2] = LLVMBuildShuffleVector(builder, src[2], src[3],
+                                   LLVMConstVector(shuffles, 4), "");
+   /* upper half of regs */
+   shuffles[0] = lp_build_const_int32(gallivm, 2);
+   shuffles[1] = lp_build_const_int32(gallivm, 3);
+   shuffles[2] = lp_build_const_int32(gallivm, 6);
+   shuffles[3] = lp_build_const_int32(gallivm, 7);
+   tmp[1] = LLVMBuildShuffleVector(builder, src[0], src[1],
+                                   LLVMConstVector(shuffles, 4), "");
+   tmp[3] = LLVMBuildShuffleVector(builder, src[2], src[3],
+                                   LLVMConstVector(shuffles, 4), "");
+   sumtmp[0] = LLVMBuildFAdd(builder, tmp[0], tmp[1], "");
+   sumtmp[1] = LLVMBuildFAdd(builder, tmp[2], tmp[3], "");
+   shuffles[0] = lp_build_const_int32(gallivm, 0);
+   shuffles[1] = lp_build_const_int32(gallivm, 2);
+   shuffles[2] = lp_build_const_int32(gallivm, 4);
+   shuffles[3] = lp_build_const_int32(gallivm, 6);
+   shuftmp[0] = LLVMBuildShuffleVector(builder, sumtmp[0], sumtmp[1],
+                                       LLVMConstVector(shuffles, 4), "");
+   shuffles[0] = lp_build_const_int32(gallivm, 1);
+   shuffles[1] = lp_build_const_int32(gallivm, 3);
+   shuffles[2] = lp_build_const_int32(gallivm, 5);
+   shuffles[3] = lp_build_const_int32(gallivm, 7);
+   shuftmp[1] = LLVMBuildShuffleVector(builder, sumtmp[0], sumtmp[1],
+                                       LLVMConstVector(shuffles, 4), "");
+   return LLVMBuildFAdd(builder, shuftmp[0], shuftmp[1], "");
+}
+/*
+ * partially horizontally add 2-4 float vectors with length nx4,
+ * i.e. only four adjacent values in each vector will be added,
+ * assuming values are really grouped in 4 which also determines
+ * output order.
+ *
+ * Return a vector of the same length as the initial vectors,
+ * with the excess elements (if any) being undefined.
+ * The element order is independent of number of input vectors.
+ * For 3 vectors x0x1x2x3x4x5x6x7, y0y1y2y3y4y5y6y7, z0z1z2z3z4z5z6z7
+ * the output order thus will be
+ * sumx0-x3,sumy0-y3,sumz0-z3,undef,sumx4-x7,sumy4-y7,sumz4z7,undef
+ */
+LLVMValueRef
+lp_build_hadd_partial4(struct lp_build_context *bld,
+                       LLVMValueRef vectors[],
+                       unsigned num_vecs)
+{
+   struct gallivm_state *gallivm = bld->gallivm;
+   LLVMBuilderRef builder = gallivm->builder;
+   LLVMValueRef ret_vec;
+   LLVMValueRef tmp[4];
+   const char *intrinsic = NULL;
+   assert(num_vecs >= 2 && num_vecs <= 4);
+   assert(bld->type.floating);
+   /* only use this with at least 2 vectors, as it is sort of expensive
+    * (depending on cpu) and we always need two horizontal adds anyway,
+    * so a shuffle/add approach might be better.
+    */
+   tmp[0] = vectors[0];
+   tmp[1] = vectors[1];
+   tmp[2] = num_vecs > 2 ? vectors[2] : vectors[0];
+   tmp[3] = num_vecs > 3 ? vectors[3] : vectors[0];
+   if (util_cpu_caps.has_sse3 && bld->type.width == 32 &&
+       bld->type.length == 4) {
+      intrinsic = "llvm.x86.sse3.hadd.ps";
+   }
+   else if (util_cpu_caps.has_avx && bld->type.width == 32 &&
+            bld->type.length == 8) {
+      intrinsic = "llvm.x86.avx.hadd.ps.256";
+   }
+   if (intrinsic) {
+      tmp[0] = lp_build_intrinsic_binary(builder, intrinsic,
+                                       lp_build_vec_type(gallivm, bld->type),
+                                       tmp[0], tmp[1]);
+      if (num_vecs > 2) {
+         tmp[1] = lp_build_intrinsic_binary(builder, intrinsic,
+                                          lp_build_vec_type(gallivm, bld->type),
+                                          tmp[2], tmp[3]);
+      }
+      else {
+         tmp[1] = tmp[0];
+      }
+      return lp_build_intrinsic_binary(builder, intrinsic,
+                                       lp_build_vec_type(gallivm, bld->type),
+                                       tmp[0], tmp[1]);
+   }
+   if (bld->type.length == 4) {
+      ret_vec = lp_build_horizontal_add4x4f(bld, tmp);
+   }
+   else {
+      LLVMValueRef partres[LP_MAX_VECTOR_LENGTH/4];
+      unsigned j;
+      unsigned num_iter = bld->type.length / 4;
+      struct lp_type parttype = bld->type;
+      parttype.length = 4;
+      for (j = 0; j < num_iter; j++) {
+         LLVMValueRef partsrc[4];
+         unsigned i;
+         for (i = 0; i < 4; i++) {
+            partsrc[i] = lp_build_extract_range(gallivm, tmp[i], j*4, 4);
+         }
+         partres[j] = lp_build_horizontal_add4x4f(bld, partsrc);
+      }
+      ret_vec = lp_build_concat(gallivm, partres, parttype, num_iter);
+   }
+   return ret_vec;
+}
+/**
+ * Generate a - b
+ */
+LLVMValueRef
+lp_build_sub(struct lp_build_context *bld,
+             LLVMValueRef a,
+             LLVMValueRef b)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMValueRef res;
+   assert(lp_check_value(type, a));
+   assert(lp_check_value(type, b));
+   if(b == bld->zero)
+      return a;
+   if(a == bld->undef || b == bld->undef)
+      return bld->undef;
+   if(a == b)
+      return bld->zero;
+   if(bld->type.norm) {
+      const char *intrinsic = NULL;
+      if(b == bld->one)
+        return bld->zero;
+      if (type.width * type.length == 128 &&
+          !type.floating && !type.fixed) {
+         if (util_cpu_caps.has_sse2) {
+           if(type.width == 8)
+              intrinsic = type.sign ? "llvm.x86.sse2.psubs.b" : "llvm.x86.sse2.psubus.b";
+           if(type.width == 16)
+              intrinsic = type.sign ? "llvm.x86.sse2.psubs.w" : "llvm.x86.sse2.psubus.w";
+         } else if (util_cpu_caps.has_altivec) {
+           if(type.width == 8)
+              intrinsic = type.sign ? "llvm.ppc.altivec.vsubsbs" : "llvm.ppc.altivec.vsububs";
+           if(type.width == 16)
+              intrinsic = type.sign ? "llvm.ppc.altivec.vsubshs" : "llvm.ppc.altivec.vsubuhs";
+         }
+      }
+      if(intrinsic)
+         return lp_build_intrinsic_binary(builder, intrinsic, lp_build_vec_type(bld->gallivm, bld->type), a, b);
+   }
+   if(type.norm && !type.floating && !type.fixed) {
+      if (type.sign) {
+         uint64_t sign = (uint64_t)1 << (type.width - 1);
+         LLVMValueRef max_val = lp_build_const_int_vec(bld->gallivm, type, sign - 1);
+         LLVMValueRef min_val = lp_build_const_int_vec(bld->gallivm, type, sign);
+         /* a_clamp_max is the maximum a for negative b,
+            a_clamp_min is the minimum a for positive b. */
+         LLVMValueRef a_clamp_max = lp_build_min_simple(bld, a, LLVMBuildAdd(builder, max_val, b, ""), GALLIVM_NAN_BEHAVIOR_UNDEFINED);
+         LLVMValueRef a_clamp_min = lp_build_max_simple(bld, a, LLVMBuildAdd(builder, min_val, b, ""), GALLIVM_NAN_BEHAVIOR_UNDEFINED);
+         a = lp_build_select(bld, lp_build_cmp(bld, PIPE_FUNC_GREATER, b, bld->zero), a_clamp_min, a_clamp_max);
+      } else {
+         a = lp_build_max_simple(bld, a, b, GALLIVM_NAN_BEHAVIOR_UNDEFINED);
+      }
+   }
+   if(LLVMIsConstant(a) && LLVMIsConstant(b))
+      if (type.floating)
+         res = LLVMConstFSub(a, b);
+      else
+         res = LLVMConstSub(a, b);
+   else
+      if (type.floating)
+         res = LLVMBuildFSub(builder, a, b, "");
+      else
+         res = LLVMBuildSub(builder, a, b, "");
+   if(bld->type.norm && (bld->type.floating || bld->type.fixed))
+      res = lp_build_max_simple(bld, res, bld->zero, GALLIVM_NAN_BEHAVIOR_UNDEFINED);
+   return res;
+}
+/**
+ * Normalized multiplication.
+ *
+ * There are several approaches for (using 8-bit normalized multiplication as
+ * an example):
+ *
+ * - alpha plus one
+ *
+ *     makes the following approximation to the division (Sree)
+ *
+ *       a*b/255 ~= (a*(b + 1)) >> 256
+ *
+ *     which is the fastest method that satisfies the following OpenGL criteria of
+ *
+ *       0*0 = 0 and 255*255 = 255
+ *
+ * - geometric series
+ *
+ *     takes the geometric series approximation to the division
+ *
+ *       t/255 = (t >> 8) + (t >> 16) + (t >> 24) ..
+ *
+ *     in this case just the first two terms to fit in 16bit arithmetic
+ *
+ *       t/255 ~= (t + (t >> 8)) >> 8
+ *
+ *     note that just by itself it doesn't satisfies the OpenGL criteria, as
+ *     255*255 = 254, so the special case b = 255 must be accounted or roundoff
+ *     must be used.
+ *
+ * - geometric series plus rounding
+ *
+ *     when using a geometric series division instead of truncating the result
+ *     use roundoff in the approximation (Jim Blinn)
+ *
+ *       t/255 ~= (t + (t >> 8) + 0x80) >> 8
+ *
+ *     achieving the exact results.
+ *
+ *
+ *
+ * @sa Alvy Ray Smith, Image Compositing Fundamentals, Tech Memo 4, Aug 15, 1995,
+ *     ftp://ftp.alvyray.com/Acrobat/4_Comp.pdf
+ * @sa Michael Herf, The "double blend trick", May 2000,
+ *     http://www.stereopsis.com/doubleblend.html
+ */
+static LLVMValueRef
+lp_build_mul_norm(struct gallivm_state *gallivm,
+                  struct lp_type wide_type,
+                  LLVMValueRef a, LLVMValueRef b)
+{
+   LLVMBuilderRef builder = gallivm->builder;
+   struct lp_build_context bld;
+   unsigned n;
+   LLVMValueRef half;
+   LLVMValueRef ab;
+   assert(!wide_type.floating);
+   assert(lp_check_value(wide_type, a));
+   assert(lp_check_value(wide_type, b));
+   lp_build_context_init(&bld, gallivm, wide_type);
+   n = wide_type.width / 2;
+   if (wide_type.sign) {
+      --n;
+   }
+   /*
+    * TODO: for 16bits normalized SSE2 vectors we could consider using PMULHUW
+    * http://ssp.impulsetrain.com/2011/07/03/multiplying-normalized-16-bit-numbers-with-sse2/
+    */
+   /*
+    * a*b / (2**n - 1) ~= (a*b + (a*b >> n) + half) >> n
+    */
+   ab = LLVMBuildMul(builder, a, b, "");
+   ab = LLVMBuildAdd(builder, ab, lp_build_shr_imm(&bld, ab, n), "");
+   /*
+    * half = sgn(ab) * 0.5 * (2 ** n) = sgn(ab) * (1 << (n - 1))
+    */
+   half = lp_build_const_int_vec(gallivm, wide_type, 1LL << (n - 1));
+   if (wide_type.sign) {
+      LLVMValueRef minus_half = LLVMBuildNeg(builder, half, "");
+      LLVMValueRef sign = lp_build_shr_imm(&bld, ab, wide_type.width - 1);
+      half = lp_build_select(&bld, sign, minus_half, half);
+   }
+   ab = LLVMBuildAdd(builder, ab, half, "");
+   /* Final division */
+   ab = lp_build_shr_imm(&bld, ab, n);
+   return ab;
+}
+/**
+ * Generate a * b
+ */
+LLVMValueRef
+lp_build_mul(struct lp_build_context *bld,
+             LLVMValueRef a,
+             LLVMValueRef b)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMValueRef shift;
+   LLVMValueRef res;
+   assert(lp_check_value(type, a));
+   assert(lp_check_value(type, b));
+   if(a == bld->zero)
+      return bld->zero;
+   if(a == bld->one)
+      return b;
+   if(b == bld->zero)
+      return bld->zero;
+   if(b == bld->one)
+      return a;
+   if(a == bld->undef || b == bld->undef)
+      return bld->undef;
+   if (!type.floating && !type.fixed && type.norm) {
+      struct lp_type wide_type = lp_wider_type(type);
+      LLVMValueRef al, ah, bl, bh, abl, abh, ab;
+      lp_build_unpack2(bld->gallivm, type, wide_type, a, &al, &ah);
+      lp_build_unpack2(bld->gallivm, type, wide_type, b, &bl, &bh);
+      /* PMULLW, PSRLW, PADDW */
+      abl = lp_build_mul_norm(bld->gallivm, wide_type, al, bl);
+      abh = lp_build_mul_norm(bld->gallivm, wide_type, ah, bh);
+      ab = lp_build_pack2(bld->gallivm, wide_type, type, abl, abh);
+      return ab;
+   }
+   if(type.fixed)
+      shift = lp_build_const_int_vec(bld->gallivm, type, type.width/2);
+   else
+      shift = NULL;
+   if(LLVMIsConstant(a) && LLVMIsConstant(b)) {
+      if (type.floating)
+         res = LLVMConstFMul(a, b);
+      else
+         res = LLVMConstMul(a, b);
+      if(shift) {
+         if(type.sign)
+            res = LLVMConstAShr(res, shift);
+         else
+            res = LLVMConstLShr(res, shift);
+      }
+   }
+   else {
+      if (type.floating)
+         res = LLVMBuildFMul(builder, a, b, "");
+      else
+         res = LLVMBuildMul(builder, a, b, "");
+      if(shift) {
+         if(type.sign)
+            res = LLVMBuildAShr(builder, res, shift, "");
+         else
+            res = LLVMBuildLShr(builder, res, shift, "");
+      }
+   }
+   return res;
+}
+/**
+ * Small vector x scale multiplication optimization.
+ */
+LLVMValueRef
+lp_build_mul_imm(struct lp_build_context *bld,
+                 LLVMValueRef a,
+                 int b)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   LLVMValueRef factor;
+   assert(lp_check_value(bld->type, a));
+   if(b == 0)
+      return bld->zero;
+   if(b == 1)
+      return a;
+   if(b == -1)
+      return lp_build_negate(bld, a);
+   if(b == 2 && bld->type.floating)
+      return lp_build_add(bld, a, a);
+   if(util_is_power_of_two(b)) {
+      unsigned shift = ffs(b) - 1;
+      if(bld->type.floating) {
+#if 0
+         /*
+          * Power of two multiplication by directly manipulating the exponent.
+          *
+          * XXX: This might not be always faster, it will introduce a small error
+          * for multiplication by zero, and it will produce wrong results
+          * for Inf and NaN.
+          */
+         unsigned mantissa = lp_mantissa(bld->type);
+         factor = lp_build_const_int_vec(bld->gallivm, bld->type, (unsigned long long)shift << mantissa);
+         a = LLVMBuildBitCast(builder, a, lp_build_int_vec_type(bld->type), "");
+         a = LLVMBuildAdd(builder, a, factor, "");
+         a = LLVMBuildBitCast(builder, a, lp_build_vec_type(bld->gallivm, bld->type), "");
+         return a;
+#endif
+      }
+      else {
+         factor = lp_build_const_vec(bld->gallivm, bld->type, shift);
+         return LLVMBuildShl(builder, a, factor, "");
+      }
+   }
+   factor = lp_build_const_vec(bld->gallivm, bld->type, (double)b);
+   return lp_build_mul(bld, a, factor);
+}
+/**
+ * Generate a / b
+ */
+LLVMValueRef
+lp_build_div(struct lp_build_context *bld,
+             LLVMValueRef a,
+             LLVMValueRef b)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   assert(lp_check_value(type, a));
+   assert(lp_check_value(type, b));
+   if(a == bld->zero)
+      return bld->zero;
+   if(a == bld->one && type.floating)
+      return lp_build_rcp(bld, b);
+   if(b == bld->zero)
+      return bld->undef;
+   if(b == bld->one)
+      return a;
+   if(a == bld->undef || b == bld->undef)
+      return bld->undef;
+   if(LLVMIsConstant(a) && LLVMIsConstant(b)) {
+      if (type.floating)
+         return LLVMConstFDiv(a, b);
+      else if (type.sign)
+         return LLVMConstSDiv(a, b);
+      else
+         return LLVMConstUDiv(a, b);
+   }
+   if(((util_cpu_caps.has_sse && type.width == 32 && type.length == 4) ||
+       (util_cpu_caps.has_avx && type.width == 32 && type.length == 8)) &&
+      type.floating)
+      return lp_build_mul(bld, a, lp_build_rcp(bld, b));
+   if (type.floating)
+      return LLVMBuildFDiv(builder, a, b, "");
+   else if (type.sign)
+      return LLVMBuildSDiv(builder, a, b, "");
+   else
+      return LLVMBuildUDiv(builder, a, b, "");
+}
+/**
+ * Linear interpolation helper.
+ *
+ * @param normalized whether we are interpolating normalized values,
+ *        encoded in normalized integers, twice as wide.
+ *
+ * @sa http://www.stereopsis.com/doubleblend.html
+ */
+static INLINE LLVMValueRef
+lp_build_lerp_simple(struct lp_build_context *bld,
+                     LLVMValueRef x,
+                     LLVMValueRef v0,
+                     LLVMValueRef v1,
+                     unsigned flags)
+{
+   unsigned half_width = bld->type.width/2;
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   LLVMValueRef delta;
+   LLVMValueRef res;
+   assert(lp_check_value(bld->type, x));
+   assert(lp_check_value(bld->type, v0));
+   assert(lp_check_value(bld->type, v1));
+   delta = lp_build_sub(bld, v1, v0);
+   if (flags & LP_BLD_LERP_WIDE_NORMALIZED) {
+      if (!bld->type.sign) {
+         if (!(flags & LP_BLD_LERP_PRESCALED_WEIGHTS)) {
+            /*
+             * Scale x from [0, 2**n - 1] to [0, 2**n] by adding the
+             * most-significant-bit to the lowest-significant-bit, so that
+             * later we can just divide by 2**n instead of 2**n - 1.
+             */
+            x = lp_build_add(bld, x, lp_build_shr_imm(bld, x, half_width - 1));
+         }
+         /* (x * delta) >> n */
+         res = lp_build_mul(bld, x, delta);
+         res = lp_build_shr_imm(bld, res, half_width);
+      } else {
+         /*
+          * The rescaling trick above doesn't work for signed numbers, so
+          * use the 2**n - 1 divison approximation in lp_build_mul_norm
+          * instead.
+          */
+         assert(!(flags & LP_BLD_LERP_PRESCALED_WEIGHTS));
+         res = lp_build_mul_norm(bld->gallivm, bld->type, x, delta);
+      }
+   } else {
+      assert(!(flags & LP_BLD_LERP_PRESCALED_WEIGHTS));
+      res = lp_build_mul(bld, x, delta);
+   }
+   res = lp_build_add(bld, v0, res);
+   if (((flags & LP_BLD_LERP_WIDE_NORMALIZED) && !bld->type.sign) ||
+       bld->type.fixed) {
+      /* We need to mask out the high order bits when lerping 8bit normalized colors stored on 16bits */
+      /* XXX: This step is necessary for lerping 8bit colors stored on 16bits,
+       * but it will be wrong for true fixed point use cases. Basically we need
+       * a more powerful lp_type, capable of further distinguishing the values
+       * interpretation from the value storage. */
+      res = LLVMBuildAnd(builder, res, lp_build_const_int_vec(bld->gallivm, bld->type, (1 << half_width) - 1), "");
+   }
+   return res;
+}
+/**
+ * Linear interpolation.
+ */
+LLVMValueRef
+lp_build_lerp(struct lp_build_context *bld,
+              LLVMValueRef x,
+              LLVMValueRef v0,
+              LLVMValueRef v1,
+              unsigned flags)
+{
+   const struct lp_type type = bld->type;
+   LLVMValueRef res;
+   assert(lp_check_value(type, x));
+   assert(lp_check_value(type, v0));
+   assert(lp_check_value(type, v1));
+   assert(!(flags & LP_BLD_LERP_WIDE_NORMALIZED));
+   if (type.norm) {
+      struct lp_type wide_type;
+      struct lp_build_context wide_bld;
+      LLVMValueRef xl, xh, v0l, v0h, v1l, v1h, resl, resh;
+      assert(type.length >= 2);
+      /*
+       * Create a wider integer type, enough to hold the
+       * intermediate result of the multiplication.
+       */
+      memset(&wide_type, 0, sizeof wide_type);
+      wide_type.sign   = type.sign;
+      wide_type.width  = type.width*2;
+      wide_type.length = type.length/2;
+      lp_build_context_init(&wide_bld, bld->gallivm, wide_type);
+      lp_build_unpack2(bld->gallivm, type, wide_type, x,  &xl,  &xh);
+      lp_build_unpack2(bld->gallivm, type, wide_type, v0, &v0l, &v0h);
+      lp_build_unpack2(bld->gallivm, type, wide_type, v1, &v1l, &v1h);
+      /*
+       * Lerp both halves.
+       */
+      flags |= LP_BLD_LERP_WIDE_NORMALIZED;
+      resl = lp_build_lerp_simple(&wide_bld, xl, v0l, v1l, flags);
+      resh = lp_build_lerp_simple(&wide_bld, xh, v0h, v1h, flags);
+      res = lp_build_pack2(bld->gallivm, wide_type, type, resl, resh);
+   } else {
+      res = lp_build_lerp_simple(bld, x, v0, v1, flags);
+   }
+   return res;
+}
+/**
+ * Bilinear interpolation.
+ *
+ * Values indices are in v_{yx}.
+ */
+LLVMValueRef
+lp_build_lerp_2d(struct lp_build_context *bld,
+                 LLVMValueRef x,
+                 LLVMValueRef y,
+                 LLVMValueRef v00,
+                 LLVMValueRef v01,
+                 LLVMValueRef v10,
+                 LLVMValueRef v11,
+                 unsigned flags)
+{
+   LLVMValueRef v0 = lp_build_lerp(bld, x, v00, v01, flags);
+   LLVMValueRef v1 = lp_build_lerp(bld, x, v10, v11, flags);
+   return lp_build_lerp(bld, y, v0, v1, flags);
+}
+LLVMValueRef
+lp_build_lerp_3d(struct lp_build_context *bld,
+                 LLVMValueRef x,
+                 LLVMValueRef y,
+                 LLVMValueRef z,
+                 LLVMValueRef v000,
+                 LLVMValueRef v001,
+                 LLVMValueRef v010,
+                 LLVMValueRef v011,
+                 LLVMValueRef v100,
+                 LLVMValueRef v101,
+                 LLVMValueRef v110,
+                 LLVMValueRef v111,
+                 unsigned flags)
+{
+   LLVMValueRef v0 = lp_build_lerp_2d(bld, x, y, v000, v001, v010, v011, flags);
+   LLVMValueRef v1 = lp_build_lerp_2d(bld, x, y, v100, v101, v110, v111, flags);
+   return lp_build_lerp(bld, z, v0, v1, flags);
+}
+/**
+ * Generate min(a, b)
+ * Do checks for special cases but not for nans.
+ */
+LLVMValueRef
+lp_build_min(struct lp_build_context *bld,
+             LLVMValueRef a,
+             LLVMValueRef b)
+{
+   assert(lp_check_value(bld->type, a));
+   assert(lp_check_value(bld->type, b));
+   if(a == bld->undef || b == bld->undef)
+      return bld->undef;
+   if(a == b)
+      return a;
+   if (bld->type.norm) {
+      if (!bld->type.sign) {
+         if (a == bld->zero || b == bld->zero) {
+            return bld->zero;
+         }
+      }
+      if(a == bld->one)
+         return b;
+      if(b == bld->one)
+         return a;
+   }
+   return lp_build_min_simple(bld, a, b, GALLIVM_NAN_BEHAVIOR_UNDEFINED);
+}
+/**
+ * Generate min(a, b)
+ * NaN's are handled according to the behavior specified by the
+ * nan_behavior argument.
+ */
+LLVMValueRef
+lp_build_min_ext(struct lp_build_context *bld,
+                 LLVMValueRef a,
+                 LLVMValueRef b,
+                 enum gallivm_nan_behavior nan_behavior)
+{
+   assert(lp_check_value(bld->type, a));
+   assert(lp_check_value(bld->type, b));
+   if(a == bld->undef || b == bld->undef)
+      return bld->undef;
+   if(a == b)
+      return a;
+   if (bld->type.norm) {
+      if (!bld->type.sign) {
+         if (a == bld->zero || b == bld->zero) {
+            return bld->zero;
+         }
+      }
+      if(a == bld->one)
+         return b;
+      if(b == bld->one)
+         return a;
+   }
+   return lp_build_min_simple(bld, a, b, nan_behavior);
+}
+/**
+ * Generate max(a, b)
+ * Do checks for special cases, but NaN behavior is undefined.
+ */
+LLVMValueRef
+lp_build_max(struct lp_build_context *bld,
+             LLVMValueRef a,
+             LLVMValueRef b)
+{
+   assert(lp_check_value(bld->type, a));
+   assert(lp_check_value(bld->type, b));
+   if(a == bld->undef || b == bld->undef)
+      return bld->undef;
+   if(a == b)
+      return a;
+   if(bld->type.norm) {
+      if(a == bld->one || b == bld->one)
+         return bld->one;
+      if (!bld->type.sign) {
+         if (a == bld->zero) {
+            return b;
+         }
+         if (b == bld->zero) {
+            return a;
+         }
+      }
+   }
+   return lp_build_max_simple(bld, a, b, GALLIVM_NAN_BEHAVIOR_UNDEFINED);
+}
+/**
+ * Generate max(a, b)
+ * Checks for special cases.
+ * NaN's are handled according to the behavior specified by the
+ * nan_behavior argument.
+ */
+LLVMValueRef
+lp_build_max_ext(struct lp_build_context *bld,
+                  LLVMValueRef a,
+                  LLVMValueRef b,
+                  enum gallivm_nan_behavior nan_behavior)
+{
+   assert(lp_check_value(bld->type, a));
+   assert(lp_check_value(bld->type, b));
+   if(a == bld->undef || b == bld->undef)
+      return bld->undef;
+   if(a == b)
+      return a;
+   if(bld->type.norm) {
+      if(a == bld->one || b == bld->one)
+         return bld->one;
+      if (!bld->type.sign) {
+         if (a == bld->zero) {
+            return b;
+         }
+         if (b == bld->zero) {
+            return a;
+         }
+      }
+   }
+   return lp_build_max_simple(bld, a, b, nan_behavior);
+}
+/**
+ * Generate clamp(a, min, max)
+ * NaN behavior (for any of a, min, max) is undefined.
+ * Do checks for special cases.
+ */
+LLVMValueRef
+lp_build_clamp(struct lp_build_context *bld,
+               LLVMValueRef a,
+               LLVMValueRef min,
+               LLVMValueRef max)
+{
+   assert(lp_check_value(bld->type, a));
+   assert(lp_check_value(bld->type, min));
+   assert(lp_check_value(bld->type, max));
+   a = lp_build_min(bld, a, max);
+   a = lp_build_max(bld, a, min);
+   return a;
+}
+/**
+ * Generate clamp(a, 0, 1)
+ * A NaN will get converted to zero.
+ */
+LLVMValueRef
+lp_build_clamp_zero_one_nanzero(struct lp_build_context *bld,
+                                LLVMValueRef a)
+{
+   a = lp_build_max_ext(bld, a, bld->zero, GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN);
+   a = lp_build_min(bld, a, bld->one);
+   return a;
+}
+/**
+ * Generate abs(a)
+ */
+LLVMValueRef
+lp_build_abs(struct lp_build_context *bld,
+             LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef vec_type = lp_build_vec_type(bld->gallivm, type);
+   assert(lp_check_value(type, a));
+   if(!type.sign)
+      return a;
+   if(type.floating) {
+      /* Mask out the sign bit */
+      LLVMTypeRef int_vec_type = lp_build_int_vec_type(bld->gallivm, type);
+      unsigned long long absMask = ~(1ULL << (type.width - 1));
+      LLVMValueRef mask = lp_build_const_int_vec(bld->gallivm, type, ((unsigned long long) absMask));
+      a = LLVMBuildBitCast(builder, a, int_vec_type, "");
+      a = LLVMBuildAnd(builder, a, mask, "");
+      a = LLVMBuildBitCast(builder, a, vec_type, "");
+      return a;
+   }
+   if(type.width*type.length == 128 && util_cpu_caps.has_ssse3) {
+      switch(type.width) {
+      case 8:
+         return lp_build_intrinsic_unary(builder, "llvm.x86.ssse3.pabs.b.128", vec_type, a);
+      case 16:
+         return lp_build_intrinsic_unary(builder, "llvm.x86.ssse3.pabs.w.128", vec_type, a);
+      case 32:
+         return lp_build_intrinsic_unary(builder, "llvm.x86.ssse3.pabs.d.128", vec_type, a);
+      }
+   }
+   else if (type.width*type.length == 256 && util_cpu_caps.has_ssse3 &&
+            (gallivm_debug & GALLIVM_DEBUG_PERF) &&
+            (type.width == 8 || type.width == 16 || type.width == 32)) {
+      debug_printf("%s: inefficient code, should split vectors manually\n",
+                   __FUNCTION__);
+   }
+   return lp_build_max(bld, a, LLVMBuildNeg(builder, a, ""));
+}
+LLVMValueRef
+lp_build_negate(struct lp_build_context *bld,
+                LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   assert(lp_check_value(bld->type, a));
+   if (bld->type.floating)
+      a = LLVMBuildFNeg(builder, a, "");
+   else
+      a = LLVMBuildNeg(builder, a, "");
+   return a;
+}
+/** Return -1, 0 or +1 depending on the sign of a */
+LLVMValueRef
+lp_build_sgn(struct lp_build_context *bld,
+             LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMValueRef cond;
+   LLVMValueRef res;
+   assert(lp_check_value(type, a));
+   /* Handle non-zero case */
+   if(!type.sign) {
+      /* if not zero then sign must be positive */
+      res = bld->one;
+   }
+   else if(type.floating) {
+      LLVMTypeRef vec_type;
+      LLVMTypeRef int_type;
+      LLVMValueRef mask;
+      LLVMValueRef sign;
+      LLVMValueRef one;
+      unsigned long long maskBit = (unsigned long long)1 << (type.width - 1);
+      int_type = lp_build_int_vec_type(bld->gallivm, type);
+      vec_type = lp_build_vec_type(bld->gallivm, type);
+      mask = lp_build_const_int_vec(bld->gallivm, type, maskBit);
+      /* Take the sign bit and add it to 1 constant */
+      sign = LLVMBuildBitCast(builder, a, int_type, "");
+      sign = LLVMBuildAnd(builder, sign, mask, "");
+      one = LLVMConstBitCast(bld->one, int_type);
+      res = LLVMBuildOr(builder, sign, one, "");
+      res = LLVMBuildBitCast(builder, res, vec_type, "");
+   }
+   else
+   {
+      /* signed int/norm/fixed point */
+      /* could use psign with sse3 and appropriate vectors here */
+      LLVMValueRef minus_one = lp_build_const_vec(bld->gallivm, type, -1.0);
+      cond = lp_build_cmp(bld, PIPE_FUNC_GREATER, a, bld->zero);
+      res = lp_build_select(bld, cond, bld->one, minus_one);
+   }
+   /* Handle zero */
+   cond = lp_build_cmp(bld, PIPE_FUNC_EQUAL, a, bld->zero);
+   res = lp_build_select(bld, cond, bld->zero, res);
+   return res;
+}
+/**
+ * Set the sign of float vector 'a' according to 'sign'.
+ * If sign==0, return abs(a).
+ * If sign==1, return -abs(a);
+ * Other values for sign produce undefined results.
+ */
+LLVMValueRef
+lp_build_set_sign(struct lp_build_context *bld,
+                  LLVMValueRef a, LLVMValueRef sign)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef int_vec_type = lp_build_int_vec_type(bld->gallivm, type);
+   LLVMTypeRef vec_type = lp_build_vec_type(bld->gallivm, type);
+   LLVMValueRef shift = lp_build_const_int_vec(bld->gallivm, type, type.width - 1);
+   LLVMValueRef mask = lp_build_const_int_vec(bld->gallivm, type,
+                             ~((unsigned long long) 1 << (type.width - 1)));
+   LLVMValueRef val, res;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   /* val = reinterpret_cast<int>(a) */
+   val = LLVMBuildBitCast(builder, a, int_vec_type, "");
+   /* val = val & mask */
+   val = LLVMBuildAnd(builder, val, mask, "");
+   /* sign = sign << shift */
+   sign = LLVMBuildShl(builder, sign, shift, "");
+   /* res = val | sign */
+   res = LLVMBuildOr(builder, val, sign, "");
+   /* res = reinterpret_cast<float>(res) */
+   res = LLVMBuildBitCast(builder, res, vec_type, "");
+   return res;
+}
+/**
+ * Convert vector of (or scalar) int to vector of (or scalar) float.
+ */
+LLVMValueRef
+lp_build_int_to_float(struct lp_build_context *bld,
+                      LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef vec_type = lp_build_vec_type(bld->gallivm, type);
+   assert(type.floating);
+   return LLVMBuildSIToFP(builder, a, vec_type, "");
+}
+static boolean
+arch_rounding_available(const struct lp_type type)
+{
+   if ((util_cpu_caps.has_sse4_1 &&
+       (type.length == 1 || type.width*type.length == 128)) ||
+       (util_cpu_caps.has_avx && type.width*type.length == 256))
+      return TRUE;
+   else if ((util_cpu_caps.has_altivec &&
+            (type.width == 32 && type.length == 4)))
+      return TRUE;
+   return FALSE;
+}
+enum lp_build_round_mode
+{
+   LP_BUILD_ROUND_NEAREST = 0,
+   LP_BUILD_ROUND_FLOOR = 1,
+   LP_BUILD_ROUND_CEIL = 2,
+   LP_BUILD_ROUND_TRUNCATE = 3
+};
+/**
+ * Helper for SSE4.1's ROUNDxx instructions.
+ *
+ * NOTE: In the SSE4.1's nearest mode, if two values are equally close, the
+ * result is the even value.  That is, rounding 2.5 will be 2.0, and not 3.0.
+ */
+static INLINE LLVMValueRef
+lp_build_round_sse41(struct lp_build_context *bld,
+                     LLVMValueRef a,
+                     enum lp_build_round_mode mode)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef i32t = LLVMInt32TypeInContext(bld->gallivm->context);
+   const char *intrinsic;
+   LLVMValueRef res;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   assert(util_cpu_caps.has_sse4_1);
+   if (type.length == 1) {
+      LLVMTypeRef vec_type;
+      LLVMValueRef undef;
+      LLVMValueRef args[3];
+      LLVMValueRef index0 = LLVMConstInt(i32t, 0, 0);
+      switch(type.width) {
+      case 32:
+         intrinsic = "llvm.x86.sse41.round.ss";
+         break;
+      case 64:
+         intrinsic = "llvm.x86.sse41.round.sd";
+         break;
+      default:
+         assert(0);
+         return bld->undef;
+      }
+      vec_type = LLVMVectorType(bld->elem_type, 4);
+      undef = LLVMGetUndef(vec_type);
+      args[0] = undef;
+      args[1] = LLVMBuildInsertElement(builder, undef, a, index0, "");
+      args[2] = LLVMConstInt(i32t, mode, 0);
+      res = lp_build_intrinsic(builder, intrinsic,
+                               vec_type, args, Elements(args));
+      res = LLVMBuildExtractElement(builder, res, index0, "");
+   }
+   else {
+      if (type.width * type.length == 128) {
+         switch(type.width) {
+         case 32:
+            intrinsic = "llvm.x86.sse41.round.ps";
+            break;
+         case 64:
+            intrinsic = "llvm.x86.sse41.round.pd";
+            break;
+         default:
+            assert(0);
+            return bld->undef;
+         }
+      }
+      else {
+         assert(type.width * type.length == 256);
+         assert(util_cpu_caps.has_avx);
+         switch(type.width) {
+         case 32:
+            intrinsic = "llvm.x86.avx.round.ps.256";
+            break;
+         case 64:
+            intrinsic = "llvm.x86.avx.round.pd.256";
+            break;
+         default:
+            assert(0);
+            return bld->undef;
+         }
+      }
+      res = lp_build_intrinsic_binary(builder, intrinsic,
+                                      bld->vec_type, a,
+                                      LLVMConstInt(i32t, mode, 0));
+   }
+   return res;
+}
+static INLINE LLVMValueRef
+lp_build_iround_nearest_sse2(struct lp_build_context *bld,
+                             LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef i32t = LLVMInt32TypeInContext(bld->gallivm->context);
+   LLVMTypeRef ret_type = lp_build_int_vec_type(bld->gallivm, type);
+   const char *intrinsic;
+   LLVMValueRef res;
+   assert(type.floating);
+   /* using the double precision conversions is a bit more complicated */
+   assert(type.width == 32);
+   assert(lp_check_value(type, a));
+   assert(util_cpu_caps.has_sse2);
+   /* This is relying on MXCSR rounding mode, which should always be nearest. */
+   if (type.length == 1) {
+      LLVMTypeRef vec_type;
+      LLVMValueRef undef;
+      LLVMValueRef arg;
+      LLVMValueRef index0 = LLVMConstInt(i32t, 0, 0);
+      vec_type = LLVMVectorType(bld->elem_type, 4);
+      intrinsic = "llvm.x86.sse.cvtss2si";
+      undef = LLVMGetUndef(vec_type);
+      arg = LLVMBuildInsertElement(builder, undef, a, index0, "");
+      res = lp_build_intrinsic_unary(builder, intrinsic,
+                                     ret_type, arg);
+   }
+   else {
+      if (type.width* type.length == 128) {
+         intrinsic = "llvm.x86.sse2.cvtps2dq";
+      }
+      else {
+         assert(type.width*type.length == 256);
+         assert(util_cpu_caps.has_avx);
+         intrinsic = "llvm.x86.avx.cvt.ps2dq.256";
+      }
+      res = lp_build_intrinsic_unary(builder, intrinsic,
+                                     ret_type, a);
+   }
+   return res;
+}
+/*
+ */
+static INLINE LLVMValueRef
+lp_build_round_altivec(struct lp_build_context *bld,
+                       LLVMValueRef a,
+                       enum lp_build_round_mode mode)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   const char *intrinsic = NULL;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   assert(util_cpu_caps.has_altivec);
+   (void)type;
+   switch (mode) {
+   case LP_BUILD_ROUND_NEAREST:
+      intrinsic = "llvm.ppc.altivec.vrfin";
+      break;
+   case LP_BUILD_ROUND_FLOOR:
+      intrinsic = "llvm.ppc.altivec.vrfim";
+      break;
+   case LP_BUILD_ROUND_CEIL:
+      intrinsic = "llvm.ppc.altivec.vrfip";
+      break;
+   case LP_BUILD_ROUND_TRUNCATE:
+      intrinsic = "llvm.ppc.altivec.vrfiz";
+      break;
+   }
+   return lp_build_intrinsic_unary(builder, intrinsic, bld->vec_type, a);
+}
+static INLINE LLVMValueRef
+lp_build_round_arch(struct lp_build_context *bld,
+                    LLVMValueRef a,
+                    enum lp_build_round_mode mode)
+{
+   if (util_cpu_caps.has_sse4_1)
+     return lp_build_round_sse41(bld, a, mode);
+   else /* (util_cpu_caps.has_altivec) */
+     return lp_build_round_altivec(bld, a, mode);
+}
+/**
+ * Return the integer part of a float (vector) value (== round toward zero).
+ * The returned value is a float (vector).
+ * Ex: trunc(-1.5) = -1.0
+ */
+LLVMValueRef
+lp_build_trunc(struct lp_build_context *bld,
+               LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   if (arch_rounding_available(type)) {
+      return lp_build_round_arch(bld, a, LP_BUILD_ROUND_TRUNCATE);
+   }
+   else {
+      const struct lp_type type = bld->type;
+      struct lp_type inttype;
+      struct lp_build_context intbld;
+      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 1<<24);
+      LLVMValueRef trunc, res, anosign, mask;
+      LLVMTypeRef int_vec_type = bld->int_vec_type;
+      LLVMTypeRef vec_type = bld->vec_type;
+      assert(type.width == 32); /* might want to handle doubles at some point */
+      inttype = type;
+      inttype.floating = 0;
+      lp_build_context_init(&intbld, bld->gallivm, inttype);
+      /* round by truncation */
+      trunc = LLVMBuildFPToSI(builder, a, int_vec_type, "");
+      res = LLVMBuildSIToFP(builder, trunc, vec_type, "floor.trunc");
+      /* mask out sign bit */
+      anosign = lp_build_abs(bld, a);
+      /*
+       * mask out all values if anosign > 2^24
+       * This should work both for large ints (all rounding is no-op for them
+       * because such floats are always exact) as well as special cases like
+       * NaNs, Infs (taking advantage of the fact they use max exponent).
+       * (2^24 is arbitrary anything between 2^24 and 2^31 should work.)
+       */
+      anosign = LLVMBuildBitCast(builder, anosign, int_vec_type, "");
+      cmpval = LLVMBuildBitCast(builder, cmpval, int_vec_type, "");
+      mask = lp_build_cmp(&intbld, PIPE_FUNC_GREATER, anosign, cmpval);
+      return lp_build_select(bld, mask, a, res);
+   }
+}
+/**
+ * Return float (vector) rounded to nearest integer (vector).  The returned
+ * value is a float (vector).
+ * Ex: round(0.9) = 1.0
+ * Ex: round(-1.5) = -2.0
+ */
+LLVMValueRef
+lp_build_round(struct lp_build_context *bld,
+               LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   if (arch_rounding_available(type)) {
+      return lp_build_round_arch(bld, a, LP_BUILD_ROUND_NEAREST);
+   }
+   else {
+      const struct lp_type type = bld->type;
+      struct lp_type inttype;
+      struct lp_build_context intbld;
+      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 1<<24);
+      LLVMValueRef res, anosign, mask;
+      LLVMTypeRef int_vec_type = bld->int_vec_type;
+      LLVMTypeRef vec_type = bld->vec_type;
+      assert(type.width == 32); /* might want to handle doubles at some point */
+      inttype = type;
+      inttype.floating = 0;
+      lp_build_context_init(&intbld, bld->gallivm, inttype);
+      res = lp_build_iround(bld, a);
+      res = LLVMBuildSIToFP(builder, res, vec_type, "");
+      /* mask out sign bit */
+      anosign = lp_build_abs(bld, a);
+      /*
+       * mask out all values if anosign > 2^24
+       * This should work both for large ints (all rounding is no-op for them
+       * because such floats are always exact) as well as special cases like
+       * NaNs, Infs (taking advantage of the fact they use max exponent).
+       * (2^24 is arbitrary anything between 2^24 and 2^31 should work.)
+       */
+      anosign = LLVMBuildBitCast(builder, anosign, int_vec_type, "");
+      cmpval = LLVMBuildBitCast(builder, cmpval, int_vec_type, "");
+      mask = lp_build_cmp(&intbld, PIPE_FUNC_GREATER, anosign, cmpval);
+      return lp_build_select(bld, mask, a, res);
+   }
+}
+/**
+ * Return floor of float (vector), result is a float (vector)
+ * Ex: floor(1.1) = 1.0
+ * Ex: floor(-1.1) = -2.0
+ */
+LLVMValueRef
+lp_build_floor(struct lp_build_context *bld,
+               LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   if (arch_rounding_available(type)) {
+      return lp_build_round_arch(bld, a, LP_BUILD_ROUND_FLOOR);
+   }
+   else {
+      const struct lp_type type = bld->type;
+      struct lp_type inttype;
+      struct lp_build_context intbld;
+      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 1<<24);
+      LLVMValueRef trunc, res, anosign, mask;
+      LLVMTypeRef int_vec_type = bld->int_vec_type;
+      LLVMTypeRef vec_type = bld->vec_type;
+      assert(type.width == 32); /* might want to handle doubles at some point */
+      inttype = type;
+      inttype.floating = 0;
+      lp_build_context_init(&intbld, bld->gallivm, inttype);
+      /* round by truncation */
+      trunc = LLVMBuildFPToSI(builder, a, int_vec_type, "");
+      res = LLVMBuildSIToFP(builder, trunc, vec_type, "floor.trunc");
+      if (type.sign) {
+         LLVMValueRef tmp;
+         /*
+          * fix values if rounding is wrong (for non-special cases)
+          * - this is the case if trunc > a
+          */
+         mask = lp_build_cmp(bld, PIPE_FUNC_GREATER, res, a);
+         /* tmp = trunc > a ? 1.0 : 0.0 */
+         tmp = LLVMBuildBitCast(builder, bld->one, int_vec_type, "");
+         tmp = lp_build_and(&intbld, mask, tmp);
+         tmp = LLVMBuildBitCast(builder, tmp, vec_type, "");
+         res = lp_build_sub(bld, res, tmp);
+      }
+      /* mask out sign bit */
+      anosign = lp_build_abs(bld, a);
+      /*
+       * mask out all values if anosign > 2^24
+       * This should work both for large ints (all rounding is no-op for them
+       * because such floats are always exact) as well as special cases like
+       * NaNs, Infs (taking advantage of the fact they use max exponent).
+       * (2^24 is arbitrary anything between 2^24 and 2^31 should work.)
+       */
+      anosign = LLVMBuildBitCast(builder, anosign, int_vec_type, "");
+      cmpval = LLVMBuildBitCast(builder, cmpval, int_vec_type, "");
+      mask = lp_build_cmp(&intbld, PIPE_FUNC_GREATER, anosign, cmpval);
+      return lp_build_select(bld, mask, a, res);
+   }
+}
+/**
+ * Return ceiling of float (vector), returning float (vector).
+ * Ex: ceil( 1.1) = 2.0
+ * Ex: ceil(-1.1) = -1.0
+ */
+LLVMValueRef
+lp_build_ceil(struct lp_build_context *bld,
+              LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   if (arch_rounding_available(type)) {
+      return lp_build_round_arch(bld, a, LP_BUILD_ROUND_CEIL);
+   }
+   else {
+      const struct lp_type type = bld->type;
+      struct lp_type inttype;
+      struct lp_build_context intbld;
+      LLVMValueRef cmpval = lp_build_const_vec(bld->gallivm, type, 1<<24);
+      LLVMValueRef trunc, res, anosign, mask, tmp;
+      LLVMTypeRef int_vec_type = bld->int_vec_type;
+      LLVMTypeRef vec_type = bld->vec_type;
+      assert(type.width == 32); /* might want to handle doubles at some point */
+      inttype = type;
+      inttype.floating = 0;
+      lp_build_context_init(&intbld, bld->gallivm, inttype);
+      /* round by truncation */
+      trunc = LLVMBuildFPToSI(builder, a, int_vec_type, "");
+      trunc = LLVMBuildSIToFP(builder, trunc, vec_type, "ceil.trunc");
+      /*
+       * fix values if rounding is wrong (for non-special cases)
+       * - this is the case if trunc < a
+       */
+      mask = lp_build_cmp(bld, PIPE_FUNC_LESS, trunc, a);
+      /* tmp = trunc < a ? 1.0 : 0.0 */
+      tmp = LLVMBuildBitCast(builder, bld->one, int_vec_type, "");
+      tmp = lp_build_and(&intbld, mask, tmp);
+      tmp = LLVMBuildBitCast(builder, tmp, vec_type, "");
+      res = lp_build_add(bld, trunc, tmp);
+      /* mask out sign bit */
+      anosign = lp_build_abs(bld, a);
+      /*
+       * mask out all values if anosign > 2^24
+       * This should work both for large ints (all rounding is no-op for them
+       * because such floats are always exact) as well as special cases like
+       * NaNs, Infs (taking advantage of the fact they use max exponent).
+       * (2^24 is arbitrary anything between 2^24 and 2^31 should work.)
+       */
+      anosign = LLVMBuildBitCast(builder, anosign, int_vec_type, "");
+      cmpval = LLVMBuildBitCast(builder, cmpval, int_vec_type, "");
+      mask = lp_build_cmp(&intbld, PIPE_FUNC_GREATER, anosign, cmpval);
+      return lp_build_select(bld, mask, a, res);
+   }
+}
+/**
+ * Return fractional part of 'a' computed as a - floor(a)
+ * Typically used in texture coord arithmetic.
+ */
+LLVMValueRef
+lp_build_fract(struct lp_build_context *bld,
+               LLVMValueRef a)
+{
+   assert(bld->type.floating);
+   return lp_build_sub(bld, a, lp_build_floor(bld, a));
+}
+/**
+ * Prevent returning a fractional part of 1.0 for very small negative values of
+ * 'a' by clamping against 0.99999(9).
+ */
+static inline LLVMValueRef
+clamp_fract(struct lp_build_context *bld, LLVMValueRef fract)
+{
+   LLVMValueRef max;
+   /* this is the largest number smaller than 1.0 representable as float */
+   max = lp_build_const_vec(bld->gallivm, bld->type,
+.0 - 1.0/(1LL << (lp_mantissa(bld->type) + 1)));
+   return lp_build_min(bld, fract, max);
+}
+/**
+ * Same as lp_build_fract, but guarantees that the result is always smaller
+ * than one.
+ */
+LLVMValueRef
+lp_build_fract_safe(struct lp_build_context *bld,
+                    LLVMValueRef a)
+{
+   return clamp_fract(bld, lp_build_fract(bld, a));
+}
+/**
+ * Return the integer part of a float (vector) value (== round toward zero).
+ * The returned value is an integer (vector).
+ * Ex: itrunc(-1.5) = -1
+ */
+LLVMValueRef
+lp_build_itrunc(struct lp_build_context *bld,
+                LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef int_vec_type = lp_build_int_vec_type(bld->gallivm, type);
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   return LLVMBuildFPToSI(builder, a, int_vec_type, "");
+}
+/**
+ * Return float (vector) rounded to nearest integer (vector).  The returned
+ * value is an integer (vector).
+ * Ex: iround(0.9) = 1
+ * Ex: iround(-1.5) = -2
+ */
+LLVMValueRef
+lp_build_iround(struct lp_build_context *bld,
+                LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef int_vec_type = bld->int_vec_type;
+   LLVMValueRef res;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   if ((util_cpu_caps.has_sse2 &&
+       ((type.width == 32) && (type.length == 1 || type.length == 4))) ||
+       (util_cpu_caps.has_avx && type.width == 32 && type.length == 8)) {
+      return lp_build_iround_nearest_sse2(bld, a);
+   }
+   if (arch_rounding_available(type)) {
+      res = lp_build_round_arch(bld, a, LP_BUILD_ROUND_NEAREST);
+   }
+   else {
+      LLVMValueRef half;
+      half = lp_build_const_vec(bld->gallivm, type, 0.5);
+      if (type.sign) {
+         LLVMTypeRef vec_type = bld->vec_type;
+         LLVMValueRef mask = lp_build_const_int_vec(bld->gallivm, type,
+                                    (unsigned long long)1 << (type.width - 1));
+         LLVMValueRef sign;
+         /* get sign bit */
+         sign = LLVMBuildBitCast(builder, a, int_vec_type, "");
+         sign = LLVMBuildAnd(builder, sign, mask, "");
+         /* sign * 0.5 */
+         half = LLVMBuildBitCast(builder, half, int_vec_type, "");
+         half = LLVMBuildOr(builder, sign, half, "");
+         half = LLVMBuildBitCast(builder, half, vec_type, "");
+      }
+      res = LLVMBuildFAdd(builder, a, half, "");
+   }
+   res = LLVMBuildFPToSI(builder, res, int_vec_type, "");
+   return res;
+}
+/**
+ * Return floor of float (vector), result is an int (vector)
+ * Ex: ifloor(1.1) = 1.0
+ * Ex: ifloor(-1.1) = -2.0
+ */
+LLVMValueRef
+lp_build_ifloor(struct lp_build_context *bld,
+                LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef int_vec_type = bld->int_vec_type;
+   LLVMValueRef res;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   res = a;
+   if (type.sign) {
+      if (arch_rounding_available(type)) {
+         res = lp_build_round_arch(bld, a, LP_BUILD_ROUND_FLOOR);
+      }
+      else {
+         struct lp_type inttype;
+         struct lp_build_context intbld;
+         LLVMValueRef trunc, itrunc, mask;
+         assert(type.floating);
+         assert(lp_check_value(type, a));
+         inttype = type;
+         inttype.floating = 0;
+         lp_build_context_init(&intbld, bld->gallivm, inttype);
+         /* round by truncation */
+         itrunc = LLVMBuildFPToSI(builder, a, int_vec_type, "");
+         trunc = LLVMBuildSIToFP(builder, itrunc, bld->vec_type, "ifloor.trunc");
+         /*
+          * fix values if rounding is wrong (for non-special cases)
+          * - this is the case if trunc > a
+          * The results of doing this with NaNs, very large values etc.
+          * are undefined but this seems to be the case anyway.
+          */
+         mask = lp_build_cmp(bld, PIPE_FUNC_GREATER, trunc, a);
+         /* cheapie minus one with mask since the mask is minus one / zero */
+         return lp_build_add(&intbld, itrunc, mask);
+      }
+   }
+   /* round to nearest (toward zero) */
+   res = LLVMBuildFPToSI(builder, res, int_vec_type, "ifloor.res");
+   return res;
+}
+/**
+ * Return ceiling of float (vector), returning int (vector).
+ * Ex: iceil( 1.1) = 2
+ * Ex: iceil(-1.1) = -1
+ */
+LLVMValueRef
+lp_build_iceil(struct lp_build_context *bld,
+               LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef int_vec_type = bld->int_vec_type;
+   LLVMValueRef res;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   if (arch_rounding_available(type)) {
+      res = lp_build_round_arch(bld, a, LP_BUILD_ROUND_CEIL);
+   }
+   else {
+      struct lp_type inttype;
+      struct lp_build_context intbld;
+      LLVMValueRef trunc, itrunc, mask;
+      assert(type.floating);
+      assert(lp_check_value(type, a));
+      inttype = type;
+      inttype.floating = 0;
+      lp_build_context_init(&intbld, bld->gallivm, inttype);
+      /* round by truncation */
+      itrunc = LLVMBuildFPToSI(builder, a, int_vec_type, "");
+      trunc = LLVMBuildSIToFP(builder, itrunc, bld->vec_type, "iceil.trunc");
+      /*
+       * fix values if rounding is wrong (for non-special cases)
+       * - this is the case if trunc < a
+       * The results of doing this with NaNs, very large values etc.
+       * are undefined but this seems to be the case anyway.
+       */
+      mask = lp_build_cmp(bld, PIPE_FUNC_LESS, trunc, a);
+      /* cheapie plus one with mask since the mask is minus one / zero */
+      return lp_build_sub(&intbld, itrunc, mask);
+   }
+   /* round to nearest (toward zero) */
+   res = LLVMBuildFPToSI(builder, res, int_vec_type, "iceil.res");
+   return res;
+}
+/**
+ * Combined ifloor() & fract().
+ *
+ * Preferred to calling the functions separately, as it will ensure that the
+ * strategy (floor() vs ifloor()) that results in less redundant work is used.
+ */
+void
+lp_build_ifloor_fract(struct lp_build_context *bld,
+                      LLVMValueRef a,
+                      LLVMValueRef *out_ipart,
+                      LLVMValueRef *out_fpart)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMValueRef ipart;
+   assert(type.floating);
+   assert(lp_check_value(type, a));
+   if (arch_rounding_available(type)) {
+      /*
+       * floor() is easier.
+       */
+      ipart = lp_build_floor(bld, a);
+      *out_fpart = LLVMBuildFSub(builder, a, ipart, "fpart");
+      *out_ipart = LLVMBuildFPToSI(builder, ipart, bld->int_vec_type, "ipart");
+   }
+   else {
+      /*
+       * ifloor() is easier.
+       */
+      *out_ipart = lp_build_ifloor(bld, a);
+      ipart = LLVMBuildSIToFP(builder, *out_ipart, bld->vec_type, "ipart");
+      *out_fpart = LLVMBuildFSub(builder, a, ipart, "fpart");
+   }
+}
+/**
+ * Same as lp_build_ifloor_fract, but guarantees that the fractional part is
+ * always smaller than one.
+ */
+void
+lp_build_ifloor_fract_safe(struct lp_build_context *bld,
+                           LLVMValueRef a,
+                           LLVMValueRef *out_ipart,
+                           LLVMValueRef *out_fpart)
+{
+   lp_build_ifloor_fract(bld, a, out_ipart, out_fpart);
+   *out_fpart = clamp_fract(bld, *out_fpart);
+}
+LLVMValueRef
+lp_build_sqrt(struct lp_build_context *bld,
+              LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef vec_type = lp_build_vec_type(bld->gallivm, type);
+   char intrinsic[32];
+   assert(lp_check_value(type, a));
+   /* TODO: optimize the constant case */
+   assert(type.floating);
+   if (type.length == 1) {
+      util_snprintf(intrinsic, sizeof intrinsic, "llvm.sqrt.f%u", type.width);
+   }
+   else {
+      util_snprintf(intrinsic, sizeof intrinsic, "llvm.sqrt.v%uf%u", type.length, type.width);
+   }
+   return lp_build_intrinsic_unary(builder, intrinsic, vec_type, a);
+}
+/**
+ * Do one Newton-Raphson step to improve reciprocate precision:
+ *
+ *   x_{i+1} = x_i * (2 - a * x_i)
+ *
+ * XXX: Unfortunately this won't give IEEE-754 conformant results for 0 or
+ * +/-Inf, giving NaN instead.  Certain applications rely on this behavior,
+ * such as Google Earth, which does RCP(RSQRT(0.0) when drawing the Earth's
+ * halo. It would be necessary to clamp the argument to prevent this.
+ *
+ * See also:
+ * - http://en.wikipedia.org/wiki/Division_(digital)#Newton.E2.80.93Raphson_division
+ * - http://softwarecommunity.intel.com/articles/eng/1818.htm
+ */
+static INLINE LLVMValueRef
+lp_build_rcp_refine(struct lp_build_context *bld,
+                    LLVMValueRef a,
+                    LLVMValueRef rcp_a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   LLVMValueRef two = lp_build_const_vec(bld->gallivm, bld->type, 2.0);
+   LLVMValueRef res;
+   res = LLVMBuildFMul(builder, a, rcp_a, "");
+   res = LLVMBuildFSub(builder, two, res, "");
+   res = LLVMBuildFMul(builder, rcp_a, res, "");
+   return res;
+}
+LLVMValueRef
+lp_build_rcp(struct lp_build_context *bld,
+             LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   assert(lp_check_value(type, a));
+   if(a == bld->zero)
+      return bld->undef;
+   if(a == bld->one)
+      return bld->one;
+   if(a == bld->undef)
+      return bld->undef;
+   assert(type.floating);
+   if(LLVMIsConstant(a))
+      return LLVMConstFDiv(bld->one, a);
+   /*
+    * We don't use RCPPS because:
+    * - it only has 10bits of precision
+    * - it doesn't even get the reciprocate of 1.0 exactly
+    * - doing Newton-Rapshon steps yields wrong (NaN) values for 0.0 or Inf
+    * - for recent processors the benefit over DIVPS is marginal, a case
+    *   dependent
+    *
+    * We could still use it on certain processors if benchmarks show that the
+    * RCPPS plus necessary workarounds are still preferrable to DIVPS; or for
+    * particular uses that require less workarounds.
+    */
+   if (FALSE && ((util_cpu_caps.has_sse && type.width == 32 && type.length == 4) ||
+         (util_cpu_caps.has_avx && type.width == 32 && type.length == 8))){
+      const unsigned num_iterations = 0;
+      LLVMValueRef res;
+      unsigned i;
+      const char *intrinsic = NULL;
+      if (type.length == 4) {
+         intrinsic = "llvm.x86.sse.rcp.ps";
+      }
+      else {
+         intrinsic = "llvm.x86.avx.rcp.ps.256";
+      }
+      res = lp_build_intrinsic_unary(builder, intrinsic, bld->vec_type, a);
+      for (i = 0; i < num_iterations; ++i) {
+         res = lp_build_rcp_refine(bld, a, res);
+      }
+      return res;
+   }
+   return LLVMBuildFDiv(builder, bld->one, a, "");
+}
+/**
+ * Do one Newton-Raphson step to improve rsqrt precision:
+ *
+ *   x_{i+1} = 0.5 * x_i * (3.0 - a * x_i * x_i)
+ *
+ * See also Intel 64 and IA-32 Architectures Optimization Manual.
+ */
+static INLINE LLVMValueRef
+lp_build_rsqrt_refine(struct lp_build_context *bld,
+                      LLVMValueRef a,
+                      LLVMValueRef rsqrt_a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   LLVMValueRef half = lp_build_const_vec(bld->gallivm, bld->type, 0.5);
+   LLVMValueRef three = lp_build_const_vec(bld->gallivm, bld->type, 3.0);
+   LLVMValueRef res;
+   res = LLVMBuildFMul(builder, rsqrt_a, rsqrt_a, "");
+   res = LLVMBuildFMul(builder, a, res, "");
+   res = LLVMBuildFSub(builder, three, res, "");
+   res = LLVMBuildFMul(builder, rsqrt_a, res, "");
+   res = LLVMBuildFMul(builder, half, res, "");
+   return res;
+}
+/**
+ * Generate 1/sqrt(a).
+ * Result is undefined for values < 0, infinity for +0.
+ */
+LLVMValueRef
+lp_build_rsqrt(struct lp_build_context *bld,
+               LLVMValueRef a)
+{
+   const struct lp_type type = bld->type;
+   assert(lp_check_value(type, a));
+   assert(type.floating);
+   /*
+    * This should be faster but all denormals will end up as infinity.
+    */
+   if (0 && lp_build_fast_rsqrt_available(type)) {
+      const unsigned num_iterations = 1;
+      LLVMValueRef res;
+      unsigned i;
+      /* rsqrt(1.0) != 1.0 here */
+      res = lp_build_fast_rsqrt(bld, a);
+      if (num_iterations) {
+         /*
+          * Newton-Raphson will result in NaN instead of infinity for zero,
+          * and NaN instead of zero for infinity.
+          * Also, need to ensure rsqrt(1.0) == 1.0.
+          * All numbers smaller than FLT_MIN will result in +infinity
+          * (rsqrtps treats all denormals as zero).
+          */
+         LLVMValueRef cmp;
+         LLVMValueRef flt_min = lp_build_const_vec(bld->gallivm, type, FLT_MIN);
+         LLVMValueRef inf = lp_build_const_vec(bld->gallivm, type, INFINITY);
+         for (i = 0; i < num_iterations; ++i) {
+            res = lp_build_rsqrt_refine(bld, a, res);
+         }
+         cmp = lp_build_compare(bld->gallivm, type, PIPE_FUNC_LESS, a, flt_min);
+         res = lp_build_select(bld, cmp, inf, res);
+         cmp = lp_build_compare(bld->gallivm, type, PIPE_FUNC_EQUAL, a, inf);
+         res = lp_build_select(bld, cmp, bld->zero, res);
+         cmp = lp_build_compare(bld->gallivm, type, PIPE_FUNC_EQUAL, a, bld->one);
+         res = lp_build_select(bld, cmp, bld->one, res);
+      }
+      return res;
+   }
+   return lp_build_rcp(bld, lp_build_sqrt(bld, a));
+}
+/**
+ * If there's a fast (inaccurate) rsqrt instruction available
+ * (caller may want to avoid to call rsqrt_fast if it's not available,
+ * i.e. for calculating x^0.5 it may do rsqrt_fast(x) * x but if
+ * unavailable it would result in sqrt/div/mul so obviously
+ * much better to just call sqrt, skipping both div and mul).
+ */
+boolean
+lp_build_fast_rsqrt_available(struct lp_type type)
+{
+   assert(type.floating);
+   if ((util_cpu_caps.has_sse && type.width == 32 && type.length == 4) ||
+       (util_cpu_caps.has_avx && type.width == 32 && type.length == 8)) {
+      return true;
+   }
+   return false;
+}
+/**
+ * Generate 1/sqrt(a).
+ * Result is undefined for values < 0, infinity for +0.
+ * Precision is limited, only ~10 bits guaranteed
+ * (rsqrt 1.0 may not be 1.0, denorms may be flushed to 0).
+ */
+LLVMValueRef
+lp_build_fast_rsqrt(struct lp_build_context *bld,
+                    LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   assert(lp_check_value(type, a));
+   if (lp_build_fast_rsqrt_available(type)) {
+      const char *intrinsic = NULL;
+      if (type.length == 4) {
+         intrinsic = "llvm.x86.sse.rsqrt.ps";
+      }
+      else {
+         intrinsic = "llvm.x86.avx.rsqrt.ps.256";
+      }
+      return lp_build_intrinsic_unary(builder, intrinsic, bld->vec_type, a);
+   }
+   else {
+      debug_printf("%s: emulating fast rsqrt with rcp/sqrt\n", __FUNCTION__);
+   }
+   return lp_build_rcp(bld, lp_build_sqrt(bld, a));
+}
+/**
+ * Generate sin(a) or cos(a) using polynomial approximation.
+ * TODO: it might be worth recognizing sin and cos using same source
+ * (i.e. d3d10 sincos opcode). Obviously doing both at the same time
+ * would be way cheaper than calculating (nearly) everything twice...
+ * Not sure it's common enough to be worth bothering however, scs
+ * opcode could also benefit from calculating both though.
+ */
+static LLVMValueRef
+lp_build_sin_or_cos(struct lp_build_context *bld,
+                    LLVMValueRef a,
+                    boolean cos)
+{
+   struct gallivm_state *gallivm = bld->gallivm;
+   LLVMBuilderRef b = gallivm->builder;
+   struct lp_type int_type = lp_int_type(bld->type);
+   /*
+    *  take the absolute value,
+    *  x = _mm_and_ps(x, *(v4sf*)_ps_inv_sign_mask);
+    */
+   LLVMValueRef inv_sig_mask = lp_build_const_int_vec(gallivm, bld->type, ~0x80000000);
+   LLVMValueRef a_v4si = LLVMBuildBitCast(b, a, bld->int_vec_type, "a_v4si");
+   LLVMValueRef absi = LLVMBuildAnd(b, a_v4si, inv_sig_mask, "absi");
+   LLVMValueRef x_abs = LLVMBuildBitCast(b, absi, bld->vec_type, "x_abs");
+   /*
+    * scale by 4/Pi
+    * y = _mm_mul_ps(x, *(v4sf*)_ps_cephes_FOPI);
+    */
+   LLVMValueRef FOPi = lp_build_const_vec(gallivm, bld->type, 1.27323954473516);
+   LLVMValueRef scale_y = LLVMBuildFMul(b, x_abs, FOPi, "scale_y");
+   /*
+    * store the integer part of y in mm0
+    * emm2 = _mm_cvttps_epi32(y);
+    */
+   LLVMValueRef emm2_i = LLVMBuildFPToSI(b, scale_y, bld->int_vec_type, "emm2_i");
+   /*
+    * j=(j+1) & (~1) (see the cephes sources)
+    * emm2 = _mm_add_epi32(emm2, *(v4si*)_pi32_1);
+    */
+   LLVMValueRef all_one = lp_build_const_int_vec(gallivm, bld->type, 1);
+   LLVMValueRef emm2_add =  LLVMBuildAdd(b, emm2_i, all_one, "emm2_add");
+   /*
+    * emm2 = _mm_and_si128(emm2, *(v4si*)_pi32_inv1);
+    */
+   LLVMValueRef inv_one = lp_build_const_int_vec(gallivm, bld->type, ~1);
+   LLVMValueRef emm2_and =  LLVMBuildAnd(b, emm2_add, inv_one, "emm2_and");
+   /*
+    * y = _mm_cvtepi32_ps(emm2);
+    */
+   LLVMValueRef y_2 = LLVMBuildSIToFP(b, emm2_and, bld->vec_type, "y_2");
+   LLVMValueRef const_2 = lp_build_const_int_vec(gallivm, bld->type, 2);
+   LLVMValueRef const_4 = lp_build_const_int_vec(gallivm, bld->type, 4);
+   LLVMValueRef const_29 = lp_build_const_int_vec(gallivm, bld->type, 29);
+   LLVMValueRef sign_mask = lp_build_const_int_vec(gallivm, bld->type, 0x80000000);
+   /*
+    * Argument used for poly selection and sign bit determination
+    * is different for sin vs. cos.
+    */
+   LLVMValueRef emm2_2 = cos ? LLVMBuildSub(b, emm2_and, const_2, "emm2_2") :
+                               emm2_and;
+   LLVMValueRef sign_bit = cos ? LLVMBuildShl(b, LLVMBuildAnd(b, const_4,
+                                                              LLVMBuildNot(b, emm2_2, ""), ""),
+                                              const_29, "sign_bit") :
+                                 LLVMBuildAnd(b, LLVMBuildXor(b, a_v4si,
+                                                              LLVMBuildShl(b, emm2_add,
+                                                                           const_29, ""), ""),
+                                              sign_mask, "sign_bit");
+   /*
+    * get the polynom selection mask
+    * there is one polynom for 0 <= x <= Pi/4
+    * and another one for Pi/4<x<=Pi/2
+    * Both branches will be computed.
+    *
+    * emm2 = _mm_and_si128(emm2, *(v4si*)_pi32_2);
+    * emm2 = _mm_cmpeq_epi32(emm2, _mm_setzero_si128());
+    */
+   LLVMValueRef emm2_3 =  LLVMBuildAnd(b, emm2_2, const_2, "emm2_3");
+   LLVMValueRef poly_mask = lp_build_compare(gallivm,
+                                             int_type, PIPE_FUNC_EQUAL,
+                                             emm2_3, lp_build_const_int_vec(gallivm, bld->type, 0));
+   /*
+    * _PS_CONST(minus_cephes_DP1, -0.78515625);
+    * _PS_CONST(minus_cephes_DP2, -2.4187564849853515625e-4);
+    * _PS_CONST(minus_cephes_DP3, -3.77489497744594108e-8);
+    */
+   LLVMValueRef DP1 = lp_build_const_vec(gallivm, bld->type, -0.78515625);
+   LLVMValueRef DP2 = lp_build_const_vec(gallivm, bld->type, -2.4187564849853515625e-4);
+   LLVMValueRef DP3 = lp_build_const_vec(gallivm, bld->type, -3.77489497744594108e-8);
+   /*
+    * The magic pass: "Extended precision modular arithmetic"
+    * x = ((x - y * DP1) - y * DP2) - y * DP3;
+    * xmm1 = _mm_mul_ps(y, xmm1);
+    * xmm2 = _mm_mul_ps(y, xmm2);
+    * xmm3 = _mm_mul_ps(y, xmm3);
+    */
+   LLVMValueRef xmm1 = LLVMBuildFMul(b, y_2, DP1, "xmm1");
+   LLVMValueRef xmm2 = LLVMBuildFMul(b, y_2, DP2, "xmm2");
+   LLVMValueRef xmm3 = LLVMBuildFMul(b, y_2, DP3, "xmm3");
+   /*
+    * x = _mm_add_ps(x, xmm1);
+    * x = _mm_add_ps(x, xmm2);
+    * x = _mm_add_ps(x, xmm3);
+    */
+   LLVMValueRef x_1 = LLVMBuildFAdd(b, x_abs, xmm1, "x_1");
+   LLVMValueRef x_2 = LLVMBuildFAdd(b, x_1, xmm2, "x_2");
+   LLVMValueRef x_3 = LLVMBuildFAdd(b, x_2, xmm3, "x_3");
+   /*
+    * Evaluate the first polynom  (0 <= x <= Pi/4)
+    *
+    * z = _mm_mul_ps(x,x);
+    */
+   LLVMValueRef z = LLVMBuildFMul(b, x_3, x_3, "z");
+   /*
+    * _PS_CONST(coscof_p0,  2.443315711809948E-005);
+    * _PS_CONST(coscof_p1, -1.388731625493765E-003);
+    * _PS_CONST(coscof_p2,  4.166664568298827E-002);
+    */
+   LLVMValueRef coscof_p0 = lp_build_const_vec(gallivm, bld->type, 2.443315711809948E-005);
+   LLVMValueRef coscof_p1 = lp_build_const_vec(gallivm, bld->type, -1.388731625493765E-003);
+   LLVMValueRef coscof_p2 = lp_build_const_vec(gallivm, bld->type, 4.166664568298827E-002);
+   /*
+    * y = *(v4sf*)_ps_coscof_p0;
+    * y = _mm_mul_ps(y, z);
+    */
+   LLVMValueRef y_3 = LLVMBuildFMul(b, z, coscof_p0, "y_3");
+   LLVMValueRef y_4 = LLVMBuildFAdd(b, y_3, coscof_p1, "y_4");
+   LLVMValueRef y_5 = LLVMBuildFMul(b, y_4, z, "y_5");
+   LLVMValueRef y_6 = LLVMBuildFAdd(b, y_5, coscof_p2, "y_6");
+   LLVMValueRef y_7 = LLVMBuildFMul(b, y_6, z, "y_7");
+   LLVMValueRef y_8 = LLVMBuildFMul(b, y_7, z, "y_8");
+   /*
+    * tmp = _mm_mul_ps(z, *(v4sf*)_ps_0p5);
+    * y = _mm_sub_ps(y, tmp);
+    * y = _mm_add_ps(y, *(v4sf*)_ps_1);
+    */
+   LLVMValueRef half = lp_build_const_vec(gallivm, bld->type, 0.5);
+   LLVMValueRef tmp = LLVMBuildFMul(b, z, half, "tmp");
+   LLVMValueRef y_9 = LLVMBuildFSub(b, y_8, tmp, "y_8");
+   LLVMValueRef one = lp_build_const_vec(gallivm, bld->type, 1.0);
+   LLVMValueRef y_10 = LLVMBuildFAdd(b, y_9, one, "y_9");
+   /*
+    * _PS_CONST(sincof_p0, -1.9515295891E-4);
+    * _PS_CONST(sincof_p1,  8.3321608736E-3);
+    * _PS_CONST(sincof_p2, -1.6666654611E-1);
+    */
+   LLVMValueRef sincof_p0 = lp_build_const_vec(gallivm, bld->type, -1.9515295891E-4);
+   LLVMValueRef sincof_p1 = lp_build_const_vec(gallivm, bld->type, 8.3321608736E-3);
+   LLVMValueRef sincof_p2 = lp_build_const_vec(gallivm, bld->type, -1.6666654611E-1);
+   /*
+    * Evaluate the second polynom  (Pi/4 <= x <= 0)
+    *
+    * y2 = *(v4sf*)_ps_sincof_p0;
+    * y2 = _mm_mul_ps(y2, z);
+    * y2 = _mm_add_ps(y2, *(v4sf*)_ps_sincof_p1);
+    * y2 = _mm_mul_ps(y2, z);
+    * y2 = _mm_add_ps(y2, *(v4sf*)_ps_sincof_p2);
+    * y2 = _mm_mul_ps(y2, z);
+    * y2 = _mm_mul_ps(y2, x);
+    * y2 = _mm_add_ps(y2, x);
+    */
+   LLVMValueRef y2_3 = LLVMBuildFMul(b, z, sincof_p0, "y2_3");
+   LLVMValueRef y2_4 = LLVMBuildFAdd(b, y2_3, sincof_p1, "y2_4");
+   LLVMValueRef y2_5 = LLVMBuildFMul(b, y2_4, z, "y2_5");
+   LLVMValueRef y2_6 = LLVMBuildFAdd(b, y2_5, sincof_p2, "y2_6");
+   LLVMValueRef y2_7 = LLVMBuildFMul(b, y2_6, z, "y2_7");
+   LLVMValueRef y2_8 = LLVMBuildFMul(b, y2_7, x_3, "y2_8");
+   LLVMValueRef y2_9 = LLVMBuildFAdd(b, y2_8, x_3, "y2_9");
+   /*
+    * select the correct result from the two polynoms
+    * xmm3 = poly_mask;
+    * y2 = _mm_and_ps(xmm3, y2); //, xmm3);
+    * y = _mm_andnot_ps(xmm3, y);
+    * y = _mm_or_ps(y,y2);
+    */
+   LLVMValueRef y2_i = LLVMBuildBitCast(b, y2_9, bld->int_vec_type, "y2_i");
+   LLVMValueRef y_i = LLVMBuildBitCast(b, y_10, bld->int_vec_type, "y_i");
+   LLVMValueRef y2_and = LLVMBuildAnd(b, y2_i, poly_mask, "y2_and");
+   LLVMValueRef poly_mask_inv = LLVMBuildNot(b, poly_mask, "poly_mask_inv");
+   LLVMValueRef y_and = LLVMBuildAnd(b, y_i, poly_mask_inv, "y_and");
+   LLVMValueRef y_combine = LLVMBuildOr(b, y_and, y2_and, "y_combine");
+   /*
+    * update the sign
+    * y = _mm_xor_ps(y, sign_bit);
+    */
+   LLVMValueRef y_sign = LLVMBuildXor(b, y_combine, sign_bit, "y_sign");
+   LLVMValueRef y_result = LLVMBuildBitCast(b, y_sign, bld->vec_type, "y_result");
+   LLVMValueRef isfinite = lp_build_isfinite(bld, a);
+   /* clamp output to be within [-1, 1] */
+   y_result = lp_build_clamp(bld, y_result,
+                             lp_build_const_vec(bld->gallivm, bld->type,  -1.f),
+                             lp_build_const_vec(bld->gallivm, bld->type,  1.f));
+   /* If a is -inf, inf or NaN then return NaN */
+   y_result = lp_build_select(bld, isfinite, y_result,
+                              lp_build_const_vec(bld->gallivm, bld->type,  NAN));
+   return y_result;
+}
+/**
+ * Generate sin(a)
+ */
+LLVMValueRef
+lp_build_sin(struct lp_build_context *bld,
+             LLVMValueRef a)
+{
+   return lp_build_sin_or_cos(bld, a, FALSE);
+}
+/**
+ * Generate cos(a)
+ */
+LLVMValueRef
+lp_build_cos(struct lp_build_context *bld,
+             LLVMValueRef a)
+{
+   return lp_build_sin_or_cos(bld, a, TRUE);
+}
+/**
+ * Generate pow(x, y)
+ */
+LLVMValueRef
+lp_build_pow(struct lp_build_context *bld,
+             LLVMValueRef x,
+             LLVMValueRef y)
+{
+   /* TODO: optimize the constant case */
+   if (gallivm_debug & GALLIVM_DEBUG_PERF &&
+       LLVMIsConstant(x) && LLVMIsConstant(y)) {
+      debug_printf("%s: inefficient/imprecise constant arithmetic\n",
+                   __FUNCTION__);
+   }
+   return lp_build_exp2(bld, lp_build_mul(bld, lp_build_log2(bld, x), y));
+}
+/**
+ * Generate exp(x)
+ */
+LLVMValueRef
+lp_build_exp(struct lp_build_context *bld,
+             LLVMValueRef x)
+{
+   /* log2(e) = 1/log(2) */
+   LLVMValueRef log2e = lp_build_const_vec(bld->gallivm, bld->type,
+.4426950408889634);
+   assert(lp_check_value(bld->type, x));
+   return lp_build_exp2(bld, lp_build_mul(bld, log2e, x));
+}
+/**
+ * Generate log(x)
+ * Behavior is undefined with infs, 0s and nans
+ */
+LLVMValueRef
+lp_build_log(struct lp_build_context *bld,
+             LLVMValueRef x)
+{
+   /* log(2) */
+   LLVMValueRef log2 = lp_build_const_vec(bld->gallivm, bld->type,
+.69314718055994529);
+   assert(lp_check_value(bld->type, x));
+   return lp_build_mul(bld, log2, lp_build_log2(bld, x));
+}
+/**
+ * Generate log(x) that handles edge cases (infs, 0s and nans)
+ */
+LLVMValueRef
+lp_build_log_safe(struct lp_build_context *bld,
+                  LLVMValueRef x)
+{
+   /* log(2) */
+   LLVMValueRef log2 = lp_build_const_vec(bld->gallivm, bld->type,
+.69314718055994529);
+   assert(lp_check_value(bld->type, x));
+   return lp_build_mul(bld, log2, lp_build_log2_safe(bld, x));
+}
+/**
+ * Generate polynomial.
+ * Ex:  coeffs[0] + x * coeffs[1] + x^2 * coeffs[2].
+ */
+LLVMValueRef
+lp_build_polynomial(struct lp_build_context *bld,
+                    LLVMValueRef x,
+                    const double *coeffs,
+                    unsigned num_coeffs)
+{
+   const struct lp_type type = bld->type;
+   LLVMValueRef even = NULL, odd = NULL;
+   LLVMValueRef x2;
+   unsigned i;
+   assert(lp_check_value(bld->type, x));
+   /* TODO: optimize the constant case */
+   if (gallivm_debug & GALLIVM_DEBUG_PERF &&
+       LLVMIsConstant(x)) {
+      debug_printf("%s: inefficient/imprecise constant arithmetic\n",
+                   __FUNCTION__);
+   }
+   /*
+    * Calculate odd and even terms seperately to decrease data dependency
+    * Ex:
+    *     c[0] + x^2 * c[2] + x^4 * c[4] ...
+    *     + x * (c[1] + x^2 * c[3] + x^4 * c[5]) ...
+    */
+   x2 = lp_build_mul(bld, x, x);
+   for (i = num_coeffs; i--; ) {
+      LLVMValueRef coeff;
+      coeff = lp_build_const_vec(bld->gallivm, type, coeffs[i]);
+      if (i % 2 == 0) {
+         if (even)
+            even = lp_build_add(bld, coeff, lp_build_mul(bld, x2, even));
+         else
+            even = coeff;
+      } else {
+         if (odd)
+            odd = lp_build_add(bld, coeff, lp_build_mul(bld, x2, odd));
+         else
+            odd = coeff;
+      }
+   }
+   if (odd)
+      return lp_build_add(bld, lp_build_mul(bld, odd, x), even);
+   else if (even)
+      return even;
+   else
+      return bld->undef;
+}
+/**
+ * Minimax polynomial fit of 2**x, in range [0, 1[
+ */
+const double lp_build_exp2_polynomial[] = {
+#if EXP_POLY_DEGREE == 5
+.000000000000000000000, /*XXX: was 0.999999925063526176901, recompute others */
+.693153073200168932794,
+.240153617044375388211,
+.0558263180532956664775,
+.00898934009049466391101,
+.00187757667519147912699
+#elif EXP_POLY_DEGREE == 4
+.00000259337069434683,
+.693003834469974940458,
+.24144275689150793076,
+.0520114606103070150235,
+.0135341679161270268764
+#elif EXP_POLY_DEGREE == 3
+.999925218562710312959,
+.695833540494823811697,
+.226067155427249155588,
+.0780245226406372992967
+#elif EXP_POLY_DEGREE == 2
+.00172476321474503578,
+.657636275736077639316,
+.33718943461968720704
+#else
+#error
+#endif
+};
+LLVMValueRef
+lp_build_exp2(struct lp_build_context *bld,
+              LLVMValueRef x)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef vec_type = lp_build_vec_type(bld->gallivm, type);
+   LLVMValueRef ipart = NULL;
+   LLVMValueRef fpart = NULL;
+   LLVMValueRef expipart = NULL;
+   LLVMValueRef expfpart = NULL;
+   LLVMValueRef res = NULL;
+   assert(lp_check_value(bld->type, x));
+   /* TODO: optimize the constant case */
+   if (gallivm_debug & GALLIVM_DEBUG_PERF &&
+       LLVMIsConstant(x)) {
+      debug_printf("%s: inefficient/imprecise constant arithmetic\n",
+                   __FUNCTION__);
+   }
+   assert(type.floating && type.width == 32);
+   /* We want to preserve NaN and make sure than for exp2 if x > 128,
+    * the result is INF  and if it's smaller than -126.9 the result is 0 */
+   x = lp_build_min_ext(bld, lp_build_const_vec(bld->gallivm, type,  128.0), x,
+                        GALLIVM_NAN_RETURN_NAN_FIRST_NONNAN);
+   x = lp_build_max_ext(bld, lp_build_const_vec(bld->gallivm, type, -126.99999),
+                        x, GALLIVM_NAN_RETURN_NAN_FIRST_NONNAN);
+   /* ipart = floor(x) */
+   /* fpart = x - ipart */
+   lp_build_ifloor_fract(bld, x, &ipart, &fpart);
+   /* expipart = (float) (1 << ipart) */
+   expipart = LLVMBuildAdd(builder, ipart,
+                           lp_build_const_int_vec(bld->gallivm, type, 127), "");
+   expipart = LLVMBuildShl(builder, expipart,
+                           lp_build_const_int_vec(bld->gallivm, type, 23), "");
+   expipart = LLVMBuildBitCast(builder, expipart, vec_type, "");
+   expfpart = lp_build_polynomial(bld, fpart, lp_build_exp2_polynomial,
+                                  Elements(lp_build_exp2_polynomial));
+   res = LLVMBuildFMul(builder, expipart, expfpart, "");
+   return res;
+}
+/**
+ * Extract the exponent of a IEEE-754 floating point value.
+ *
+ * Optionally apply an integer bias.
+ *
+ * Result is an integer value with
+ *
+ *   ifloor(log2(x)) + bias
+ */
+LLVMValueRef
+lp_build_extract_exponent(struct lp_build_context *bld,
+                          LLVMValueRef x,
+                          int bias)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   unsigned mantissa = lp_mantissa(type);
+   LLVMValueRef res;
+   assert(type.floating);
+   assert(lp_check_value(bld->type, x));
+   x = LLVMBuildBitCast(builder, x, bld->int_vec_type, "");
+   res = LLVMBuildLShr(builder, x,
+                       lp_build_const_int_vec(bld->gallivm, type, mantissa), "");
+   res = LLVMBuildAnd(builder, res,
+                      lp_build_const_int_vec(bld->gallivm, type, 255), "");
+   res = LLVMBuildSub(builder, res,
+                      lp_build_const_int_vec(bld->gallivm, type, 127 - bias), "");
+   return res;
+}
+/**
+ * Extract the mantissa of the a floating.
+ *
+ * Result is a floating point value with
+ *
+ *   x / floor(log2(x))
+ */
+LLVMValueRef
+lp_build_extract_mantissa(struct lp_build_context *bld,
+                          LLVMValueRef x)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   unsigned mantissa = lp_mantissa(type);
+   LLVMValueRef mantmask = lp_build_const_int_vec(bld->gallivm, type,
+                                                  (1ULL << mantissa) - 1);
+   LLVMValueRef one = LLVMConstBitCast(bld->one, bld->int_vec_type);
+   LLVMValueRef res;
+   assert(lp_check_value(bld->type, x));
+   assert(type.floating);
+   x = LLVMBuildBitCast(builder, x, bld->int_vec_type, "");
+   /* res = x / 2**ipart */
+   res = LLVMBuildAnd(builder, x, mantmask, "");
+   res = LLVMBuildOr(builder, res, one, "");
+   res = LLVMBuildBitCast(builder, res, bld->vec_type, "");
+   return res;
+}
+/**
+ * Minimax polynomial fit of log2((1.0 + sqrt(x))/(1.0 - sqrt(x)))/sqrt(x) ,for x in range of [0, 1/9[
+ * These coefficients can be generate with
+ * http://www.boost.org/doc/libs/1_36_0/libs/math/doc/sf_and_dist/html/math_toolkit/toolkit/internals2/minimax.html
+ */
+const double lp_build_log2_polynomial[] = {
+#if LOG_POLY_DEGREE == 5
+.88539008148777786488L,
+.961796878841293367824L,
+.577058946784739859012L,
+.412914355135828735411L,
+.308591899232910175289L,
+.352376952300281371868L,
+#elif LOG_POLY_DEGREE == 4
+.88539009343309178325L,
+.961791550404184197881L,
+.577440339438736392009L,
+.403343858251329912514L,
+.406718052498846252698L,
+#elif LOG_POLY_DEGREE == 3
+.88538959748872753838L,
+.961932915889597772928L,
+.571118517972136195241L,
+.493997535084709500285L,
+#else
+#error
+#endif
+};
+/**
+ * See http://www.devmaster.net/forums/showthread.php?p=43580
+ * http://en.wikipedia.org/wiki/Logarithm#Calculation
+ * http://www.nezumi.demon.co.uk/consult/logx.htm
+ *
+ * If handle_edge_cases is true the function will perform computations
+ * to match the required D3D10+ behavior for each of the edge cases.
+ * That means that if input is:
+ * - less than zero (to and including -inf) then NaN will be returned
+ * - equal to zero (-denorm, -0, +0 or +denorm), then -inf will be returned
+ * - +infinity, then +infinity will be returned
+ * - NaN, then NaN will be returned
+ *
+ * Those checks are fairly expensive so if you don't need them make sure
+ * handle_edge_cases is false.
+ */
+void
+lp_build_log2_approx(struct lp_build_context *bld,
+                     LLVMValueRef x,
+                     LLVMValueRef *p_exp,
+                     LLVMValueRef *p_floor_log2,
+                     LLVMValueRef *p_log2,
+                     boolean handle_edge_cases)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   const struct lp_type type = bld->type;
+   LLVMTypeRef vec_type = lp_build_vec_type(bld->gallivm, type);
+   LLVMTypeRef int_vec_type = lp_build_int_vec_type(bld->gallivm, type);
+   LLVMValueRef expmask = lp_build_const_int_vec(bld->gallivm, type, 0x7f800000);
+   LLVMValueRef mantmask = lp_build_const_int_vec(bld->gallivm, type, 0x007fffff);
+   LLVMValueRef one = LLVMConstBitCast(bld->one, int_vec_type);
+   LLVMValueRef i = NULL;
+   LLVMValueRef y = NULL;
+   LLVMValueRef z = NULL;
+   LLVMValueRef exp = NULL;
+   LLVMValueRef mant = NULL;
+   LLVMValueRef logexp = NULL;
+   LLVMValueRef logmant = NULL;
+   LLVMValueRef res = NULL;
+   assert(lp_check_value(bld->type, x));
+   if(p_exp || p_floor_log2 || p_log2) {
+      /* TODO: optimize the constant case */
+      if (gallivm_debug & GALLIVM_DEBUG_PERF &&
+          LLVMIsConstant(x)) {
+         debug_printf("%s: inefficient/imprecise constant arithmetic\n",
+                      __FUNCTION__);
+      }
+      assert(type.floating && type.width == 32);
+      /*
+       * We don't explicitly handle denormalized numbers. They will yield a
+       * result in the neighbourhood of -127, which appears to be adequate
+       * enough.
+       */
+      i = LLVMBuildBitCast(builder, x, int_vec_type, "");
+      /* exp = (float) exponent(x) */
+      exp = LLVMBuildAnd(builder, i, expmask, "");
+   }
+   if(p_floor_log2 || p_log2) {
+      logexp = LLVMBuildLShr(builder, exp, lp_build_const_int_vec(bld->gallivm, type, 23), "");
+      logexp = LLVMBuildSub(builder, logexp, lp_build_const_int_vec(bld->gallivm, type, 127), "");
+      logexp = LLVMBuildSIToFP(builder, logexp, vec_type, "");
+   }
+   if(p_log2) {
+      /* mant = 1 + (float) mantissa(x) */
+      mant = LLVMBuildAnd(builder, i, mantmask, "");
+      mant = LLVMBuildOr(builder, mant, one, "");
+      mant = LLVMBuildBitCast(builder, mant, vec_type, "");
+      /* y = (mant - 1) / (mant + 1) */
+      y = lp_build_div(bld,
+         lp_build_sub(bld, mant, bld->one),
+         lp_build_add(bld, mant, bld->one)
+      );
+      /* z = y^2 */
+      z = lp_build_mul(bld, y, y);
+      /* compute P(z) */
+      logmant = lp_build_polynomial(bld, z, lp_build_log2_polynomial,
+                                    Elements(lp_build_log2_polynomial));
+      /* logmant = y * P(z) */
+      logmant = lp_build_mul(bld, y, logmant);
+      res = lp_build_add(bld, logmant, logexp);
+      if (type.floating && handle_edge_cases) {
+         LLVMValueRef negmask, infmask,  zmask;
+         negmask = lp_build_cmp(bld, PIPE_FUNC_LESS, x,
+                                lp_build_const_vec(bld->gallivm, type,  0.0f));
+         zmask = lp_build_cmp(bld, PIPE_FUNC_EQUAL, x,
+                              lp_build_const_vec(bld->gallivm, type,  0.0f));
+         infmask = lp_build_cmp(bld, PIPE_FUNC_GEQUAL, x,
+                                lp_build_const_vec(bld->gallivm, type,  INFINITY));
+         /* If x is qual to inf make sure we return inf */
+         res = lp_build_select(bld, infmask,
+                               lp_build_const_vec(bld->gallivm, type,  INFINITY),
+                               res);
+         /* If x is qual to 0, return -inf */
+         res = lp_build_select(bld, zmask,
+                               lp_build_const_vec(bld->gallivm, type,  -INFINITY),
+                               res);
+         /* If x is nan or less than 0, return nan */
+         res = lp_build_select(bld, negmask,
+                               lp_build_const_vec(bld->gallivm, type,  NAN),
+                               res);
+      }
+   }
+   if(p_exp) {
+      exp = LLVMBuildBitCast(builder, exp, vec_type, "");
+      *p_exp = exp;
+   }
+   if(p_floor_log2)
+      *p_floor_log2 = logexp;
+   if(p_log2)
+      *p_log2 = res;
+}
+/*
+ * log2 implementation which doesn't have special code to
+ * handle edge cases (-inf, 0, inf, NaN). It's faster but
+ * the results for those cases are undefined.
+ */
+LLVMValueRef
+lp_build_log2(struct lp_build_context *bld,
+              LLVMValueRef x)
+{
+   LLVMValueRef res;
+   lp_build_log2_approx(bld, x, NULL, NULL, &res, FALSE);
+   return res;
+}
+/*
+ * Version of log2 which handles all edge cases.
+ * Look at documentation of lp_build_log2_approx for
+ * description of the behavior for each of the edge cases.
+ */
+LLVMValueRef
+lp_build_log2_safe(struct lp_build_context *bld,
+                   LLVMValueRef x)
+{
+   LLVMValueRef res;
+   lp_build_log2_approx(bld, x, NULL, NULL, &res, TRUE);
+   return res;
+}
+/**
+ * Faster (and less accurate) log2.
+ *
+ *    log2(x) = floor(log2(x)) - 1 + x / 2**floor(log2(x))
+ *
+ * Piece-wise linear approximation, with exact results when x is a
+ * power of two.
+ *
+ * See http://www.flipcode.com/archives/Fast_log_Function.shtml
+ */
+LLVMValueRef
+lp_build_fast_log2(struct lp_build_context *bld,
+                   LLVMValueRef x)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   LLVMValueRef ipart;
+   LLVMValueRef fpart;
+   assert(lp_check_value(bld->type, x));
+   assert(bld->type.floating);
+   /* ipart = floor(log2(x)) - 1 */
+   ipart = lp_build_extract_exponent(bld, x, -1);
+   ipart = LLVMBuildSIToFP(builder, ipart, bld->vec_type, "");
+   /* fpart = x / 2**ipart */
+   fpart = lp_build_extract_mantissa(bld, x);
+   /* ipart + fpart */
+   return LLVMBuildFAdd(builder, ipart, fpart, "");
+}
+/**
+ * Fast implementation of iround(log2(x)).
+ *
+ * Not an approximation -- it should give accurate results all the time.
+ */
+LLVMValueRef
+lp_build_ilog2(struct lp_build_context *bld,
+               LLVMValueRef x)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   LLVMValueRef sqrt2 = lp_build_const_vec(bld->gallivm, bld->type, M_SQRT2);
+   LLVMValueRef ipart;
+   assert(bld->type.floating);
+   assert(lp_check_value(bld->type, x));
+   /* x * 2^(0.5)   i.e., add 0.5 to the log2(x) */
+   x = LLVMBuildFMul(builder, x, sqrt2, "");
+   /* ipart = floor(log2(x) + 0.5)  */
+   ipart = lp_build_extract_exponent(bld, x, 0);
+   return ipart;
+}
+LLVMValueRef
+lp_build_mod(struct lp_build_context *bld,
+             LLVMValueRef x,
+             LLVMValueRef y)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   LLVMValueRef res;
+   const struct lp_type type = bld->type;
+   assert(lp_check_value(type, x));
+   assert(lp_check_value(type, y));
+   if (type.floating)
+      res = LLVMBuildFRem(builder, x, y, "");
+   else if (type.sign)
+      res = LLVMBuildSRem(builder, x, y, "");
+   else
+      res = LLVMBuildURem(builder, x, y, "");
+   return res;
+}
+/*
+ * For floating inputs it creates and returns a mask
+ * which is all 1's for channels which are NaN.
+ * Channels inside x which are not NaN will be 0.
+ */
+LLVMValueRef
+lp_build_isnan(struct lp_build_context *bld,
+               LLVMValueRef x)
+{
+   LLVMValueRef mask;
+   LLVMTypeRef int_vec_type = lp_build_int_vec_type(bld->gallivm, bld->type);
+   assert(bld->type.floating);
+   assert(lp_check_value(bld->type, x));
+   mask = LLVMBuildFCmp(bld->gallivm->builder, LLVMRealOEQ, x, x,
+                        "isnotnan");
+   mask = LLVMBuildNot(bld->gallivm->builder, mask, "");
+   mask = LLVMBuildSExt(bld->gallivm->builder, mask, int_vec_type, "isnan");
+   return mask;
+}
+/* Returns all 1's for floating point numbers that are
+ * finite numbers and returns all zeros for -inf,
+ * inf and nan's */
+LLVMValueRef
+lp_build_isfinite(struct lp_build_context *bld,
+                  LLVMValueRef x)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   LLVMTypeRef int_vec_type = lp_build_int_vec_type(bld->gallivm, bld->type);
+   struct lp_type int_type = lp_int_type(bld->type);
+   LLVMValueRef intx = LLVMBuildBitCast(builder, x, int_vec_type, "");
+   LLVMValueRef infornan32 = lp_build_const_int_vec(bld->gallivm, bld->type,
+x7f800000);
+   if (!bld->type.floating) {
+      return lp_build_const_int_vec(bld->gallivm, bld->type, 0);
+   }
+   assert(bld->type.floating);
+   assert(lp_check_value(bld->type, x));
+   assert(bld->type.width == 32);
+   intx = LLVMBuildAnd(builder, intx, infornan32, "");
+   return lp_build_compare(bld->gallivm, int_type, PIPE_FUNC_NOTEQUAL,
+                           intx, infornan32);
+}
+/*
+ * Returns true if the number is nan or inf and false otherwise.
+ * The input has to be a floating point vector.
+ */
+LLVMValueRef
+lp_build_is_inf_or_nan(struct gallivm_state *gallivm,
+                       const struct lp_type type,
+                       LLVMValueRef x)
+{
+   LLVMBuilderRef builder = gallivm->builder;
+   struct lp_type int_type = lp_int_type(type);
+   LLVMValueRef const0 = lp_build_const_int_vec(gallivm, int_type,
+x7f800000);
+   LLVMValueRef ret;
+   assert(type.floating);
+   ret = LLVMBuildBitCast(builder, x, lp_build_vec_type(gallivm, int_type), "");
+   ret = LLVMBuildAnd(builder, ret, const0, "");
+   ret = lp_build_compare(gallivm, int_type, PIPE_FUNC_EQUAL,
+                          ret, const0);
+   return ret;
+}
+LLVMValueRef
+lp_build_fpstate_get(struct gallivm_state *gallivm)
+{
+   if (util_cpu_caps.has_sse) {
+      LLVMBuilderRef builder = gallivm->builder;
+      LLVMValueRef mxcsr_ptr = lp_build_alloca(
+         gallivm,
+         LLVMInt32TypeInContext(gallivm->context),
+         "mxcsr_ptr");
+      LLVMValueRef mxcsr_ptr8 = LLVMBuildPointerCast(builder, mxcsr_ptr,
+          LLVMPointerType(LLVMInt8TypeInContext(gallivm->context), 0), "");
+      lp_build_intrinsic(builder,
+                         "llvm.x86.sse.stmxcsr",
+                         LLVMVoidTypeInContext(gallivm->context),
+                         &mxcsr_ptr8, 1);
+      return mxcsr_ptr;
+   }
+   return 0;
+}
+void
+lp_build_fpstate_set_denorms_zero(struct gallivm_state *gallivm,
+                                  boolean zero)
+{
+   if (util_cpu_caps.has_sse) {
+      /* turn on DAZ (64) | FTZ (32768) = 32832 if available */
+      int daz_ftz = _MM_FLUSH_ZERO_MASK;
+      LLVMBuilderRef builder = gallivm->builder;
+      LLVMValueRef mxcsr_ptr = lp_build_fpstate_get(gallivm);
+      LLVMValueRef mxcsr =
+         LLVMBuildLoad(builder, mxcsr_ptr, "mxcsr");
+      if (util_cpu_caps.has_daz) {
+         /* Enable denormals are zero mode */
+         daz_ftz |= _MM_DENORMALS_ZERO_MASK;
+      }
+      if (zero) {
+         mxcsr = LLVMBuildOr(builder, mxcsr,
+                             LLVMConstInt(LLVMTypeOf(mxcsr), daz_ftz, 0), "");
+      } else {
+         mxcsr = LLVMBuildAnd(builder, mxcsr,
+                              LLVMConstInt(LLVMTypeOf(mxcsr), ~daz_ftz, 0), "");
+      }
+      LLVMBuildStore(builder, mxcsr, mxcsr_ptr);
+      lp_build_fpstate_set(gallivm, mxcsr_ptr);
+   }
+}
+void
+lp_build_fpstate_set(struct gallivm_state *gallivm,
+                     LLVMValueRef mxcsr_ptr)
+{
+   if (util_cpu_caps.has_sse) {
+      LLVMBuilderRef builder = gallivm->builder;
+      mxcsr_ptr = LLVMBuildPointerCast(builder, mxcsr_ptr,
+                     LLVMPointerType(LLVMInt8TypeInContext(gallivm->context), 0), "");
+      lp_build_intrinsic(builder,
+                         "llvm.x86.sse.ldmxcsr",
+                         LLVMVoidTypeInContext(gallivm->context),
+                         &mxcsr_ptr, 1);
+   }
+}

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