Several fixes to handling of int CC register:
(1) An int CC live range must be spilled if there are any interferences,
even if no other "neighbour" in the interf. graph has been allocated
that reg. yet. This is actually true of any class with only one reg!
(2) SparcIntCCRegClass::colorIGNode sets the color even if the LR must
be spilled so that the machine-independent spill code doesn't have to
make the machine-dependent decision of which CC name to use based on
operand type: %xcc or %icc. (These are two halves of the same register.)
(3) LR->isMarkedForSpill() is no longer the same as LR->hasColor().
These should never have been the same, and this is necessary now for #2.
(4) All RDCCR and WRCCR instructions are directly generated with the
phony number for %ccr so that EmitAssembly/EmitBinary doesn't have to
deal with this.
llvm-svn: 7151
diff --git a/llvm/lib/Target/Sparc/SparcRegClassInfo.cpp b/llvm/lib/Target/Sparc/SparcRegClassInfo.cpp
index 8c20ab0..038ccb3 100644
--- a/llvm/lib/Target/Sparc/SparcRegClassInfo.cpp
+++ b/llvm/lib/Target/Sparc/SparcRegClassInfo.cpp
@@ -117,7 +117,8 @@
//
// Algorithm:
//
-// If the single int CC register is used (either as icc or xcc)
+// If (node has any interferences)
+// /* all interference operations can use only one register! */
// mark the LR for spilling
// else {
// if (the LR is a 64-bit comparison) use %xcc
@@ -130,30 +131,33 @@
void SparcIntCCRegClass::colorIGNode(IGNode *Node,
std::vector<bool> &IsColorUsedArr) const
{
- if (IsColorUsedArr[xcc] && IsColorUsedArr[icc])
+ if (Node->getNumOfNeighbors() > 0)
Node->getParentLR()->markForSpill();
- else {
- // Choose whether to use %xcc or %icc based on type of value compared
- const LiveRange* ccLR = Node->getParentLR();
- const Type* setCCType = (* ccLR->begin())->getType(); // any Value in LR
- assert(setCCType->isIntegral() || isa<PointerType>(setCCType));
- int ccReg = ((isa<PointerType>(setCCType) || setCCType == Type::LongTy)
- ? xcc : icc);
+
+ // Mark the appropriate register in any case (even if it needs to be spilled)
+ // because there is only one possible register, but more importantly, the
+ // spill algorithm cannot find it. In particular, we have to choose
+ // whether to use %xcc or %icc based on type of value compared
+ //
+ const LiveRange* ccLR = Node->getParentLR();
+ const Type* setCCType = (* ccLR->begin())->getType(); // any Value in LR
+ assert(setCCType->isIntegral() || isa<PointerType>(setCCType));
+ int ccReg = ((isa<PointerType>(setCCType) || setCCType == Type::LongTy)
+ ? xcc : icc);
#ifndef NDEBUG
- // Let's just make sure values of two different types have not been
- // coalesced into this LR.
- for (ValueSet::const_iterator I=ccLR->begin(), E=ccLR->end(); I!=E; ++I) {
- const Type* ccType = (*I)->getType();
- assert((ccReg == xcc && (isa<PointerType>(ccType)
- || ccType == Type::LongTy)) ||
- (ccReg == icc && ccType->isIntegral() && ccType != Type::LongTy)
- && "Comparisons needing different intCC regs coalesced in LR!");
- }
+ // Let's just make sure values of two different types have not been
+ // coalesced into this LR.
+ for (ValueSet::const_iterator I=ccLR->begin(), E=ccLR->end(); I!=E; ++I) {
+ const Type* ccType = (*I)->getType();
+ assert((ccReg == xcc && (isa<PointerType>(ccType)
+ || ccType == Type::LongTy)) ||
+ (ccReg == icc && ccType->isIntegral() && ccType != Type::LongTy)
+ && "Comparisons needing different intCC regs coalesced in LR!");
+ }
#endif
- Node->setColor(ccReg); // only one int cc reg is available
- }
+ Node->setColor(ccReg); // only one int cc reg is available
}