From e81739493a0cacc1efe3295f9d287d5d31b1a989 Mon Sep 17 00:00:00 2001
From: ReinUsesLisp <reinuseslisp@airmail.cc>
Date: Fri, 5 Feb 2021 05:58:02 -0300
Subject: shader: Constant propagation and global memory to storage buffer
---
.../ir_opt/constant_propagation_pass.cpp | 146 +++++++++++++++++++++
1 file changed, 146 insertions(+)
create mode 100644 src/shader_recompiler/ir_opt/constant_propagation_pass.cpp
(limited to 'src/shader_recompiler/ir_opt/constant_propagation_pass.cpp')
diff --git a/src/shader_recompiler/ir_opt/constant_propagation_pass.cpp b/src/shader_recompiler/ir_opt/constant_propagation_pass.cpp
new file mode 100644
index 0000000000..02f5b653d4
--- /dev/null
+++ b/src/shader_recompiler/ir_opt/constant_propagation_pass.cpp
@@ -0,0 +1,146 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <type_traits>
+
+#include "common/bit_util.h"
+#include "shader_recompiler/exception.h"
+#include "shader_recompiler/frontend/ir/microinstruction.h"
+#include "shader_recompiler/ir_opt/passes.h"
+
+namespace Shader::Optimization {
+namespace {
+[[nodiscard]] u32 BitFieldUExtract(u32 base, u32 shift, u32 count) {
+ if (static_cast<size_t>(shift) + static_cast<size_t>(count) > Common::BitSize<u32>()) {
+ throw LogicError("Undefined result in BitFieldUExtract({}, {}, {})", base, shift, count);
+ }
+ return (base >> shift) & ((1U << count) - 1);
+}
+
+template <typename T>
+[[nodiscard]] T Arg(const IR::Value& value) {
+ if constexpr (std::is_same_v<T, bool>) {
+ return value.U1();
+ } else if constexpr (std::is_same_v<T, u32>) {
+ return value.U32();
+ } else if constexpr (std::is_same_v<T, u64>) {
+ return value.U64();
+ }
+}
+
+template <typename ImmFn>
+bool FoldCommutative(IR::Inst& inst, ImmFn&& imm_fn) {
+ const auto arg = [](const IR::Value& value) {
+ if constexpr (std::is_invocable_r_v<bool, ImmFn, bool, bool>) {
+ return value.U1();
+ } else if constexpr (std::is_invocable_r_v<u32, ImmFn, u32, u32>) {
+ return value.U32();
+ } else if constexpr (std::is_invocable_r_v<u64, ImmFn, u64, u64>) {
+ return value.U64();
+ }
+ };
+ const IR::Value lhs{inst.Arg(0)};
+ const IR::Value rhs{inst.Arg(1)};
+
+ const bool is_lhs_immediate{lhs.IsImmediate()};
+ const bool is_rhs_immediate{rhs.IsImmediate()};
+
+ if (is_lhs_immediate && is_rhs_immediate) {
+ const auto result{imm_fn(arg(lhs), arg(rhs))};
+ inst.ReplaceUsesWith(IR::Value{result});
+ return false;
+ }
+ if (is_lhs_immediate && !is_rhs_immediate) {
+ IR::Inst* const rhs_inst{rhs.InstRecursive()};
+ if (rhs_inst->Opcode() == inst.Opcode() && rhs_inst->Arg(1).IsImmediate()) {
+ const auto combined{imm_fn(arg(lhs), arg(rhs_inst->Arg(1)))};
+ inst.SetArg(0, rhs_inst->Arg(0));
+ inst.SetArg(1, IR::Value{combined});
+ } else {
+ // Normalize
+ inst.SetArg(0, rhs);
+ inst.SetArg(1, lhs);
+ }
+ }
+ if (!is_lhs_immediate && is_rhs_immediate) {
+ const IR::Inst* const lhs_inst{lhs.InstRecursive()};
+ if (lhs_inst->Opcode() == inst.Opcode() && lhs_inst->Arg(1).IsImmediate()) {
+ const auto combined{imm_fn(arg(rhs), arg(lhs_inst->Arg(1)))};
+ inst.SetArg(0, lhs_inst->Arg(0));
+ inst.SetArg(1, IR::Value{combined});
+ }
+ }
+ return true;
+}
+
+void FoldGetRegister(IR::Inst& inst) {
+ if (inst.Arg(0).Reg() == IR::Reg::RZ) {
+ inst.ReplaceUsesWith(IR::Value{u32{0}});
+ }
+}
+
+void FoldGetPred(IR::Inst& inst) {
+ if (inst.Arg(0).Pred() == IR::Pred::PT) {
+ inst.ReplaceUsesWith(IR::Value{true});
+ }
+}
+
+template <typename T>
+void FoldAdd(IR::Inst& inst) {
+ if (inst.HasAssociatedPseudoOperation()) {
+ return;
+ }
+ if (!FoldCommutative(inst, [](T a, T b) { return a + b; })) {
+ return;
+ }
+ const IR::Value rhs{inst.Arg(1)};
+ if (rhs.IsImmediate() && Arg<T>(rhs) == 0) {
+ inst.ReplaceUsesWith(inst.Arg(0));
+ }
+}
+
+void FoldLogicalAnd(IR::Inst& inst) {
+ if (!FoldCommutative(inst, [](bool a, bool b) { return a && b; })) {
+ return;
+ }
+ const IR::Value rhs{inst.Arg(1)};
+ if (rhs.IsImmediate()) {
+ if (rhs.U1()) {
+ inst.ReplaceUsesWith(inst.Arg(0));
+ } else {
+ inst.ReplaceUsesWith(IR::Value{false});
+ }
+ }
+}
+
+void ConstantPropagation(IR::Inst& inst) {
+ switch (inst.Opcode()) {
+ case IR::Opcode::GetRegister:
+ return FoldGetRegister(inst);
+ case IR::Opcode::GetPred:
+ return FoldGetPred(inst);
+ case IR::Opcode::IAdd32:
+ return FoldAdd<u32>(inst);
+ case IR::Opcode::IAdd64:
+ return FoldAdd<u64>(inst);
+ case IR::Opcode::BitFieldUExtract:
+ if (inst.AreAllArgsImmediates() && !inst.HasAssociatedPseudoOperation()) {
+ inst.ReplaceUsesWith(IR::Value{
+ BitFieldUExtract(inst.Arg(0).U32(), inst.Arg(1).U32(), inst.Arg(2).U32())});
+ }
+ break;
+ case IR::Opcode::LogicalAnd:
+ return FoldLogicalAnd(inst);
+ default:
+ break;
+ }
+}
+} // Anonymous namespace
+
+void ConstantPropagationPass(IR::Block& block) {
+ std::ranges::for_each(block, ConstantPropagation);
+}
+
+} // namespace Shader::Optimization
--
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