diff options
| -rw-r--r-- | lib/Target/ARM/ARMISelLowering.cpp | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp index 6094811..04370c0 100644 --- a/lib/Target/ARM/ARMISelLowering.cpp +++ b/lib/Target/ARM/ARMISelLowering.cpp @@ -9046,12 +9046,19 @@ bool ARMTargetLowering::isLegalICmpImmediate(int64_t Imm) const { return Imm >= 0 && Imm <= 255; } -/// isLegalAddImmediate - Return true if the specified immediate is legal -/// add immediate, that is the target has add instructions which can add -/// a register with the immediate without having to materialize the +/// isLegalAddImmediate - Return true if the specified immediate is a legal add +/// *or sub* immediate, that is the target has add or sub instructions which can +/// add a register with the immediate without having to materialize the /// immediate into a register. bool ARMTargetLowering::isLegalAddImmediate(int64_t Imm) const { - return ARM_AM::getSOImmVal(Imm) != -1; + // Same encoding for add/sub, just flip the sign. + int64_t AbsImm = llvm::abs64(Imm); + if (!Subtarget->isThumb()) + return ARM_AM::getSOImmVal(AbsImm) != -1; + if (Subtarget->isThumb2()) + return ARM_AM::getT2SOImmVal(AbsImm) != -1; + // Thumb1 only has 8-bit unsigned immediate. + return AbsImm >= 0 && AbsImm <= 255; } static bool getARMIndexedAddressParts(SDNode *Ptr, EVT VT, |