1 files changed, 59 insertions, 0 deletions

diff --git a/src/video_core/shader/decode/ffma.cpp b/src/video_core/shader/decode/ffma.cpp
new file mode 100644
index 000000000..be8dc2230
--- /dev/null
+++ b/src/video_core/shader/decode/ffma.cpp
@@ -0,0 +1,59 @@
+// 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::DecodeFfma(BasicBlock& bb, const BasicBlock& code, u32 pc) {
+    const Instruction instr = {program_code[pc]};
+    const auto opcode = OpCode::Decode(instr);
+
+    UNIMPLEMENTED_IF_MSG(instr.ffma.cc != 0, "FFMA cc not implemented");
+    UNIMPLEMENTED_IF_MSG(instr.ffma.tab5980_0 != 1, "FFMA tab5980_0({}) not implemented",
+                         instr.ffma.tab5980_0.Value()); // Seems to be 1 by default based on SMO
+    UNIMPLEMENTED_IF_MSG(instr.ffma.tab5980_1 != 0, "FFMA tab5980_1({}) not implemented",
+                         instr.ffma.tab5980_1.Value());
+
+    const Node op_a = GetRegister(instr.gpr8);
+
+    auto [op_b, op_c] = [&]() -> std::tuple<Node, Node> {
+        switch (opcode->get().GetId()) {
+        case OpCode::Id::FFMA_CR: {
+            return {GetConstBuffer(instr.cbuf34.index, instr.cbuf34.offset),
+                    GetRegister(instr.gpr39)};
+        }
+        case OpCode::Id::FFMA_RR:
+            return {GetRegister(instr.gpr20), GetRegister(instr.gpr39)};
+        case OpCode::Id::FFMA_RC: {
+            return {GetRegister(instr.gpr39),
+                    GetConstBuffer(instr.cbuf34.index, instr.cbuf34.offset)};
+        }
+        case OpCode::Id::FFMA_IMM:
+            return {GetImmediate19(instr), GetRegister(instr.gpr39)};
+        default:
+            UNIMPLEMENTED_MSG("Unhandled FFMA instruction: {}", opcode->get().GetName());
+            return {Immediate(0), Immediate(0)};
+        }
+    }();
+
+    op_b = GetOperandAbsNegFloat(op_b, false, instr.ffma.negate_b);
+    op_c = GetOperandAbsNegFloat(op_c, false, instr.ffma.negate_c);
+
+    Node value = Operation(OperationCode::FFma, PRECISE, op_a, op_b, op_c);
+    value = GetSaturatedFloat(value, instr.alu.saturate_d);
+
+    SetInternalFlagsFromFloat(bb, value, instr.generates_cc);
+    SetRegister(bb, instr.gpr0, value);
+
+    return pc;
+}
+
+} // namespace VideoCommon::Shader
\ No newline at end of file