[RISCV] Correct RISCVTTIImpl::getRegUsageForType for vectors of pointers.

[craig.topper]

Summary

getPrimitiveSizeInBits returns 0 for pointers, we need to query
the size via DataLayout instead.

[craig.topper]

Add test case

[reames]

LGTM

llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp

 }
 
 void RISCVTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
                                          TTI::PeelingPreferences &PP) {
   BaseT::getPeelingPreferences(L, SE, PP);
 }
 
 unsigned RISCVTTIImpl::getRegUsageForType(Type *Ty) {
-  TypeSize Size = Ty->getPrimitiveSizeInBits();
+  TypeSize Size = DL.getTypeSizeInBits(Ty);
   if (Ty->isVectorTy()) {
     if (Size.isScalable() && ST->hasVInstructions())
       return divideCeil(Size.getKnownMinValue(), RISCV::RVVBitsPerBlock);
 
     if (ST->useRVVForFixedLengthVectors())
       return divideCeil(Size, ST->getRealMinVLen());
   }
 

llvm/test/Transforms/LoopVectorize/RISCV/reg-usage.ll

for.body:
   %1 = load float, float* %arrayidx2, align 4
   %add = fadd float %0, %1
   %arrayidx3 = getelementptr inbounds float, float* %result, i64 %i.011
   store float %add, float* %arrayidx3, align 4
   %add4 = add nuw nsw i64 %i.011, 1
   %exitcond.not = icmp eq i64 %add4, %conv
   br i1 %exitcond.not, label %for.cond.cleanup, label %for.body
 }
+
+define void @goo(i32** nocapture noundef %a, i32 noundef signext %n) {
+; CHECK-LABEL: goo
+; CHECK-SCALAR:      LV(REG): Found max usage: 1 item
+; CHECK-SCALAR-NEXT: LV(REG): RegisterClass: RISCV::GPRRC, 3 registers
+; CHECK-LMUL1:       LV(REG): Found max usage: 2 item
+; CHECK-LMUL1-NEXT:  LV(REG): RegisterClass: RISCV::GPRRC, 2 registers
+; CHECK-LMUL1-NEXT:  LV(REG): RegisterClass: RISCV::VRRC, 1 registers
+; CHECK-LMUL2:       LV(REG): Found max usage: 2 item
+; CHECK-LMUL2-NEXT:  LV(REG): RegisterClass: RISCV::GPRRC, 2 registers
+; CHECK-LMUL2-NEXT:  LV(REG): RegisterClass: RISCV::VRRC, 2 registers
+; CHECK-LMUL4:       LV(REG): Found max usage: 2 item
+; CHECK-LMUL4-NEXT:  LV(REG): RegisterClass: RISCV::GPRRC, 2 registers
+; CHECK-LMUL4-NEXT:  LV(REG): RegisterClass: RISCV::VRRC, 4 registers
+; CHECK-LMUL8:       LV(REG): Found max usage: 2 item
+; CHECK-LMUL8-NEXT:  LV(REG): RegisterClass: RISCV::GPRRC, 2 registers
+; CHECK-LMUL8-NEXT:  LV(REG): RegisterClass: RISCV::VRRC, 8 registers
+entry:
+  %cmp3 = icmp sgt i32 %n, 0
+  br i1 %cmp3, label %for.body.preheader, label %for.cond.cleanup
+
+for.body.preheader:                               ; preds = %entry
+  %wide.trip.count = zext i32 %n to i64
+  br label %for.body
+
+for.cond.cleanup.loopexit:                        ; preds = %for.body
+  br label %for.cond.cleanup
+
+for.cond.cleanup:                                 ; preds = %for.cond.cleanup.loopexit, %entry
+  ret void
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+  %indvars.iv = phi i64 [ 0, %for.body.preheader ], [ %indvars.iv.next, %for.body ]
+  %arrayidx = getelementptr inbounds i32*, i32** %a, i64 %indvars.iv
+  %0 = load i32*, i32** %arrayidx, align 8
+  %add.ptr = getelementptr inbounds i32, i32* %0, i64 1
+  store i32* %add.ptr, i32** %arrayidx, align 8
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
+  br i1 %exitcond.not, label %for.cond.cleanup.loopexit, label %for.body
+}