[llvm-commits] [llvm] r58979 - /llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
Dale Johannesen
dalej at apple.com
Sun Nov 9 23:16:43 PST 2008
Author: johannes
Date: Mon Nov 10 01:16:42 2008
New Revision: 58979
URL: http://llvm.org/viewvc/llvm-project?rev=58979&view=rev
Log:
Really fix testb optimization on big-endian.
Fixes ppc32 bootstrap.
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp?rev=58979&r1=58978&r2=58979&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp Mon Nov 10 01:16:42 2008
@@ -1353,7 +1353,6 @@
}
}
-#if 0
// If the LHS is '(and load, const)', the RHS is 0,
// the test is for equality or unsigned, and all 1 bits of the const are
// in the same partial word, see if we can shorten the load.
@@ -1364,17 +1363,23 @@
isa<ConstantSDNode>(N0.getOperand(1))) {
LoadSDNode *Lod = cast<LoadSDNode>(N0.getOperand(0));
uint64_t Mask = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
+ uint64_t bestMask = 0;
unsigned bestWidth = 0, bestOffset = 0;
- if (!Lod->isVolatile()) {
+ if (!Lod->isVolatile() && Lod->isUnindexed()) {
unsigned origWidth = N0.getValueType().getSizeInBits();
+ // We can narrow (e.g.) 16-bit extending loads on 32-bit target to
+ // 8 bits, but have to be careful...
+ if (Lod->getExtensionType() != ISD::NON_EXTLOAD)
+ origWidth = Lod->getMemoryVT().getSizeInBits();
for (unsigned width = origWidth / 2; width>=8; width /= 2) {
uint64_t newMask = (1ULL << width) - 1;
for (unsigned offset=0; offset<origWidth/width; offset++) {
if ((newMask & Mask)==Mask) {
if (!TD->isLittleEndian())
bestOffset = (origWidth/width - offset - 1) * (width/8);
- else
+ else
bestOffset = (uint64_t)offset * (width/8);
+ bestMask = Mask >> (offset * 8);
bestWidth = width;
break;
}
@@ -1385,7 +1390,6 @@
if (bestWidth) {
MVT newVT = MVT::getIntegerVT(bestWidth);
if (newVT.isRound()) {
- uint64_t bestMask = Mask >> (bestOffset * 8);
MVT PtrType = Lod->getOperand(1).getValueType();
SDValue Ptr = Lod->getBasePtr();
if (bestOffset != 0)
@@ -1402,7 +1406,6 @@
}
}
}
-#endif
// If the LHS is a ZERO_EXTEND, perform the comparison on the input.
if (N0.getOpcode() == ISD::ZERO_EXTEND) {
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