Skip to content

JitArm64: Minor subfzex optimizations #14516

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Sintendo wants to merge 2 commits into
base: master
Choose a base branch
from
+16 −0
Open

JitArm64: Minor subfzex optimizations #14516

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
9be878c
JitArm64_Integer: subfzex - Optimize a == 0 with in-host carry
Sintendo Mar 26, 2026
21c2605
JitArm64_Integer: subfzex - Optimize a == -1 with in-host carry
Sintendo Mar 26, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 16 additions & 0 deletions Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1326,6 +1326,22 @@ void JitArm64::subfzex(UGeckoInstruction inst)
gpr.SetImmediate(d, imm + carry);
ComputeCarry(Interpreter::Helper_Carry(imm, carry));
}
else if (gpr.IsImm(a, 0) && js.carryFlag == CarryFlag::InHostCarry)
{
gpr.BindToRegister(d, false);
// RD = ~0 + carry = -1 + carry = carry ? 0 : -1
// Note that CSETM sets the destination to -1 if the condition is true,
// and 0 otherwise. Hence, the condition must be carry clear.
CSETM(gpr.R(d), CC_CC);
// Carry remains unchanged.
}
else if (gpr.IsImm(a, 0xFFFFFFFF) && js.carryFlag == CarryFlag::InHostCarry)
{
gpr.BindToRegister(d, false);
// RD = ~(-1) + carry = 0 + carry = carry ? 1 : 0
CSET(gpr.R(d), CC_CS);
ComputeCarry(false);
}
else
{
gpr.BindToRegister(d, d == a);
Expand Down