Merge pull request #1927 from ReinUsesLisp/shader-ir

video_core: Replace gl_shader_decompiler with an IR based decompiler

1 files changed, 49 insertions, 0 deletions

diff --git a/src/video_core/shader/decode/bfe.cpp b/src/video_core/shader/decode/bfe.cpp
new file mode 100644
index 000000000..0734141b0
--- /dev/null
+++ b/src/video_core/shader/decode/bfe.cpp
@@ -0,0 +1,49 @@
+// 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::DecodeBfe(BasicBlock& bb, const BasicBlock& code, u32 pc) {
+    const Instruction instr = {program_code[pc]};
+    const auto opcode = OpCode::Decode(instr);
+
+    UNIMPLEMENTED_IF(instr.bfe.negate_b);
+
+    Node op_a = GetRegister(instr.gpr8);
+    op_a = GetOperandAbsNegInteger(op_a, false, instr.bfe.negate_a, false);
+
+    switch (opcode->get().GetId()) {
+    case OpCode::Id::BFE_IMM: {
+        UNIMPLEMENTED_IF_MSG(instr.generates_cc,
+                             "Condition codes generation in BFE is not implemented");
+
+        const Node inner_shift_imm = Immediate(static_cast<u32>(instr.bfe.GetLeftShiftValue()));
+        const Node outer_shift_imm =
+            Immediate(static_cast<u32>(instr.bfe.GetLeftShiftValue() + instr.bfe.shift_position));
+
+        const Node inner_shift =
+            Operation(OperationCode::ILogicalShiftLeft, NO_PRECISE, op_a, inner_shift_imm);
+        const Node outer_shift =
+            Operation(OperationCode::ILogicalShiftRight, NO_PRECISE, inner_shift, outer_shift_imm);
+
+        SetInternalFlagsFromInteger(bb, outer_shift, instr.generates_cc);
+        SetRegister(bb, instr.gpr0, outer_shift);
+        break;
+    }
+    default:
+        UNIMPLEMENTED_MSG("Unhandled BFE instruction: {}", opcode->get().GetName());
+    }
+
+    return pc;
+}
+
+} // namespace VideoCommon::Shader
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