https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115674
Bug ID: 115674
Summary: "Checking if number is within interval" missed
optimization when number is from a smaller int type
Product: gcc
Version: 14.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: Explorer09 at gmail dot com
Target Milestone: ---
```c
#include <stdbool.h>
#include <stdint.h>
bool func1(uint8_t x) {
uint32_t value;
value = x;
if (value < 0xC2 || value > 0xF4) {
return false;
}
return true;
}
bool func2(uint8_t x) {
uint32_t value;
value = x;
if ((uint8_t)value < 0xC2 || (uint8_t)value > 0xF4) {
return false;
}
return true;
}
```
x86_64 gcc with -Os option produces:
```x86asm
func1:
movzx edi, dil
sub edi, 194
cmp edi, 50
setbe al
ret
func2:
add edi, 62
cmp dil, 50
setbe al
ret
```
For x86-64, the expected result is func1 transformed to func2.
For ARM and RISC-V targets, I expect the other way around, that is, transform
func2 to func1, so that it saves a "bitwise AND 0xFF" operation.
