diff options
| -rw-r--r-- | lib/Transforms/IPO/GlobalDCE.cpp | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/lib/Transforms/IPO/GlobalDCE.cpp b/lib/Transforms/IPO/GlobalDCE.cpp index 2f938079a8..a0614e2bf3 100644 --- a/lib/Transforms/IPO/GlobalDCE.cpp +++ b/lib/Transforms/IPO/GlobalDCE.cpp @@ -6,9 +6,10 @@ //===----------------------------------------------------------------------===// #include "llvm/Transforms/IPO/GlobalDCE.h" -#include "llvm/Analysis/CallGraph.h" #include "llvm/Module.h" #include "llvm/Function.h" +#include "llvm/GlobalVariable.h" +#include "llvm/Analysis/CallGraph.h" #include "Support/DepthFirstIterator.h" static bool RemoveUnreachableFunctions(Module *M, CallGraph &CallGraph) { @@ -45,6 +46,22 @@ static bool RemoveUnreachableFunctions(Module *M, CallGraph &CallGraph) { return true; } +static bool RemoveUnreachableGlobalVariables(Module *M) { + bool Changed = false; + // Eliminate all global variables that are unused, and that are internal, or + // do not have an initializer. + // + for (Module::giterator I = M->gbegin(); I != M->gend(); ) + if (!(*I)->use_empty() || + ((*I)->hasExternalLinkage() && (*I)->hasInitializer())) + ++I; // Cannot eliminate global variable + else { + delete M->getGlobalList().remove(I); + Changed = true; + } + return Changed; +} + namespace { struct GlobalDCE : public Pass { const char *getPassName() const { return "Dead Global Elimination"; } @@ -53,7 +70,8 @@ namespace { // the specified callgraph to reflect the changes. // bool run(Module *M) { - return RemoveUnreachableFunctions(M, getAnalysis<CallGraph>()); + return RemoveUnreachableFunctions(M, getAnalysis<CallGraph>()) | + RemoveUnreachableGlobalVariables(M); } // getAnalysisUsage - This function works on the call graph of a module. |