https://github.com/nikic created https://github.com/llvm/llvm-project/pull/146494
https://reviews.llvm.org/D104808 set the alignment of long double to 64 bits. This is also the alignment specified in the LLVM data layout. However, the alignment of __float128 was left at 128 bits. I assume that this was just an oversight, rather than an intentional divergence. The C ABI document currently does not make any statement about `__float128`: https://github.com/WebAssembly/tool-conventions/blob/main/BasicCABI.md >From 3588d824c944aeaca1e0ce2bd170b60bf08ecad4 Mon Sep 17 00:00:00 2001 From: Nikita Popov <npo...@redhat.com> Date: Tue, 1 Jul 2025 10:44:06 +0200 Subject: [PATCH] [Clang][Wasm] Set __float128 alignment to 64 for emscripten https://reviews.llvm.org/D104808 set the alignment of long double to 64 bits. This is also the alignment specified in the LLVM data layout. However, the alignment of __float128 was left at 128 bits. I assume that this was just an oversight, rather than an intentional divergence. The C ABI document currently does not make any statement about `__float128`: https://github.com/WebAssembly/tool-conventions/blob/main/BasicCABI.md --- clang/lib/Basic/Targets/OSTargets.h | 1 + clang/lib/CodeGen/CodeGenModule.cpp | 3 +-- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/clang/lib/Basic/Targets/OSTargets.h b/clang/lib/Basic/Targets/OSTargets.h index 5dac699c2bb45..30d861a7ca605 100644 --- a/clang/lib/Basic/Targets/OSTargets.h +++ b/clang/lib/Basic/Targets/OSTargets.h @@ -1002,6 +1002,7 @@ class LLVM_LIBRARY_VISIBILITY EmscriptenTargetInfo // Emscripten's ABI is unstable and we may change this back to 128 to match // the WebAssembly default in the future. this->LongDoubleAlign = 64; + this->Float128Align = 64; } }; diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index e6d150f7e13d6..c8866f15745c2 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -388,8 +388,7 @@ static void checkDataLayoutConsistency(const TargetInfo &Target, llvm::Type::getFloatingPointTy(Context, *Target.LongDoubleFormat), Target.LongDoubleAlign); } - // FIXME: Wasm has a mismatch in f128 alignment between Clang and LLVM. - if (Target.hasFloat128Type() && !Triple.isWasm()) + if (Target.hasFloat128Type()) Check("__float128", llvm::Type::getFP128Ty(Context), Target.Float128Align); if (Target.hasIbm128Type()) Check("__ibm128", llvm::Type::getPPC_FP128Ty(Context), Target.Ibm128Align); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
