https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101039
Bug ID: 101039
Summary: Some simple fold_cond_expr_with_comparison with CMP 0
is not simplified
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Take at -O2:
int f0(int A)
{
// A == 0? A : -A same as -A
if (A == 0) return A;
return -A;
}
int f1(int A)
{
// A != 0? A : -A same as A
if (A != 0) return A;
return -A;
}
int f2(int A)
{
// A >= 0? A : -A same as abs (A)
if (A >= 0) return A;
return -A;
}
int f3(int A)
{
// A > 0? A : -A same as abs (A)
if (A > 0) return A;
return -A;
}
int f4(int A)
{
// A <= 0? A : -A same as -abs (A)
if (A <= 0) return A;
return -A;
}
int f5(int A)
{
// A < 0? A : -A same as -abs (A)
if (A < 0) return A;
return -A;
}
------ CUT -------
Only f1-f3 are optimized at the gimple level. f0, f4, f5 are not.
With -Dint=float -Ofast, only f0 is not optimized but note f1 takes until
*.phiopt3 be optimized; and unlike int, f4 and f5 are optimized in phiopt2.
Note phiopt1 is still confused by predictor but I think there might be another
bug for that.
