[clang] [llvm] [clang][CodeGen][AA] Introduce `!llvm.errno.tbaa` for errno alias disambiguation (PR #125258)

[Nikita Popov via cfe-commits]

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@@ -0,0 +1,90 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -S -passes=instcombine < %s | FileCheck %s
+
+; sinf clobbering errno, but %p cannot alias errno per C/C++ strict aliasing rules via TBAA.
+; Hence, can do constant store-to-load forwarding.
+define float @does_not_alias_errno(ptr noundef %p, float noundef %f) {
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nikic wrote:

Shouldn't need the noundef attributes.

https://github.com/llvm/llvm-project/pull/125258