diff options
Diffstat (limited to 'llvm/lib/Analysis/BasicAliasAnalysis.cpp')
| -rw-r--r-- | llvm/lib/Analysis/BasicAliasAnalysis.cpp | 19 |
1 files changed, 2 insertions, 17 deletions
diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp index 8cf947c..ea02110 100644 --- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp +++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp @@ -657,23 +657,8 @@ BasicAAResult::DecomposeGEPExpression(const Value *V, const DataLayout &DL, // The GEP index scale ("Scale") scales C1*V+C2, yielding (C1*V+C2)*Scale. // This gives us an aggregate computation of (C1*Scale)*V + C2*Scale. - - // It can be the case that, even through C1*V+C2 does not overflow for - // relevant values of V, (C2*Scale) can overflow. In that case, we cannot - // decompose the expression in this way. - // - // FIXME: C1*Scale and the other operations in the decomposed - // (C1*Scale)*V+C2*Scale can also overflow. We should check for this - // possibility. - bool Overflow; - APInt ScaledOffset = LE.Offset.sextOrTrunc(MaxPointerSize) - .smul_ov(Scale, Overflow); - if (Overflow) { - LE = LinearExpression(CastedValue(Index, 0, SExtBits, TruncBits)); - } else { - Decomposed.Offset += ScaledOffset; - Scale *= LE.Scale.sextOrTrunc(MaxPointerSize); - } + Decomposed.Offset += LE.Offset.sextOrTrunc(MaxPointerSize) * Scale; + Scale *= LE.Scale.sextOrTrunc(MaxPointerSize); // If we already had an occurrence of this index variable, merge this // scale into it. For example, we want to handle: |