diff options
| -rw-r--r-- | lib/Target/ARM/ARMBaseInstrInfo.cpp | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp index 26558d900d..f3c7452861 100644 --- a/lib/Target/ARM/ARMBaseInstrInfo.cpp +++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp @@ -40,6 +40,10 @@ static cl::opt<bool> EnableARM3Addr("enable-arm-3-addr-conv", cl::Hidden, cl::desc("Enable ARM 2-addr to 3-addr conv")); +static cl::opt<bool> +OldARMIfConv("old-arm-if-conversion", cl::Hidden, + cl::desc("Use old-style ARM if-conversion heuristics")); + ARMBaseInstrInfo::ARMBaseInstrInfo(const ARMSubtarget& STI) : TargetInstrInfoImpl(ARMInsts, array_lengthof(ARMInsts)), Subtarget(STI) { @@ -1201,6 +1205,16 @@ bool ARMBaseInstrInfo::isProfitableToIfCvt(MachineBasicBlock &MBB, if (!NumInstrs) return false; + // Use old-style heuristics + if (OldARMIfConv) { + if (Subtarget.getCPUString() == "generic") + // Generic (and overly aggressive) if-conversion limits for testing. + return NumInstrs <= 10; + else if (Subtarget.hasV7Ops()) + return NumInstrs <= 3; + return NumInstrs <= 2; + } + // Attempt to estimate the relative costs of predication versus branching. float UnpredCost = Probability * NumInstrs; UnpredCost += 1.0; // The branch itself @@ -1216,6 +1230,11 @@ bool ARMBaseInstrInfo:: isProfitableToIfCvt(MachineBasicBlock &TMBB, unsigned NumT, MachineBasicBlock &FMBB, unsigned NumF, float Probability) const { + // Use old-style if-conversion heuristics + if (OldARMIfConv) { + return NumT && NumF && NumT <= 2 && NumF <= 2; + } + if (!NumT || !NumF) return false; |