[PATCH] D112142: [InstCombine][ConstantFolding] Make ConstantFoldLoadThroughBitcast TypeSize-aware

[Paul Walker via Phabricator via llvm-commits]

paulwalker-arm added a comment.

My `vscale_range` comment is not concerning the implementation but rather about ensuring the ll tests do not contain potentially undefined behaviour. You can ignore this because I've commented below with an alternative that is simpler.



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Comment at: llvm/test/Transforms/InstCombine/vscale_load.ll:27
+  %cast_to_fixed = bitcast <vscale x 16 x i1>* %stack_var to <8 x i8>*
+  %a = load <8 x i8>, <8 x i8>* %cast_to_fixed, align 16
+  ret <8 x i8> %a
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This is potentially undefined behaviour (the load can read beyond the alloca).  A better option is for both tests to replace the alloca with a pointer parameter.  That way the bounds of the storage are unknown and it becomes only about the store and load.


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  https://reviews.llvm.org/D112142/new/

https://reviews.llvm.org/D112142