[PPC64] Support got-based relocations.

Differential Revison: https://reviews.llvm.org/D54859

llvm-svn: 349511

lld/ELF/Arch/PPC64.cpp

@@ -412,6 +412,13 @@ void PPC64::relaxTlsIeToLe(uint8_t *Loc, RelType Type, uint64_t Val) const {
 RelExpr PPC64::getRelExpr(RelType Type, const Symbol &S,
                           const uint8_t *Loc) const {
   switch (Type) {
+  case R_PPC64_GOT16:
+  case R_PPC64_GOT16_DS:
+  case R_PPC64_GOT16_HA:
+  case R_PPC64_GOT16_HI:
+  case R_PPC64_GOT16_LO:
+  case R_PPC64_GOT16_LO_DS:
+    return R_GOT_OFF;
   case R_PPC64_TOC16:
   case R_PPC64_TOC16_DS:
   case R_PPC64_TOC16_HA:
@@ -526,30 +533,36 @@ static std::pair<RelType, uint64_t> toAddr16Rel(RelType Type, uint64_t Val) {
 
   switch (Type) {
   // TOC biased relocation.
+  case R_PPC64_GOT16:
   case R_PPC64_GOT_TLSGD16:
   case R_PPC64_GOT_TLSLD16:
   case R_PPC64_TOC16:
     return {R_PPC64_ADDR16, TocBiasedVal};
+  case R_PPC64_GOT16_DS:
   case R_PPC64_TOC16_DS:
   case R_PPC64_GOT_TPREL16_DS:
   case R_PPC64_GOT_DTPREL16_DS:
     return {R_PPC64_ADDR16_DS, TocBiasedVal};
+  case R_PPC64_GOT16_HA:
   case R_PPC64_GOT_TLSGD16_HA:
   case R_PPC64_GOT_TLSLD16_HA:
   case R_PPC64_GOT_TPREL16_HA:
   case R_PPC64_GOT_DTPREL16_HA:
   case R_PPC64_TOC16_HA:
     return {R_PPC64_ADDR16_HA, TocBiasedVal};
+  case R_PPC64_GOT16_HI:
   case R_PPC64_GOT_TLSGD16_HI:
   case R_PPC64_GOT_TLSLD16_HI:
   case R_PPC64_GOT_TPREL16_HI:
   case R_PPC64_GOT_DTPREL16_HI:
   case R_PPC64_TOC16_HI:
     return {R_PPC64_ADDR16_HI, TocBiasedVal};
+  case R_PPC64_GOT16_LO:
   case R_PPC64_GOT_TLSGD16_LO:
   case R_PPC64_GOT_TLSLD16_LO:
   case R_PPC64_TOC16_LO:
     return {R_PPC64_ADDR16_LO, TocBiasedVal};
+  case R_PPC64_GOT16_LO_DS:
   case R_PPC64_TOC16_LO_DS:
   case R_PPC64_GOT_TPREL16_LO_DS:
   case R_PPC64_GOT_DTPREL16_LO_DS:
@@ -590,9 +603,11 @@ static bool isTocRelType(RelType Type) {
 }
 
 void PPC64::relocateOne(uint8_t *Loc, RelType Type, uint64_t Val) const {
-  // For a TOC-relative relocation, proceed in terms of the corresponding
-  // ADDR16 relocation type.
+  // We need to save the original relocation type to determine if we should
+  // toc-optimize the instructions being relocated.
   bool IsTocRelType = isTocRelType(Type);
+  // For TOC-relative and GOT-indirect relocations, proceed in terms of the
+  // corresponding ADDR16 relocation type.
   std::tie(Type, Val) = toAddr16Rel(Type, Val);
 
   switch (Type) {

lld/test/ELF/ppc64-got-off.s

@@ -0,0 +1,50 @@
+# REQUIRES: ppc
+
+# RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
+# RUN: ld.lld -shared --no-toc-optimize %t.o -o %t
+# RUN: llvm-objdump -d %t | FileCheck %s
+
+# RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %s -o %t.o
+# RUN: ld.lld -shared --no-toc-optimize %t.o -o %t
+# RUN: llvm-objdump -d %t | FileCheck %s
+
+        .abiversion 2
+        .section ".text"
+
+        .p2align 2
+        .global func
+        .type func, @function
+func:
+.Lfunc_gep:
+        addis 2, 12, .TOC.-.Lfunc_gep@ha
+        addi 2, 2, .TOC.-.Lfunc_gep@l
+.Lfunc_lep:
+        .localentry func, .-func
+        addis 3, 2, a@got@ha
+        ld    3, a@got@l(3)
+        ld    4, a@got(2)
+        lis   5, a@got@h
+        ori   5, 5, a@got@l
+        li    6, 0
+        ori   6, 6, a@got
+        blr
+
+# CHECK-LABEL: func
+# CHECK:         addis 3, 2, 0
+# CHECK-NEXT:    ld 3, -32760(3)
+# CHECK-NEXT:    ld 4, -32760(2)
+# CHECK-NEXT:    lis 5, -1
+# CHECK-NEXT:    ori 5, 5, 32776
+# CHECK-NEXT:    li  6, 0
+# CHECK-NEXT:    ori 6, 6, 32776
+
+# Since the got entry for a is .got[1] and the TOC base points to
+# .got + 0x8000, the offset for a@got is -0x7FF8 --> -32760
+
+        .section ".data"
+        .global a
+        .type a, @object
+        .size a, 4
+        .p2align 2
+a:
+        .long 0x1000