//
//===----------------------------------------------------------------------===//
+#include "ARMSubtarget.h"
#include "Thumb1InstrInfo.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
MachineBasicBlock::iterator I, DebugLoc DL,
unsigned DestReg, unsigned SrcReg,
bool KillSrc) const {
- AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tMOVr), DestReg)
- .addReg(SrcReg, getKillRegState(KillSrc)));
+ // Need to check the arch.
+ MachineFunction &MF = *MBB.getParent();
+ const ARMSubtarget &st = MF.getTarget().getSubtarget<ARMSubtarget>();
+
assert(ARM::GPRRegClass.contains(DestReg, SrcReg) &&
"Thumb1 can only copy GPR registers");
+
+ if (st.hasV6Ops() || ARM::hGPRRegClass.contains(SrcReg)
+ || !ARM::tGPRRegClass.contains(DestReg))
+ AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tMOVr), DestReg)
+ .addReg(SrcReg, getKillRegState(KillSrc)));
+ else {
+ // FIXME: The performance consequences of this are going to be atrocious.
+ // Some things to try that should be better:
+ // * 'mov hi, $src; mov $dst, hi', with hi as either r10 or r11
+ // * 'movs $dst, $src' if cpsr isn't live
+ // See: http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/075998.html
+
+ // 'MOV lo, lo' is unpredictable on < v6, so use the stack to do it
+ AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tPUSH)))
+ .addReg(SrcReg, getKillRegState(KillSrc));
+ AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::tPOP)))
+ .addReg(DestReg, getDefRegState(true));
+ }
}
void Thumb1InstrInfo::