[SelectionDAGBuilder] Update signature of getRegsAndSizes().

The mapping between registers and relative size has been updated to
use TypeSize to account for the size of scalable EVTs.

The patch is a NFCI, if not for the fact that with this change the
function `getUnderlyingArgRegs` does not raise a warning for implicit
conversion of `TypeSize` to `unsigned` when generating machine code
from the test added to the patch.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D92096

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -980,14 +980,14 @@ void RegsForValue::AddInlineAsmOperands(unsigned Code, bool HasMatching,
   }
 }
 
-SmallVector<std::pair<unsigned, unsigned>, 4>
+SmallVector<std::pair<unsigned, TypeSize>, 4>
 RegsForValue::getRegsAndSizes() const {
-  SmallVector<std::pair<unsigned, unsigned>, 4> OutVec;
+  SmallVector<std::pair<unsigned, TypeSize>, 4> OutVec;
   unsigned I = 0;
   for (auto CountAndVT : zip_first(RegCount, RegVTs)) {
     unsigned RegCount = std::get<0>(CountAndVT);
     MVT RegisterVT = std::get<1>(CountAndVT);
-    unsigned RegisterSize = RegisterVT.getSizeInBits();
+    TypeSize RegisterSize = RegisterVT.getSizeInBits();
     for (unsigned E = I + RegCount; I != E; ++I)
       OutVec.push_back(std::make_pair(Regs[I], RegisterSize));
   }
@@ -5317,7 +5317,7 @@ static SDValue expandDivFix(unsigned Opcode, const SDLoc &DL,
 // getUnderlyingArgRegs - Find underlying registers used for a truncated,
 // bitcasted, or split argument. Returns a list of <Register, size in bits>
 static void
-getUnderlyingArgRegs(SmallVectorImpl<std::pair<unsigned, unsigned>> &Regs,
+getUnderlyingArgRegs(SmallVectorImpl<std::pair<unsigned, TypeSize>> &Regs,
                      const SDValue &N) {
   switch (N.getOpcode()) {
   case ISD::CopyFromReg: {
@@ -5428,7 +5428,7 @@ bool SelectionDAGBuilder::EmitFuncArgumentDbgValue(
   if (FI != std::numeric_limits<int>::max())
     Op = MachineOperand::CreateFI(FI);
 
-  SmallVector<std::pair<unsigned, unsigned>, 8> ArgRegsAndSizes;
+  SmallVector<std::pair<unsigned, TypeSize>, 8> ArgRegsAndSizes;
   if (!Op && N.getNode()) {
     getUnderlyingArgRegs(ArgRegsAndSizes, N);
     Register Reg;
@@ -5458,8 +5458,8 @@ bool SelectionDAGBuilder::EmitFuncArgumentDbgValue(
 
   if (!Op) {
     // Create a DBG_VALUE for each decomposed value in ArgRegs to cover Reg
-    auto splitMultiRegDbgValue
-      = [&](ArrayRef<std::pair<unsigned, unsigned>> SplitRegs) {
+    auto splitMultiRegDbgValue = [&](ArrayRef<std::pair<unsigned, TypeSize>>
+                                         SplitRegs) {
       unsigned Offset = 0;
       for (auto RegAndSize : SplitRegs) {
         // If the expression is already a fragment, the current register

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h

@@ -895,7 +895,7 @@ struct RegsForValue {
   }
 
   /// Return a list of registers and their sizes.
-  SmallVector<std::pair<unsigned, unsigned>, 4> getRegsAndSizes() const;
+  SmallVector<std::pair<unsigned, TypeSize>, 4> getRegsAndSizes() const;
 };
 
 } // end namespace llvm

llvm/test/CodeGen/AArch64/sdag-no-typesize-warnings-regandsizes.ll

@@ -0,0 +1,30 @@
+; RUN: llc -mtriple=aarch64-unknown-linux-gnu -mattr=+sve < %s 2>%t | FileCheck %s
+; RUN: FileCheck --check-prefix=WARN --allow-empty %s <%t
+
+; If this check fails please read
+; clang/test/CodeGen/aarch64-sve-intrinsics/README for instructions on
+; how to resolve it.
+
+; WARN-NOT: warning
+
+; CHECK-LABEL: do_something:
+define <vscale x 2 x double> @do_something(<vscale x 2 x double> %vx) {
+entry:
+  call void @llvm.dbg.value(metadata <vscale x 2 x double> %vx, metadata !3, metadata !DIExpression()), !dbg !5
+  %0 = tail call <vscale x 2 x double> @f(<vscale x 2 x double> %vx)
+  ret <vscale x 2 x double> %0
+}
+
+declare <vscale x 2 x double> @f(<vscale x 2 x double>)
+
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1)
+!1 = !DIFile(filename: "file.c", directory: "/")
+!2 = !{i32 2, !"Debug Info Version", i32 3}
+!3 = !DILocalVariable(scope: !4)
+!4 = distinct !DISubprogram(unit: !0)
+!5 = !DILocation(scope: !4)