shader: Implement FLO

2 files changed, 46 insertions, 12 deletions

diff --git a/src/shader_recompiler/frontend/maxwell/translate/impl/find_leading_one.cpp b/src/shader_recompiler/frontend/maxwell/translate/impl/find_leading_one.cpp
new file mode 100644
index 000000000..d5361bec5
--- /dev/null
+++ b/src/shader_recompiler/frontend/maxwell/translate/impl/find_leading_one.cpp
@@ -0,0 +1,46 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/bit_field.h"
+#include "common/common_types.h"
+#include "shader_recompiler/frontend/maxwell/translate/impl/impl.h"
+
+namespace Shader::Maxwell {
+namespace {
+void FLO(TranslatorVisitor& v, u64 insn, const IR::U32& src) {
+    union {
+        u64 insn;
+        BitField<0, 8, IR::Reg> dest_reg;
+        BitField<40, 1, u64> tilde;
+        BitField<41, 1, u64> shift;
+        BitField<48, 1, u64> is_signed;
+    } const flo{insn};
+
+    const bool invert{flo.tilde != 0};
+    const bool is_signed{flo.is_signed != 0};
+    const bool shift_op{flo.shift != 0};
+
+    const IR::U32 operand{invert ? v.ir.BitwiseNot(src) : src};
+    const IR::U32 find_result{is_signed ? v.ir.FindSMsb(operand) : v.ir.FindUMsb(operand)};
+    const IR::U1 find_fail{v.ir.IEqual(find_result, v.ir.Imm32(-1))};
+    const IR::U32 offset{v.ir.Imm32(31)};
+    const IR::U32 success_result{shift_op ? IR::U32{v.ir.ISub(offset, find_result)} : find_result};
+
+    const IR::U32 result{v.ir.Select(find_fail, find_result, success_result)};
+    v.X(flo.dest_reg, result);
+}
+} // Anonymous namespace
+
+void TranslatorVisitor::FLO_reg(u64 insn) {
+    FLO(*this, insn, GetReg20(insn));
+}
+
+void TranslatorVisitor::FLO_cbuf(u64 insn) {
+    FLO(*this, insn, GetCbuf(insn));
+}
+
+void TranslatorVisitor::FLO_imm(u64 insn) {
+    FLO(*this, insn, GetImm20(insn));
+}
+} // namespace Shader::Maxwell
diff --git a/src/shader_recompiler/frontend/maxwell/translate/impl/not_implemented.cpp b/src/shader_recompiler/frontend/maxwell/translate/impl/not_implemented.cpp
index f327e6fa5..2da0b87c4 100644
--- a/src/shader_recompiler/frontend/maxwell/translate/impl/not_implemented.cpp
+++ b/src/shader_recompiler/frontend/maxwell/translate/impl/not_implemented.cpp
@@ -217,18 +217,6 @@ void TranslatorVisitor::FCMP_imm(u64) {
     ThrowNotImplemented(Opcode::FCMP_imm);
 }
 
-void TranslatorVisitor::FLO_reg(u64) {
-    ThrowNotImplemented(Opcode::FLO_reg);
-}
-
-void TranslatorVisitor::FLO_cbuf(u64) {
-    ThrowNotImplemented(Opcode::FLO_cbuf);
-}
-
-void TranslatorVisitor::FLO_imm(u64) {
-    ThrowNotImplemented(Opcode::FLO_imm);
-}
-
 void TranslatorVisitor::FMNMX_reg(u64) {
     ThrowNotImplemented(Opcode::FMNMX_reg);
 }