[GlobalISel][AArch64] Fold FI into LDR/STR ui addressing mode.
A majority of loads and stores at O0 access an alloca.
It's trivial to fold the G_FRAME_INDEX into the instruction; do it.
llvm-svn: 298864
diff --git a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
index be0f6eb..70c11c1 100644
--- a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
@@ -792,6 +792,11 @@
}
}
+ // If we haven't folded anything into our addressing mode yet, try to fold
+ // a frame index into the base+offset.
+ if (!Offset && PtrMI->getOpcode() == TargetOpcode::G_FRAME_INDEX)
+ I.getOperand(1).ChangeToFrameIndex(PtrMI->getOperand(1).getIndex());
+
I.addOperand(MachineOperand::CreateImm(Offset));
// If we're storing a 0, use WZR/XZR.