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emit_x64: Inline nzcv computation into EmitFPCompare32 and EmitFPCompare64

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This commit is contained in:
MerryMage 2016-12-04 11:43:31 +00:00
parent 52fdec5892
commit 25f21b5371
1 changed files with 23 additions and 30 deletions
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53
src/backend_x64/emit_x64.cpp
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@ -1772,22 +1772,27 @@ void EmitX64::EmitFPSub64(IR::Block& block, IR::Inst* inst) {
FPThreeOp64(code, reg_alloc, block, inst, &Xbyak::CodeGenerator::subsd);
}
static void SetFpscrNzcvFromLahf(JitState* jit_state, u8 lahf) {
switch (lahf) {
case 0b01000111:
jit_state->FPSCR_nzcv = 0x30000000;
return;
case 0b00000010:
jit_state->FPSCR_nzcv = 0x20000000;
return;
case 0b00000011:
jit_state->FPSCR_nzcv = 0x80000000;
return;
case 0b01000010:
jit_state->FPSCR_nzcv = 0x60000000;
return;
}
ASSERT_MSG(false, "<internal error>");
static void SetFpscrNzcvFromFlags(BlockOfCode* code, RegAlloc& reg_alloc) {
reg_alloc.ScratchGpr({HostLoc::RAX}); // lahf requires use of ah
Xbyak::Reg32 nzcv_imm = reg_alloc.ScratchGpr().cvt32();
Xbyak::Reg32 nzcv = reg_alloc.ScratchGpr().cvt32();
using namespace Xbyak::util;
code->lahf();
code->mov(nzcv_imm, 0x30000000);
code->cmp(ah, 0b01000111);
code->cmove(nzcv, nzcv_imm);
code->mov(nzcv_imm, 0x20000000);
code->cmp(ah, 0b00000010);
code->cmove(nzcv, nzcv_imm);
code->mov(nzcv_imm, 0x80000000);
code->cmp(ah, 0b00000011);
code->cmove(nzcv, nzcv_imm);
code->mov(nzcv_imm, 0x60000000);
code->cmp(ah, 0b01000010);
code->cmove(nzcv, nzcv_imm);
code->mov(dword[r15 + offsetof(JitState, FPSCR_nzcv)], nzcv);
}
void EmitX64::EmitFPCompare32(IR::Block& block, IR::Inst* inst) {
@ -1804,13 +1809,7 @@ void EmitX64::EmitFPCompare32(IR::Block& block, IR::Inst* inst) {
code->comiss(reg_a, reg_b);
}
reg_alloc.EndOfAllocScope();
reg_alloc.HostCall();
code->lahf();
code->mov(code->ABI_PARAM1, code->r15);
code->mov(code->ABI_PARAM2.cvt8(), code->ah);
code->CallFunction(&SetFpscrNzcvFromLahf);
SetFpscrNzcvFromFlags(code, reg_alloc);
}
void EmitX64::EmitFPCompare64(IR::Block& block, IR::Inst* inst) {
@ -1827,13 +1826,7 @@ void EmitX64::EmitFPCompare64(IR::Block& block, IR::Inst* inst) {
code->comisd(reg_a, reg_b);
}
reg_alloc.EndOfAllocScope();
reg_alloc.HostCall();
code->lahf();
code->mov(code->ABI_PARAM1, code->r15);
code->mov(code->ABI_PARAM2.cvt8(), code->ah);
code->CallFunction(&SetFpscrNzcvFromLahf);
SetFpscrNzcvFromFlags(code, reg_alloc);
}
void EmitX64::EmitFPSingleToDouble(IR::Block& block, IR::Inst* inst) {