[clang] [X86] Add ABI handling for __float128 (PR #75156)

[Phoebe Wang via cfe-commits]

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@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 -triple x86_64-linux -emit-llvm  -target-feature +sse2 < %s | FileCheck %s --check-prefixes=CHECK
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phoebewang wrote:

This patch only changes for 64-bit ABI, non-SSE is not a valid case for 64-bit.
OTOH, -sse just generate identical output with +sse2, which doesn't match with GCC https://godbolt.org/z/4nxnhnovd
I think we may need to add a semacheck for it. Do you think we should add it with this patch or a follow up?

https://github.com/llvm/llvm-project/pull/75156