[PATCH] D127854: [InstCombine] Use known bits to determine exact int->fp cast

Thu Jun 16 03:21:48 PDT 2022

Allen marked an inline comment as done.
Allen added inline comments.

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Comment at: llvm/test/Transforms/InstCombine/sitofp.ll:245
+
+define i25 @overflow_masked_input(i25 %A) {
+; CHECK-LABEL: @overflow_masked_input(
----------------
nikic wrote:
> According to alive, this mask would be fine: https://alive2.llvm.org/ce/z/PdpF6F This is because this is a mask of the form `0b1000...` rather than `0b1111...`. The right mask to test would be: https://alive2.llvm.org/ce/z/GYxTRu (We could also make use of these low zero bits, but I think that would be better as a separate change.)
> 
> 
good catch. Thanks @nikic for the detailed explanations, I'll address this after this change.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D127854/new/

https://reviews.llvm.org/D127854