[llvm] 3b19851 - GlobalISel: Fix narrowing of G_CTPOP

[Matt Arsenault via llvm-commits]

Author: Matt Arsenault
Date: 2020-02-07T06:58:00-08:00
New Revision: 3b198518ad540f789f45490e896565d4f0862c16

URL: https://github.com/llvm/llvm-project/commit/3b198518ad540f789f45490e896565d4f0862c16
DIFF: https://github.com/llvm/llvm-project/commit/3b198518ad540f789f45490e896565d4f0862c16.diff

LOG: GlobalISel: Fix narrowing of G_CTPOP

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

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 88da57bfb591..153d42c4e368 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -4040,16 +4040,17 @@ LegalizerHelper::narrowScalarCTPOP(MachineInstr &MI, unsigned TypeIdx,
   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;

diff  --git a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
index 04e017d8b82e..762e07149592 100644
--- a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
@@ -216,6 +216,7 @@ MipsLegalizerInfo::MipsLegalizerInfo(const MipsSubtarget &ST) {
 
   getActionDefinitionsBuilder(G_CTPOP)
       .lowerFor({{s32, s32}})
+      .clampScalar(0, s32, s32)
       .clampScalar(1, s32, s32);
 
   // FP instructions