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403539ab64
Summary: The computeKnownBits and ComputeNumSignBits functions in ValueTracking can now do a simple look-through of ExtractElement. Reviewers: majnemer, spatel Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D24955 llvm-svn: 283434
29 lines
1.1 KiB
LLVM
29 lines
1.1 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -instsimplify -S | FileCheck %s
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; If computeKnownBits can do a simple look-through for extractelement
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; then instsimplify will know that %elt1 is non-negative at icmp.
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define i1 @computeKnownBits_look_through_extractelt(<2 x i8> %vecin) {
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; CHECK-LABEL: @computeKnownBits_look_through_extractelt(
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; CHECK-NEXT: ret i1 false
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;
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%vec = zext <2 x i8> %vecin to <2 x i32>
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%elt1 = extractelement <2 x i32> %vec, i32 1
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%bool = icmp slt i32 %elt1, 0
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ret i1 %bool
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}
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; If computeNumSignBits can do a simple look-through for extractelement
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; then instsimplify will remove the ashr.
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define i32 @computeNumSignBits_look_through_extractelt(<2 x i1> %vecin) {
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; CHECK-LABEL: @computeNumSignBits_look_through_extractelt(
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; CHECK-NEXT: [[VEC:%.*]] = sext <2 x i1> [[VEC:%.*]]in to <2 x i32>
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; CHECK-NEXT: [[ELT0:%.*]] = extractelement <2 x i32> [[VEC]], i32 0
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; CHECK-NEXT: ret i32 [[ELT0]]
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;
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%vec = sext <2 x i1> %vecin to <2 x i32>
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%elt0 = extractelement <2 x i32> %vec, i32 0
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%ashr = ashr i32 %elt0, 5
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ret i32 %ashr
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}
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