Add TargetLowering::isLegalICmpImmediate. It tells LSR what immediate can be folded into target icmp instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86858 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 4945fdfc1d..1b1446cc39 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -3706,6 +3706,18 @@ bool ARMTargetLowering::isLegalAddressingMode(const AddrMode &AM,
   return true;
 }
 
+/// isLegalICmpImmediate - Return true if the specified immediate is legal
+/// icmp immediate, that is the target has icmp instructions which can compare
+/// a register against the immediate without having to materialize the
+/// immediate into a register.
+bool ARMTargetLowering::isLegalICmpImmediate(uint64_t Imm) const {
+  if (!Subtarget->isThumb())
+    return ARM_AM::getSOImmVal(Imm) != -1;
+  if (Subtarget->isThumb2())
+    return ARM_AM::getT2SOImmVal(Imm) != -1; 
+  return Imm < 256;
+}
+
 static bool getARMIndexedAddressParts(SDNode *Ptr, EVT VT,
                                       bool isSEXTLoad, SDValue &Base,
                                       SDValue &Offset, bool &isInc,