| Issue |
100907
|
| Summary |
[LoongArch] Backend Optimizers too aggressive for SIMD, causing worsen codegen
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
trcrsired
|
I tried to check the assembly output for loongarch for my sha512 algorithms:
GCC sysroots being here:
https://github.com/trcrsired/gcc-releases/releases
```
clang++ -S sha512.cc -I../../include -std=c++26 -o sha512_loongarch64_clang.s --target=loongarch64-linux-gnu -O3 --sysroot=$HOME/toolchains/x86_64-generic-linux-gnu/loongarch64-linux-gnu
```
https://github.com/cppfastio/fast_io/blob/next/benchmark/0012.isa/sha512_loongarch64_clang.s
```
clang++ -S sha512.cc -I../../include -std=c++26 -o sha512_loongarch64_clang.s --target=loongarch64-linux-gnu -O3 --sysroot=$HOME/toolchains/x86_64-generic-linux-gnu/loongarch64-linux-gnu -msimd=none
```
https://github.com/cppfastio/fast_io/blob/next/benchmark/0012.isa/sha512_loongarch64_clang_nosimd.s
The simd optimizer for the long arch backend seems too aggressive, while this issue does not exist for aarch64 or x86_64 with APX.
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