Subzero: Fix g++ warnings.

src/IceInstARM32.cpp

 //===- subzero/src/IceInstARM32.cpp - ARM32 instruction implementation ----===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 329 matching lines @@
     // named after the bit fields they represent. See "A7.5.1 Operation of
     // modified immediate constants, Floating-point" in the ARM ARM.
     static constexpr uint32_t a = 0x80000000u;
     static constexpr uint32_t B = 0x40000000;
     static constexpr uint32_t bbbbb = 0x3E000000;
     static constexpr uint32_t cdefgh = 0x01F80000;
     static constexpr uint32_t AllowedBits = a | B | bbbbb | cdefgh;
     static_assert(AllowedBits == 0xFFF80000u,
                   "Invalid mask for f32 modified immediates.");
     const float F32 = llvm::cast<ConstantFloat>(C)->getValue();
-    const uint32_t I32 = *reinterpret_cast<const uint32_t *>(&F32);
+    const uint32_t I32 = Utils::bitCopy<uint32_t>(F32);
     if (I32 & ~AllowedBits) {
       // constant has disallowed bits.
       return false;
     }
 
     if ((I32 & bbbbb) != bbbbb && (I32 & bbbbb)) {
       // not all bbbbb bits are 0 or 1.
       return false;
     }
 
     if (((I32 & B) != 0) == ((I32 & bbbbb) != 0)) {
       // B ^ b = 0;
       return false;
     }
 
     *ModifiedImm = ((I32 & a) ? 0x80 : 0x00) | ((I32 & bbbbb) ? 0x40 : 0x00) |
                    ((I32 & cdefgh) >> 19);
     return true;
   }
   case IceType_f64: {
     static constexpr uint32_t a = 0x80000000u;
     static constexpr uint32_t B = 0x40000000;
     static constexpr uint32_t bbbbbbbb = 0x3FC00000;
     static constexpr uint32_t cdefgh = 0x003F0000;
     static constexpr uint32_t AllowedBits = a | B | bbbbbbbb | cdefgh;
     static_assert(AllowedBits == 0xFFFF0000u,
                   "Invalid mask for f64 modified immediates.");
     const double F64 = llvm::cast<ConstantDouble>(C)->getValue();
-    const uint64_t I64 = *reinterpret_cast<const uint64_t *>(&F64);
+    const uint64_t I64 = Utils::bitCopy<uint64_t>(F64);
     if (I64 & 0xFFFFFFFFu) {
       // constant has disallowed bits.
       return false;
     }
     const uint32_t I32 = I64 >> 32;
 
     if (I32 & ~AllowedBits) {
       // constant has disallowed bits.
       return false;
     }
@@ skipping 1703 matching lines @@
 static_assert(AllowedBits == 0xFF,
               "Invalid mask for f32/f64 constant rematerialization.");
 
 // There's no loss in always returning the modified immediate as float.
 // TODO(jpp): returning a double causes problems when outputting the constants
 // for filetype=asm. Why?
 float materializeFloatImmediate(uint32_t ModifiedImm) {
   const uint32_t Ret = ((ModifiedImm & a) ? 0x80000000 : 0) |
                        ((ModifiedImm & b) ? 0x3E000000 : 0x40000000) |
                        ((ModifiedImm & cdefgh) << 19);
-  return *reinterpret_cast<const float *>(&Ret);
+  return Utils::bitCopy<float>(Ret);
 }
 
 } // end of anonymous namespace
 
 void OperandARM32FlexFpImm::emit(const Cfg *Func) const {
   if (!BuildDefs::dump())
     return;
   Ostream &Str = Func->getContext()->getStrEmit();
   switch (Ty) {
   default:
@@ skipping 102 matching lines @@
 
 template class InstARM32FourAddrGPR<InstARM32::Mla>;
 template class InstARM32FourAddrGPR<InstARM32::Mls>;
 
 template class InstARM32CmpLike<InstARM32::Cmn>;
 template class InstARM32CmpLike<InstARM32::Cmp>;
 template class InstARM32CmpLike<InstARM32::Tst>;
 
 } // end of namespace ARM32
 } // end of namespace Ice