[libcxx-commits] [libcxx] [libc++][test] Migrate _BitInt probe to __BITINT_MAXWIDTH__ and fix latent test bugs (PR #203876)

[Xavier Roche via libcxx-commits]

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@@ -8,9 +8,21 @@
 
 // REQUIRES: std-at-least-c++26
 
+// Clang <= 22 mis-evaluates saturating_mul on non-byte-aligned _BitInt at
+// compile time: clang-21 asserts in ExprConstant.cpp (IntExprEvaluator::
+// Success bitwidth mismatch), clang-22 produces the wrong value (the unsigned
+// product gets sign-extended, so the equality assert fires). Fixed in
+// clang-23.
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xroche wrote:

I created https://github.com/llvm/llvm-project/issues/204085 for this (will close it as it was closed in trunk)

https://github.com/llvm/llvm-project/pull/203876