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Jit64: Correct negative overflow handling for divw

This commit is contained in:
Lioncash 2018-05-22 11:38:49 -04:00
parent 2ca1ac3370
commit 5abe6c264a
1 changed files with 20 additions and 20 deletions
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40
Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp
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@ -1223,7 +1223,8 @@ void Jit64::divwx(UGeckoInstruction inst)
s32 i = gpr.R(a).SImm32(), j = gpr.R(b).SImm32(); s32 i = gpr.R(a).SImm32(), j = gpr.R(b).SImm32();
if (j == 0 || (i == (s32)0x80000000 && j == -1)) if (j == 0 || (i == (s32)0x80000000 && j == -1))
{ {
gpr.SetImmediate32(d, (i >> 31) ^ j); const u32 result = i < 0 ? 0xFFFFFFFF : 0x00000000;
gpr.SetImmediate32(d, result);
if (inst.OE) if (inst.OE)
GenerateConstantOverflow(true); GenerateConstantOverflow(true);
} }
@ -1241,38 +1242,37 @@ void Jit64::divwx(UGeckoInstruction inst)
gpr.FlushLockX(EAX, EDX); gpr.FlushLockX(EAX, EDX);
gpr.BindToRegister(d, (d == a || d == b), true); gpr.BindToRegister(d, (d == a || d == b), true);
MOV(32, R(EAX), gpr.R(a)); MOV(32, R(EAX), gpr.R(a));
CDQ();
gpr.BindToRegister(b, true, false); gpr.BindToRegister(b, true, false);
TEST(32, gpr.R(b), gpr.R(b)); TEST(32, gpr.R(b), gpr.R(b));
FixupBranch not_div_by_zero = J_CC(CC_NZ); const FixupBranch overflow = J_CC(CC_E);
MOV(32, gpr.R(d), R(EDX));
if (inst.OE) CMP(32, R(EAX), Imm32(0x80000000));
{ const FixupBranch normal_path1 = J_CC(CC_NE);
GenerateConstantOverflow(true);
} CMP(32, gpr.R(b), Imm32(0xFFFFFFFF));
FixupBranch end1 = J(); const FixupBranch normal_path2 = J_CC(CC_NE);
SetJumpTarget(not_div_by_zero);
CMP(32, gpr.R(b), R(EDX)); SetJumpTarget(overflow);
FixupBranch not_div_by_neg_one = J_CC(CC_NZ); SAR(32, R(EAX), Imm8(31));
MOV(32, gpr.R(d), R(EAX)); MOV(32, gpr.R(d), R(EAX));
NEG(32, gpr.R(d));
FixupBranch no_overflow = J_CC(CC_NO);
XOR(32, gpr.R(d), gpr.R(d));
if (inst.OE) if (inst.OE)
{ {
GenerateConstantOverflow(true); GenerateConstantOverflow(true);
} }
FixupBranch end2 = J(); const FixupBranch done = J();
SetJumpTarget(not_div_by_neg_one);
SetJumpTarget(normal_path1);
SetJumpTarget(normal_path2);
CDQ();
IDIV(32, gpr.R(b)); IDIV(32, gpr.R(b));
MOV(32, gpr.R(d), R(EAX)); MOV(32, gpr.R(d), R(EAX));
SetJumpTarget(no_overflow);
if (inst.OE) if (inst.OE)
{ {
GenerateConstantOverflow(false); GenerateConstantOverflow(false);
} }
SetJumpTarget(end1); SetJumpTarget(done);
SetJumpTarget(end2);
} }
if (inst.Rc) if (inst.Rc)
ComputeRC(gpr.R(d)); ComputeRC(gpr.R(d));