[llvm-commits] CVS: llvm/lib/Transforms/IPO/GlobalDCE.cpp

[Anton Korobeynikov]

Changes in directory llvm/lib/Transforms/IPO:

GlobalDCE.cpp updated: 1.42 -> 1.43
---
Log message:

Implement aliases. This fixes PR1017: http://llvm.org/PR1017  and it's dependent bugs. CFE part 
will follow.


---
Diffs of the changes:  (+12 -1)

 GlobalDCE.cpp |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletion(-)


Index: llvm/lib/Transforms/IPO/GlobalDCE.cpp
diff -u llvm/lib/Transforms/IPO/GlobalDCE.cpp:1.42 llvm/lib/Transforms/IPO/GlobalDCE.cpp:1.43
--- llvm/lib/Transforms/IPO/GlobalDCE.cpp:1.42	Mon Feb  5 17:32:05 2007
+++ llvm/lib/Transforms/IPO/GlobalDCE.cpp	Wed Apr 25 09:27:10 2007
@@ -62,7 +62,8 @@
       GlobalIsNeeded(I);
   }
 
-  for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I) {
+  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
+       I != E; ++I) {
     Changed |= RemoveUnusedGlobalValue(*I);
     // Externally visible & appending globals are needed, if they have an
     // initializer.
@@ -72,6 +73,13 @@
   }
 
 
+  for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
+       I != E; ++I) {
+    Changed |= RemoveUnusedGlobalValue(*I);
+    // Aliases are always needed even if they are not used.
+    GlobalIsNeeded(I);
+  }
+
   // Now that all globals which are needed are in the AliveGlobals set, we loop
   // through the program, deleting those which are not alive.
   //
@@ -135,6 +143,9 @@
     // referenced by the initializer to the alive set.
     if (GV->hasInitializer())
       MarkUsedGlobalsAsNeeded(GV->getInitializer());
+  } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(G)) {
+    // If this is a global alias we also need it's aliasee
+    GlobalIsNeeded(const_cast<GlobalValue*>(GA->getAliasee()));
   } else {
     // Otherwise this must be a function object.  We have to scan the body of
     // the function looking for constants and global values which are used as