[BasicTTI] Account for vector of pointers in getMemoryOpCost

[reames]

Summary

By using getPrimitiveSizeInBits, we were getting 0 for every pointer type. This code is trying to account for the cost of truncating a store or extending a load to convert from the source vector element type to the legal vector element type.

I'd originally seen this as a crash when trying to scalarize a <vscale x 1 x ptr> type coming from the vectorizer. Here's a minimum reproducer to exercise the code in question.

void e(int *argv[], int *p) {
  for (int i = 0; i < 1024; i++)
    argv[i] = p;
}

This was checked in as the splat_ptr test in 2cf320d. After bbf3fd, this no longer crashes since we correctly return invalid if the extending load/truncating store isn't legal.

[reames]

Rebase over newly added tests - after thinking about this a bit more, I realized this was exerciseable through CostModel.

[craig.topper]

LGTM

llvm/include/llvm/CodeGen/BasicTTIImpl.h

InstructionCost getMemoryOpCost(unsigned Opcode, Type *Src,
     InstructionCost Cost = LT.first;
     if (CostKind != TTI::TCK_RecipThroughput)
       return Cost;
 
     if (Src->isVectorTy() &&
         // In practice it's not currently possible to have a change in lane
         // length for extending loads or truncating stores so both types should
         // have the same scalable property.
-        TypeSize::isKnownLT(Src->getPrimitiveSizeInBits(),
+        TypeSize::isKnownLT(DL.getTypeStoreSizeInBits(Src),
                             LT.second.getSizeInBits())) {
       // This is a vector load that legalizes to a larger type than the vector
       // itself. Unless the corresponding extending load or truncating store is
       // legal, then this will scalarize.
       TargetLowering::LegalizeAction LA = TargetLowering::Expand;
       EVT MemVT = getTLI()->getValueType(DL, Src);
       if (Opcode == Instruction::Store)
         LA = getTLI()->getTruncStoreAction(LT.second, MemVT);

llvm/test/Analysis/CostModel/RISCV/rvv-load-store.ll

 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %46 = load <32 x i64>, ptr %p, align 256
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %47 = load <vscale x 1 x i64>, ptr %p, align 8
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %48 = load <vscale x 2 x i64>, ptr %p, align 16
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %49 = load <vscale x 4 x i64>, ptr %p, align 32
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %50 = load <vscale x 8 x i64>, ptr %p, align 64
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %51 = load <vscale x 16 x i64>, ptr %p, align 128
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 4 for instruction: %52 = load <vscale x 32 x i64>, ptr %p, align 256
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %53 = load ptr, ptr %p, align 8
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %54 = load <1 x ptr>, ptr %p, align 8
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %55 = load <2 x ptr>, ptr %p, align 16
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %54 = load <1 x ptr>, ptr %p, align 8
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %55 = load <2 x ptr>, ptr %p, align 16
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %56 = load <4 x ptr>, ptr %p, align 32
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 4 for instruction: %57 = load <8 x ptr>, ptr %p, align 64
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 8 for instruction: %58 = load <16 x ptr>, ptr %p, align 128
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: %59 = load <32 x ptr>, ptr %p, align 256
-; CHECK-NEXT:  Cost Model: Invalid cost for instruction: %60 = load <vscale x 1 x ptr>, ptr %p, align 8
-; CHECK-NEXT:  Cost Model: Invalid cost for instruction: %61 = load <vscale x 2 x ptr>, ptr %p, align 16
-; CHECK-NEXT:  Cost Model: Invalid cost for instruction: %62 = load <vscale x 4 x ptr>, ptr %p, align 32
-; CHECK-NEXT:  Cost Model: Invalid cost for instruction: %63 = load <vscale x 8 x ptr>, ptr %p, align 64
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %60 = load <vscale x 1 x ptr>, ptr %p, align 8
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %61 = load <vscale x 2 x ptr>, ptr %p, align 16
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %62 = load <vscale x 4 x ptr>, ptr %p, align 32
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %63 = load <vscale x 8 x ptr>, ptr %p, align 64
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %64 = load <vscale x 16 x ptr>, ptr %p, align 128
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 4 for instruction: %65 = load <vscale x 32 x ptr>, ptr %p, align 256
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret void
 ;
   load i8, ptr %p
   load <1 x i8>, ptr %p
   load <2 x i8>, ptr %p
   load <4 x i8>, ptr %p

 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: store <32 x i64> undef, ptr %p, align 256
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store <vscale x 1 x i64> undef, ptr %p, align 8
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store <vscale x 2 x i64> undef, ptr %p, align 16
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store <vscale x 4 x i64> undef, ptr %p, align 32
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store <vscale x 8 x i64> undef, ptr %p, align 64
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: store <vscale x 16 x i64> undef, ptr %p, align 128
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 4 for instruction: store <vscale x 32 x i64> undef, ptr %p, align 256
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store ptr undef, ptr %p, align 8
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: store <1 x ptr> undef, ptr %p, align 8
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: store <2 x ptr> undef, ptr %p, align 16
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 6 for instruction: store <4 x ptr> undef, ptr %p, align 32
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 12 for instruction: store <8 x ptr> undef, ptr %p, align 64
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 24 for instruction: store <16 x ptr> undef, ptr %p, align 128
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 48 for instruction: store <32 x ptr> undef, ptr %p, align 256
-; CHECK-NEXT:  Cost Model: Invalid cost for instruction: store <vscale x 1 x ptr> undef, ptr %p, align 8
-; CHECK-NEXT:  Cost Model: Invalid cost for instruction: store <vscale x 2 x ptr> undef, ptr %p, align 16
-; CHECK-NEXT:  Cost Model: Invalid cost for instruction: store <vscale x 4 x ptr> undef, ptr %p, align 32
-; CHECK-NEXT:  Cost Model: Invalid cost for instruction: store <vscale x 8 x ptr> undef, ptr %p, align 64
-; CHECK-NEXT:  Cost Model: Invalid cost for instruction: store <vscale x 16 x ptr> undef, ptr %p, align 128
-; CHECK-NEXT:  Cost Model: Invalid cost for instruction: store <vscale x 32 x ptr> undef, ptr %p, align 256
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store <1 x ptr> undef, ptr %p, align 8
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store <2 x ptr> undef, ptr %p, align 16
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: store <4 x ptr> undef, ptr %p, align 32
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 4 for instruction: store <8 x ptr> undef, ptr %p, align 64
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 8 for instruction: store <16 x ptr> undef, ptr %p, align 128
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 16 for instruction: store <32 x ptr> undef, ptr %p, align 256
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store <vscale x 1 x ptr> undef, ptr %p, align 8
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store <vscale x 2 x ptr> undef, ptr %p, align 16
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store <vscale x 4 x ptr> undef, ptr %p, align 32
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: store <vscale x 8 x ptr> undef, ptr %p, align 64
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: store <vscale x 16 x ptr> undef, ptr %p, align 128
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 4 for instruction: store <vscale x 32 x ptr> undef, ptr %p, align 256
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret void
 ;
   store i8 undef, ptr %p
   store <1 x i8> undef, ptr %p
   store <2 x i8> undef, ptr %p
   store <4 x i8> undef, ptr %p
   store <8 x i8> undef, ptr %p
   store <16 x i8> undef, ptr %p