1 //===-- AutoUpgrade.cpp - Implement auto-upgrade helper functions ---------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the auto-upgrade helper functions
12 //===----------------------------------------------------------------------===//
14 #include "llvm/AutoUpgrade.h"
15 #include "llvm/Constants.h"
16 #include "llvm/Function.h"
17 #include "llvm/Instruction.h"
18 #include "llvm/LLVMContext.h"
19 #include "llvm/Module.h"
20 #include "llvm/IntrinsicInst.h"
21 #include "llvm/ADT/DenseMap.h"
22 #include "llvm/ADT/SmallPtrSet.h"
23 #include "llvm/ADT/SmallVector.h"
24 #include "llvm/Support/CallSite.h"
25 #include "llvm/Support/CFG.h"
26 #include "llvm/Support/ErrorHandling.h"
27 #include "llvm/Support/IRBuilder.h"
32 static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
33 assert(F && "Illegal to upgrade a non-existent Function.");
35 // Quickly eliminate it, if it's not a candidate.
36 StringRef Name = F->getName();
37 if (Name.size() <= 8 || !Name.startswith("llvm."))
39 Name = Name.substr(5); // Strip off "llvm."
44 if (Name == "memory.barrier")
49 // This may not belong here. This function is effectively being overloaded
50 // to both detect an intrinsic which needs upgrading, and to provide the
51 // upgraded form of the intrinsic. We should perhaps have two separate
52 // functions for this.
56 bool llvm::UpgradeIntrinsicFunction(Function *F, Function *&NewFn) {
58 bool Upgraded = UpgradeIntrinsicFunction1(F, NewFn);
60 // Upgrade intrinsic attributes. This does not change the function.
63 if (unsigned id = F->getIntrinsicID())
64 F->setAttributes(Intrinsic::getAttributes((Intrinsic::ID)id));
68 bool llvm::UpgradeGlobalVariable(GlobalVariable *GV) {
73 // UpgradeIntrinsicCall - Upgrade a call to an old intrinsic to be a call the
74 // upgraded intrinsic. All argument and return casting must be provided in
75 // order to seamlessly integrate with existing context.
76 void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
77 Function *F = CI->getCalledFunction();
78 LLVMContext &C = CI->getContext();
79 ImmutableCallSite CS(CI);
81 assert(F && "CallInst has no function associated with it.");
84 if (F->getName() == "llvm.memory.barrier") {
85 IRBuilder<> Builder(C);
86 Builder.SetInsertPoint(CI->getParent(), CI);
88 // Note that this conversion ignores the "device" bit; it was not really
89 // well-defined, and got abused because nobody paid enough attention to
90 // get it right. In practice, this probably doesn't matter; application
91 // code generally doesn't need anything stronger than
92 // SequentiallyConsistent (and realistically, SequentiallyConsistent
93 // is lowered to a strong enough barrier for almost anything).
95 if (cast<ConstantInt>(CI->getArgOperand(1))->getZExtValue())
96 Builder.CreateFence(SequentiallyConsistent);
97 else if (!cast<ConstantInt>(CI->getArgOperand(0))->getZExtValue())
98 Builder.CreateFence(Release);
99 else if (!cast<ConstantInt>(CI->getArgOperand(3))->getZExtValue())
100 Builder.CreateFence(Acquire);
102 Builder.CreateFence(AcquireRelease);
105 CI->eraseFromParent();
107 llvm_unreachable("Unknown function for CallInst upgrade.");
113 // This tests each Function to determine if it needs upgrading. When we find
114 // one we are interested in, we then upgrade all calls to reflect the new
116 void llvm::UpgradeCallsToIntrinsic(Function* F) {
117 assert(F && "Illegal attempt to upgrade a non-existent intrinsic.");
119 // Upgrade the function and check if it is a totaly new function.
121 if (UpgradeIntrinsicFunction(F, NewFn)) {
123 // Replace all uses to the old function with the new one if necessary.
124 for (Value::use_iterator UI = F->use_begin(), UE = F->use_end();
126 if (CallInst *CI = dyn_cast<CallInst>(*UI++))
127 UpgradeIntrinsicCall(CI, NewFn);
129 // Remove old function, no longer used, from the module.
130 F->eraseFromParent();