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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2010-02-11 20:58:45 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2010-02-11 20:58:45 +0000 |
| commit | a875fd0fdbf5fd111e97fa909e13ad48936856d1 (patch) | |
| tree | e01b128378bc5fbe27a18b9ae3f2f6465d372b8c /lib | |
| parent | e4c7f0f6ec2fdc1b58541dab4445761a5e9c6e2a (diff) | |
| download | external_llvm-a875fd0fdbf5fd111e97fa909e13ad48936856d1.zip external_llvm-a875fd0fdbf5fd111e97fa909e13ad48936856d1.tar.gz external_llvm-a875fd0fdbf5fd111e97fa909e13ad48936856d1.tar.bz2 | |
It is always good to do a cross-class join when the large register has a tiny interval.
Also avoid division by zero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95917 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/CodeGen/SimpleRegisterCoalescing.cpp | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp index 0d35b29..ac19f48 100644 --- a/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -1148,12 +1148,14 @@ SimpleRegisterCoalescing::isWinToJoinCrossClass(unsigned LargeReg, LiveInterval &SmallInt = li_->getInterval(SmallReg); unsigned LargeSize = li_->getApproximateInstructionCount(LargeInt); unsigned SmallSize = li_->getApproximateInstructionCount(SmallInt); - if (SmallSize > Threshold || LargeSize > Threshold) - if ((float)std::distance(mri_->use_nodbg_begin(SmallReg), - mri_->use_nodbg_end()) / SmallSize < - (float)std::distance(mri_->use_nodbg_begin(LargeReg), - mri_->use_nodbg_end()) / LargeSize) + if (LargeSize > Threshold) { + unsigned SmallUses = std::distance(mri_->use_nodbg_begin(SmallReg), + mri_->use_nodbg_end()); + unsigned LargeUses = std::distance(mri_->use_nodbg_begin(LargeReg), + mri_->use_nodbg_end()); + if (SmallUses*LargeSize < LargeUses*SmallSize) return false; + } return true; } @@ -1561,7 +1563,10 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) { (isExtSubReg || DstRC->isASubClass()) && !isWinToJoinCrossClass(LargeReg, SmallReg, allocatableRCRegs_[NewRC].count())) { - DEBUG(dbgs() << "\tSrc/Dest are different register classes.\n"); + DEBUG(dbgs() << "\tSrc/Dest are different register classes: " + << SrcRC->getName() << "/" + << DstRC->getName() << " -> " + << NewRC->getName() << ".\n"); // Allow the coalescer to try again in case either side gets coalesced to // a physical register that's compatible with the other side. e.g. // r1024 = MOV32to32_ r1025 |