| Issue |
97884
|
| Summary |
[AArch64] Special optimazation for sdiv 2
|
| Labels |
new issue
|
| Assignees |
vfdff
|
| Reporter |
vfdff
|
* test: https://gcc.godbolt.org/z/j4EqrToT7
```
int foo_int2 (int diff) {
diff = diff / 2;
return diff;
}
```
> When I take a look at the issue [PR97821](https://github.com/llvm/llvm-project/issues/97821), I find gcc has some special addressing for **sdiv 2**, so we can also enhance this case.
* **gcc**: 2 instructions
```
foo_int2:
add w0, w0, w0, lsr 31
asr w0, w0, 1
ret
```
* **llvm**: 3 instructions
```
foo_int2: // @foo_int2
cmp w0, #0
cinc w8, w0, lt
asr w0, w8, #1
ret
```
![]()
_______________________________________________
llvm-bugs mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
