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JitArm64_Integer: subfzex - Constant folding

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When both the input register and the carry flag are constants, the
result can be precomputed.

Before:
0x52800016   mov    w22, #0x0                 ; =0
0x2a3603f6   mvn    w22, w22

After:
This commit is contained in:
Sintendo 2024-12-28 20:57:55 +01:00
parent fa13457abb
commit 7410bc2025
1 changed files with 40 additions and 30 deletions
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70
Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
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@ -1359,39 +1359,49 @@ void JitArm64::subfzex(UGeckoInstruction inst)
int a = inst.RA, d = inst.RD; int a = inst.RA, d = inst.RD;
gpr.BindToRegister(d, d == a); if (gpr.IsImm(a) && HasConstantCarry())
{
const u32 imm = ~gpr.GetImm(a);
const u32 carry = js.carryFlag == CarryFlag::ConstantTrue;
gpr.SetImmediate(d, imm + carry);
ComputeCarry(Interpreter::Helper_Carry(imm, carry));
}
else
{
gpr.BindToRegister(d, d == a);
switch (js.carryFlag) switch (js.carryFlag)
{
case CarryFlag::InPPCState:
{
{ {
auto WA = gpr.GetScopedReg(); case CarryFlag::InPPCState:
LDRB(IndexType::Unsigned, WA, PPC_REG, PPCSTATE_OFF(xer_ca)); {
MVN(gpr.R(d), gpr.R(a)); {
CARRY_IF_NEEDED(ADD, ADDS, gpr.R(d), gpr.R(d), WA); auto WA = gpr.GetScopedReg();
LDRB(IndexType::Unsigned, WA, PPC_REG, PPCSTATE_OFF(xer_ca));
MVN(gpr.R(d), gpr.R(a));
CARRY_IF_NEEDED(ADD, ADDS, gpr.R(d), gpr.R(d), WA);
}
ComputeCarry();
break;
}
case CarryFlag::InHostCarry:
{
CARRY_IF_NEEDED(SBC, SBCS, gpr.R(d), ARM64Reg::WZR, gpr.R(a));
ComputeCarry();
break;
}
case CarryFlag::ConstantTrue:
{
CARRY_IF_NEEDED(NEG, NEGS, gpr.R(d), gpr.R(a));
ComputeCarry();
break;
}
case CarryFlag::ConstantFalse:
{
MVN(gpr.R(d), gpr.R(a));
ComputeCarry(false);
break;
}
} }
ComputeCarry();
break;
}
case CarryFlag::InHostCarry:
{
CARRY_IF_NEEDED(SBC, SBCS, gpr.R(d), ARM64Reg::WZR, gpr.R(a));
ComputeCarry();
break;
}
case CarryFlag::ConstantTrue:
{
CARRY_IF_NEEDED(NEG, NEGS, gpr.R(d), gpr.R(a));
ComputeCarry();
break;
}
case CarryFlag::ConstantFalse:
{
MVN(gpr.R(d), gpr.R(a));
ComputeCarry(false);
break;
}
} }
if (inst.Rc) if (inst.Rc)