[PATCH] D126354: [GuardWidening] Remove nuw/nsw flags for hoisted instructions

Serguei Katkov via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Wed May 25 23:32:06 PDT 2022


This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGc2eccc67ce07: [GuardWidening] Remove nuw/nsw flags for hoisted instructions (authored by skatkov).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D126354/new/

https://reviews.llvm.org/D126354

Files:
  llvm/lib/Transforms/Scalar/GuardWidening.cpp
  llvm/test/Transforms/GuardWidening/range-check-merging.ll


Index: llvm/test/Transforms/GuardWidening/range-check-merging.ll
===================================================================
--- llvm/test/Transforms/GuardWidening/range-check-merging.ll
+++ llvm/test/Transforms/GuardWidening/range-check-merging.ll
@@ -340,7 +340,7 @@
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[LENGTH:%.*]] = load i32, i32* [[LENGTH_BUF:%.*]], align 4, !range [[RNG0]]
 ; CHECK-NEXT:    [[CHK0:%.*]] = icmp ult i32 [[X:%.*]], [[LENGTH]]
-; CHECK-NEXT:    [[X_INC1:%.*]] = add nuw nsw i32 [[X]], 1
+; CHECK-NEXT:    [[X_INC1:%.*]] = add i32 [[X]], 1
 ; CHECK-NEXT:    [[CHK1:%.*]] = icmp ult i32 [[X_INC1]], [[LENGTH]]
 ; CHECK-NEXT:    [[WIDE_CHK:%.*]] = and i1 [[CHK0]], [[CHK1]]
 ; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 [[WIDE_CHK]]) [ "deopt"() ]
Index: llvm/lib/Transforms/Scalar/GuardWidening.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/GuardWidening.cpp
+++ llvm/lib/Transforms/Scalar/GuardWidening.cpp
@@ -495,6 +495,9 @@
     makeAvailableAt(Op, Loc);
 
   Inst->moveBefore(Loc);
+  // If we moved instruction before guard we must clean nuw, nsw flags.
+  Inst->setHasNoUnsignedWrap(false);
+  Inst->setHasNoSignedWrap(false);
 }
 
 bool GuardWideningImpl::widenCondCommon(Value *Cond0, Value *Cond1,


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