Remove "JumpTableDataSection" from TAI, instead, have AsmPrinter

compute it based on what it knows.  As part of this, rename getSectionForMergeableConstant
to getSectionForConstant because it works for non-mergable constants also.

The only functionality change from this is that Xcore will start dropping
its jump tables into readonly section instead of data section in -static mode.
This should be fine as the linker resolves the relocations.  If this is a
problem, let me know and we'll come up with another solution.

llvm-svn: 77833

7 files changed, 23 insertions, 25 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 7c9fcf5fd60..f9839ddc68c 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -349,8 +349,7 @@ void AsmPrinter::EmitConstantPool(MachineConstantPool *MCP) {
     }
     }
 
-    const MCSection *S =
-      getObjFileLowering().getSectionForMergeableConstant(Kind);
+    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
     
     // The number of sections are small, just do a linear search from the
     // last section to the first.
@@ -419,22 +418,21 @@ void AsmPrinter::EmitJumpTableInfo(MachineJumpTableInfo *MJTI,
   // the appropriate section.
   TargetLowering *LoweringInfo = TM.getTargetLowering();
 
-  const char *JumpTableDataSection = TAI->getJumpTableDataSection();
   const Function *F = MF.getFunction();
-  
-  const MCSection *FuncSection =
-    getObjFileLowering().SectionForGlobal(F, Mang, TM);
-
   bool JTInDiffSection = false;
-  if ((IsPic && !LoweringInfo->usesGlobalOffsetTable()) ||
-      !JumpTableDataSection || F->isWeakForLinker()) {
+  if (F->isWeakForLinker() ||
+      (IsPic && !LoweringInfo->usesGlobalOffsetTable())) {
     // In PIC mode, we need to emit the jump table to the same section as the
     // function body itself, otherwise the label differences won't make sense.
     // We should also do if the section name is NULL or function is declared in
     // discardable section.
-    SwitchToSection(FuncSection);
+    SwitchToSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
   } else {
-    SwitchToDataSection(JumpTableDataSection);
+    // Otherwise, drop it in the readonly section.
+    const MCSection *ReadOnlySection = 
+      getObjFileLowering().getSectionForConstant(
+                                       SectionKind::get(SectionKind::ReadOnly));
+    SwitchToSection(ReadOnlySection);
     JTInDiffSection = true;
   }
   
diff --git a/llvm/lib/CodeGen/ELFWriter.cpp b/llvm/lib/CodeGen/ELFWriter.cpp
index 1d33c7e1fef..be1e6bfe751 100644
--- a/llvm/lib/CodeGen/ELFWriter.cpp
+++ b/llvm/lib/CodeGen/ELFWriter.cpp
@@ -178,7 +178,13 @@ void ELFWriter::addExternalSymbol(const char *External) {
 // Get jump table section on the section name returned by TAI
 ELFSection &ELFWriter::getJumpTableSection() {
   unsigned Align = TM.getTargetData()->getPointerABIAlignment();
-  return getSection(TAI->getJumpTableDataSection(),
+  
+  const TargetLoweringObjectFile &TLOF =
+    TM.getTargetLowering()->getObjFileLowering();
+
+  return getSection(TLOF.getSectionForConstant(
+                                      SectionKind::get(SectionKind::ReadOnly))
+                    ->getName(),
                     ELFSection::SHT_PROGBITS,
                     ELFSection::SHF_ALLOC, Align);
 }
@@ -204,7 +210,7 @@ ELFSection &ELFWriter::getConstantPoolSection(MachineConstantPoolEntry &CPE) {
   const TargetLoweringObjectFile &TLOF =
     TM.getTargetLowering()->getObjFileLowering();
 
-  return getSection(TLOF.getSectionForMergeableConstant(Kind)->getName(),
+  return getSection(TLOF.getSectionForConstant(Kind)->getName(),
                     ELFSection::SHT_PROGBITS,
                     ELFSection::SHF_MERGE | ELFSection::SHF_ALLOC,
                     CPE.getAlignment());
diff --git a/llvm/lib/Target/DarwinTargetAsmInfo.cpp b/llvm/lib/Target/DarwinTargetAsmInfo.cpp
index 7000b4f023c..cca12c01cb0 100644
--- a/llvm/lib/Target/DarwinTargetAsmInfo.cpp
+++ b/llvm/lib/Target/DarwinTargetAsmInfo.cpp
@@ -49,8 +49,6 @@ DarwinTargetAsmInfo::DarwinTargetAsmInfo(const TargetMachine &TM)
   HiddenDirective = "\t.private_extern ";
     
   // Sections:
-  JumpTableDataSection = "\t.const";
-
   if (TM.getRelocationModel() == Reloc::Static) {
     StaticCtorsSection = ".constructor";
     StaticDtorsSection = ".destructor";
diff --git a/llvm/lib/Target/TargetAsmInfo.cpp b/llvm/lib/Target/TargetAsmInfo.cpp
index 1fb65632959..add1dbf5c37 100644
--- a/llvm/lib/Target/TargetAsmInfo.cpp
+++ b/llvm/lib/Target/TargetAsmInfo.cpp
@@ -69,7 +69,6 @@ TargetAsmInfo::TargetAsmInfo(const TargetMachine &tm) : TM(tm) {
   TextSectionStartSuffix = "";
   DataSectionStartSuffix = "";
   SectionEndDirectiveSuffix = 0;
-  JumpTableDataSection = "\t.section .rodata";
   JumpTableDirective = 0;
   // FIXME: Flags are ELFish - replace with normal section stuff.
   StaticCtorsSection = "\t.section .ctors,\"aw\",@progbits";
diff --git a/llvm/lib/Target/TargetLoweringObjectFile.cpp b/llvm/lib/Target/TargetLoweringObjectFile.cpp
index 84247790f45..7eb9a4a4ebf 100644
--- a/llvm/lib/Target/TargetLoweringObjectFile.cpp
+++ b/llvm/lib/Target/TargetLoweringObjectFile.cpp
@@ -228,12 +228,11 @@ TargetLoweringObjectFile::SelectSectionForGlobal(const GlobalValue *GV,
   return getDataSection();
 }
 
-/// getSectionForMergableConstant - Given a mergable constant with the
+/// getSectionForConstant - Given a mergable constant with the
 /// specified size and relocation information, return a section that it
 /// should be placed in.
 const MCSection *
-TargetLoweringObjectFile::
-getSectionForMergeableConstant(SectionKind Kind) const {
+TargetLoweringObjectFile::getSectionForConstant(SectionKind Kind) const {
   if (Kind.isReadOnly() && ReadOnlySection != 0)
     return ReadOnlySection;
   
@@ -459,11 +458,11 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
   return DataRelROSection;
 }
 
-/// getSectionForMergeableConstant - Given a mergeable constant with the
+/// getSectionForConstant - Given a mergeable constant with the
 /// specified size and relocation information, return a section that it
 /// should be placed in.
 const MCSection *TargetLoweringObjectFileELF::
-getSectionForMergeableConstant(SectionKind Kind) const {
+getSectionForConstant(SectionKind Kind) const {
   if (Kind.isMergeableConst4())
     return MergeableConst4Section;
   if (Kind.isMergeableConst8())
@@ -582,8 +581,7 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
 }
 
 const MCSection *
-TargetLoweringObjectFileMachO::
-getSectionForMergeableConstant(SectionKind Kind) const {
+TargetLoweringObjectFileMachO::getSectionForConstant(SectionKind Kind) const {
   // If this constant requires a relocation, we have to put it in the data
   // segment, not in the text segment.
   if (Kind.isDataRel())
diff --git a/llvm/lib/Target/X86/X86TargetAsmInfo.cpp b/llvm/lib/Target/X86/X86TargetAsmInfo.cpp
index c13d9ac3cee..c30f3378b7b 100644
--- a/llvm/lib/Target/X86/X86TargetAsmInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetAsmInfo.cpp
@@ -228,7 +228,6 @@ X86WinTargetAsmInfo::X86WinTargetAsmInfo(const X86TargetMachine &TM):
 
   AlignmentIsInBytes = true;
 
-  JumpTableDataSection = NULL;
   SwitchToSectionDirective = "";
   TextSectionStartSuffix = "\tSEGMENT PARA 'CODE'";
   DataSectionStartSuffix = "\tSEGMENT PARA 'DATA'";
diff --git a/llvm/lib/Target/XCore/XCoreTargetAsmInfo.cpp b/llvm/lib/Target/XCore/XCoreTargetAsmInfo.cpp
index 33a7eedc743..48502d07f63 100644
--- a/llvm/lib/Target/XCore/XCoreTargetAsmInfo.cpp
+++ b/llvm/lib/Target/XCore/XCoreTargetAsmInfo.cpp
@@ -18,7 +18,7 @@ XCoreTargetAsmInfo::XCoreTargetAsmInfo(const TargetMachine &TM)
   Data64bitsDirective = 0;
   ZeroDirective = "\t.space\t";
   CommentString = "#";
-  JumpTableDataSection = "\t.section\t.dp.data,\"awd\",@progbits";
+    
   PrivateGlobalPrefix = ".L";
   AscizDirective = ".asciiz";
   WeakDefDirective = "\t.weak\t";