Finally fix (the right way) the problem where functions like this:
void foo() {
G = 1;
}
would have an empty DSGraph even though G (a global) is directly used
in the function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20619 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/EquivClassGraphs.cpp b/lib/Analysis/DataStructure/EquivClassGraphs.cpp
index daefb67..2ddc684 100644
--- a/lib/Analysis/DataStructure/EquivClassGraphs.cpp
+++ b/lib/Analysis/DataStructure/EquivClassGraphs.cpp
@@ -16,6 +16,7 @@
#define DEBUG_TYPE "ECGraphs"
#include "llvm/Analysis/DataStructure/EquivClassGraphs.h"
+#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
#include "llvm/Analysis/DataStructure/DSGraph.h"
@@ -123,6 +124,29 @@
DSGraph::IgnoreGlobals);
}
+ // Final processing. Note that dead node elimination may actually remove
+ // globals from a function graph that are immediately used. If there are no
+ // scalars pointing to the node (e.g. because the only use is a direct store
+ // to a scalar global) we have to make sure to rematerialize the globals back
+ // into the graphs here, or clients will break!
+ for (Module::global_iterator GI = M.global_begin(), E = M.global_end();
+ GI != E; ++GI)
+ // This only happens to first class typed globals.
+ if (GI->getType()->getElementType()->isFirstClassType())
+ for (Value::use_iterator UI = GI->use_begin(), E = GI->use_end();
+ UI != E; ++UI)
+ // This only happens to direct uses by instructions.
+ if (Instruction *User = dyn_cast<Instruction>(*UI)) {
+ DSGraph &DSG = getOrCreateGraph(*User->getParent()->getParent());
+ if (!DSG.getScalarMap().count(GI)) {
+ // If this global does not exist in the graph, but it is immediately
+ // used by an instruction in the graph, clone it over from the
+ // globals graph.
+ ReachabilityCloner RC(DSG, *GlobalsGraph, 0);
+ RC.getClonedNH(GlobalsGraph->getNodeForValue(GI));
+ }
+ }
+
return false;
}