1 //===- SSAContext.cpp -------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 /// \file
9 ///
10 /// This file defines a specialization of the GenericSSAContext<X>
11 /// template class for LLVM IR.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/IR/SSAContext.h"
16 #include "llvm/IR/Argument.h"
17 #include "llvm/IR/BasicBlock.h"
18 #include "llvm/IR/Function.h"
19 #include "llvm/IR/Instruction.h"
20 #include "llvm/IR/Instructions.h"
21 #include "llvm/Support/raw_ostream.h"
22 
23 using namespace llvm;
24 
25 Value *SSAContext::ValueRefNull = nullptr;
26 
27 void SSAContext::setFunction(Function &Fn) { F = &Fn; }
28 
29 BasicBlock *SSAContext::getEntryBlock(Function &F) {
30   return &F.getEntryBlock();
31 }
32 
33 const BasicBlock *SSAContext::getEntryBlock(const Function &F) {
34   return &F.getEntryBlock();
35 }
36 
37 void SSAContext::appendBlockDefs(SmallVectorImpl<Value *> &defs,
38                                  BasicBlock &block) {
39   for (auto &instr : block.instructionsWithoutDebug(/*SkipPseudoOp=*/true)) {
40     if (instr.isTerminator())
41       break;
42     if (instr.getType()->isVoidTy())
43       continue;
44     auto *def = &instr;
45     defs.push_back(def);
46   }
47 }
48 
49 void SSAContext::appendBlockDefs(SmallVectorImpl<const Value *> &defs,
50                                  const BasicBlock &block) {
51   for (auto &instr : block) {
52     if (instr.isTerminator())
53       break;
54     defs.push_back(&instr);
55   }
56 }
57 
58 void SSAContext::appendBlockTerms(SmallVectorImpl<Instruction *> &terms,
59                                   BasicBlock &block) {
60   terms.push_back(block.getTerminator());
61 }
62 
63 void SSAContext::appendBlockTerms(SmallVectorImpl<const Instruction *> &terms,
64                                   const BasicBlock &block) {
65   terms.push_back(block.getTerminator());
66 }
67 
68 const BasicBlock *SSAContext::getDefBlock(const Value *value) const {
69   if (const auto *instruction = dyn_cast<Instruction>(value))
70     return instruction->getParent();
71   return nullptr;
72 }
73 
74 bool SSAContext::comesBefore(const Instruction *lhs, const Instruction *rhs) {
75   return lhs->comesBefore(rhs);
76 }
77 
78 bool SSAContext::isConstantValuePhi(const Instruction &Instr) {
79   if (auto *Phi = dyn_cast<PHINode>(&Instr))
80     return Phi->hasConstantValue();
81   return false;
82 }
83 
84 Printable SSAContext::print(const Value *V) const {
85   return Printable([V](raw_ostream &Out) { V->print(Out); });
86 }
87 
88 Printable SSAContext::print(const Instruction *Inst) const {
89   return print(cast<Value>(Inst));
90 }
91 
92 Printable SSAContext::print(const BasicBlock *BB) const {
93   if (!BB)
94     return Printable([](raw_ostream &Out) { Out << "<nullptr>"; });
95   if (BB->hasName())
96     return Printable([BB](raw_ostream &Out) { Out << BB->getName(); });
97 
98   return Printable([BB](raw_ostream &Out) {
99     ModuleSlotTracker MST{BB->getParent()->getParent(), false};
100     MST.incorporateFunction(*BB->getParent());
101     Out << MST.getLocalSlot(BB);
102   });
103 }
104