[PATCH] D121358: [InstCombine] Add vector support to icmp(add(X,C1),add(Y,C2)) -> icmp(add(X,C1-C2),Y) fold

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri accepted this revision.
lebedev.ri added a comment.
This revision is now accepted and ready to land.

Seems pretty straight-forward to me, thanks.



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Comment at: llvm/test/Transforms/InstCombine/icmp.ll:1645
 ; CHECK-LABEL: @icmp_sub57_sge_sub20_vec_undef(
-; CHECK-NEXT:    [[TMP1:%.*]] = add nsw <2 x i32> [[X:%.*]], <i32 -57, i32 undef>
-; CHECK-NEXT:    [[TMP2:%.*]] = add nsw <2 x i32> [[Y:%.*]], <i32 -20, i32 undef>
-; CHECK-NEXT:    [[CMP:%.*]] = icmp sge <2 x i32> [[TMP1]], [[TMP2]]
+; CHECK-NEXT:    [[TMP1:%.*]] = add nsw <2 x i32> [[X:%.*]], <i32 -37, i32 -37>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge <2 x i32> [[TMP1]], [[Y:%.*]]
----------------
If some channel is `undef` in both constants, it can be `undef` in the new constant.
https://alive2.llvm.org/ce/z/XJTfst


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D121358/new/

https://reviews.llvm.org/D121358