diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/RegUsageInfoCollector.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/RegUsageInfoCollector.cpp | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/contrib/llvm/lib/CodeGen/RegUsageInfoCollector.cpp b/contrib/llvm/lib/CodeGen/RegUsageInfoCollector.cpp index ece44c28e9ed..855aa37ff3c3 100644 --- a/contrib/llvm/lib/CodeGen/RegUsageInfoCollector.cpp +++ b/contrib/llvm/lib/CodeGen/RegUsageInfoCollector.cpp @@ -103,9 +103,27 @@ bool RegUsageInfoCollector::runOnMachineFunction(MachineFunction &MF) { DEBUG(dbgs() << "Clobbered Registers: "); - for (unsigned PReg = 1, PRegE = TRI->getNumRegs(); PReg < PRegE; ++PReg) - if (MRI->isPhysRegModified(PReg, true)) - RegMask[PReg / 32] &= ~(1u << PReg % 32); + const BitVector &UsedPhysRegsMask = MRI->getUsedPhysRegsMask(); + auto SetRegAsDefined = [&RegMask] (unsigned Reg) { + RegMask[Reg / 32] &= ~(1u << Reg % 32); + }; + // Scan all the physical registers. When a register is defined in the current + // function set it and all the aliasing registers as defined in the regmask. + for (unsigned PReg = 1, PRegE = TRI->getNumRegs(); PReg < PRegE; ++PReg) { + // If a register is in the UsedPhysRegsMask set then mark it as defined. + // All it's aliases will also be in the set, so we can skip setting + // as defined all the aliases here. + if (UsedPhysRegsMask.test(PReg)) { + SetRegAsDefined(PReg); + continue; + } + // If a register is defined by an instruction mark it as defined together + // with all it's aliases. + if (!MRI->def_empty(PReg)) { + for (MCRegAliasIterator AI(PReg, TRI, true); AI.isValid(); ++AI) + SetRegAsDefined(*AI); + } + } if (!TargetFrameLowering::isSafeForNoCSROpt(F)) { const uint32_t *CallPreservedMask = |