Merge pull request #1927 from ReinUsesLisp/shader-ir

video_core: Replace gl_shader_decompiler with an IR based decompiler

1 files changed, 50 insertions, 0 deletions

diff --git a/src/video_core/shader/decode/integer_set.cpp b/src/video_core/shader/decode/integer_set.cpp
new file mode 100644
index 000000000..85e67b03b
--- /dev/null
+++ b/src/video_core/shader/decode/integer_set.cpp
@@ -0,0 +1,50 @@
+// Copyright 2018 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/assert.h"
+#include "common/common_types.h"
+#include "video_core/engines/shader_bytecode.h"
+#include "video_core/shader/shader_ir.h"
+
+namespace VideoCommon::Shader {
+
+using Tegra::Shader::Instruction;
+using Tegra::Shader::OpCode;
+
+u32 ShaderIR::DecodeIntegerSet(BasicBlock& bb, const BasicBlock& code, u32 pc) {
+    const Instruction instr = {program_code[pc]};
+    const auto opcode = OpCode::Decode(instr);
+
+    const Node op_a = GetRegister(instr.gpr8);
+    const Node op_b = [&]() {
+        if (instr.is_b_imm) {
+            return Immediate(instr.alu.GetSignedImm20_20());
+        } else if (instr.is_b_gpr) {
+            return GetRegister(instr.gpr20);
+        } else {
+            return GetConstBuffer(instr.cbuf34.index, instr.cbuf34.offset);
+        }
+    }();
+
+    // The iset instruction sets a register to 1.0 or -1 (depending on the bf bit) if the condition
+    // is true, and to 0 otherwise.
+    const Node second_pred = GetPredicate(instr.iset.pred39, instr.iset.neg_pred != 0);
+    const Node first_pred =
+        GetPredicateComparisonInteger(instr.iset.cond, instr.iset.is_signed, op_a, op_b);
+
+    const OperationCode combiner = GetPredicateCombiner(instr.iset.op);
+
+    const Node predicate = Operation(combiner, first_pred, second_pred);
+
+    const Node true_value = instr.iset.bf ? Immediate(1.0f) : Immediate(-1);
+    const Node false_value = instr.iset.bf ? Immediate(0.0f) : Immediate(0);
+    const Node value =
+        Operation(OperationCode::Select, PRECISE, predicate, true_value, false_value);
+
+    SetRegister(bb, instr.gpr0, value);
+
+    return pc;
+}
+
+} // namespace VideoCommon::Shader
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