[NFC] Fix compiler warnings due to integer comparison of different signedness

[nullptr.cpp]

Summary

Fix by directly using INT_MAX and INT32_MAX.

[nullptr.cpp]

I don't have commit access, can anyone help me commit this and D86997?
Yang Fan <[e-mail]>
Thanks!

[RKSimon]

Couldn't we avoid a lot of this of this casting + template ugliness by just using the <climit> / <cstdint> INT_MAX / INT32_MAX defines?

[nullptr.cpp]

Fix by directly using INT_MAX and INT32_MAX.

[nullptr.cpp]

I don't have commit access, can anyone help me commit this with "Yang Fan <[e-mail]>" ?
Thanks!

[nullptr.cpp]

This comment was removed by nullptr.cpp.

[RKSimon]

LGTM - I'll try to commit this later today

clang/lib/Lex/Pragma.cpp

if (II && II->isStr("push")) {
         }
 
         // Collect the warning ids.
         SmallVector<int, 4> Ids;
         PP.Lex(Tok);
         while (Tok.is(tok::numeric_constant)) {
           uint64_t Value;
           if (!PP.parseSimpleIntegerLiteral(Tok, Value) || Value == 0 ||
-              Value > std::numeric_limits<int>::max()) {
+              Value > static_cast<uint64_t>(std::numeric_limits<int>::max())) {
             PP.Diag(Tok, diag::warn_pragma_warning_expected_number);
             return;
           }
           Ids.push_back(int(Value));
         }
         if (Callbacks)
           Callbacks->PragmaWarning(DiagLoc, Specifier, Ids);
 

llvm/lib/Analysis/VectorUtils.cpp

if (Scale == 1) {
     ScaledMask.assign(Mask.begin(), Mask.end());
     return;
   }
 
   ScaledMask.clear();
   for (int MaskElt : Mask) {
     if (MaskElt >= 0) {
       assert(((uint64_t)Scale * MaskElt + (Scale - 1)) <=
-                 std::numeric_limits<int32_t>::max() &&
+                 static_cast<uint64_t>(std::numeric_limits<int32_t>::max()) &&
              "Overflowed 32-bits");
     }
     for (int SliceElt = 0; SliceElt != Scale; ++SliceElt)
       ScaledMask.push_back(MaskElt < 0 ? MaskElt : Scale * MaskElt + SliceElt);
   }
 }
 
 bool llvm::widenShuffleMaskElts(int Scale, ArrayRef<int> Mask,

llvm/lib/MC/WasmObjectWriter.cpp

uint32_t WasmObjectWriter::writeDataSection(const MCAsmLayout &Layout) {
 
   encodeULEB128(DataSegments.size(), W.OS); // count
 
   for (const WasmDataSegment &Segment : DataSegments) {
     encodeULEB128(Segment.InitFlags, W.OS); // flags
     if (Segment.InitFlags & wasm::WASM_SEGMENT_HAS_MEMINDEX)
       encodeULEB128(0, W.OS); // memory index
     if ((Segment.InitFlags & wasm::WASM_SEGMENT_IS_PASSIVE) == 0) {
-      W.OS << char(Segment.Offset > std::numeric_limits<int32_t>().max()
+      W.OS << char(Segment.Offset > static_cast<uint64_t>(
+                                        std::numeric_limits<int32_t>().max())
                        ? wasm::WASM_OPCODE_I64_CONST
                        : wasm::WASM_OPCODE_I32_CONST);
       encodeSLEB128(Segment.Offset, W.OS); // offset
       W.OS << char(wasm::WASM_OPCODE_END);
     }
     encodeULEB128(Segment.Data.size(), W.OS); // size
     Segment.Section->setSectionOffset(W.OS.tell() - Section.ContentsOffset);
     W.OS << Segment.Data; // data
   }
 

llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp

static Instruction *foldTruncShuffle(ShuffleVectorInst &Shuf,
   // element in the result.
   uint64_t TruncRatio =
       SrcType->getScalarSizeInBits() / DestType->getScalarSizeInBits();
   ArrayRef<int> Mask = Shuf.getShuffleMask();
   for (unsigned i = 0, e = Mask.size(); i != e; ++i) {
     if (Mask[i] == UndefMaskElem)
       continue;
     uint64_t LSBIndex = IsBigEndian ? (i + 1) * TruncRatio - 1 : i * TruncRatio;
-    assert(LSBIndex <= std::numeric_limits<int32_t>::max() &&
+    assert(LSBIndex <=
+               static_cast<uint64_t>(std::numeric_limits<int32_t>::max()) &&
            "Overflowed 32-bits");
     if (Mask[i] != (int)LSBIndex)
       return nullptr;
   }
 
   return new TruncInst(X, DestType);
 }