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.startswith("ctlz.") && F->arg_size() == 1) {
45 F->setName(Name + ".old");
46 NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctlz,
47 F->arg_begin()->getType());
50 if (Name.startswith("cttz.") && F->arg_size() == 1) {
51 F->setName(Name + ".old");
52 NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::cttz,
53 F->arg_begin()->getType());
60 // This may not belong here. This function is effectively being overloaded
61 // to both detect an intrinsic which needs upgrading, and to provide the
62 // upgraded form of the intrinsic. We should perhaps have two separate
63 // functions for this.
67 bool llvm::UpgradeIntrinsicFunction(Function *F, Function *&NewFn) {
69 bool Upgraded = UpgradeIntrinsicFunction1(F, NewFn);
71 // Upgrade intrinsic attributes. This does not change the function.
74 if (unsigned id = F->getIntrinsicID())
75 F->setAttributes(Intrinsic::getAttributes((Intrinsic::ID)id));
79 bool llvm::UpgradeGlobalVariable(GlobalVariable *GV) {
84 // UpgradeIntrinsicCall - Upgrade a call to an old intrinsic to be a call the
85 // upgraded intrinsic. All argument and return casting must be provided in
86 // order to seamlessly integrate with existing context.
87 void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
88 assert(CI->getCalledFunction() && "Intrinsic call is not direct?");
91 LLVMContext &C = CI->getContext();
92 IRBuilder<> Builder(C);
93 Builder.SetInsertPoint(CI->getParent(), CI);
95 switch (NewFn->getIntrinsicID()) {
97 llvm_unreachable("Unknown function for CallInst upgrade.");
100 case Intrinsic::cttz:
101 assert(CI->getNumArgOperands() == 1 &&
102 "Mismatch between function args and call args");
103 StringRef Name = CI->getName();
104 CI->setName(Name + ".old");
105 CI->replaceAllUsesWith(Builder.CreateCall2(NewFn, CI->getArgOperand(0),
106 Builder.getFalse(), Name));
107 CI->eraseFromParent();
112 // This tests each Function to determine if it needs upgrading. When we find
113 // one we are interested in, we then upgrade all calls to reflect the new
115 void llvm::UpgradeCallsToIntrinsic(Function* F) {
116 assert(F && "Illegal attempt to upgrade a non-existent intrinsic.");
118 // Upgrade the function and check if it is a totaly new function.
120 if (UpgradeIntrinsicFunction(F, NewFn)) {
122 // Replace all uses to the old function with the new one if necessary.
123 for (Value::use_iterator UI = F->use_begin(), UE = F->use_end();
125 if (CallInst *CI = dyn_cast<CallInst>(*UI++))
126 UpgradeIntrinsicCall(CI, NewFn);
128 // Remove old function, no longer used, from the module.
129 F->eraseFromParent();