macro_jit_x64: fix miscompilation of bit extraction operations

This commit is contained in:
Liam 2022-10-01 20:31:21 -04:00
parent d9e375acc3
commit 1225627515

View File

@ -279,28 +279,13 @@ void MacroJITx64Impl::Compile_ExtractInsert(Macro::Opcode opcode) {
auto dst = Compile_GetRegister(opcode.src_a, RESULT);
auto src = Compile_GetRegister(opcode.src_b, eax);
if (opcode.bf_src_bit != 0 && opcode.bf_src_bit != 31) {
shr(src, opcode.bf_src_bit);
} else if (opcode.bf_src_bit == 31) {
xor_(src, src);
}
// Don't bother masking the whole register since we're using a 32 bit register
if (opcode.bf_size != 31 && opcode.bf_size != 0) {
and_(src, opcode.GetBitfieldMask());
} else if (opcode.bf_size == 0) {
xor_(src, src);
}
if (opcode.bf_dst_bit != 31 && opcode.bf_dst_bit != 0) {
shl(src, opcode.bf_dst_bit);
} else if (opcode.bf_dst_bit == 31) {
xor_(src, src);
}
const u32 mask = ~(opcode.GetBitfieldMask() << opcode.bf_dst_bit);
if (mask != 0xffffffff) {
and_(dst, mask);
}
and_(dst, mask);
shr(src, opcode.bf_src_bit);
and_(src, opcode.GetBitfieldMask());
shl(src, opcode.bf_dst_bit);
or_(dst, src);
Compile_ProcessResult(opcode.result_operation, opcode.dst);
}
@ -309,17 +294,9 @@ void MacroJITx64Impl::Compile_ExtractShiftLeftImmediate(Macro::Opcode opcode) {
const auto src = Compile_GetRegister(opcode.src_b, RESULT);
shr(src, dst.cvt8());
if (opcode.bf_size != 0 && opcode.bf_size != 31) {
and_(src, opcode.GetBitfieldMask());
} else if (opcode.bf_size == 0) {
xor_(src, src);
}
and_(src, opcode.GetBitfieldMask());
shl(src, opcode.bf_dst_bit);
if (opcode.bf_dst_bit != 0 && opcode.bf_dst_bit != 31) {
shl(src, opcode.bf_dst_bit);
} else if (opcode.bf_dst_bit == 31) {
xor_(src, src);
}
Compile_ProcessResult(opcode.result_operation, opcode.dst);
}
@ -327,13 +304,8 @@ void MacroJITx64Impl::Compile_ExtractShiftLeftRegister(Macro::Opcode opcode) {
const auto dst = Compile_GetRegister(opcode.src_a, ecx);
const auto src = Compile_GetRegister(opcode.src_b, RESULT);
if (opcode.bf_src_bit != 0) {
shr(src, opcode.bf_src_bit);
}
if (opcode.bf_size != 31) {
and_(src, opcode.GetBitfieldMask());
}
shr(src, opcode.bf_src_bit);
and_(src, opcode.GetBitfieldMask());
shl(src, dst.cvt8());
Compile_ProcessResult(opcode.result_operation, opcode.dst);