[llvm-commits] [llvm] r147971 - in /llvm/trunk: include/llvm/GlobalValue.h lib/Transforms/IPO/ConstantMerge.cpp
Eli Friedman
eli.friedman at gmail.com
Wed Jan 11 14:06:46 PST 2012
Author: efriedma
Date: Wed Jan 11 16:06:46 2012
New Revision: 147971
URL: http://llvm.org/viewvc/llvm-project?rev=147971&view=rev
Log:
Re-fix the issue Bill fixed in r147899 in a slightly different way, which doesn't abuse the semantics of linker_private. We don't really want to merge any string constant with a weak_odr global.
Modified:
llvm/trunk/include/llvm/GlobalValue.h
llvm/trunk/lib/Transforms/IPO/ConstantMerge.cpp
Modified: llvm/trunk/include/llvm/GlobalValue.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/GlobalValue.h?rev=147971&r1=147970&r2=147971&view=diff
==============================================================================
--- llvm/trunk/include/llvm/GlobalValue.h (original)
+++ llvm/trunk/include/llvm/GlobalValue.h Wed Jan 11 16:06:46 2012
@@ -192,14 +192,6 @@
Linkage == LinkerPrivateWeakDefAutoLinkage;
}
- /// mayBeRemovedByLinker - Whether the definition of this global may be
- /// removed at link time.
- static bool mayBeRemovedByLinker(LinkageTypes Linkage) {
- return isLinkerPrivateLinkage(Linkage) ||
- isLinkerPrivateWeakLinkage(Linkage) ||
- isLinkerPrivateWeakDefAutoLinkage(Linkage);
- }
-
bool hasExternalLinkage() const { return isExternalLinkage(Linkage); }
bool hasAvailableExternallyLinkage() const {
return isAvailableExternallyLinkage(Linkage);
@@ -233,8 +225,6 @@
bool isWeakForLinker() const { return isWeakForLinker(Linkage); }
- bool mayBeRemovedByLinker() const { return mayBeRemovedByLinker(Linkage); }
-
/// copyAttributesFrom - copy all additional attributes (those not needed to
/// create a GlobalValue) from the GlobalValue Src to this one.
virtual void copyAttributesFrom(const GlobalValue *Src);
Modified: llvm/trunk/lib/Transforms/IPO/ConstantMerge.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/ConstantMerge.cpp?rev=147971&r1=147970&r2=147971&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/ConstantMerge.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/ConstantMerge.cpp Wed Jan 11 16:06:46 2012
@@ -140,8 +140,11 @@
UsedGlobals.count(GV))
continue;
- // Ignore any constants which may be removed by the linker.
- if (GV->mayBeRemovedByLinker())
+ // This transformation is legal for weak ODR globals in the sense it
+ // doesn't change semantics, but we really don't want to perform it
+ // anyway; it's likely to pessimize code generation, and some tools
+ // (like the Darwin linker in cases involving CFString) don't expect it.
+ if (GV->isWeakForLinker())
continue;
Constant *Init = GV->getInitializer();
@@ -172,9 +175,8 @@
UsedGlobals.count(GV))
continue;
- // We can only replace constants with local linkage and which aren't
- // removed by the linker.
- if (!GV->hasLocalLinkage() || GV->mayBeRemovedByLinker())
+ // We can only replace constant with local linkage.
+ if (!GV->hasLocalLinkage())
continue;
Constant *Init = GV->getInitializer();
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