/**************************************************************************
*
* Copyright 2009 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 functions for packing/unpacking.
*
* Pack/unpacking is necessary for conversion between types of different
* bit width.
*
* They are also commonly used when an computation needs higher
* precision for the intermediate values. For example, if one needs the
* function:
*
* c = compute(a, b);
*
* to use more precision for intermediate results then one should implement it
* as:
*
* LLVMValueRef
* compute(LLVMBuilderRef builder struct lp_type type, LLVMValueRef a, LLVMValueRef b)
* {
* struct lp_type wide_type = lp_wider_type(type);
* LLVMValueRef al, ah, bl, bh, cl, ch, c;
*
* lp_build_unpack2(builder, type, wide_type, a, &al, &ah);
* lp_build_unpack2(builder, type, wide_type, b, &bl, &bh);
*
* cl = compute_half(al, bl);
* ch = compute_half(ah, bh);
*
* c = lp_build_pack2(bld->builder, wide_type, type, cl, ch);
*
* return c;
* }
*
* where compute_half() would do the computation for half the elements with
* twice the precision.
*
* @author Jose Fonseca <jfonseca@vmware.com>
*/
#include "util/u_debug.h"
#include "util/u_math.h"
#include "util/u_cpu_detect.h"
#include "util/u_memory.h"
#include "lp_bld_type.h"
#include "lp_bld_const.h"
#include "lp_bld_init.h"
#include "lp_bld_intr.h"
#include "lp_bld_arit.h"
#include "lp_bld_pack.h"
#include "lp_bld_swizzle.h"
/**
* Build shuffle vectors that match PUNPCKLxx and PUNPCKHxx instructions.
*/
static LLVMValueRef
lp_build_const_unpack_shuffle(struct gallivm_state *gallivm,
unsigned n, unsigned lo_hi)
{
LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
unsigned i, j;
assert(n
<= LP_MAX_VECTOR_LENGTH
);
/* TODO: cache results in a static table */
for(i = 0, j = lo_hi*n/2; i < n; i += 2, ++j) {
elems[i + 0] = lp_build_const_int32(gallivm, 0 + j);
elems[i + 1] = lp_build_const_int32(gallivm, n + j);
}
return LLVMConstVector(elems, n);
}
/**
* Similar to lp_build_const_unpack_shuffle but for special AVX 256bit unpack.
* See comment above lp_build_interleave2_half for more details.
*/
static LLVMValueRef
lp_build_const_unpack_shuffle_half(struct gallivm_state *gallivm,
unsigned n, unsigned lo_hi)
{
LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
unsigned i, j;
assert(n
<= LP_MAX_VECTOR_LENGTH
);
for (i = 0, j = lo_hi*(n/4); i < n; i += 2, ++j) {
if (i == (n / 2))
j += n / 4;
elems[i + 0] = lp_build_const_int32(gallivm, 0 + j);
elems[i + 1] = lp_build_const_int32(gallivm, n + j);
}
return LLVMConstVector(elems, n);
}
/**
* Build shuffle vectors that match PACKxx (SSE) instructions or
* VPERM (Altivec).
*/
static LLVMValueRef
lp_build_const_pack_shuffle(struct gallivm_state *gallivm, unsigned n)
{
LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
unsigned i;
assert(n
<= LP_MAX_VECTOR_LENGTH
);
for(i = 0; i < n; ++i)
#ifdef PIPE_ARCH_LITTLE_ENDIAN
elems[i] = lp_build_const_int32(gallivm, 2*i);
#else
elems[i] = lp_build_const_int32(gallivm, 2*i+1);
#endif
return LLVMConstVector(elems, n);
}
/**
* Return a vector with elements src[start:start+size]
* Most useful for getting half the values out of a 256bit sized vector,
* otherwise may cause data rearrangement to happen.
*/
LLVMValueRef
lp_build_extract_range(struct gallivm_state *gallivm,
LLVMValueRef src,
unsigned start,
unsigned size)
{
LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
unsigned i;
assert(size
<= Elements
(elems
));
for (i = 0; i < size; ++i)
elems[i] = lp_build_const_int32(gallivm, i + start);
if (size == 1) {
return LLVMBuildExtractElement(gallivm->builder, src, elems[0], "");
}
else {
return LLVMBuildShuffleVector(gallivm->builder, src, src,
LLVMConstVector(elems, size), "");
}
}
/**
* Concatenates several (must be a power of 2) vectors (of same type)
* into a larger one.
* Most useful for building up a 256bit sized vector out of two 128bit ones.
*/
LLVMValueRef
lp_build_concat(struct gallivm_state *gallivm,
LLVMValueRef src[],
struct lp_type src_type,
unsigned num_vectors)
{
unsigned new_length, i;
LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH/2];
LLVMValueRef shuffles[LP_MAX_VECTOR_LENGTH];
assert(src_type.
length * num_vectors
<= Elements
(shuffles
)); assert(util_is_power_of_two
(num_vectors
));
new_length = src_type.length;
for (i = 0; i < num_vectors; i++)
tmp[i] = src[i];
while (num_vectors > 1) {
num_vectors >>= 1;
new_length <<= 1;
for (i = 0; i < new_length; i++) {
shuffles[i] = lp_build_const_int32(gallivm, i);
}
for (i = 0; i < num_vectors; i++) {
tmp[i] = LLVMBuildShuffleVector(gallivm->builder, tmp[i*2], tmp[i*2 + 1],
LLVMConstVector(shuffles, new_length), "");
}
}
return tmp[0];
}
/**
* Combines vectors to reduce from num_srcs to num_dsts.
* Returns the number of src vectors concatenated in a single dst.
*
* num_srcs must be exactly divisible by num_dsts.
*
* e.g. For num_srcs = 4 and src = [x, y, z, w]
* num_dsts = 1 dst = [xyzw] return = 4
* num_dsts = 2 dst = [xy, zw] return = 2
*/
int
lp_build_concat_n(struct gallivm_state *gallivm,
struct lp_type src_type,
LLVMValueRef *src,
unsigned num_srcs,
LLVMValueRef *dst,
unsigned num_dsts)
{
int size = num_srcs / num_dsts;
int i;
assert((num_srcs
% size
) == 0);
if (num_srcs == num_dsts) {
for (i = 0; i < num_dsts; ++i) {
dst[i] = src[i];
}
return 1;
}
for (i = 0; i < num_dsts; ++i) {
dst[i] = lp_build_concat(gallivm, &src[i * size], src_type, size);
}
return size;
}
/**
* Interleave vector elements.
*
* Matches the PUNPCKLxx and PUNPCKHxx SSE instructions
* (but not for 256bit AVX vectors).
*/
LLVMValueRef
lp_build_interleave2(struct gallivm_state *gallivm,
struct lp_type type,
LLVMValueRef a,
LLVMValueRef b,
unsigned lo_hi)
{
LLVMValueRef shuffle;
if (type.length == 2 && type.width == 128 && util_cpu_caps.has_avx) {
/*
* XXX: This is a workaround for llvm code generation deficiency. Strangely
* enough, while this needs vinsertf128/vextractf128 instructions (hence
* a natural match when using 2x128bit vectors) the "normal" unpack shuffle
* generates code ranging from atrocious (llvm 3.1) to terrible (llvm 3.2, 3.3).
* So use some different shuffles instead (the exact shuffles don't seem to
* matter, as long as not using 128bit wide vectors, works with 8x32 or 4x64).
*/
struct lp_type tmp_type = type;
LLVMValueRef srchalf[2], tmpdst;
tmp_type.length = 4;
tmp_type.width = 64;
a = LLVMBuildBitCast(gallivm->builder, a, lp_build_vec_type(gallivm, tmp_type), "");
b = LLVMBuildBitCast(gallivm->builder, b, lp_build_vec_type(gallivm, tmp_type), "");
srchalf[0] = lp_build_extract_range(gallivm, a, lo_hi * 2, 2);
srchalf[1] = lp_build_extract_range(gallivm, b, lo_hi * 2, 2);
tmp_type.length = 2;
tmpdst = lp_build_concat(gallivm, srchalf, tmp_type, 2);
return LLVMBuildBitCast(gallivm->builder, tmpdst, lp_build_vec_type(gallivm, type), "");
}
shuffle = lp_build_const_unpack_shuffle(gallivm, type.length, lo_hi);
return LLVMBuildShuffleVector(gallivm->builder, a, b, shuffle, "");
}
/**
* Interleave vector elements but with 256 bit,
* treats it as interleave with 2 concatenated 128 bit vectors.
*
* This differs to lp_build_interleave2 as that function would do the following (for lo):
* a0 b0 a1 b1 a2 b2 a3 b3, and this does not compile into an AVX unpack instruction.
*
*
* An example interleave 8x float with 8x float on AVX 256bit unpack:
* a0 a1 a2 a3 a4 a5 a6 a7 <-> b0 b1 b2 b3 b4 b5 b6 b7
*
* Equivalent to interleaving 2x 128 bit vectors
* a0 a1 a2 a3 <-> b0 b1 b2 b3 concatenated with a4 a5 a6 a7 <-> b4 b5 b6 b7
*
* So interleave-lo would result in:
* a0 b0 a1 b1 a4 b4 a5 b5
*
* And interleave-hi would result in:
* a2 b2 a3 b3 a6 b6 a7 b7
*/
LLVMValueRef
lp_build_interleave2_half(struct gallivm_state *gallivm,
struct lp_type type,
LLVMValueRef a,
LLVMValueRef b,
unsigned lo_hi)
{
if (type.length * type.width == 256) {
LLVMValueRef shuffle = lp_build_const_unpack_shuffle_half(gallivm, type.length, lo_hi);
return LLVMBuildShuffleVector(gallivm->builder, a, b, shuffle, "");
} else {
return lp_build_interleave2(gallivm, type, a, b, lo_hi);
}
}
/**
* Double the bit width.
*
* This will only change the number of bits the values are represented, not the
* values themselves.
*/
void
lp_build_unpack2(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type dst_type,
LLVMValueRef src,
LLVMValueRef *dst_lo,
LLVMValueRef *dst_hi)
{
LLVMBuilderRef builder = gallivm->builder;
LLVMValueRef msb;
LLVMTypeRef dst_vec_type;
assert(dst_type.
width == src_type.
width * 2); assert(dst_type.
length * 2 == src_type.
length);
if(dst_type.sign && src_type.sign) {
/* Replicate the sign bit in the most significant bits */
msb = LLVMBuildAShr(builder, src, lp_build_const_int_vec(gallivm, src_type, src_type.width - 1), "");
}
else
/* Most significant bits always zero */
msb = lp_build_zero(gallivm, src_type);
/* Interleave bits */
#ifdef PIPE_ARCH_LITTLE_ENDIAN
*dst_lo = lp_build_interleave2(gallivm, src_type, src, msb, 0);
*dst_hi = lp_build_interleave2(gallivm, src_type, src, msb, 1);
#else
*dst_lo = lp_build_interleave2(gallivm, src_type, msb, src, 0);
*dst_hi = lp_build_interleave2(gallivm, src_type, msb, src, 1);
#endif
/* Cast the result into the new type (twice as wide) */
dst_vec_type = lp_build_vec_type(gallivm, dst_type);
*dst_lo = LLVMBuildBitCast(builder, *dst_lo, dst_vec_type, "");
*dst_hi = LLVMBuildBitCast(builder, *dst_hi, dst_vec_type, "");
}
/**
* Expand the bit width.
*
* This will only change the number of bits the values are represented, not the
* values themselves.
*/
void
lp_build_unpack(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type dst_type,
LLVMValueRef src,
LLVMValueRef *dst, unsigned num_dsts)
{
unsigned num_tmps;
unsigned i;
/* Register width must remain constant */
assert(src_type.
width * src_type.
length == dst_type.
width * dst_type.
length);
/* We must not loose or gain channels. Only precision */
assert(src_type.
length == dst_type.
length * num_dsts
);
num_tmps = 1;
dst[0] = src;
while(src_type.width < dst_type.width) {
struct lp_type tmp_type = src_type;
tmp_type.width *= 2;
tmp_type.length /= 2;
for(i = num_tmps; i--; ) {
lp_build_unpack2(gallivm, src_type, tmp_type, dst[i], &dst[2*i + 0], &dst[2*i + 1]);
}
src_type = tmp_type;
num_tmps *= 2;
}
}
/**
* Non-interleaved pack.
*
* This will move values as
* (LSB) (MSB)
* lo = l0 __ l1 __ l2 __.. __ ln __
* hi = h0 __ h1 __ h2 __.. __ hn __
* res = l0 l1 l2 .. ln h0 h1 h2 .. hn
*
* This will only change the number of bits the values are represented, not the
* values themselves.
*
* It is assumed the values are already clamped into the destination type range.
* Values outside that range will produce undefined results. Use
* lp_build_packs2 instead.
*/
LLVMValueRef
lp_build_pack2(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type dst_type,
LLVMValueRef lo,
LLVMValueRef hi)
{
LLVMBuilderRef builder = gallivm->builder;
LLVMTypeRef dst_vec_type = lp_build_vec_type(gallivm, dst_type);
LLVMValueRef shuffle;
LLVMValueRef res = NULL;
struct lp_type intr_type = dst_type;
assert(src_type.
width == dst_type.
width * 2); assert(src_type.
length * 2 == dst_type.
length);
/* Check for special cases first */
if((util_cpu_caps.has_sse2 || util_cpu_caps.has_altivec) &&
src_type.width * src_type.length >= 128) {
const char *intrinsic = NULL;
boolean swap_intrinsic_operands = FALSE;
switch(src_type.width) {
case 32:
if (util_cpu_caps.has_sse2) {
if(dst_type.sign) {
intrinsic = "llvm.x86.sse2.packssdw.128";
}
else {
if (util_cpu_caps.has_sse4_1) {
intrinsic = "llvm.x86.sse41.packusdw";
}
}
} else if (util_cpu_caps.has_altivec) {
if (dst_type.sign) {
intrinsic = "llvm.ppc.altivec.vpkswus";
} else {
intrinsic = "llvm.ppc.altivec.vpkuwus";
}
#ifdef PIPE_ARCH_LITTLE_ENDIAN
swap_intrinsic_operands = TRUE;
#endif
}
break;
case 16:
if (dst_type.sign) {
if (util_cpu_caps.has_sse2) {
intrinsic = "llvm.x86.sse2.packsswb.128";
} else if (util_cpu_caps.has_altivec) {
intrinsic = "llvm.ppc.altivec.vpkshss";
#ifdef PIPE_ARCH_LITTLE_ENDIAN
swap_intrinsic_operands = TRUE;
#endif
}
} else {
if (util_cpu_caps.has_sse2) {
intrinsic = "llvm.x86.sse2.packuswb.128";
} else if (util_cpu_caps.has_altivec) {
intrinsic = "llvm.ppc.altivec.vpkshus";
#ifdef PIPE_ARCH_LITTLE_ENDIAN
swap_intrinsic_operands = TRUE;
#endif
}
}
break;
/* default uses generic shuffle below */
}
if (intrinsic) {
if (src_type.width * src_type.length == 128) {
LLVMTypeRef intr_vec_type = lp_build_vec_type(gallivm, intr_type);
if (swap_intrinsic_operands) {
res = lp_build_intrinsic_binary(builder, intrinsic, intr_vec_type, hi, lo);
} else {
res = lp_build_intrinsic_binary(builder, intrinsic, intr_vec_type, lo, hi);
}
if (dst_vec_type != intr_vec_type) {
res = LLVMBuildBitCast(builder, res, dst_vec_type, "");
}
}
else {
int num_split = src_type.width * src_type.length / 128;
int i;
int nlen = 128 / src_type.width;
int lo_off = swap_intrinsic_operands ? nlen : 0;
int hi_off = swap_intrinsic_operands ? 0 : nlen;
struct lp_type ndst_type = lp_type_unorm(dst_type.width, 128);
struct lp_type nintr_type = lp_type_unorm(intr_type.width, 128);
LLVMValueRef tmpres[LP_MAX_VECTOR_WIDTH / 128];
LLVMValueRef tmplo, tmphi;
LLVMTypeRef ndst_vec_type = lp_build_vec_type(gallivm, ndst_type);
LLVMTypeRef nintr_vec_type = lp_build_vec_type(gallivm, nintr_type);
assert(num_split
<= LP_MAX_VECTOR_WIDTH
/ 128);
for (i = 0; i < num_split / 2; i++) {
tmplo = lp_build_extract_range(gallivm,
lo, i*nlen*2 + lo_off, nlen);
tmphi = lp_build_extract_range(gallivm,
lo, i*nlen*2 + hi_off, nlen);
tmpres[i] = lp_build_intrinsic_binary(builder, intrinsic,
nintr_vec_type, tmplo, tmphi);
if (ndst_vec_type != nintr_vec_type) {
tmpres[i] = LLVMBuildBitCast(builder, tmpres[i], ndst_vec_type, "");
}
}
for (i = 0; i < num_split / 2; i++) {
tmplo = lp_build_extract_range(gallivm,
hi, i*nlen*2 + lo_off, nlen);
tmphi = lp_build_extract_range(gallivm,
hi, i*nlen*2 + hi_off, nlen);
tmpres[i+num_split/2] = lp_build_intrinsic_binary(builder, intrinsic,
nintr_vec_type,
tmplo, tmphi);
if (ndst_vec_type != nintr_vec_type) {
tmpres[i+num_split/2] = LLVMBuildBitCast(builder, tmpres[i+num_split/2],
ndst_vec_type, "");
}
}
res = lp_build_concat(gallivm, tmpres, ndst_type, num_split);
}
return res;
}
}
/* generic shuffle */
lo = LLVMBuildBitCast(builder, lo, dst_vec_type, "");
hi = LLVMBuildBitCast(builder, hi, dst_vec_type, "");
shuffle = lp_build_const_pack_shuffle(gallivm, dst_type.length);
res = LLVMBuildShuffleVector(builder, lo, hi, shuffle, "");
return res;
}
/**
* Non-interleaved pack and saturate.
*
* Same as lp_build_pack2 but will saturate values so that they fit into the
* destination type.
*/
LLVMValueRef
lp_build_packs2(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type dst_type,
LLVMValueRef lo,
LLVMValueRef hi)
{
boolean clamp;
assert(src_type.
sign == dst_type.
sign); assert(src_type.
width == dst_type.
width * 2); assert(src_type.
length * 2 == dst_type.
length);
clamp = TRUE;
/* All X86 SSE non-interleaved pack instructions take signed inputs and
* saturate them, so no need to clamp for those cases. */
if(util_cpu_caps.has_sse2 &&
src_type.width * src_type.length >= 128 &&
src_type.sign &&
(src_type.width == 32 || src_type.width == 16))
clamp = FALSE;
if(clamp) {
struct lp_build_context bld;
unsigned dst_bits = dst_type.sign ? dst_type.width - 1 : dst_type.width;
LLVMValueRef dst_max = lp_build_const_int_vec(gallivm, src_type, ((unsigned long long)1 << dst_bits) - 1);
lp_build_context_init(&bld, gallivm, src_type);
lo = lp_build_min(&bld, lo, dst_max);
hi = lp_build_min(&bld, hi, dst_max);
/* FIXME: What about lower bound? */
}
return lp_build_pack2(gallivm, src_type, dst_type, lo, hi);
}
/**
* Truncate the bit width.
*
* TODO: Handle saturation consistently.
*/
LLVMValueRef
lp_build_pack(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type dst_type,
boolean clamped,
const LLVMValueRef *src, unsigned num_srcs)
{
LLVMValueRef (*pack2)(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type dst_type,
LLVMValueRef lo,
LLVMValueRef hi);
LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH];
unsigned i;
/* Register width must remain constant */
assert(src_type.
width * src_type.
length == dst_type.
width * dst_type.
length);
/* We must not loose or gain channels. Only precision */
assert(src_type.
length * num_srcs
== dst_type.
length);
if(clamped)
pack2 = &lp_build_pack2;
else
pack2 = &lp_build_packs2;
for(i = 0; i < num_srcs; ++i)
tmp[i] = src[i];
while(src_type.width > dst_type.width) {
struct lp_type tmp_type = src_type;
tmp_type.width /= 2;
tmp_type.length *= 2;
/* Take in consideration the sign changes only in the last step */
if(tmp_type.width == dst_type.width)
tmp_type.sign = dst_type.sign;
num_srcs /= 2;
for(i = 0; i < num_srcs; ++i)
tmp[i] = pack2(gallivm, src_type, tmp_type,
tmp[2*i + 0], tmp[2*i + 1]);
src_type = tmp_type;
}
return tmp[0];
}
/**
* Truncate or expand the bitwidth.
*
* NOTE: Getting the right sign flags is crucial here, as we employ some
* intrinsics that do saturation.
*/
void
lp_build_resize(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type dst_type,
const LLVMValueRef *src, unsigned num_srcs,
LLVMValueRef *dst, unsigned num_dsts)
{
LLVMBuilderRef builder = gallivm->builder;
LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH];
unsigned i;
/*
* We don't support float <-> int conversion here. That must be done
* before/after calling this function.
*/
assert(src_type.
floating == dst_type.
floating);
/*
* We don't support double <-> float conversion yet, although it could be
* added with little effort.
*/
assert((!src_type.
floating && !dst_type.
floating) || src_type.width == dst_type.width);
/* We must not loose or gain channels. Only precision */
assert(src_type.
length * num_srcs
== dst_type.
length * num_dsts
);
assert(src_type.
length <= LP_MAX_VECTOR_LENGTH
); assert(dst_type.
length <= LP_MAX_VECTOR_LENGTH
); assert(num_srcs
<= LP_MAX_VECTOR_LENGTH
); assert(num_dsts
<= LP_MAX_VECTOR_LENGTH
);
if (src_type.width > dst_type.width) {
/*
* Truncate bit width.
*/
/* Conversion must be M:1 */
if (src_type.width * src_type.length == dst_type.width * dst_type.length) {
/*
* Register width remains constant -- use vector packing intrinsics
*/
tmp[0] = lp_build_pack(gallivm, src_type, dst_type, TRUE, src, num_srcs);
}
else {
if (src_type.width / dst_type.width > num_srcs) {
/*
* First change src vectors size (with shuffle) so they have the
* same size as the destination vector, then pack normally.
* Note: cannot use cast/extract because llvm generates atrocious code.
*/
unsigned size_ratio = (src_type.width * src_type.length) /
(dst_type.length * dst_type.width);
unsigned new_length = src_type.length / size_ratio;
for (i = 0; i < size_ratio * num_srcs; i++) {
unsigned start_index = (i % size_ratio) * new_length;
tmp[i] = lp_build_extract_range(gallivm, src[i / size_ratio],
start_index, new_length);
}
num_srcs *= size_ratio;
src_type.length = new_length;
tmp[0] = lp_build_pack(gallivm, src_type, dst_type, TRUE, tmp, num_srcs);
}
else {
/*
* Truncate bit width but expand vector size - first pack
* then expand simply because this should be more AVX-friendly
* for the cases we probably hit.
*/
unsigned size_ratio = (dst_type.width * dst_type.length) /
(src_type.length * src_type.width);
unsigned num_pack_srcs = num_srcs / size_ratio;
dst_type.length = dst_type.length / size_ratio;
for (i = 0; i < size_ratio; i++) {
tmp[i] = lp_build_pack(gallivm, src_type, dst_type, TRUE,
&src[i*num_pack_srcs], num_pack_srcs);
}
tmp[0] = lp_build_concat(gallivm, tmp, dst_type, size_ratio);
}
}
}
else if (src_type.width < dst_type.width) {
/*
* Expand bit width.
*/
/* Conversion must be 1:N */
if (src_type.width * src_type.length == dst_type.width * dst_type.length) {
/*
* Register width remains constant -- use vector unpack intrinsics
*/
lp_build_unpack(gallivm, src_type, dst_type, src[0], tmp, num_dsts);
}
else {
/*
* Do it element-wise.
*/
assert(src_type.
length * num_srcs
== dst_type.
length * num_dsts
);
for (i = 0; i < num_dsts; i++) {
tmp[i] = lp_build_undef(gallivm, dst_type);
}
for (i = 0; i < src_type.length; ++i) {
unsigned j = i / dst_type.length;
LLVMValueRef srcindex = lp_build_const_int32(gallivm, i);
LLVMValueRef dstindex = lp_build_const_int32(gallivm, i % dst_type.length);
LLVMValueRef val = LLVMBuildExtractElement(builder, src[0], srcindex, "");
if (src_type.sign && dst_type.sign) {
val = LLVMBuildSExt(builder, val, lp_build_elem_type(gallivm, dst_type), "");
} else {
val = LLVMBuildZExt(builder, val, lp_build_elem_type(gallivm, dst_type), "");
}
tmp[j] = LLVMBuildInsertElement(builder, tmp[j], val, dstindex, "");
}
}
}
else {
/*
* No-op
*/
/* "Conversion" must be N:N */
for(i = 0; i < num_dsts; ++i)
tmp[i] = src[i];
}
for(i = 0; i < num_dsts; ++i)
dst[i] = tmp[i];
}
/**
* Expands src vector from src.length to dst_length
*/
LLVMValueRef
lp_build_pad_vector(struct gallivm_state *gallivm,
LLVMValueRef src,
unsigned dst_length)
{
LLVMValueRef elems[LP_MAX_VECTOR_LENGTH];
LLVMValueRef undef;
LLVMTypeRef type;
unsigned i, src_length;
type = LLVMTypeOf(src);
if (LLVMGetTypeKind(type) != LLVMVectorTypeKind) {
/* Can't use ShuffleVector on non-vector type */
undef = LLVMGetUndef(LLVMVectorType(type, dst_length));
return LLVMBuildInsertElement(gallivm->builder, undef, src, lp_build_const_int32(gallivm, 0), "");
}
undef = LLVMGetUndef(type);
src_length = LLVMGetVectorSize(type);
assert(dst_length
<= Elements
(elems
)); assert(dst_length
>= src_length
);
if (src_length == dst_length)
return src;
/* All elements from src vector */
for (i = 0; i < src_length; ++i)
elems[i] = lp_build_const_int32(gallivm, i);
/* Undef fill remaining space */
for (i = src_length; i < dst_length; ++i)
elems[i] = lp_build_const_int32(gallivm, src_length);
/* Combine the two vectors */
return LLVMBuildShuffleVector(gallivm->builder, src, undef, LLVMConstVector(elems, dst_length), "");
}