From 08a9e95905fa90d9d2455c9aedf66cebcfc6f6ba Mon Sep 17 00:00:00 2001
From: ameerj <52414509+ameerj@users.noreply.github.com>
Date: Sat, 27 Feb 2021 16:37:49 -0500
Subject: [PATCH] shader: Implement BFI

---
 src/shader_recompiler/CMakeLists.txt          |  1 +
 .../translate/impl/bitfield_insert.cpp        | 56 +++++++++++++++++++
 .../translate/impl/not_implemented.cpp        | 16 ------
 3 files changed, 57 insertions(+), 16 deletions(-)
 create mode 100644 src/shader_recompiler/frontend/maxwell/translate/impl/bitfield_insert.cpp

diff --git a/src/shader_recompiler/CMakeLists.txt b/src/shader_recompiler/CMakeLists.txt
index 8be2d353f..2e5de7f95 100644
--- a/src/shader_recompiler/CMakeLists.txt
+++ b/src/shader_recompiler/CMakeLists.txt
@@ -60,6 +60,7 @@ add_library(shader_recompiler STATIC
     frontend/maxwell/program.cpp
     frontend/maxwell/program.h
     frontend/maxwell/translate/impl/bitfield_extract.cpp
+    frontend/maxwell/translate/impl/bitfield_insert.cpp
     frontend/maxwell/translate/impl/common_encoding.h
     frontend/maxwell/translate/impl/floating_point_add.cpp
     frontend/maxwell/translate/impl/floating_point_conversion_integer.cpp
diff --git a/src/shader_recompiler/frontend/maxwell/translate/impl/bitfield_insert.cpp b/src/shader_recompiler/frontend/maxwell/translate/impl/bitfield_insert.cpp
new file mode 100644
index 000000000..ee312c30d
--- /dev/null
+++ b/src/shader_recompiler/frontend/maxwell/translate/impl/bitfield_insert.cpp
@@ -0,0 +1,56 @@
+// 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 BFI(TranslatorVisitor& v, u64 insn, const IR::U32& src_a, const IR::U32& base) {
+    union {
+        u64 insn;
+        BitField<0, 8, IR::Reg> dest_reg;
+        BitField<8, 8, IR::Reg> insert_reg;
+    } const bfi{insn};
+
+    const IR::U32 offset{v.ir.BitFieldExtract(src_a, v.ir.Imm32(0), v.ir.Imm32(8), false)};
+    const IR::U32 unsafe_count{v.ir.BitFieldExtract(src_a, v.ir.Imm32(8), v.ir.Imm32(8), false)};
+    const IR::U32 max_size{v.ir.Imm32(32)};
+
+    // Edge case conditions
+    const IR::U1 zero_offset{v.ir.IEqual(offset, v.ir.Imm32(0))};
+    const IR::U1 exceed_offset{v.ir.IGreaterThanEqual(offset, max_size, false)};
+    const IR::U1 exceed_count{v.ir.IGreaterThanEqual(unsafe_count, max_size, false)};
+
+    const IR::U32 remaining_size{v.ir.ISub(max_size, offset)};
+    const IR::U32 safe_count{v.ir.Select(exceed_count, remaining_size, unsafe_count)};
+
+    const IR::U32 insert{v.X(bfi.insert_reg)};
+    IR::U32 result{v.ir.BitFieldInsert(base, insert, offset, safe_count)};
+
+    result = IR::U32{v.ir.Select(exceed_offset, base, result)};
+    result = IR::U32{v.ir.Select(zero_offset, base, result)};
+
+    v.X(bfi.dest_reg, result);
+}
+} // Anonymous namespace
+
+void TranslatorVisitor::BFI_reg(u64 insn) {
+    BFI(*this, insn, GetReg20(insn), GetReg39(insn));
+}
+
+void TranslatorVisitor::BFI_rc(u64 insn) {
+    BFI(*this, insn, GetReg39(insn), GetCbuf(insn));
+}
+
+void TranslatorVisitor::BFI_cr(u64 insn) {
+    BFI(*this, insn, GetCbuf(insn), GetReg39(insn));
+}
+
+void TranslatorVisitor::BFI_imm(u64 insn) {
+    BFI(*this, insn, GetImm20(insn), GetReg39(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 3714f5f4f..ed2cfac60 100644
--- a/src/shader_recompiler/frontend/maxwell/translate/impl/not_implemented.cpp
+++ b/src/shader_recompiler/frontend/maxwell/translate/impl/not_implemented.cpp
@@ -49,22 +49,6 @@ void TranslatorVisitor::BAR(u64) {
     ThrowNotImplemented(Opcode::BAR);
 }
 
-void TranslatorVisitor::BFI_reg(u64) {
-    ThrowNotImplemented(Opcode::BFI_reg);
-}
-
-void TranslatorVisitor::BFI_rc(u64) {
-    ThrowNotImplemented(Opcode::BFI_rc);
-}
-
-void TranslatorVisitor::BFI_cr(u64) {
-    ThrowNotImplemented(Opcode::BFI_cr);
-}
-
-void TranslatorVisitor::BFI_imm(u64) {
-    ThrowNotImplemented(Opcode::BFI_imm);
-}
-
 void TranslatorVisitor::BPT(u64) {
     ThrowNotImplemented(Opcode::BPT);
 }