Merge pull request #6585 from ameerj/hades

Shader Decompiler Rewrite

1 files changed, 252 insertions, 0 deletions

diff --git a/src/shader_recompiler/backend/glsl/emit_glsl.cpp b/src/shader_recompiler/backend/glsl/emit_glsl.cpp
new file mode 100644
index 000000000..8a430d573
--- /dev/null
+++ b/src/shader_recompiler/backend/glsl/emit_glsl.cpp
@@ -0,0 +1,252 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <string>
+#include <tuple>
+#include <type_traits>
+
+#include "common/div_ceil.h"
+#include "common/settings.h"
+#include "shader_recompiler/backend/glsl/emit_context.h"
+#include "shader_recompiler/backend/glsl/emit_glsl.h"
+#include "shader_recompiler/backend/glsl/emit_glsl_instructions.h"
+#include "shader_recompiler/frontend/ir/ir_emitter.h"
+
+namespace Shader::Backend::GLSL {
+namespace {
+template <class Func>
+struct FuncTraits {};
+
+template <class ReturnType_, class... Args>
+struct FuncTraits<ReturnType_ (*)(Args...)> {
+    using ReturnType = ReturnType_;
+
+    static constexpr size_t NUM_ARGS = sizeof...(Args);
+
+    template <size_t I>
+    using ArgType = std::tuple_element_t<I, std::tuple<Args...>>;
+};
+
+template <auto func, typename... Args>
+void SetDefinition(EmitContext& ctx, IR::Inst* inst, Args... args) {
+    inst->SetDefinition<Id>(func(ctx, std::forward<Args>(args)...));
+}
+
+template <typename ArgType>
+auto Arg(EmitContext& ctx, const IR::Value& arg) {
+    if constexpr (std::is_same_v<ArgType, std::string_view>) {
+        return ctx.var_alloc.Consume(arg);
+    } else if constexpr (std::is_same_v<ArgType, const IR::Value&>) {
+        return arg;
+    } else if constexpr (std::is_same_v<ArgType, u32>) {
+        return arg.U32();
+    } else if constexpr (std::is_same_v<ArgType, IR::Attribute>) {
+        return arg.Attribute();
+    } else if constexpr (std::is_same_v<ArgType, IR::Patch>) {
+        return arg.Patch();
+    } else if constexpr (std::is_same_v<ArgType, IR::Reg>) {
+        return arg.Reg();
+    }
+}
+
+template <auto func, bool is_first_arg_inst, size_t... I>
+void Invoke(EmitContext& ctx, IR::Inst* inst, std::index_sequence<I...>) {
+    using Traits = FuncTraits<decltype(func)>;
+    if constexpr (std::is_same_v<typename Traits::ReturnType, Id>) {
+        if constexpr (is_first_arg_inst) {
+            SetDefinition<func>(
+                ctx, inst, *inst,
+                Arg<typename Traits::template ArgType<I + 2>>(ctx, inst->Arg(I))...);
+        } else {
+            SetDefinition<func>(
+                ctx, inst, Arg<typename Traits::template ArgType<I + 1>>(ctx, inst->Arg(I))...);
+        }
+    } else {
+        if constexpr (is_first_arg_inst) {
+            func(ctx, *inst, Arg<typename Traits::template ArgType<I + 2>>(ctx, inst->Arg(I))...);
+        } else {
+            func(ctx, Arg<typename Traits::template ArgType<I + 1>>(ctx, inst->Arg(I))...);
+        }
+    }
+}
+
+template <auto func>
+void Invoke(EmitContext& ctx, IR::Inst* inst) {
+    using Traits = FuncTraits<decltype(func)>;
+    static_assert(Traits::NUM_ARGS >= 1, "Insufficient arguments");
+    if constexpr (Traits::NUM_ARGS == 1) {
+        Invoke<func, false>(ctx, inst, std::make_index_sequence<0>{});
+    } else {
+        using FirstArgType = typename Traits::template ArgType<1>;
+        static constexpr bool is_first_arg_inst = std::is_same_v<FirstArgType, IR::Inst&>;
+        using Indices = std::make_index_sequence<Traits::NUM_ARGS - (is_first_arg_inst ? 2 : 1)>;
+        Invoke<func, is_first_arg_inst>(ctx, inst, Indices{});
+    }
+}
+
+void EmitInst(EmitContext& ctx, IR::Inst* inst) {
+    switch (inst->GetOpcode()) {
+#define OPCODE(name, result_type, ...)                                                             \
+    case IR::Opcode::name:                                                                         \
+        return Invoke<&Emit##name>(ctx, inst);
+#include "shader_recompiler/frontend/ir/opcodes.inc"
+#undef OPCODE
+    }
+    throw LogicError("Invalid opcode {}", inst->GetOpcode());
+}
+
+bool IsReference(IR::Inst& inst) {
+    return inst.GetOpcode() == IR::Opcode::Reference;
+}
+
+void PrecolorInst(IR::Inst& phi) {
+    // Insert phi moves before references to avoid overwritting other phis
+    const size_t num_args{phi.NumArgs()};
+    for (size_t i = 0; i < num_args; ++i) {
+        IR::Block& phi_block{*phi.PhiBlock(i)};
+        auto it{std::find_if_not(phi_block.rbegin(), phi_block.rend(), IsReference).base()};
+        IR::IREmitter ir{phi_block, it};
+        const IR::Value arg{phi.Arg(i)};
+        if (arg.IsImmediate()) {
+            ir.PhiMove(phi, arg);
+        } else {
+            ir.PhiMove(phi, IR::Value{arg.InstRecursive()});
+        }
+    }
+    for (size_t i = 0; i < num_args; ++i) {
+        IR::IREmitter{*phi.PhiBlock(i)}.Reference(IR::Value{&phi});
+    }
+}
+
+void Precolor(const IR::Program& program) {
+    for (IR::Block* const block : program.blocks) {
+        for (IR::Inst& phi : block->Instructions()) {
+            if (!IR::IsPhi(phi)) {
+                break;
+            }
+            PrecolorInst(phi);
+        }
+    }
+}
+
+void EmitCode(EmitContext& ctx, const IR::Program& program) {
+    for (const IR::AbstractSyntaxNode& node : program.syntax_list) {
+        switch (node.type) {
+        case IR::AbstractSyntaxNode::Type::Block:
+            for (IR::Inst& inst : node.data.block->Instructions()) {
+                EmitInst(ctx, &inst);
+            }
+            break;
+        case IR::AbstractSyntaxNode::Type::If:
+            ctx.Add("if({}){{", ctx.var_alloc.Consume(node.data.if_node.cond));
+            break;
+        case IR::AbstractSyntaxNode::Type::EndIf:
+            ctx.Add("}}");
+            break;
+        case IR::AbstractSyntaxNode::Type::Break:
+            if (node.data.break_node.cond.IsImmediate()) {
+                if (node.data.break_node.cond.U1()) {
+                    ctx.Add("break;");
+                }
+            } else {
+                ctx.Add("if({}){{break;}}", ctx.var_alloc.Consume(node.data.break_node.cond));
+            }
+            break;
+        case IR::AbstractSyntaxNode::Type::Return:
+        case IR::AbstractSyntaxNode::Type::Unreachable:
+            ctx.Add("return;");
+            break;
+        case IR::AbstractSyntaxNode::Type::Loop:
+            ctx.Add("for(;;){{");
+            break;
+        case IR::AbstractSyntaxNode::Type::Repeat:
+            if (Settings::values.disable_shader_loop_safety_checks) {
+                ctx.Add("if(!{}){{break;}}}}", ctx.var_alloc.Consume(node.data.repeat.cond));
+            } else {
+                ctx.Add("if(--loop{}<0 || !{}){{break;}}}}", ctx.num_safety_loop_vars++,
+                        ctx.var_alloc.Consume(node.data.repeat.cond));
+            }
+            break;
+        default:
+            throw NotImplementedException("AbstractSyntaxNode Type {}", node.type);
+        }
+    }
+}
+
+std::string GlslVersionSpecifier(const EmitContext& ctx) {
+    if (ctx.uses_y_direction || ctx.info.stores.Legacy() || ctx.info.loads.Legacy()) {
+        return " compatibility";
+    }
+    return "";
+}
+
+bool IsPreciseType(GlslVarType type) {
+    switch (type) {
+    case GlslVarType::PrecF32:
+    case GlslVarType::PrecF64:
+        return true;
+    default:
+        return false;
+    }
+}
+
+void DefineVariables(const EmitContext& ctx, std::string& header) {
+    for (u32 i = 0; i < static_cast<u32>(GlslVarType::Void); ++i) {
+        const auto type{static_cast<GlslVarType>(i)};
+        const auto& tracker{ctx.var_alloc.GetUseTracker(type)};
+        const auto type_name{ctx.var_alloc.GetGlslType(type)};
+        const bool has_precise_bug{ctx.stage == Stage::Fragment && ctx.profile.has_gl_precise_bug};
+        const auto precise{!has_precise_bug && IsPreciseType(type) ? "precise " : ""};
+        // Temps/return types that are never used are stored at index 0
+        if (tracker.uses_temp) {
+            header += fmt::format("{}{} t{}={}(0);", precise, type_name,
+                                  ctx.var_alloc.Representation(0, type), type_name);
+        }
+        for (u32 index = 0; index < tracker.num_used; ++index) {
+            header += fmt::format("{}{} {}={}(0);", precise, type_name,
+                                  ctx.var_alloc.Representation(index, type), type_name);
+        }
+    }
+    for (u32 i = 0; i < ctx.num_safety_loop_vars; ++i) {
+        header += fmt::format("int loop{}=0x2000;", i);
+    }
+}
+} // Anonymous namespace
+
+std::string EmitGLSL(const Profile& profile, const RuntimeInfo& runtime_info, IR::Program& program,
+                     Bindings& bindings) {
+    EmitContext ctx{program, bindings, profile, runtime_info};
+    Precolor(program);
+    EmitCode(ctx, program);
+    const std::string version{fmt::format("#version 450{}\n", GlslVersionSpecifier(ctx))};
+    ctx.header.insert(0, version);
+    if (program.shared_memory_size > 0) {
+        const auto requested_size{program.shared_memory_size};
+        const auto max_size{profile.gl_max_compute_smem_size};
+        const bool needs_clamp{requested_size > max_size};
+        if (needs_clamp) {
+            LOG_WARNING(Shader_GLSL, "Requested shared memory size ({}) exceeds device limit ({})",
+                        requested_size, max_size);
+        }
+        const auto smem_size{needs_clamp ? max_size : requested_size};
+        ctx.header += fmt::format("shared uint smem[{}];", Common::DivCeil(smem_size, 4U));
+    }
+    ctx.header += "void main(){\n";
+    if (program.local_memory_size > 0) {
+        ctx.header += fmt::format("uint lmem[{}];", Common::DivCeil(program.local_memory_size, 4U));
+    }
+    DefineVariables(ctx, ctx.header);
+    if (ctx.uses_cc_carry) {
+        ctx.header += "uint carry;";
+    }
+    if (program.info.uses_subgroup_shuffles) {
+        ctx.header += "bool shfl_in_bounds;";
+    }
+    ctx.code.insert(0, ctx.header);
+    ctx.code += '}';
+    return ctx.code;
+}
+
+} // namespace Shader::Backend::GLSL