diff options
| -rw-r--r-- | lib/Target/PowerPC/PPCInstrInfo.cpp | 23 | ||||
| -rw-r--r-- | lib/Target/PowerPC/PPCInstrInfo.h | 4 |
2 files changed, 24 insertions, 3 deletions
diff --git a/lib/Target/PowerPC/PPCInstrInfo.cpp b/lib/Target/PowerPC/PPCInstrInfo.cpp index 8abe5ff2e3..c9674575d7 100644 --- a/lib/Target/PowerPC/PPCInstrInfo.cpp +++ b/lib/Target/PowerPC/PPCInstrInfo.cpp @@ -876,6 +876,29 @@ bool PPCInstrInfo::FoldImmediate(MachineInstr *UseMI, MachineInstr *DefMI, return true; } +static bool MBBDefinesCTR(MachineBasicBlock &MBB) { + for (MachineBasicBlock::iterator I = MBB.begin(), IE = MBB.end(); + I != IE; ++I) + if (I->definesRegister(PPC::CTR) || I->definesRegister(PPC::CTR8)) + return true; + return false; +} + +// We should make sure that, if we're going to predicate both sides of a +// condition (a diamond), that both sides don't define the counter register. We +// can predicate counter-decrement-based branches, but while that predicates +// the branching, it does not predicate the counter decrement. If we tried to +// merge the triangle into one predicated block, we'd decrement the counter +// twice. +bool PPCInstrInfo::isProfitableToIfCvt(MachineBasicBlock &TMBB, + unsigned NumT, unsigned ExtraT, + MachineBasicBlock &FMBB, + unsigned NumF, unsigned ExtraF, + const BranchProbability &Probability) const { + return !(MBBDefinesCTR(TMBB) && MBBDefinesCTR(FMBB)); +} + + bool PPCInstrInfo::isPredicated(const MachineInstr *MI) const { unsigned OpC = MI->getOpcode(); switch (OpC) { diff --git a/lib/Target/PowerPC/PPCInstrInfo.h b/lib/Target/PowerPC/PPCInstrInfo.h index a6ab617407..b5fcc85ce4 100644 --- a/lib/Target/PowerPC/PPCInstrInfo.h +++ b/lib/Target/PowerPC/PPCInstrInfo.h @@ -173,9 +173,7 @@ public: unsigned NumT, unsigned ExtraT, MachineBasicBlock &FMBB, unsigned NumF, unsigned ExtraF, - const BranchProbability &Probability) const { - return true; - } + const BranchProbability &Probability) const; virtual bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles, |