diff options
Diffstat (limited to 'llvm/lib/Analysis')
| -rw-r--r-- | llvm/lib/Analysis/ScalarEvolution.cpp | 34 |
1 files changed, 14 insertions, 20 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index 60cd1cb4127..8fe500f150b 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -8808,7 +8808,13 @@ bool ScalarEvolution::SimplifyICmpOperands(ICmpInst::Predicate &Pred, const SCEV *&LHS, const SCEV *&RHS, unsigned Depth) { bool Changed = false; - + // Simplifies ICMP to trivial true or false by turning it into '0 == 0' or + // '0 != 0'. + auto TrivialCase = [&](bool TriviallyTrue) { + LHS = RHS = getConstant(ConstantInt::getFalse(getContext())); + Pred = TriviallyTrue ? ICmpInst::ICMP_EQ : ICmpInst::ICMP_NE; + return true; + }; // If we hit the max recursion limit bail out. if (Depth >= 3) return false; @@ -8820,9 +8826,9 @@ bool ScalarEvolution::SimplifyICmpOperands(ICmpInst::Predicate &Pred, if (ConstantExpr::getICmp(Pred, LHSC->getValue(), RHSC->getValue())->isNullValue()) - goto trivially_false; + return TrivialCase(false); else - goto trivially_true; + return TrivialCase(true); } // Otherwise swap the operands to put the constant on the right. std::swap(LHS, RHS); @@ -8852,9 +8858,9 @@ bool ScalarEvolution::SimplifyICmpOperands(ICmpInst::Predicate &Pred, if (!ICmpInst::isEquality(Pred)) { ConstantRange ExactCR = ConstantRange::makeExactICmpRegion(Pred, RA); if (ExactCR.isFullSet()) - goto trivially_true; + return TrivialCase(true); else if (ExactCR.isEmptySet()) - goto trivially_false; + return TrivialCase(false); APInt NewRHS; CmpInst::Predicate NewPred; @@ -8890,7 +8896,7 @@ bool ScalarEvolution::SimplifyICmpOperands(ICmpInst::Predicate &Pred, // The "Should have been caught earlier!" messages refer to the fact // that the ExactCR.isFullSet() or ExactCR.isEmptySet() check above // should have fired on the corresponding cases, and canonicalized the - // check to trivially_true or trivially_false. + // check to trivial case. case ICmpInst::ICMP_UGE: assert(!RA.isMinValue() && "Should have been caught earlier!"); @@ -8923,9 +8929,9 @@ bool ScalarEvolution::SimplifyICmpOperands(ICmpInst::Predicate &Pred, // Check for obvious equality. if (HasSameValue(LHS, RHS)) { if (ICmpInst::isTrueWhenEqual(Pred)) - goto trivially_true; + return TrivialCase(true); if (ICmpInst::isFalseWhenEqual(Pred)) - goto trivially_false; + return TrivialCase(false); } // If possible, canonicalize GE/LE comparisons to GT/LT comparisons, by @@ -8993,18 +8999,6 @@ bool ScalarEvolution::SimplifyICmpOperands(ICmpInst::Predicate &Pred, return SimplifyICmpOperands(Pred, LHS, RHS, Depth+1); return Changed; - -trivially_true: - // Return 0 == 0. - LHS = RHS = getConstant(ConstantInt::getFalse(getContext())); - Pred = ICmpInst::ICMP_EQ; - return true; - -trivially_false: - // Return 0 != 0. - LHS = RHS = getConstant(ConstantInt::getFalse(getContext())); - Pred = ICmpInst::ICMP_NE; - return true; } bool ScalarEvolution::isKnownNegative(const SCEV *S) { |
