suyu/dynarmic
26
1
Fork 1
Code Issues Pull requests Projects Releases Packages Wiki Activity

emit_x64_data_processing: Reduce codesize of LogicalShiftRight32 for carry case

Browse source
This commit is contained in:
MerryMage 2021-04-26 21:45:10 +01:00
parent 58ff457339
commit a2a687f208
1 changed files with 9 additions and 29 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

38
src/backend/x64/emit_x64_data_processing.cpp
View file

@ -492,38 +492,18 @@ void EmitX64::EmitLogicalShiftRight32(EmitContext& ctx, IR::Inst* inst) {
ctx.EraseInstruction(carry_inst);
ctx.reg_alloc.DefineValue(inst, result);
} else {
ctx.reg_alloc.Use(shift_arg, HostLoc::RCX);
const Xbyak::Reg32 result = ctx.reg_alloc.UseScratchGpr(operand_arg).cvt32();
ctx.reg_alloc.UseScratch(shift_arg, HostLoc::RCX);
const Xbyak::Reg32 operand = ctx.reg_alloc.UseGpr(operand_arg).cvt32();
const Xbyak::Reg32 result = ctx.reg_alloc.ScratchGpr().cvt32();
const Xbyak::Reg32 carry = ctx.reg_alloc.UseScratchGpr(carry_arg).cvt32();
// TODO: Optimize this.
code.inLocalLabel();
code.cmp(code.cl, 32);
code.ja(".Rs_gt32");
code.je(".Rs_eq32");
// if (Rs & 0xFF == 0) goto end;
code.test(code.cl, code.cl);
code.jz(".end");
// if (Rs & 0xFF < 32) {
code.shr(result, code.cl);
code.mov(result, 63);
code.cmp(code.cl, 63);
code.cmovnb(code.ecx, result);
code.mov(result, operand);
code.bt(carry.cvt32(), 0);
code.shr(result.cvt64(), code.cl);
code.setc(carry.cvt8());
code.jmp(".end");
// } else if (Rs & 0xFF > 32) {
code.L(".Rs_gt32");
code.xor_(result, result);
code.xor_(carry, carry);
code.jmp(".end");
// } else if (Rs & 0xFF == 32) {
code.L(".Rs_eq32");
code.bt(result, 31);
code.setc(carry.cvt8());
code.xor_(result, result);
// }
code.L(".end");
code.outLocalLabel();
ctx.reg_alloc.DefineValue(carry_inst, carry);
ctx.EraseInstruction(carry_inst);