resolve comment

Author: XChy

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

@@ -7678,15 +7678,9 @@ LegalizerHelper::lowerBitCount(MachineInstr &MI) {
     unsigned Size = Ty.getSizeInBits();
     MachineIRBuilder &B = MIRBuilder;
 
-    // Lift odd-size integer to multiple of 8 bit.
-    if (Size % 8 != 0) {
-      LLT NewTy = LLT::scalar(alignTo(Size, 8));
-      Observer.changingInstr(MI);
-      widenScalarSrc(MI, NewTy, 1, TargetOpcode::G_ZEXT);
-      widenScalarDst(MI, NewTy, 0);
-      Observer.changedInstr(MI);
-      return Legalized;
-    }
+    // Bail out on irregular type lengths.
+    if (Size >= 128 || Size % 8 != 0)
+      return UnableToLegalize;
 
     // Count set bits in blocks of 2 bits. Default approach would be
     // B2Count = { val & 0x55555555 } + { (val >> 1) & 0x55555555 }

llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.cpp

@@ -238,7 +238,10 @@ RISCVLegalizerInfo::RISCVLegalizerInfo(const RISCVSubtarget &ST)
         .clampScalar(0, sXLen, sXLen)
         .scalarSameSizeAs(1, 0);
   } else {
-    CTPOPActions.maxScalar(0, sXLen).scalarSameSizeAs(1, 0).lower();
+    CTPOPActions.widenScalarToNextPow2(0, /*Min*/ 8)
+        .clampScalar(0, s8, sXLen)
+        .scalarSameSizeAs(1, 0)
+        .lower();
   }
 
   getActionDefinitionsBuilder(G_CONSTANT)