[lld] 8131ef5 - [LLD][PowerPC] Add support for R_PPC64_GOT_PCREL34

[Kamau Bridgeman via llvm-commits]

Author: Stefan Pintilie
Date: 2020-06-24T07:40:35-05:00
New Revision: 8131ef5d635bc01b398c8648ea921f2891aaa9d2

URL: https://github.com/llvm/llvm-project/commit/8131ef5d635bc01b398c8648ea921f2891aaa9d2
DIFF: https://github.com/llvm/llvm-project/commit/8131ef5d635bc01b398c8648ea921f2891aaa9d2.diff

LOG: [LLD][PowerPC] Add support for R_PPC64_GOT_PCREL34

Add support for the 34bit relocation R_PPC64_GOT_PCREL34 for
PC Relative in LLD.

Reviewers: sfertile, MaskRay

Differential Revision: https://reviews.llvm.org/D81948

Added: 
    lld/test/ELF/ppc64-reloc-got-pcrel34.s

Modified: 
    lld/ELF/Arch/PPC64.cpp

Removed: 
    


################################################################################
diff  --git a/lld/ELF/Arch/PPC64.cpp b/lld/ELF/Arch/PPC64.cpp
index cadbf9ad3ec2..0764dabe45f8 100644
--- a/lld/ELF/Arch/PPC64.cpp
+++ b/lld/ELF/Arch/PPC64.cpp
@@ -671,6 +671,8 @@ RelExpr PPC64::getRelExpr(RelType type, const Symbol &s,
   case R_PPC64_TOC16_HI:
   case R_PPC64_TOC16_LO:
     return R_GOTREL;
+  case R_PPC64_GOT_PCREL34:
+    return R_GOT_PC;
   case R_PPC64_TOC16_HA:
   case R_PPC64_TOC16_LO_DS:
     return config->tocOptimize ? R_PPC64_RELAX_TOC : R_GOTREL;
@@ -1012,6 +1014,17 @@ void PPC64::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
                              (val & si1Mask));
     break;
   }
+  case R_PPC64_GOT_PCREL34: {
+    const uint64_t si0Mask = 0x00000003ffff0000;
+    const uint64_t si1Mask = 0x000000000000ffff;
+    const uint64_t fullMask = 0x0003ffff0000ffff;
+    checkInt(loc, val, 34, rel);
+
+    uint64_t instr = readPrefixedInstruction(loc) & ~fullMask;
+    writePrefixedInstruction(loc, instr | ((val & si0Mask) << 16) |
+                             (val & si1Mask));
+    break;
+  }
   default:
     llvm_unreachable("unknown relocation");
   }

diff  --git a/lld/test/ELF/ppc64-reloc-got-pcrel34.s b/lld/test/ELF/ppc64-reloc-got-pcrel34.s
new file mode 100644
index 000000000000..4e5cf97b7ae9
--- /dev/null
+++ b/lld/test/ELF/ppc64-reloc-got-pcrel34.s
@@ -0,0 +1,51 @@
+# REQUIRES: ppc
+# RUN: echo 'SECTIONS { \
+# RUN:       .text_low 0x10010000: { *(.text_low) } \
+# RUN:       .text_high 0x10080000 : { *(.text_high) } \
+# RUN:       }' > %t.script
+
+# RUN: llvm-mc -filetype=obj -triple=powerpc64le %s -o %t.o
+# RUN: ld.lld -T %t.script --shared %t.o -o %t
+# RUN: llvm-readelf -s %t | FileCheck %s --check-prefix=SYMBOL
+# RUN: llvm-readelf -r %t | FileCheck %s --check-prefix=RELA
+# RUN: llvm-objdump -d --no-show-raw-insn --mcpu=future %t | FileCheck %s
+
+# RUN: llvm-mc -filetype=obj -triple=powerpc64 %s -o %t.o
+# RUN: ld.lld -T %t.script --shared %t.o -o %t
+# RUN: llvm-readelf -s %t | FileCheck %s --check-prefix=SYMBOL
+# RUN: llvm-readelf -r %t | FileCheck %s --check-prefix=RELA
+# RUN: llvm-objdump -d --no-show-raw-insn --mcpu=future %t | FileCheck %s
+
+.text
+.section .text_low, "ax", %progbits
+# CHECK-LABEL: <GlobIntPCRel>:
+# CHECK-NEXT:    pld 3, 458928(0), 1
+# CHECK-NEXT:    lwa 3, 0(3)
+# SYMBOL: Symbol table '.dynsym' contains 4 entries:
+# SYMBOL:      00000000     0 NOTYPE  GLOBAL  DEFAULT     UND glob_int
+# RELA:        100800b0  0000000100000014 R_PPC64_GLOB_DAT       0000000000000000 glob_int + 0
+GlobIntPCRel:
+  pld 3, glob_int at got@PCREL(0), 1
+  lwa 3, 0(3)
+  blr
+
+# CHECK-LABEL: <GlobIntPCRelOffset>:
+# CHECK-NEXT:    pld 3, 458920(0), 1
+# CHECK-NEXT:    lwa 3, 8(3)
+# SYMBOL:      00000000     0 NOTYPE  GLOBAL  DEFAULT     UND glob_int8
+# RELA:        100800b8  0000000200000014 R_PPC64_GLOB_DAT       0000000000000000 glob_int8 + 0
+GlobIntPCRelOffset:
+  pld 3, glob_int8 at got@PCREL(0), 1
+  lwa 3, 8(3)
+  blr
+
+# CHECK-LABEL: <GlobIntPCRelBigOffset>:
+# CHECK-NEXT:    pld 3, 192(0), 1
+# CHECK-NEXT:    lwa 3, 64(3)
+# SYMBOL:      00000000     0 NOTYPE  GLOBAL  DEFAULT     UND glob_int8_big
+# RELA:        100800c0  0000000300000014 R_PPC64_GLOB_DAT       0000000000000000 glob_int8_big + 0
+.section .text_high, "ax", %progbits
+GlobIntPCRelBigOffset:
+  pld 3, glob_int8_big at got@PCREL(0), 1
+  lwa 3, 64(3)
+  blr