Initial patch for x32 ABI support.

Add the x32 environment kind to the triple, and separate the concept of
pointer size and callee save stack slot size, since they're not equal
on x32.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173175 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 34 insertions, 5 deletions

diff --git a/include/llvm/ADT/Triple.h b/include/llvm/ADT/Triple.h
index 49d9f68404..7968a129cc 100644
--- a/include/llvm/ADT/Triple.h
+++ b/include/llvm/ADT/Triple.h
@@ -111,6 +111,7 @@ public:
     GNU,
     GNUEABI,
     GNUEABIHF,
+    GNUX32,
     EABI,
     MachO,
     Android,
diff --git a/include/llvm/MC/MCAsmInfo.h b/include/llvm/MC/MCAsmInfo.h
index 97114bb034..7474ac8d0f 100644
--- a/include/llvm/MC/MCAsmInfo.h
+++ b/include/llvm/MC/MCAsmInfo.h
@@ -48,6 +48,11 @@ namespace llvm {
     ///               Default is 4.
     unsigned PointerSize;
 
+    /// CalleeSaveStackSlotSize - Size of the stack slot reserved for
+    ///                           callee-saved registers, in bytes.
+    ///                           Default is same as pointer size.
+    unsigned CalleeSaveStackSlotSize;
+
     /// IsLittleEndian - True if target is little endian.
     ///                  Default is true.
     bool IsLittleEndian;
@@ -343,7 +348,18 @@ namespace llvm {
       return PointerSize;
     }
 
-    /// islittleendian - True if the target is little endian.
+    /// getCalleeSaveStackSlotSize - Get the callee-saved register stack slot
+    /// size in bytes.
+    unsigned getCalleeSaveStackSlotSize() const {
+      // If a target doesn't explicitly initialize this member, PointerSize is
+      // used by default.
+      if (CalleeSaveStackSlotSize == 0)
+        return PointerSize;
+      else
+        return CalleeSaveStackSlotSize;
+    }
+
+    /// isLittleEndian - True if the target is little endian.
     bool isLittleEndian() const {
       return IsLittleEndian;
     }
diff --git a/lib/MC/MCAsmInfo.cpp b/lib/MC/MCAsmInfo.cpp
index a6fa6582ab..de1095bf8a 100644
--- a/lib/MC/MCAsmInfo.cpp
+++ b/lib/MC/MCAsmInfo.cpp
@@ -24,6 +24,8 @@ using namespace llvm;
 
 MCAsmInfo::MCAsmInfo() {
   PointerSize = 4;
+  CalleeSaveStackSlotSize = 0; // 0 means PointerSize is used in getter.
+
   IsLittleEndian = true;
   StackGrowsUp = false;
   HasSubsectionsViaSymbols = false;
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index 74851ce140..3cf47bc6c5 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -792,7 +792,7 @@ void MCGenDwarfLabelEntry::Make(MCSymbol *Symbol, MCStreamer *MCOS,
 static int getDataAlignmentFactor(MCStreamer &streamer) {
   MCContext &context = streamer.getContext();
   const MCAsmInfo &asmInfo = context.getAsmInfo();
-  int size = asmInfo.getPointerSize();
+  int size = asmInfo.getCalleeSaveStackSlotSize();
   if (asmInfo.isStackGrowthDirectionUp())
     return size;
   else
diff --git a/lib/Support/Triple.cpp b/lib/Support/Triple.cpp
index eefb96bfee..ad7b18942e 100644
--- a/lib/Support/Triple.cpp
+++ b/lib/Support/Triple.cpp
@@ -140,6 +140,7 @@ const char *Triple::getEnvironmentTypeName(EnvironmentType Kind) {
   case GNU: return "gnu";
   case GNUEABIHF: return "gnueabihf";
   case GNUEABI: return "gnueabi";
+  case GNUX32: return "gnux32";
   case EABI: return "eabi";
   case MachO: return "macho";
   case Android: return "android";
@@ -284,6 +285,7 @@ static Triple::EnvironmentType parseEnvironment(StringRef EnvironmentName) {
     .StartsWith("eabi", Triple::EABI)
     .StartsWith("gnueabihf", Triple::GNUEABIHF)
     .StartsWith("gnueabi", Triple::GNUEABI)
+    .StartsWith("gnux32", Triple::GNUX32)
     .StartsWith("gnu", Triple::GNU)
     .StartsWith("macho", Triple::MachO)
     .StartsWith("android", Triple::Android)
diff --git a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
index 16488eb7ae..7815ae98c9 100644
--- a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
@@ -44,7 +44,7 @@ void X86MCAsmInfoDarwin::anchor() { }
 X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T) {
   bool is64Bit = T.getArch() == Triple::x86_64;
   if (is64Bit)
-    PointerSize = 8;
+    PointerSize = CalleeSaveStackSlotSize = 8;
 
   AssemblerDialect = AsmWriterFlavor;
 
@@ -76,8 +76,16 @@ X86_64MCAsmInfoDarwin::X86_64MCAsmInfoDarwin(const Triple &Triple)
 void X86ELFMCAsmInfo::anchor() { }
 
 X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
-  if (T.getArch() == Triple::x86_64)
-    PointerSize = 8;
+  bool is64Bit = T.getArch() == Triple::x86_64;
+  bool isX32 = T.getEnvironment() == Triple::GNUX32;
+
+  // For ELF, x86-64 pointer size depends on the ABI.
+  // For x86-64 without the x32 ABI, pointer size is 8. For x86 and for x86-64
+  // with the x32 ABI, pointer size remains the default 4.
+  PointerSize = (is64Bit && !isX32) ? 8 : 4;
+
+  // OTOH, stack slot size is always 8 for x86-64, even with the x32 ABI.
+  CalleeSaveStackSlotSize = is64Bit ? 8 : 4;
 
   AssemblerDialect = AsmWriterFlavor;