https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109638
Bug ID: 109638
Summary: unsigned > 1 ? 0 : n is not optimized to n == 1
Product: gcc
Version: 13.0
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:
```
unsigned test_cst (unsigned n)
{
if (n > 1)
n = 0;
return n;
}
unsigned test_cst1 (unsigned n)
{
return (n == 1);
}
```
For gimple at least the second one is smaller. I suspect for x86 the second
version is also faster because it uses sete rather than cmov.
But these 2 functions should produce the same code.
I found this on accident while looking at gcc.dg/tree-ssa/builtin-snprintf-2.c
testcase.
This can only be done for 1 too.
