[Mips64][mcjit] Add R_MIPS_PC32 relocation.

[vradosavljevic]

Summary

This patch adds R_MIPS_PC32 relocation for Mips64.

[dsanders]

LGTM

[petarj]

lgtm

llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp

RuntimeDyldELF::evaluateMIPS64Relocation(const SectionEntry &Section,
   case ELF::R_MIPS_GPREL32: {
     uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
     return Value + Addend - (GOTAddr + 0x7ff0);
   }
   case ELF::R_MIPS_PC16: {
     uint64_t FinalAddress = (Section.LoadAddress + Offset);
     return ((Value + Addend - FinalAddress - 4) >> 2) & 0xffff;
   }
+  case ELF::R_MIPS_PC32: {
+    uint64_t FinalAddress = (Section.LoadAddress + Offset);
+    return Value + Addend - FinalAddress;
+  }
   case ELF::R_MIPS_PC18_S3: {
     uint64_t FinalAddress = (Section.LoadAddress + Offset);
     return ((Value + Addend - ((FinalAddress | 7) ^ 7)) >> 3) & 0x3ffff;
   }
   case ELF::R_MIPS_PC19_S2: {
     uint64_t FinalAddress = (Section.LoadAddress + Offset);
     return ((Value + Addend - FinalAddress) >> 2) & 0x7ffff;
   }
void RuntimeDyldELF::applyMIPS64Relocation(uint8_t *TargetPtr,
                                            uint32_t Type) {
   uint32_t Insn = readBytesUnaligned(TargetPtr, 4);
 
   switch (Type) {
     default:
       break;
     case ELF::R_MIPS_32:
     case ELF::R_MIPS_GPREL32:
+    case ELF::R_MIPS_PC32:
       writeBytesUnaligned(CalculatedValue & 0xffffffff, TargetPtr, 4);
       break;
     case ELF::R_MIPS_64:
     case ELF::R_MIPS_SUB:
       writeBytesUnaligned(CalculatedValue, TargetPtr, 8);
       break;
     case ELF::R_MIPS_26:
     case ELF::R_MIPS_PC26_S2:

llvm/trunk/test/ExecutionEngine/RuntimeDyld/Mips/ELF_Mips64r2N64_PIC_relocations.s

 # RUN: llvm-mc -triple=mips64el-unknown-linux -relocation-model=pic -code-model=small -filetype=obj -o %T/test_ELF_Mips64N64.o %s
 # RUN: llc -mtriple=mips64el-unknown-linux -relocation-model=pic -filetype=obj -o %T/test_ELF_ExternalFunction_Mips64N64.o %S/Inputs/ExternalFunction.ll
 # RUN: llvm-rtdyld -triple=mips64el-unknown-linux -verify -map-section test_ELF_Mips64N64.o,.text=0x1000 -map-section test_ELF_ExternalFunction_Mips64N64.o,.text=0x10000 -check=%s %/T/test_ELF_Mips64N64.o %T/test_ELF_ExternalFunction_Mips64N64.o
 
+  .data
+# Test R_MIPS_PC32 relocation.
+# rtdyld-check: *{4}(R_MIPS_PC32) = (foo - R_MIPS_PC32)[31:0]
+R_MIPS_PC32:
+  .word foo-.
+# rtdyld-check: *{4}(R_MIPS_PC32 + 4) = (foo - tmp1)[31:0]
+tmp1:
+  .4byte foo-tmp1
+
   .text
   .abicalls
   .section  .mdebug.abi64,"",@progbits
   .nan  legacy
   .file "ELF_Mips64N64_PIC_relocations.ll"
   .text
   .globl  bar
   .align  3