[PATCH] D123577: WIP [MIPS][SelectionDAG] Enable TargetLowering::hasBitTest for masks that fit in ANDI.

[LiqinWeng via Phabricator via llvm-commits]

Miss_Grape created this revision.
Miss_Grape added reviewers: benshi001, craig.topper.
Herald added subscribers: StephenFan, ecnelises, atanasyan, jrtc27, hiraditya, arichardson, sdardis.
Herald added a project: All.
Miss_Grape requested review of this revision.
Herald added subscribers: llvm-commits, jacquesguan.
Herald added a project: LLVM.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D123577

Files:
  llvm/lib/Target/Mips/MipsISelLowering.cpp
  llvm/lib/Target/Mips/MipsISelLowering.h


Index: llvm/lib/Target/Mips/MipsISelLowering.h
===================================================================
--- llvm/lib/Target/Mips/MipsISelLowering.h
+++ llvm/lib/Target/Mips/MipsISelLowering.h
@@ -282,6 +282,7 @@
 
     bool isCheapToSpeculateCttz() const override;
     bool isCheapToSpeculateCtlz() const override;
+    bool hasBitTest(SDValue X, SDValue Y) const override;
     bool shouldFoldConstantShiftPairToMask(const SDNode *N,
                                            CombineLevel Level) const override;
 
Index: llvm/lib/Target/Mips/MipsISelLowering.cpp
===================================================================
--- llvm/lib/Target/Mips/MipsISelLowering.cpp
+++ llvm/lib/Target/Mips/MipsISelLowering.cpp
@@ -1174,6 +1174,12 @@
   return Subtarget.hasMips32();
 }
 
+bool MipsTargetLowering::hasBitTest(SDValue X, SDValue Y) const {
+  // We can use ANDI+SEQZ/SNEZ as a bit test. Y contains the bit position.
+  auto *C = dyn_cast<ConstantSDNode>(Y);
+  return C && C->getAPIntValue().ule(14);
+}
+
 bool MipsTargetLowering::shouldFoldConstantShiftPairToMask(
     const SDNode *N, CombineLevel Level) const {
   if (N->getOperand(0).getValueType().isVector())


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D123577.422145.patch
Type: text/x-patch
Size: 1194 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220412/d907e556/attachment.bin>