diff options
Diffstat (limited to 'lib/CodeGen/RegAllocLocal.cpp')
| -rw-r--r-- | lib/CodeGen/RegAllocLocal.cpp | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp index c435c34f49..e3f3ab6fa3 100644 --- a/lib/CodeGen/RegAllocLocal.cpp +++ b/lib/CodeGen/RegAllocLocal.cpp @@ -103,8 +103,8 @@ namespace { } void MarkPhysRegRecentlyUsed(unsigned Reg) { - if(PhysRegsUseOrder.empty() || - PhysRegsUseOrder.back() == Reg) return; // Already most recently used + if (PhysRegsUseOrder.empty() || + PhysRegsUseOrder.back() == Reg) return; // Already most recently used for (unsigned i = PhysRegsUseOrder.size(); i != 0; --i) if (areRegsEqual(Reg, PhysRegsUseOrder[i-1])) { @@ -408,10 +408,15 @@ unsigned RA::getReg(MachineBasicBlock &MBB, MachineInstr *I, } else { // If one of the registers aliased to the current register is // compatible, use it. - for (const unsigned *AliasSet = RegInfo->getAliasSet(R); - *AliasSet; ++AliasSet) { - if (RC->contains(*AliasSet)) { - PhysReg = *AliasSet; // Take an aliased register + for (const unsigned *AliasIt = RegInfo->getAliasSet(R); + *AliasIt; ++AliasIt) { + if (RC->contains(*AliasIt) && + // If this is pinned down for some reason, don't use it. For + // example, if CL is pinned, and we run across CH, don't use + // CH as justification for using scavenging ECX (which will + // fail). + PhysRegsUsed[*AliasIt] != 0) { + PhysReg = *AliasIt; // Take an aliased register break; } } |