| 0,0 → 1,311 |
|---|
| /* |
| * Copyright 2013 Vadim Girlin <vadimgirlin@gmail.com> |
| * |
| * 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 |
| * on 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 |
| * THE AUTHOR(S) AND/OR THEIR 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. |
| * |
| * Authors: |
| * Vadim Girlin |
| */ |
| |
| #define IFC_DEBUG 0 |
| |
| #if IFC_DEBUG |
| #define IFC_DUMP(q) do { q } while (0) |
| #else |
| #define IFC_DUMP(q) |
| #endif |
| |
| #include "sb_shader.h" |
| #include "sb_pass.h" |
| |
| namespace r600_sb { |
| |
| int if_conversion::run() { |
| |
| regions_vec &rv = sh.get_regions(); |
| |
| unsigned converted = 0; |
| |
| for (regions_vec::reverse_iterator N, I = rv.rbegin(), E = rv.rend(); |
| I != E; I = N) { |
| N = I; ++N; |
| |
| region_node *r = *I; |
| if (run_on(r)) { |
| rv.erase(I.base() - 1); |
| ++converted; |
| } |
| } |
| return 0; |
| } |
| |
| void if_conversion::convert_kill_instructions(region_node *r, |
| value *em, bool branch, |
| container_node *c) { |
| value *cnd = NULL; |
| |
| for (node_iterator I = c->begin(), E = c->end(), N; I != E; I = N) { |
| N = I + 1; |
| |
| if (!I->is_alu_inst()) |
| continue; |
| |
| alu_node *a = static_cast<alu_node*>(*I); |
| unsigned flags = a->bc.op_ptr->flags; |
| |
| if (!(flags & AF_KILL)) |
| continue; |
| |
| // ignore predicated or non-const kill instructions |
| if (a->pred || !a->src[0]->is_const() || !a->src[1]->is_const()) |
| continue; |
| |
| literal l0 = a->src[0]->literal_value; |
| literal l1 = a->src[1]->literal_value; |
| |
| expr_handler::apply_alu_src_mod(a->bc, 0, l0); |
| expr_handler::apply_alu_src_mod(a->bc, 1, l1); |
| |
| if (expr_handler::evaluate_condition(flags, l0, l1)) { |
| // kill with constant 'true' condition, we'll convert it to the |
| // conditional kill outside of the if-then-else block |
| |
| a->remove(); |
| |
| if (!cnd) { |
| cnd = get_select_value_for_em(sh, em); |
| } else { |
| // more than one kill with the same condition, just remove it |
| continue; |
| } |
| |
| r->insert_before(a); |
| a->bc.set_op(branch ? ALU_OP2_KILLE_INT : ALU_OP2_KILLNE_INT); |
| |
| a->src[0] = cnd; |
| a->src[1] = sh.get_const_value(0); |
| // clear modifiers |
| memset(&a->bc.src[0], 0, sizeof(bc_alu_src)); |
| memset(&a->bc.src[1], 0, sizeof(bc_alu_src)); |
| } else { |
| // kill with constant 'false' condition, this shouldn't happen |
| // but remove it anyway |
| a->remove(); |
| } |
| } |
| } |
| |
| bool if_conversion::check_and_convert(region_node *r) { |
| |
| depart_node *nd1 = static_cast<depart_node*>(r->first); |
| if (!nd1->is_depart()) |
| return false; |
| if_node *nif = static_cast<if_node*>(nd1->first); |
| if (!nif->is_if()) |
| return false; |
| depart_node *nd2 = static_cast<depart_node*>(nif->first); |
| if (!nd2->is_depart()) |
| return false; |
| |
| value* &em = nif->cond; |
| |
| node_stats s; |
| |
| r->collect_stats(s); |
| |
| IFC_DUMP( |
| sblog << "ifcvt: region " << r->region_id << " :\n"; |
| s.dump(); |
| ); |
| |
| if (s.region_count || s.fetch_count || s.alu_kill_count || |
| s.if_count != 1 || s.repeat_count) |
| return false; |
| |
| unsigned real_alu_count = s.alu_count - s.alu_copy_mov_count; |
| |
| // if_conversion allows to eliminate JUMP-ALU_POP_AFTER or |
| // JUMP-ALU-ELSE-ALU_POP_AFTER, for now let's assume that 3 CF instructions |
| // are eliminated. According to the docs, cost of CF instruction is |
| // equal to ~40 ALU VLIW instructions (instruction groups), |
| // so we have eliminated cost equal to ~120 groups in total. |
| // Let's also assume that we have avg 3 ALU instructions per group, |
| // This means that potential eliminated cost is about 360 single alu inst. |
| // On the other hand, we are speculatively executing conditional code now, |
| // so we are increasing the cost in some cases. In the worst case, we'll |
| // have to execute real_alu_count additional alu instructions instead of |
| // jumping over them. Let's assume for now that average added cost is |
| // |
| // (0.9 * real_alu_count) |
| // |
| // So we should perform if_conversion if |
| // |
| // (0.9 * real_alu_count) < 360, or |
| // |
| // real_alu_count < 400 |
| // |
| // So if real_alu_count is more than 400, than we think that if_conversion |
| // doesn't make sense. |
| |
| // FIXME: We can use more precise heuristic, taking into account sizes of |
| // the branches and their probability instead of total size. |
| // Another way to improve this is to consider the number of the groups |
| // instead of the number of instructions (taking into account actual VLIW |
| // packing). |
| // (Currently we don't know anything about packing at this stage, but |
| // probably we can make some more precise estimations anyway) |
| |
| if (real_alu_count > 400) |
| return false; |
| |
| IFC_DUMP( sblog << "if_cvt: processing...\n"; ); |
| |
| value *select = get_select_value_for_em(sh, em); |
| |
| if (!select) |
| return false; |
| |
| for (node_iterator I = r->phi->begin(), E = r->phi->end(); I != E; ++I) { |
| node *n = *I; |
| |
| alu_node *ns = convert_phi(select, n); |
| |
| if (ns) |
| r->insert_after(ns); |
| } |
| |
| nd2->expand(); |
| nif->expand(); |
| nd1->expand(); |
| r->expand(); |
| |
| return true; |
| } |
| |
| bool if_conversion::run_on(region_node* r) { |
| |
| if (r->dep_count() != 2 || r->rep_count() != 1) |
| return false; |
| |
| depart_node *nd1 = static_cast<depart_node*>(r->first); |
| if (!nd1->is_depart()) |
| return false; |
| if_node *nif = static_cast<if_node*>(nd1->first); |
| if (!nif->is_if()) |
| return false; |
| depart_node *nd2 = static_cast<depart_node*>(nif->first); |
| if (!nd2->is_depart()) |
| return false; |
| |
| value* &em = nif->cond; |
| |
| convert_kill_instructions(r, em, true, nd2); |
| convert_kill_instructions(r, em, false, nd1); |
| |
| if (check_and_convert(r)) |
| return true; |
| |
| if (nd2->empty() && nif->next) { |
| // empty true branch, non-empty false branch |
| // we'll invert it to get rid of 'else' |
| |
| assert(em && em->def); |
| |
| alu_node *predset = static_cast<alu_node*>(em->def); |
| |
| // create clone of PREDSET instruction with inverted condition. |
| // PREDSET has 3 dst operands in our IR (value written to gpr, |
| // predicate value and exec mask value), we'll split it such that |
| // new PREDSET will define exec mask value only, and two others will |
| // be defined in the old PREDSET (if they are not used then DCE will |
| // simply remove old PREDSET). |
| |
| alu_node *newpredset = sh.clone(predset); |
| predset->insert_after(newpredset); |
| |
| predset->dst[2] = NULL; |
| |
| newpredset->dst[0] = NULL; |
| newpredset->dst[1] = NULL; |
| |
| em->def = newpredset; |
| |
| unsigned cc = newpredset->bc.op_ptr->flags & AF_CC_MASK; |
| unsigned cmptype = newpredset->bc.op_ptr->flags & AF_CMP_TYPE_MASK; |
| bool swapargs = false; |
| |
| cc = invert_setcc_condition(cc, swapargs); |
| |
| if (swapargs) { |
| std::swap(newpredset->src[0], newpredset->src[1]); |
| std::swap(newpredset->bc.src[0], newpredset->bc.src[1]); |
| } |
| |
| unsigned newopcode = get_predsetcc_op(cc, cmptype); |
| newpredset->bc.set_op(newopcode); |
| |
| // move the code from the 'false' branch ('else') to the 'true' branch |
| nd2->move(nif->next, NULL); |
| |
| // swap phi operands |
| for (node_iterator I = r->phi->begin(), E = r->phi->end(); I != E; |
| ++I) { |
| node *p = *I; |
| assert(p->src.size() == 2); |
| std::swap(p->src[0], p->src[1]); |
| } |
| } |
| |
| return false; |
| } |
| |
| alu_node* if_conversion::convert_phi(value* select, node* phi) { |
| assert(phi->dst.size() == 1 || phi->src.size() == 2); |
| |
| value *d = phi->dst[0]; |
| value *v1 = phi->src[0]; |
| value *v2 = phi->src[1]; |
| |
| assert(d); |
| |
| if (!d->is_any_gpr()) |
| return NULL; |
| |
| if (v1->is_undef()) { |
| if (v2->is_undef()) { |
| return NULL; |
| } else { |
| return sh.create_mov(d, v2); |
| } |
| } else if (v2->is_undef()) |
| return sh.create_mov(d, v1); |
| |
| alu_node* n = sh.create_alu(); |
| |
| n->bc.set_op(ALU_OP3_CNDE_INT); |
| n->dst.push_back(d); |
| n->src.push_back(select); |
| n->src.push_back(v1); |
| n->src.push_back(v2); |
| |
| return n; |
| } |
| |
| } // namespace r600_sb |