Fix failing test cases with joined live intervals. It turns out that
when joining we need to check if we overlap with the second interval
or any of its aliases.
Also make joining intervals the default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10973 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index fb11ff0..75fcfd0 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -49,7 +49,7 @@
cl::opt<bool>
join("join-liveintervals",
cl::desc("Join compatible live intervals"),
- cl::init(false));
+ cl::init(true));
};
void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const
@@ -387,26 +387,31 @@
Intervals::iterator srcInt = r2iSrc->second;
Intervals::iterator dstInt = r2iDst->second;
+ // src is a physical register
if (srcInt->reg < MRegisterInfo::FirstVirtualRegister) {
if (dstInt->reg == srcInt->reg ||
(dstInt->reg >= MRegisterInfo::FirstVirtualRegister &&
- !dstInt->overlaps(*srcInt))) {
+ !srcInt->overlaps(*dstInt) &&
+ !overlapsAliases(*srcInt, *dstInt))) {
srcInt->join(*dstInt);
r2iDst->second = r2iSrc->second;
r2rMap_.insert(std::make_pair(dstInt->reg, srcInt->reg));
intervals_.erase(dstInt);
}
}
+ // dst is a physical register
else if (dstInt->reg < MRegisterInfo::FirstVirtualRegister) {
if (srcInt->reg == dstInt->reg ||
(srcInt->reg >= MRegisterInfo::FirstVirtualRegister &&
- !srcInt->overlaps(*dstInt))) {
+ !dstInt->overlaps(*srcInt) &&
+ !overlapsAliases(*dstInt, *srcInt))) {
dstInt->join(*srcInt);
r2iSrc->second = r2iDst->second;
r2rMap_.insert(std::make_pair(srcInt->reg, dstInt->reg));
intervals_.erase(srcInt);
}
}
+ // neither src nor dst are physical registers
else {
const TargetRegisterClass *srcRc, *dstRc;
srcRc = mf_->getSSARegMap()->getRegClass(srcInt->reg);
@@ -432,6 +437,22 @@
}
+bool LiveIntervals::overlapsAliases(const Interval& lhs,
+ const Interval& rhs) const
+{
+ assert(lhs.reg < MRegisterInfo::FirstVirtualRegister &&
+ "first interval must describe a physical register");
+
+ for (const unsigned* as = mri_->getAliasSet(lhs.reg); *as; ++as) {
+ Reg2IntervalMap::const_iterator r2i = r2iMap_.find(*as);
+ assert(r2i != r2iMap_.end() && "alias does not have interval?");
+ if (rhs.overlaps(*r2i->second))
+ return true;
+ }
+
+ return false;
+}
+
LiveIntervals::Interval::Interval(unsigned r)
: reg(r),
weight((r < MRegisterInfo::FirstVirtualRegister ?