[RISCV][GISEL] Legalize G_ICMP for scalable vector types

The result of a vector G_ICMP is a vector with an s1 element type. The
input vectors can be integer, floating-point, or boolean element type.

Author: michaelmaitland

llvm/lib/CodeGen/GlobalISel/LegalizerInfo.cpp

@@ -154,7 +154,8 @@ static bool mutationIsSane(const LegalizeRule &Rule,
   case WidenScalar: {
     if (OldTy.isVector()) {
       // Number of elements should not change.
-      if (!NewTy.isVector() || OldTy.getNumElements() != NewTy.getNumElements())
+      if (!NewTy.isVector() ||
+          OldTy.getElementCount() != NewTy.getElementCount())
         return false;
     } else {
       // Both types must be vectors

llvm/lib/CodeGen/MachineVerifier.cpp

@@ -1506,7 +1506,8 @@ void MachineVerifier::verifyPreISelGenericInstruction(const MachineInstr *MI) {
     LLT SrcTy = MRI->getType(MI->getOperand(2).getReg());
 
     if ((DstTy.isVector() != SrcTy.isVector()) ||
-        (DstTy.isVector() && DstTy.getNumElements() != SrcTy.getNumElements()))
+        (DstTy.isVector() &&
+         DstTy.getElementCount() != SrcTy.getElementCount()))
       report("Generic vector icmp/fcmp must preserve number of lanes", MI);
 
     break;

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

@@ -231,6 +231,9 @@ RISCVLegalizerInfo::RISCVLegalizerInfo(const RISCVSubtarget &ST)
 
   getActionDefinitionsBuilder(G_ICMP)
       .legalFor({{sXLen, sXLen}, {sXLen, p0}})
+      .widenScalarOrEltToNextPow2OrMinSize(1, 8)
+      .legalIf(all(typeIsLegalBoolVec(0, BoolVecTys, ST),
+                   typeIsLegalIntOrFPVec(1, IntOrFPVecTys, ST)))
       .widenScalarToNextPow2(1)
       .clampScalar(1, sXLen, sXLen)
       .clampScalar(0, sXLen, sXLen);