[libc-commits] [libc] fix ppc64le builds without IEEE double long (PR #184995)

[via libc-commits]

Trupti603 wrote:

Update : Adrian Bunk has implemented a workaround in Debian that disables offloading for ppc64el to work around this issue ([Debian Bug #1129949](https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1129949)).

The workaround involves two changes:
1. Removing ppc64el from offloading architectures:
```diff
-OFFLOAD_ARCHS = amd64 arm64 loong64 ppc64el riscv64
+OFFLOAD_ARCHS = amd64 arm64 loong64 riscv64
```

2. Removing llvm-libunwind1/libllvm22 from build dependencies

   This allows llvm-toolchain-21 to build successfully on ppc64el, though at the cost of GPU offloading support  
    
    Although this is a short-term fix on the Debian side, we need to work on fixing this issue permanently to restore full
   functionality on ppc64el.


I've tested and confirmed the build failures on ppc64el match the FPBits issues described here. Happy to test any patches on ppc64el hardware.

Thanks 

https://github.com/llvm/llvm-project/pull/184995