https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102008
Bug ID: 102008
Summary: [12 Regression] no cmov generated for loads next to
each other
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Target: x86_64-*-*
Take:
struct Foo { int a; int b; };
int test(int side, const Foo *foo) {
if (side == 1) return foo->a;
return foo->b;
}
----- CUT ----
Before r12-897, GCC was able to produce a cmov for this case but now we don't.
Note for aarch64 we produce now:
cmp w0, 1
add x0, x1, 4
csel x0, x0, x1, ne
ldr w0, [x0]
Which is actually reasonible still.
Note I noticed this while looking into PR 68274.
