https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102793
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target| |aarch64
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
I wonder why tail-merging doesn't do it's job here. It does (on x86_64-linux):
find_duplicates: <bb 3> duplicate of <bb 5>
Removing basic block 5
;; basic block 5, loop depth 0
;; pred:
_12 = foo_10(D) ();
;; succ: 6
and .optimized:
int noccmp (uint64_t * s1, uint64_t * s2, int (*<T3aa>) (void) foo)
{
uint64_t bar;
uint64_t d2;
uint64_t d1;
long unsigned int _1;
int _2;
int _14;
<bb 2> [local count: 1073741824]:
d1_6 = *s1_4(D);
d2_8 = *s2_7(D);
_1 = d1_6 ^ d2_8;
bar_9 = _1 & 43981;
if (bar_9 == 0)
goto <bb 3>; [34.00%]
else
goto <bb 4>; [66.00%]
<bb 3> [local count: 719407024]:
_14 = foo_10(D) (); [tail call]
goto <bb 5>; [100.00%]
<bb 4> [local count: 708669601]:
if (d1_6 != d2_8)
goto <bb 3>; [50.00%]
else
goto <bb 5>; [50.00%]
<bb 5> [local count: 1073741824]:
# _2 = PHI <_14(3), 0(4)>
return _2;
}
but what's missing is possibly some if-combine?
IMHO ccmp expansion should be re-written to a pre RTL expansion GIMPLE
transform.
