[PATCH] D103788: [InstCombine] Eliminate casts to optimize ctlz operation

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added reviewers: lebedev.ri, spatel.
RKSimon added inline comments.


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Comment at: llvm/test/Transforms/InstCombine/zext-ctlz-trunc-to-ctlz-add.ll:11
+declare i32 @llvm.ctlz.i32 (i32, i1);
+declare i16 @llvm.ctlz.i16 (i16, i1);
+
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Drop the ;


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Comment at: llvm/test/Transforms/InstCombine/zext-ctlz-trunc-to-ctlz-add.ll:13
+
+define i16 @src0(i16 %x) {
+; CHECK-LABEL: @src0(
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please can you use descriptive test names - @src0 etc. don't give themselves to searching (or when variant tests get added in the middle of the file...).

@trunc_ctlz_zext_i32 etc. would be better


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Comment at: llvm/test/Transforms/InstCombine/zext-ctlz-trunc-to-ctlz-add.ll:71
+  ret i16 %zz
+}
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We need vector type coverage as well - at least fixed vectors, scalable vectors as well would be a bonus

declare <2 x i32> @llvm.ctlz.v2i32 (<2 x i32>, i1)

declare <vscale x 2 x i32> @llvm.ctlz.v2i32 (<vscale x 2 x i32>, i1)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103788/new/

https://reviews.llvm.org/D103788