Fix frame index elimination to correctly handle thumb-2 addressing modes that don't allow negative offsets. During frame elimination convert *i12 opcode to a *i8 when necessary due to a negative offset.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76883 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/Thumb2InstrInfo.cpp b/lib/Target/ARM/Thumb2InstrInfo.cpp
index 081cf4f..d92856c 100644
--- a/lib/Target/ARM/Thumb2InstrInfo.cpp
+++ b/lib/Target/ARM/Thumb2InstrInfo.cpp
@@ -88,6 +88,29 @@
return false;
}
+unsigned
+Thumb2InstrInfo::unsignedOffsetOpcodeToSigned(unsigned opcode,
+ unsigned *NumBits) const
+{
+ if (NumBits != NULL)
+ *NumBits = 8;
+
+ switch (opcode) {
+ case ARM::t2LDRi12: return ARM::t2LDRi8;
+ case ARM::t2LDRHi12: return ARM::t2LDRHi8;
+ case ARM::t2LDRBi12: return ARM::t2LDRBi8;
+ case ARM::t2LDRSHi12: return ARM::t2LDRSHi8;
+ case ARM::t2LDRSBi12: return ARM::t2LDRSBi8;
+ case ARM::t2STRi12: return ARM::t2STRi8;
+ case ARM::t2STRBi12: return ARM::t2STRBi8;
+ case ARM::t2STRHi12: return ARM::t2STRHi8;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
bool
Thumb2InstrInfo::copyRegToReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,