some comment improvements.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123243 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2011-01-11 17:11:59 +00:00
parent 3a5004dc3e
commit 6038a6351e
2 changed files with 7 additions and 5 deletions

View File

@ -537,8 +537,9 @@ namespace llvm {
/// ///
const SCEV *getNotSCEV(const SCEV *V); const SCEV *getNotSCEV(const SCEV *V);
/// getMinusSCEV - Return LHS-RHS. /// getMinusSCEV - Return LHS-RHS. Minus is represented in SCEV as A+B*-1,
/// /// and thus the HasNUW and HasNSW bits apply to the resultant add, not
/// whether the sub would have overflowed.
const SCEV *getMinusSCEV(const SCEV *LHS, const SCEV *RHS, const SCEV *getMinusSCEV(const SCEV *LHS, const SCEV *RHS,
bool HasNUW = false, bool HasNSW = false); bool HasNUW = false, bool HasNSW = false);

View File

@ -2446,8 +2446,9 @@ const SCEV *ScalarEvolution::getNotSCEV(const SCEV *V) {
return getMinusSCEV(AllOnes, V); return getMinusSCEV(AllOnes, V);
} }
/// getMinusSCEV - Return a SCEV corresponding to LHS - RHS. /// getMinusSCEV - Return LHS-RHS. Minus is represented in SCEV as A+B*-1,
/// /// and thus the HasNUW and HasNSW bits apply to the resultant add, not
/// whether the sub would have overflowed.
const SCEV *ScalarEvolution::getMinusSCEV(const SCEV *LHS, const SCEV *RHS, const SCEV *ScalarEvolution::getMinusSCEV(const SCEV *LHS, const SCEV *RHS,
bool HasNUW, bool HasNSW) { bool HasNUW, bool HasNSW) {
// Fast path: X - X --> 0. // Fast path: X - X --> 0.
@ -4021,7 +4022,7 @@ static const SCEV *getMinusSCEVForExitTest(const SCEV *LHS, const SCEV *RHS,
cast<SCEVConstant>(RHSA->getOperand(1))->getValue(); cast<SCEVConstant>(RHSA->getOperand(1))->getValue();
// If the strides are equal, then this is just a (complex) loop invariant // If the strides are equal, then this is just a (complex) loop invariant
// comparison of a/b. // comparison of a and b.
if (LHSStride == RHSStride) if (LHSStride == RHSStride)
return SE.getMinusSCEV(LHSA->getStart(), RHSA->getStart()); return SE.getMinusSCEV(LHSA->getStart(), RHSA->getStart());