pr6652: Use LDM to restore PC to the return address on ARMv4.
Patch by John Tytgat!
llvm-svn: 99096
diff --git a/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp b/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
index d0a3179b..bdbec30 100644
--- a/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
@@ -1155,19 +1155,24 @@
};
}
-/// MergeReturnIntoLDM - If this is a exit BB, try merging the return op
-/// (bx lr) into the preceeding stack restore so it directly restore the value
-/// of LR into pc.
-/// ldmfd sp!, {r7, lr}
+/// MergeReturnIntoLDM - If this is a exit BB, try merging the return ops
+/// ("bx lr" and "mov pc, lr") into the preceeding stack restore so it
+/// directly restore the value of LR into pc.
+/// ldmfd sp!, {..., lr}
/// bx lr
+/// or
+/// ldmfd sp!, {..., lr}
+/// mov pc, lr
/// =>
-/// ldmfd sp!, {r7, pc}
+/// ldmfd sp!, {..., pc}
bool ARMLoadStoreOpt::MergeReturnIntoLDM(MachineBasicBlock &MBB) {
if (MBB.empty()) return false;
MachineBasicBlock::iterator MBBI = prior(MBB.end());
if (MBBI != MBB.begin() &&
- (MBBI->getOpcode() == ARM::BX_RET || MBBI->getOpcode() == ARM::tBX_RET)) {
+ (MBBI->getOpcode() == ARM::BX_RET ||
+ MBBI->getOpcode() == ARM::tBX_RET ||
+ MBBI->getOpcode() == ARM::MOVPCLR)) {
MachineInstr *PrevMI = prior(MBBI);
if (PrevMI->getOpcode() == ARM::LDM_UPD ||
PrevMI->getOpcode() == ARM::t2LDM_UPD) {