| Issue |
202695
|
| Summary |
Possible Missed Optimization in O3
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
Apochens
|
Reproducer: https://godbolt.org/z/7aq8fcz3v
Description: LLVM cannot optimize the following C function annotated with value range information, while GCC can.
```c
#include <stdint.h>
uint8_t src(uint8_t v1_u8, uint8_t v2_u8) {
if (!(((uint8_t)14 <= v1_u8) && (v1_u8 <= (uint8_t)15))) __builtin_unreachable();
if (!(((uint8_t)34 <= v2_u8) && (v2_u8 <= (uint8_t)35))) __builtin_unreachable();
uint8_t i0_u8 = (uint8_t)(v2_u8 % v1_u8);
uint8_t i1_u8 = (uint8_t)((uint8_t)i0_u8 >> (uint8_t)(uint8_t)2);
return i1_u8;
}
```
LLVM's assembly result:
```assembly
```
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