[mips][mc] Add basic support for R_MIPS_JALR/R_MICROMIPS_JALR

R_MIPS_JALR/R_MICROMIPS_JALR can now be parsed in .s files and emitted to .o.
They are still not generated with JALR.

Differential revision: https://reviews.llvm.org/D54721

llvm-svn: 347398

lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp

@@ -339,6 +339,8 @@ Optional<MCFixupKind> MipsAsmBackend::getFixupKind(StringRef Name) const {
             (MCFixupKind)Mips::fixup_MICROMIPS_TLS_TPREL_HI16)
       .Case("R_MICROMIPS_TLS_TPREL_LO16",
             (MCFixupKind)Mips::fixup_MICROMIPS_TLS_TPREL_LO16)
+      .Case("R_MIPS_JALR", (MCFixupKind)Mips::fixup_Mips_JALR)
+      .Case("R_MICROMIPS_JALR", (MCFixupKind)Mips::fixup_MICROMIPS_JALR)
       .Default(MCAsmBackend::getFixupKind(Name));
 }
 
@@ -417,7 +419,9 @@ getFixupKindInfo(MCFixupKind Kind) const {
     { "fixup_MICROMIPS_TLS_TPREL_HI16",  0,     16,   0 },
     { "fixup_MICROMIPS_TLS_TPREL_LO16",  0,     16,   0 },
     { "fixup_Mips_SUB",                  0,     64,   0 },
-    { "fixup_MICROMIPS_SUB",             0,     64,   0 }
+    { "fixup_MICROMIPS_SUB",             0,     64,   0 },
+    { "fixup_Mips_JALR",                 0,     32,   0 },
+    { "fixup_MICROMIPS_JALR",            0,     32,   0 }
   };
   static_assert(array_lengthof(LittleEndianInfos) == Mips::NumTargetFixupKinds,
                 "Not all MIPS little endian fixup kinds added!");
@@ -495,7 +499,9 @@ getFixupKindInfo(MCFixupKind Kind) const {
     { "fixup_MICROMIPS_TLS_TPREL_HI16",  16,     16,   0 },
     { "fixup_MICROMIPS_TLS_TPREL_LO16",  16,     16,   0 },
     { "fixup_Mips_SUB",                   0,     64,   0 },
-    { "fixup_MICROMIPS_SUB",              0,     64,   0 }
+    { "fixup_MICROMIPS_SUB",              0,     64,   0 },
+    { "fixup_Mips_JALR",                  0,     32,   0 },
+    { "fixup_MICROMIPS_JALR",             0,     32,   0 }
   };
   static_assert(array_lengthof(BigEndianInfos) == Mips::NumTargetFixupKinds,
                 "Not all MIPS big endian fixup kinds added!");
@@ -553,6 +559,7 @@ bool MipsAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
   case Mips::fixup_Mips_TLSLDM:
   case Mips::fixup_Mips_TPREL_HI:
   case Mips::fixup_Mips_TPREL_LO:
+  case Mips::fixup_Mips_JALR:
   case Mips::fixup_MICROMIPS_CALL16:
   case Mips::fixup_MICROMIPS_GOT_DISP:
   case Mips::fixup_MICROMIPS_GOT_PAGE:
@@ -565,6 +572,7 @@ bool MipsAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
   case Mips::fixup_MICROMIPS_TLS_LDM:
   case Mips::fixup_MICROMIPS_TLS_TPREL_HI16:
   case Mips::fixup_MICROMIPS_TLS_TPREL_LO16:
+  case Mips::fixup_MICROMIPS_JALR:
     return true;
   }
 }

lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp

@@ -401,6 +401,10 @@ unsigned MipsELFObjectWriter::getRelocType(MCContext &Ctx,
     return ELF::R_MICROMIPS_HIGHER;
   case Mips::fixup_MICROMIPS_HIGHEST:
     return ELF::R_MICROMIPS_HIGHEST;
+  case Mips::fixup_Mips_JALR:
+    return ELF::R_MIPS_JALR;
+  case Mips::fixup_MICROMIPS_JALR:
+    return ELF::R_MICROMIPS_JALR;
   }
 
   llvm_unreachable("invalid fixup kind!");

lib/Target/Mips/MCTargetDesc/MipsFixupKinds.h

@@ -222,6 +222,10 @@ namespace Mips {
     fixup_Mips_SUB,
     fixup_MICROMIPS_SUB,
 
+    // resulting in - R_MIPS_JALR/R_MICROMIPS_JALR
+    fixup_Mips_JALR,
+    fixup_MICROMIPS_JALR,
+
     // Marker
     LastTargetFixupKind,
     NumTargetFixupKinds = LastTargetFixupKind - FirstTargetFixupKind

test/MC/Mips/reloc-directive.s

@@ -79,6 +79,10 @@ foo:
   nop
   .reloc 124, R_MICROMIPS_TLS_TPREL_LO16, 4     # ASM: .reloc 124, R_MICROMIPS_TLS_TPREL_LO16, 4
   nop
+  .reloc 128, R_MIPS_JALR, 4            # ASM: .reloc 128, R_MIPS_JALR, 4
+  nop
+  .reloc 132, R_MICROMIPS_JALR, 4       # ASM: .reloc 132, R_MICROMIPS_JALR, 4
+  nop
 
 # OBJ-O32-LABEL: Name: .text
 # OBJ-O32:       0000: 00000000 00000000 00000008 00000000
@@ -89,6 +93,7 @@ foo:
 # OBJ-O32-NEXT:  0050: 00000000 00000004 00000004 00000004
 # OBJ-O32-NEXT:  0060: 00000000 00000000 00000000 00000000
 # OBJ-O32-NEXT:  0070: 00000000 00000000 00000000 00000000
+# OBJ-O32-NEXT:  0080: 00000000 00000000
 # OBJ-O32-LABEL: }
 # OBJ-O32-LABEL: Relocations [
 # OBJ-O32:       0x0 R_MIPS_NONE .text 0x0
@@ -121,6 +126,8 @@ foo:
 # OBJ-O32-NEXT:  0x74 R_MICROMIPS_TLS_LDM - 0x0
 # OBJ-O32-NEXT:  0x78 R_MICROMIPS_TLS_TPREL_HI16 - 0x0
 # OBJ-O32-NEXT:  0x7C R_MICROMIPS_TLS_TPREL_LO16 - 0x0
+# OBJ-O32-NEXT:  0x80 R_MIPS_JALR - 0x0
+# OBJ-O32-NEXT:  0x84 R_MICROMIPS_JALR - 0x0
 # OBJ-O32-NEXT:  0x1C R_MIPS_GOT16 - 0x0
 # OBJ-O32-NEXT:  0x60 R_MICROMIPS_GOT16 - 0x0
 
@@ -133,6 +140,7 @@ foo:
 # OBJ-N32-NEXT:  0050: 00000000 00000000 00000000 00000000
 # OBJ-N32-NEXT:  0060: 00000000 00000000 00000000 00000000
 # OBJ-N32-NEXT:  0070: 00000000 00000000 00000000 00000000
+# OBJ-N32-NEXT:  0080: 00000000 00000000
 # OBJ-N32-LABEL: }
 # OBJ-N32-LABEL: Relocations [
 
@@ -168,6 +176,8 @@ foo:
 # OBJ-N32-NEXT:  0x74 R_MICROMIPS_TLS_LDM - 0x4
 # OBJ-N32-NEXT:  0x78 R_MICROMIPS_TLS_TPREL_HI16 - 0x4
 # OBJ-N32-NEXT:  0x7C R_MICROMIPS_TLS_TPREL_LO16 - 0x4
+# OBJ-N32-NEXT:  0x80 R_MIPS_JALR - 0x4
+# OBJ-N32-NEXT:  0x84 R_MICROMIPS_JALR - 0x4
 
 # OBJ-N64-LABEL: Name: .text
 # OBJ-N64:       0000: 00000000 00000000 00000000 00000000
@@ -178,6 +188,7 @@ foo:
 # OBJ-N64-NEXT:  0050: 00000000 00000000 00000000 00000000
 # OBJ-N64-NEXT:  0060: 00000000 00000000 00000000 00000000
 # OBJ-N64-NEXT:  0070: 00000000 00000000 00000000 00000000
+# OBJ-N64-NEXT:  0080: 00000000 00000000
 # OBJ-N64-LABEL: }
 # OBJ-N64-LABEL: Relocations [
 # OBJ-N64:       0x4 R_MIPS_NONE/R_MIPS_NONE/R_MIPS_NONE .text 0x0
@@ -212,3 +223,5 @@ foo:
 # OBJ-N64-NEXT:  0x74 R_MICROMIPS_TLS_LDM/R_MIPS_NONE/R_MIPS_NONE - 0x4
 # OBJ-N64-NEXT:  0x78 R_MICROMIPS_TLS_TPREL_HI16/R_MIPS_NONE/R_MIPS_NONE - 0x4
 # OBJ-N64-NEXT:  0x7C R_MICROMIPS_TLS_TPREL_LO16/R_MIPS_NONE/R_MIPS_NONE - 0x4
+# OBJ-N64-NEXT:  0x80 R_MIPS_JALR/R_MIPS_NONE/R_MIPS_NONE - 0x4
+# OBJ-N64-NEXT:  0x84 R_MICROMIPS_JALR/R_MIPS_NONE/R_MIPS_NONE - 0x4