• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 //===-- ubsan_value.cc ----------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // Representation of a runtime value, as marshaled from the generated code to
11 // the ubsan runtime.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "ubsan_value.h"
16 
17 using namespace __ubsan;
18 
getSIntValue() const19 SIntMax Value::getSIntValue() const {
20   CHECK(getType().isSignedIntegerTy());
21   if (isInlineInt()) {
22     // Val was zero-extended to ValueHandle. Sign-extend from original width
23     // to SIntMax.
24     const unsigned ExtraBits =
25       sizeof(SIntMax) * 8 - getType().getIntegerBitWidth();
26     return SIntMax(Val) << ExtraBits >> ExtraBits;
27   }
28   if (getType().getIntegerBitWidth() == 64)
29     return *reinterpret_cast<s64*>(Val);
30 #if HAVE_INT128_T
31   if (getType().getIntegerBitWidth() == 128)
32     return *reinterpret_cast<s128*>(Val);
33 #else
34   if (getType().getIntegerBitWidth() == 128)
35     UNREACHABLE("libclang_rt.ubsan was built without __int128 support");
36 #endif
37   UNREACHABLE("unexpected bit width");
38 }
39 
getUIntValue() const40 UIntMax Value::getUIntValue() const {
41   CHECK(getType().isUnsignedIntegerTy());
42   if (isInlineInt())
43     return Val;
44   if (getType().getIntegerBitWidth() == 64)
45     return *reinterpret_cast<u64*>(Val);
46 #if HAVE_INT128_T
47   if (getType().getIntegerBitWidth() == 128)
48     return *reinterpret_cast<u128*>(Val);
49 #else
50   if (getType().getIntegerBitWidth() == 128)
51     UNREACHABLE("libclang_rt.ubsan was built without __int128 support");
52 #endif
53   UNREACHABLE("unexpected bit width");
54 }
55 
getPositiveIntValue() const56 UIntMax Value::getPositiveIntValue() const {
57   if (getType().isUnsignedIntegerTy())
58     return getUIntValue();
59   SIntMax Val = getSIntValue();
60   CHECK(Val >= 0);
61   return Val;
62 }
63 
64 /// Get the floating-point value of this object, extended to a long double.
65 /// These are always passed by address (our calling convention doesn't allow
66 /// them to be passed in floating-point registers, so this has little cost).
getFloatValue() const67 FloatMax Value::getFloatValue() const {
68   CHECK(getType().isFloatTy());
69   switch (getType().getFloatBitWidth()) {
70 #if 0
71   // FIXME: OpenCL / NEON 'half' type. LLVM can't lower the conversion
72   //        from this to 'long double'.
73   case 16: return *reinterpret_cast<__fp16*>(Val);
74 #endif
75   case 32: return *reinterpret_cast<float*>(Val);
76   case 64: return *reinterpret_cast<double*>(Val);
77   case 80: return *reinterpret_cast<long double*>(Val);
78   case 128: return *reinterpret_cast<long double*>(Val);
79   }
80   UNREACHABLE("unexpected floating point bit width");
81 }
82