ShuriZma
/
dolphin
mirror of https://github.com/dolphin-emu/dolphin.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp
View File

@ -1223,7 +1223,8 @@ void Jit64::divwx(UGeckoInstruction inst)
s32 i = gpr.R(a).SImm32(), j = gpr.R(b).SImm32();
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)
GenerateConstantOverflow(true);
}
@ -1241,38 +1242,37 @@ void Jit64::divwx(UGeckoInstruction inst)
gpr.FlushLockX(EAX, EDX);
gpr.BindToRegister(d, (d == a || d == b), true);
MOV(32, R(EAX), gpr.R(a));
CDQ();
gpr.BindToRegister(b, true, false);
TEST(32, gpr.R(b), gpr.R(b));
FixupBranch not_div_by_zero = J_CC(CC_NZ);
MOV(32, gpr.R(d), R(EDX));
if (inst.OE)
{
GenerateConstantOverflow(true);
}
FixupBranch end1 = J();
SetJumpTarget(not_div_by_zero);
CMP(32, gpr.R(b), R(EDX));
FixupBranch not_div_by_neg_one = J_CC(CC_NZ);
const FixupBranch overflow = J_CC(CC_E);
CMP(32, R(EAX), Imm32(0x80000000));
const FixupBranch normal_path1 = J_CC(CC_NE);
CMP(32, gpr.R(b), Imm32(0xFFFFFFFF));
const FixupBranch normal_path2 = J_CC(CC_NE);
SetJumpTarget(overflow);
SAR(32, R(EAX), Imm8(31));
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)
{
GenerateConstantOverflow(true);
}
FixupBranch end2 = J();
SetJumpTarget(not_div_by_neg_one);
const FixupBranch done = J();
SetJumpTarget(normal_path1);
SetJumpTarget(normal_path2);
CDQ();
IDIV(32, gpr.R(b));
MOV(32, gpr.R(d), R(EAX));
SetJumpTarget(no_overflow);
if (inst.OE)
{
GenerateConstantOverflow(false);
}
SetJumpTarget(end1);
SetJumpTarget(end2);
SetJumpTarget(done);
}
if (inst.Rc)
ComputeRC(gpr.R(d));