diff options
| -rw-r--r-- | llvm/lib/Analysis/ScalarEvolution.cpp | 7 | ||||
| -rw-r--r-- | llvm/test/Analysis/ScalarEvolution/pr76234.ll | 23 |
2 files changed, 27 insertions, 3 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index 580fe11..623814c 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -7914,9 +7914,10 @@ const SCEV *ScalarEvolution::createSCEV(Value *V) { // expression. We already checked that ShlAmt < BitWidth, so // the multiplier, 1 << (ShlAmt - AShrAmt), fits into TruncTy as // ShlAmt - AShrAmt < Amt. - uint64_t ShlAmt = ShlAmtCI->getZExtValue(); - if (ShlAmtCI->getValue().ult(BitWidth) && ShlAmt >= AShrAmt) { - APInt Mul = APInt::getOneBitSet(BitWidth - AShrAmt, ShlAmt - AShrAmt); + const APInt &ShlAmt = ShlAmtCI->getValue(); + if (ShlAmt.ult(BitWidth) && ShlAmt.uge(AShrAmt)) { + APInt Mul = APInt::getOneBitSet(BitWidth - AShrAmt, + ShlAmtCI->getZExtValue() - AShrAmt); const SCEV *CompositeExpr = getMulExpr(AddTruncateExpr, getConstant(Mul)); if (L->getOpcode() != Instruction::Shl) diff --git a/llvm/test/Analysis/ScalarEvolution/pr76234.ll b/llvm/test/Analysis/ScalarEvolution/pr76234.ll new file mode 100644 index 0000000..0d82f0e --- /dev/null +++ b/llvm/test/Analysis/ScalarEvolution/pr76234.ll @@ -0,0 +1,23 @@ +; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 4 +; RUN: opt < %s -disable-output "-passes=print<scalar-evolution>" 2>&1 | FileCheck %s + +; Reduced from https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=65278 +define i32 @PR76234() { +; CHECK-LABEL: 'PR76234' +; CHECK-NEXT: Classifying expressions for: @PR76234 +; CHECK-NEXT: %B9 = shl i896 0, -264147265567832623176169892458258303259423663018060761063980354513336951278362429737208627943828593947337197496628564339441173779751342768625269489231469788454193341999502542084365758838213220526512116454105594202074014146375780869419198449383518238244769290448868999168 +; CHECK-NEXT: --> %B9 U: [0,1) S: [0,1) +; CHECK-NEXT: %B39 = ashr i896 %B9, 1 +; CHECK-NEXT: --> %B39 U: [0,1) S: [0,1) Exits: <<Unknown>> LoopDispositions: { %1: Variant } +; CHECK-NEXT: Determining loop execution counts for: @PR76234 +; CHECK-NEXT: Loop %1: <multiple exits> Unpredictable backedge-taken count. +; CHECK-NEXT: Loop %1: Unpredictable constant max backedge-taken count. +; CHECK-NEXT: Loop %1: Unpredictable symbolic max backedge-taken count. +; CHECK-NEXT: Loop %1: Unpredictable predicated backedge-taken count. +; + %B9 = shl i896 0, -264147265567832623176169892458258303259423663018060761063980354513336951278362429737208627943828593947337197496628564339441173779751342768625269489231469788454193341999502542084365758838213220526512116454105594202074014146375780869419198449383518238244769290448868999168 + br label %1 +1: + %B39 = ashr i896 %B9, 1 + br label %1 +} |