Add some (disabled code) to print out negative strides.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126102 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2011-02-21 02:08:54 +00:00
parent 477a98824a
commit 408b534e43

View File

@ -31,6 +31,11 @@
// void foo(_Complex float *P)
// for (i) { __real__(*P) = 0; __imag__(*P) = 0; }
//
// We should enhance this to handle negative strides through memory.
// Alternatively (and perhaps better) we could rely on an earlier pass to force
// forward iteration through memory, which is generally better for cache
// behavior. Negative strides *do* happen for memset/memcpy loops.
//
// This could recognize common matrix multiplies and dot product idioms and
// replace them with calls to BLAS (if linked in??).
//
@ -272,10 +277,17 @@ bool LoopIdiomRecognize::processLoopStore(StoreInst *SI, const SCEV *BECount) {
unsigned StoreSize = (unsigned)SizeInBits >> 3;
const SCEVConstant *Stride = dyn_cast<SCEVConstant>(StoreEv->getOperand(1));
// TODO: Could also handle negative stride here someday, that will require the
// validity check in mayLoopAccessLocation to be updated though.
if (Stride == 0 || StoreSize != Stride->getValue()->getValue())
if (Stride == 0 || StoreSize != Stride->getValue()->getValue()) {
// TODO: Could also handle negative stride here someday, that will require
// the validity check in mayLoopAccessLocation to be updated though.
// Enable this to print exact negative strides.
if (0 && StoreSize == -Stride->getValue()->getValue()) {
dbgs() << "NEGATIVE STRIDE: " << *SI << "\n";
dbgs() << "BB: " << *SI->getParent();
}
return false;
}
// See if we can optimize just this store in isolation.
if (processLoopStridedStore(StorePtr, StoreSize, SI->getAlignment(),