llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-llvm-transforms Author: None (llvmbot) <details> <summary>Changes</summary> Backport c9a5e1b665dbba898e9981fd7d48881947e6560e Requested by: @<!-- -->nikic --- Full diff: https://github.com/llvm/llvm-project/pull/106892.diff 2 Files Affected: - (modified) llvm/lib/Transforms/Utils/SimplifyIndVar.cpp (+17-11) - (added) llvm/test/Transforms/IndVarSimplify/pr106239.ll (+36) ``````````diff diff --git a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp index 5bda7c50c62c66..0b4a75e0bc52de 100644 --- a/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyIndVar.cpp @@ -1928,18 +1928,24 @@ Instruction *WidenIV::widenIVUse(WidenIV::NarrowIVDefUse DU, if (!WideAddRec.first) return nullptr; - // Reuse the IV increment that SCEVExpander created. Recompute flags, unless - // the flags for both increments agree and it is safe to use the ones from - // the original inc. In that case, the new use of the wide increment won't - // be more poisonous. - bool NeedToRecomputeFlags = - !SCEVExpander::canReuseFlagsFromOriginalIVInc(OrigPhi, WidePhi, - DU.NarrowUse, WideInc) || - DU.NarrowUse->hasNoUnsignedWrap() != WideInc->hasNoUnsignedWrap() || - DU.NarrowUse->hasNoSignedWrap() != WideInc->hasNoSignedWrap(); + auto CanUseWideInc = [&]() { + if (!WideInc) + return false; + // Reuse the IV increment that SCEVExpander created. Recompute flags, + // unless the flags for both increments agree and it is safe to use the + // ones from the original inc. In that case, the new use of the wide + // increment won't be more poisonous. + bool NeedToRecomputeFlags = + !SCEVExpander::canReuseFlagsFromOriginalIVInc( + OrigPhi, WidePhi, DU.NarrowUse, WideInc) || + DU.NarrowUse->hasNoUnsignedWrap() != WideInc->hasNoUnsignedWrap() || + DU.NarrowUse->hasNoSignedWrap() != WideInc->hasNoSignedWrap(); + return WideAddRec.first == WideIncExpr && + Rewriter.hoistIVInc(WideInc, DU.NarrowUse, NeedToRecomputeFlags); + }; + Instruction *WideUse = nullptr; - if (WideAddRec.first == WideIncExpr && - Rewriter.hoistIVInc(WideInc, DU.NarrowUse, NeedToRecomputeFlags)) + if (CanUseWideInc()) WideUse = WideInc; else { WideUse = cloneIVUser(DU, WideAddRec.first); diff --git a/llvm/test/Transforms/IndVarSimplify/pr106239.ll b/llvm/test/Transforms/IndVarSimplify/pr106239.ll new file mode 100644 index 00000000000000..8d5aa99539a5a7 --- /dev/null +++ b/llvm/test/Transforms/IndVarSimplify/pr106239.ll @@ -0,0 +1,36 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5 +; RUN: opt -S -passes=indvars < %s | FileCheck %s + +target datalayout = "n8:16:32:64" + +; Make sure it does not crash. + +define i32 @m() { +; CHECK-LABEL: define i32 @m() { +; CHECK-NEXT: [[ENTRY:.*:]] +; CHECK-NEXT: br label %[[FOR_BODY_I6:.*]] +; CHECK: [[FOR_BODY_I6]]: +; CHECK-NEXT: br i1 true, label %[[I_EXIT:.*]], label %[[IF_END_I:.*]] +; CHECK: [[IF_END_I]]: +; CHECK-NEXT: store i64 0, ptr null, align 8 +; CHECK-NEXT: br label %[[FOR_BODY_I6]] +; CHECK: [[I_EXIT]]: +; CHECK-NEXT: ret i32 0 +; +entry: + %div.i4 = sdiv i32 1, 0 + br label %for.body.i6 + +for.body.i6: ; preds = %if.end.i, %entry + %add57.i = phi i32 [ %add.i7, %if.end.i ], [ 0, %entry ] + br i1 true, label %i.exit, label %if.end.i + +if.end.i: ; preds = %for.body.i6 + %add.i7 = add i32 %add57.i, %div.i4 + %conv.i = zext i32 %add57.i to i64 + store i64 %conv.i, ptr null, align 8 + br label %for.body.i6 + +i.exit: ; preds = %for.body.i6 + ret i32 0 +} `````````` </details> https://github.com/llvm/llvm-project/pull/106892 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
