[SPARC][MC] Fix %gdop_hix22() and %gdop_lox10() to use correct relocations (llvm#137915)

1bfc5e7 introduced support for `%gdop_hix22()` and `%gdop_lox10()`.
However, it incorrectly mapped them to `R_SPARC_GOTDATA_HIX22` and
`R_SPARC_GOTDATA_LOX10`. They should in fact emit
`R_SPARC_GOTDATA_OP_HIX22` and `R_SPARC_GOTDATA_OP_LOX10`.

This became a problem when assembling glibc's PIC startup code:

```asm
sethi %gdop_hix22(main), %o0
xor %o0, %gdop_lox10(main), %o0
ldx [%l7 + %o0], %o0, %gdop(main)
```

After the `xor`, `%o0` should contain the GOT offset for `main`, but
because of the incorrect relocations, it actually ends up containing the
address of `main`, which of course makes the following `ldx` fail.

Author: alexrp

llvm/lib/Target/Sparc/MCTargetDesc/SparcAsmBackend.cpp

@@ -82,11 +82,6 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
 
   case Sparc::fixup_sparc_hm:
     return (Value >> 32) & 0x3ff;
-
-  case Sparc::fixup_sparc_gotdata_lox10:
-  case Sparc::fixup_sparc_gotdata_hix22:
-  case Sparc::fixup_sparc_gotdata_op:
-    return 0;
   }
 }
 
@@ -137,6 +132,7 @@ namespace {
     }
 
     MCFixupKindInfo getFixupKindInfo(MCFixupKind Kind) const override {
+      // clang-format off
       const static MCFixupKindInfo InfosBE[Sparc::NumTargetFixupKinds] = {
         // name                    offset bits  flags
         { "fixup_sparc_call30",     2,     30,  MCFixupKindInfo::FKF_IsPCRel },
@@ -157,9 +153,6 @@ namespace {
         { "fixup_sparc_wplt30",     2,     30,  MCFixupKindInfo::FKF_IsPCRel },
         { "fixup_sparc_hix22",         10, 22,  0 },
         { "fixup_sparc_lox10",         19, 13,  0 },
-        { "fixup_sparc_gotdata_hix22",  0,  0,  0 },
-        { "fixup_sparc_gotdata_lox10",  0,  0,  0 },
-        { "fixup_sparc_gotdata_op",     0,  0,  0 },
       };
 
       const static MCFixupKindInfo InfosLE[Sparc::NumTargetFixupKinds] = {
@@ -182,10 +175,8 @@ namespace {
         { "fixup_sparc_wplt30",      0,     30,  MCFixupKindInfo::FKF_IsPCRel },
         { "fixup_sparc_hix22",          0, 22,  0 },
         { "fixup_sparc_lox10",          0, 13,  0 },
-        { "fixup_sparc_gotdata_hix22",  0,  0,  0 },
-        { "fixup_sparc_gotdata_lox10",  0,  0,  0 },
-        { "fixup_sparc_gotdata_op",     0,  0,  0 },
       };
+      // clang-format on
 
       // Fixup kinds from .reloc directive are like R_SPARC_NONE. They do
       // not require any extra processing.

llvm/lib/Target/Sparc/MCTargetDesc/SparcELFObjectWriter.cpp

@@ -98,6 +98,7 @@ unsigned SparcELFObjectWriter::getRelocType(MCContext &Ctx,
     }
   }
 
+  // clang-format off
   switch(Fixup.getTargetKind()) {
   default:
     llvm_unreachable("Unimplemented fixup -> relocation");
@@ -127,10 +128,8 @@ unsigned SparcELFObjectWriter::getRelocType(MCContext &Ctx,
   case Sparc::fixup_sparc_lm:    return ELF::R_SPARC_LM22;
   case Sparc::fixup_sparc_hix22:         return ELF::R_SPARC_HIX22;
   case Sparc::fixup_sparc_lox10:         return ELF::R_SPARC_LOX10;
-  case Sparc::fixup_sparc_gotdata_hix22: return ELF::R_SPARC_GOTDATA_HIX22;
-  case Sparc::fixup_sparc_gotdata_lox10: return ELF::R_SPARC_GOTDATA_LOX10;
-  case Sparc::fixup_sparc_gotdata_op:    return ELF::R_SPARC_GOTDATA_OP;
   }
+  // clang-format on
 
   return ELF::R_SPARC_NONE;
 }

llvm/lib/Target/Sparc/MCTargetDesc/SparcFixupKinds.h

@@ -13,6 +13,7 @@
 
 namespace llvm {
   namespace Sparc {
+  // clang-format off
     enum Fixups {
       // fixup_sparc_call30 - 30-bit PC relative relocation for call
       fixup_sparc_call30 = FirstTargetFixupKind,
@@ -70,17 +71,11 @@ namespace llvm {
       /// 13-bit fixup corresponding to %lox(foo)
       fixup_sparc_lox10,
 
-      /// 22-bit fixup corresponding to %gdop_hix22(foo)
-      fixup_sparc_gotdata_hix22,
-      /// 13-bit fixup corresponding to %gdop_lox10(foo)
-      fixup_sparc_gotdata_lox10,
-      /// 32-bit fixup corresponding to %gdop(foo)
-      fixup_sparc_gotdata_op,
-
       // Marker
       LastTargetFixupKind,
       NumTargetFixupKinds = LastTargetFixupKind - FirstTargetFixupKind
     };
+  // clang-format on
   }
 }
 

llvm/lib/Target/Sparc/MCTargetDesc/SparcMCExpr.cpp

@@ -80,9 +80,9 @@ StringRef SparcMCExpr::getSpecifierName(SparcMCExpr::Specifier S) {
   case VK_TLS_LE_LOX10:  return "tle_lox10";
   case VK_HIX22:         return "hix";
   case VK_LOX10:         return "lox";
-  case VK_GOTDATA_HIX22: return "gdop_hix22";
-  case VK_GOTDATA_LOX10: return "gdop_lox10";
-  case VK_GOTDATA_OP:    return "gdop";
+  case VK_GOTDATA_OP_HIX22: return "gdop_hix22";
+  case VK_GOTDATA_OP_LOX10: return "gdop_lox10";
+  case VK_GOTDATA_OP:       return "gdop";
   }
   // clang-format on
   llvm_unreachable("Unhandled SparcMCExpr::Specifier");
@@ -126,8 +126,8 @@ SparcMCExpr::Specifier SparcMCExpr::parseSpecifier(StringRef name) {
       .Case("tle_lox10", VK_TLS_LE_LOX10)
       .Case("hix", VK_HIX22)
       .Case("lox", VK_LOX10)
-      .Case("gdop_hix22", VK_GOTDATA_HIX22)
-      .Case("gdop_lox10", VK_GOTDATA_LOX10)
+      .Case("gdop_hix22", VK_GOTDATA_OP_HIX22)
+      .Case("gdop_lox10", VK_GOTDATA_OP_LOX10)
       .Case("gdop", VK_GOTDATA_OP)
       .Default(VK_None);
 }
@@ -172,9 +172,9 @@ uint16_t SparcMCExpr::getFixupKind() const {
   case VK_TLS_LE_LOX10:  return ELF::R_SPARC_TLS_LE_LOX10;
   case VK_HIX22:         return Sparc::fixup_sparc_hix22;
   case VK_LOX10:         return Sparc::fixup_sparc_lox10;
-  case VK_GOTDATA_HIX22: return Sparc::fixup_sparc_gotdata_hix22;
-  case VK_GOTDATA_LOX10: return Sparc::fixup_sparc_gotdata_lox10;
-  case VK_GOTDATA_OP:    return Sparc::fixup_sparc_gotdata_op;
+  case VK_GOTDATA_OP_HIX22: return ELF::R_SPARC_GOTDATA_OP_HIX22;
+  case VK_GOTDATA_OP_LOX10: return ELF::R_SPARC_GOTDATA_OP_LOX10;
+  case VK_GOTDATA_OP:       return ELF::R_SPARC_GOTDATA_OP;
   }
   // clang-format on
 }

llvm/lib/Target/Sparc/MCTargetDesc/SparcMCExpr.h

@@ -61,8 +61,8 @@ class SparcMCExpr : public MCTargetExpr {
     VK_TLS_LE_LOX10,
     VK_HIX22,
     VK_LOX10,
-    VK_GOTDATA_HIX22,
-    VK_GOTDATA_LOX10,
+    VK_GOTDATA_OP_HIX22,
+    VK_GOTDATA_OP_LOX10,
     VK_GOTDATA_OP,
   };
 

llvm/test/MC/Sparc/relocation-specifier.s

@@ -63,8 +63,8 @@ sethi %lm(sym), %l0
 # ASM-NEXT: ldx [%l7+%l1], %l2, %gdop(sym)
 # OBJDUMP: R_SPARC_HIX22 sym
 # OBJDUMP: R_SPARC_LOX10 sym
-# OBJDUMP: R_SPARC_GOTDATA_HIX22 sym
-# OBJDUMP: R_SPARC_GOTDATA_LOX10 sym
+# OBJDUMP: R_SPARC_GOTDATA_OP_HIX22 sym
+# OBJDUMP: R_SPARC_GOTDATA_OP_LOX10 sym
 # OBJDUMP: R_SPARC_GOTDATA_OP sym
 sethi %hix(sym), %g1
 xor %g1, %lox(sym), %g1