1 //===-- InstrinsicInst.cpp - Intrinsic Instruction Wrappers ---------------===//
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 // This file implements methods that make it really easy to deal with intrinsic
11 // functions.
12 //
13 // All intrinsic function calls are instances of the call instruction, so these
14 // are all subclasses of the CallInst class. Note that none of these classes
15 // has state or virtual methods, which is an important part of this gross/neat
16 // hack working.
17 //
18 // In some cases, arguments to intrinsics need to be generic and are defined as
19 // type pointer to empty struct { }*. To access the real item of interest the
20 // cast instruction needs to be stripped away.
21 //
22 //===----------------------------------------------------------------------===//
23
24 #include "llvm/IR/IntrinsicInst.h"
25 #include "llvm/IR/Constants.h"
26 #include "llvm/IR/GlobalVariable.h"
27 #include "llvm/IR/Metadata.h"
28 #include "llvm/Support/raw_ostream.h"
29 using namespace llvm;
30
31 //===----------------------------------------------------------------------===//
32 /// DbgInfoIntrinsic - This is the common base class for debug info intrinsics
33 ///
34
getVariableLocation(bool AllowNullOp) const35 Value *DbgInfoIntrinsic::getVariableLocation(bool AllowNullOp) const {
36 Value *Op = getArgOperand(0);
37 if (AllowNullOp && !Op)
38 return nullptr;
39
40 auto *MD = cast<MetadataAsValue>(Op)->getMetadata();
41 if (auto *V = dyn_cast<ValueAsMetadata>(MD))
42 return V->getValue();
43
44 // When the value goes to null, it gets replaced by an empty MDNode.
45 assert(!cast<MDNode>(MD)->getNumOperands() && "Expected an empty MDNode");
46 return nullptr;
47 }
48
lookupLLVMIntrinsicByName(ArrayRef<const char * > NameTable,StringRef Name)49 int llvm::Intrinsic::lookupLLVMIntrinsicByName(ArrayRef<const char *> NameTable,
50 StringRef Name) {
51 assert(Name.startswith("llvm."));
52
53 // Do successive binary searches of the dotted name components. For
54 // "llvm.gc.experimental.statepoint.p1i8.p1i32", we will find the range of
55 // intrinsics starting with "llvm.gc", then "llvm.gc.experimental", then
56 // "llvm.gc.experimental.statepoint", and then we will stop as the range is
57 // size 1. During the search, we can skip the prefix that we already know is
58 // identical. By using strncmp we consider names with differing suffixes to
59 // be part of the equal range.
60 size_t CmpStart = 0;
61 size_t CmpEnd = 4; // Skip the "llvm" component.
62 const char *const *Low = NameTable.begin();
63 const char *const *High = NameTable.end();
64 const char *const *LastLow = Low;
65 while (CmpEnd < Name.size() && High - Low > 0) {
66 CmpStart = CmpEnd;
67 CmpEnd = Name.find('.', CmpStart + 1);
68 CmpEnd = CmpEnd == StringRef::npos ? Name.size() : CmpEnd;
69 auto Cmp = [CmpStart, CmpEnd](const char *LHS, const char *RHS) {
70 return strncmp(LHS + CmpStart, RHS + CmpStart, CmpEnd - CmpStart) < 0;
71 };
72 LastLow = Low;
73 std::tie(Low, High) = std::equal_range(Low, High, Name.data(), Cmp);
74 }
75 if (High - Low > 0)
76 LastLow = Low;
77
78 if (LastLow == NameTable.end())
79 return -1;
80 StringRef NameFound = *LastLow;
81 if (Name == NameFound ||
82 (Name.startswith(NameFound) && Name[NameFound.size()] == '.'))
83 return LastLow - NameTable.begin();
84 return -1;
85 }
86