PowerPC: Simplify handling of fixups.

MCTargetDesc/PPCMCCodeEmitter.cpp current has code like:

 if (isSVR4ABI() && is64BitMode())
   Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
                                    (MCFixupKind)PPC::fixup_ppc_toc16));
 else
   Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
                                    (MCFixupKind)PPC::fixup_ppc_lo16));

This is a problem for the asm parser, since it requires knowledge of
the ABI / 64-bit mode to be set up.  However, more fundamentally,
at this point we shouldn't make such distinctions anyway; in an assembler
file, it always ought to be possible to e.g. generate TOC relocations even
when the main ABI is one that doesn't use TOC.

Fortunately, this is actually completely unnecessary; that code was added
to decide whether to generate TOC relocations, but that information is in
fact already encoded in the VariantKind of the underlying symbol.

This commit therefore merges those fixup types into one, and then decides
which relocation to use based on the VariantKind.

No changes in generated code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178007 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 19 insertions, 70 deletions

diff --git a/include/llvm/Support/ELF.h b/include/llvm/Support/ELF.h
index cc9151ef50..ea597fc1a2 100644
--- a/include/llvm/Support/ELF.h
+++ b/include/llvm/Support/ELF.h
@@ -480,6 +480,8 @@ enum {
   R_PPC64_TOC16_LO            = 48,
   R_PPC64_TOC16_HA            = 50,
   R_PPC64_TOC                 = 51,
+  R_PPC64_ADDR16_DS           = 56,
+  R_PPC64_ADDR16_LO_DS        = 57,
   R_PPC64_TOC16_DS            = 63,
   R_PPC64_TOC16_LO_DS         = 64,
   R_PPC64_TLS                 = 67,
diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp
index f24edf62ed..ec2657403e 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp
@@ -30,13 +30,9 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
   case FK_Data_2:
   case FK_Data_4:
   case FK_Data_8:
-  case PPC::fixup_ppc_toc:
   case PPC::fixup_ppc_tlsreg:
   case PPC::fixup_ppc_nofixup:
     return Value;
-  case PPC::fixup_ppc_lo14:
-  case PPC::fixup_ppc_toc16_ds:
-    return (Value & 0xffff) << 2;
   case PPC::fixup_ppc_brcond14:
     return Value & 0xfffc;
   case PPC::fixup_ppc_br24:
@@ -48,8 +44,9 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
   case PPC::fixup_ppc_ha16:
     return ((Value >> 16) + ((Value & 0x8000) ? 1 : 0)) & 0xffff;
   case PPC::fixup_ppc_lo16:
-  case PPC::fixup_ppc_toc16:
     return Value & 0xffff;
+  case PPC::fixup_ppc_lo16_ds:
+    return Value & 0xfffc;
   }
 }
 
@@ -82,10 +79,7 @@ public:
       { "fixup_ppc_brcond14",    16,     14,   MCFixupKindInfo::FKF_IsPCRel },
       { "fixup_ppc_lo16",        16,     16,   0 },
       { "fixup_ppc_ha16",        16,     16,   0 },
-      { "fixup_ppc_lo14",        16,     14,   0 },
-      { "fixup_ppc_toc",          0,     64,   0 },
-      { "fixup_ppc_toc16",       16,     16,   0 },
-      { "fixup_ppc_toc16_ds",    16,     14,   0 },
+      { "fixup_ppc_lo16_ds",     16,     14,   0 },
       { "fixup_ppc_tlsreg",       0,      0,   0 },
       { "fixup_ppc_nofixup",      0,      0,   0 }
     };
diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp
index 61868d446f..84e4175e63 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCELFObjectWriter.cpp
@@ -133,6 +133,9 @@ unsigned PPCELFObjectWriter::getRelocTypeInner(const MCValue &Target,
       case MCSymbolRefExpr::VK_None:
         Type = ELF::R_PPC_ADDR16_LO;
 	break;
+      case MCSymbolRefExpr::VK_PPC_TOC_ENTRY:
+        Type = ELF::R_PPC64_TOC16;
+        break;
       case MCSymbolRefExpr::VK_PPC_TOC16_LO:
         Type = ELF::R_PPC64_TOC16_LO;
         break;
@@ -144,35 +147,12 @@ unsigned PPCELFObjectWriter::getRelocTypeInner(const MCValue &Target,
         break;
       }
       break;
-    case PPC::fixup_ppc_lo14:
-      Type = ELF::R_PPC_ADDR14;
-      break;
-    case PPC::fixup_ppc_toc:
-      Type = ELF::R_PPC64_TOC;
-      break;
-    case PPC::fixup_ppc_toc16:
+    case PPC::fixup_ppc_lo16_ds:
       switch (Modifier) {
       default: llvm_unreachable("Unsupported Modifier");
-      case MCSymbolRefExpr::VK_PPC_TPREL16_LO:
-        Type = ELF::R_PPC64_TPREL16_LO;
-        break;
-      case MCSymbolRefExpr::VK_PPC_DTPREL16_LO:
-        Type = ELF::R_PPC64_DTPREL16_LO;
-        break;
       case MCSymbolRefExpr::VK_None:
-        Type = ELF::R_PPC64_TOC16;
-	break;
-      case MCSymbolRefExpr::VK_PPC_TOC16_LO:
-        Type = ELF::R_PPC64_TOC16_LO;
-        break;
-      case MCSymbolRefExpr::VK_PPC_GOT_TLSLD16_LO:
-        Type = ELF::R_PPC64_GOT_TLSLD16_LO;
+        Type = ELF::R_PPC64_ADDR16_DS;
         break;
-      }
-      break;
-    case PPC::fixup_ppc_toc16_ds:
-      switch (Modifier) {
-      default: llvm_unreachable("Unsupported Modifier");
       case MCSymbolRefExpr::VK_PPC_TOC_ENTRY:
         Type = ELF::R_PPC64_TOC16_DS;
 	break;
@@ -253,8 +233,7 @@ adjustFixupOffset(const MCFixup &Fixup, uint64_t &RelocOffset) {
   switch ((unsigned)Fixup.getKind()) {
     case PPC::fixup_ppc_ha16:
     case PPC::fixup_ppc_lo16:
-    case PPC::fixup_ppc_toc16:
-    case PPC::fixup_ppc_toc16_ds:
+    case PPC::fixup_ppc_lo16_ds:
       RelocOffset += 2;
       break;
     default:
diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCFixupKinds.h b/lib/Target/PowerPC/MCTargetDesc/PPCFixupKinds.h
index 709daa4e4b..86c44f57a5 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCFixupKinds.h
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCFixupKinds.h
@@ -33,19 +33,9 @@ enum Fixups {
   /// like 'lis'.
   fixup_ppc_ha16,
   
-  /// fixup_ppc_lo14 - A 14-bit fixup corresponding to lo16(_foo) for instrs
-  /// like 'std'.
-  fixup_ppc_lo14,
-
-  /// fixup_ppc_toc - Insert value of TOC base (.TOC.).
-  fixup_ppc_toc,
-
-  /// fixup_ppc_toc16 - A 16-bit signed fixup relative to the TOC base.
-  fixup_ppc_toc16,
-
-  /// fixup_ppc_toc16_ds - A 14-bit signed fixup relative to the TOC base with
-  /// implied 2 zero bits
-  fixup_ppc_toc16_ds,
+  /// fixup_ppc_lo16_ds - A 14-bit fixup corresponding to lo16(_foo) with
+  /// implied 2 zero bits for instrs like 'std'.
+  fixup_ppc_lo16_ds,
 
   /// fixup_ppc_tlsreg - Insert thread-pointer register number.
   fixup_ppc_tlsreg,
diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
index df2cf8f010..b518ee66d7 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
@@ -43,14 +43,6 @@ public:
   
   ~PPCMCCodeEmitter() {}
 
-  bool is64BitMode() const {
-    return (STI.getFeatureBits() & PPC::Feature64Bit) != 0;
-  }
-
-  bool isSVR4ABI() const {
-    return TT.isMacOSX() == 0;
-  }
-
   unsigned getDirectBrEncoding(const MCInst &MI, unsigned OpNo,
                                SmallVectorImpl<MCFixup> &Fixups) const;
   unsigned getCondBrEncoding(const MCInst &MI, unsigned OpNo,
@@ -177,12 +169,8 @@ unsigned PPCMCCodeEmitter::getMemRIEncoding(const MCInst &MI, unsigned OpNo,
     return (getMachineOpValue(MI, MO, Fixups) & 0xFFFF) | RegBits;
   
   // Add a fixup for the displacement field.
-  if (isSVR4ABI() && is64BitMode())
-    Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
-                                     (MCFixupKind)PPC::fixup_ppc_toc16));
-  else
-    Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
-                                     (MCFixupKind)PPC::fixup_ppc_lo16));
+  Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
+                                   (MCFixupKind)PPC::fixup_ppc_lo16));
   return RegBits;
 }
 
@@ -198,13 +186,9 @@ unsigned PPCMCCodeEmitter::getMemRIXEncoding(const MCInst &MI, unsigned OpNo,
   if (MO.isImm())
     return (getMachineOpValue(MI, MO, Fixups) & 0x3FFF) | RegBits;
   
-  // Add a fixup for the branch target.
-  if (isSVR4ABI() && is64BitMode())
-    Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
-                                     (MCFixupKind)PPC::fixup_ppc_toc16_ds));
-  else
-    Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
-                                     (MCFixupKind)PPC::fixup_ppc_lo14));
+  // Add a fixup for the displacement field.
+  Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
+                                   (MCFixupKind)PPC::fixup_ppc_lo16_ds));
   return RegBits;
 }