[PATCH] D74189: GlobalISel: Fix narrowing of G_CTPOP

[Matt Arsenault via Phabricator via llvm-commits]

arsenm created this revision.
arsenm added reviewers: aemerson, aditya_nandakumar, paquette, Petar.Avramovic.
Herald added subscribers: volkan, atanasyan, hiraditya, tpr, rovka, wdng, sdardis.
Herald added a project: LLVM.

The result type is separate from the source type. Tests will be
included in a future AMDGPU patch which uses this from
RegBankSelect/applyMappingImpl.


https://reviews.llvm.org/D74189

Files:
  llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
  llvm/lib/Target/Mips/MipsLegalizerInfo.cpp


Index: llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
===================================================================
--- llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
+++ llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
@@ -216,6 +216,7 @@
 
   getActionDefinitionsBuilder(G_CTPOP)
       .lowerFor({{s32, s32}})
+      .clampScalar(0, s32, s32)
       .clampScalar(1, s32, s32);
 
   // FP instructions
Index: llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -4040,16 +4040,17 @@
   if (TypeIdx != 1)
     return UnableToLegalize;
 
+  Register DstReg = MI.getOperand(0).getReg();
+  LLT DstTy = MRI.getType(DstReg);
   LLT SrcTy = MRI.getType(MI.getOperand(1).getReg());
   unsigned NarrowSize = NarrowTy.getSizeInBits();
 
   if (SrcTy.isScalar() && SrcTy.getSizeInBits() == 2 * NarrowSize) {
     auto UnmergeSrc = MIRBuilder.buildUnmerge(NarrowTy, MI.getOperand(1));
 
-    auto LoCTPOP = MIRBuilder.buildCTPOP(NarrowTy, UnmergeSrc.getReg(0));
-    auto HiCTPOP = MIRBuilder.buildCTPOP(NarrowTy, UnmergeSrc.getReg(1));
-    auto Out = MIRBuilder.buildAdd(NarrowTy, HiCTPOP, LoCTPOP);
-    MIRBuilder.buildZExt(MI.getOperand(0), Out);
+    auto LoCTPOP = MIRBuilder.buildCTPOP(DstTy, UnmergeSrc.getReg(0));
+    auto HiCTPOP = MIRBuilder.buildCTPOP(DstTy, UnmergeSrc.getReg(1));
+    MIRBuilder.buildAdd(DstReg, HiCTPOP, LoCTPOP);
 
     MI.eraseFromParent();
     return Legalized;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D74189.243069.patch
Type: text/x-patch
Size: 1553 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200207/e90197a1/attachment.bin>