[llvm-commits] [llvm] r93844 - in /llvm/trunk: lib/Target/TargetLoweringObjectFile.cpp lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp test/CodeGen/X86/global-sections.ll

[Chris Lattner]

Author: lattner
Date: Mon Jan 18 21:06:01 2010
New Revision: 93844

URL: http://llvm.org/viewvc/llvm-project?rev=93844&view=rev
Log:
fix a significant difference between llvm and gcc on ELF systems:
GCC would put weak zero initialized mutable data in the .bss section,
we would put it into a crasy '.gnu.linkonce.b.test,"aw", at nobits' 
section.  Fixing this will allow simplifications next up.

Modified:
    llvm/trunk/lib/Target/TargetLoweringObjectFile.cpp
    llvm/trunk/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
    llvm/trunk/test/CodeGen/X86/global-sections.ll

Modified: llvm/trunk/lib/Target/TargetLoweringObjectFile.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/TargetLoweringObjectFile.cpp?rev=93844&r1=93843&r2=93844&view=diff

==============================================================================
--- llvm/trunk/lib/Target/TargetLoweringObjectFile.cpp (original)
+++ llvm/trunk/lib/Target/TargetLoweringObjectFile.cpp Mon Jan 18 21:06:01 2010
@@ -565,7 +565,6 @@
   if (Kind.isThreadData())           return ".gnu.linkonce.td.";
   if (Kind.isThreadBSS())            return ".gnu.linkonce.tb.";
 
-  if (Kind.isBSS())                  return ".gnu.linkonce.b.";
   if (Kind.isDataNoRel())            return ".gnu.linkonce.d.";
   if (Kind.isDataRelLocal())         return ".gnu.linkonce.d.rel.local.";
   if (Kind.isDataRel())              return ".gnu.linkonce.d.rel.";
@@ -581,7 +580,7 @@
 
   // If this global is linkonce/weak and the target handles this by emitting it
   // into a 'uniqued' section name, create and return the section now.
-  if (GV->isWeakForLinker() && !Kind.isCommon()) {
+  if (GV->isWeakForLinker() && !Kind.isCommon() && !Kind.isBSS()) {
     const char *Prefix = getSectionPrefixForUniqueGlobal(Kind);
     SmallString<128> Name;
     Name.append(Prefix, Prefix+strlen(Prefix));
@@ -634,6 +633,9 @@
   if (Kind.isThreadData())           return TLSDataSection;
   if (Kind.isThreadBSS())            return TLSBSSSection;
 
+  // Note: we claim that common symbols are put in BSSSection, but they are
+  // really emitted with the magic .comm directive, which creates a symbol table
+  // entry but not a section.
   if (Kind.isBSS() || Kind.isCommon()) return BSSSection;
 
   if (Kind.isDataNoRel())            return DataSection;

Modified: llvm/trunk/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp?rev=93844&r1=93843&r2=93844&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/X86/AsmPrinter/X86AsmPrinter.cpp Mon Jan 18 21:06:01 2010
@@ -718,7 +718,7 @@
       // Don't put things that should go in the cstring section into "comm".
       !TheSection->getKind().isMergeableCString() &&
       !GVar->isThreadLocal() &&
-      (GVar->hasLocalLinkage() || GVar->isWeakForLinker())) {
+      (GVar->hasLocalLinkage())) {
     if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 
     if (const char *LComm = MAI->getLCOMMDirective()) {

Modified: llvm/trunk/test/CodeGen/X86/global-sections.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/global-sections.ll?rev=93844&r1=93843&r2=93844&view=diff

==============================================================================
--- llvm/trunk/test/CodeGen/X86/global-sections.ll (original)
+++ llvm/trunk/test/CodeGen/X86/global-sections.ll Mon Jan 18 21:06:01 2010
@@ -119,4 +119,19 @@
 ; LINUX:G9
 
 
+ at G10 = weak global [100 x i32] zeroinitializer, align 32 ; <[100 x i32]*> [#uses=0]
+
+
+; DARWIN: 	.section	__DATA,__datacoal_nt,coalesced
+; DARWIN: .globl _G10
+; DARWIN:	.weak_definition _G10
+; DARWIN:	.align	5
+; DARWIN: _G10:
+; DARWIN:	.space	400
+
+; LINUX:	.bss
+; LINUX:	.weak	G10
+; LINUX:	.align	32
+; LINUX: G10:
+; LINUX:	.zero	400