diff options
| -rw-r--r-- | lib/Analysis/ScalarEvolution.cpp | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index 75331fdab4..cebf4d704f 100644 --- a/lib/Analysis/ScalarEvolution.cpp +++ b/lib/Analysis/ScalarEvolution.cpp @@ -654,6 +654,10 @@ SCEVHandle ScalarEvolution::getTruncateExpr(const SCEVHandle &Op, const Type *Ty return getUnknown( ConstantExpr::getTrunc(SC->getValue(), Ty)); + // trunc(trunc(x)) --> trunc(x) + if (SCEVTruncateExpr *ST = dyn_cast<SCEVTruncateExpr>(Op)) + return getTruncateExpr(ST->getOperand(), Ty); + // If the input value is a chrec scev made out of constants, truncate // all of the constants. if (SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(Op)) { @@ -685,6 +689,10 @@ SCEVHandle ScalarEvolution::getZeroExtendExpr(const SCEVHandle &Op, return getUnknown(C); } + // zext(zext(x)) --> zext(x) + if (SCEVZeroExtendExpr *SZ = dyn_cast<SCEVZeroExtendExpr>(Op)) + return getZeroExtendExpr(SZ->getOperand(), Ty); + // FIXME: If the input value is a chrec scev, and we can prove that the value // did not overflow the old, smaller, value, we can zero extend all of the // operands (often constants). This would allow analysis of something like @@ -706,6 +714,10 @@ SCEVHandle ScalarEvolution::getSignExtendExpr(const SCEVHandle &Op, const Type * return getUnknown(C); } + // sext(sext(x)) --> sext(x) + if (SCEVSignExtendExpr *SS = dyn_cast<SCEVSignExtendExpr>(Op)) + return getSignExtendExpr(SS->getOperand(), Ty); + // FIXME: If the input value is a chrec scev, and we can prove that the value // did not overflow the old, smaller, value, we can sign extend all of the // operands (often constants). This would allow analysis of something like |