[AMDGPU] Handle R_AMDGPU_ABS64 relocation

[kzhuravl]

Summary

This is needed for the following case (OpenCL example):

__global int Var = 0; 
__global int* Ptr[] = {&Var}; 
...

[ruiu]

LGTM with a nit.

ELF/Target.cpp

1491

Move to line 1487 to sort.

[kzhuravl]

ELF/Target.cpp

1491

Thanks, fixed this before committing.

ELF/Target.cpp

void AMDGPUTargetInfo::relocateOne(uint8_t *Loc, uint32_t Type,
   case R_AMDGPU_REL32:
   case R_AMDGPU_REL32_LO:
     write32le(Loc, Val);
     break;
   case R_AMDGPU_GOTPCREL32_HI:
   case R_AMDGPU_REL32_HI:
     write32le(Loc, Val >> 32);
     break;
+  case R_AMDGPU_ABS64:
+    write64le(Loc, Val);
+    break;
   default:
     fatal("unrecognized reloc " + Twine(Type));
   }
 }
 
 RelExpr AMDGPUTargetInfo::getRelExpr(uint32_t Type, const SymbolBody &S) const {
   switch (Type) {
   case R_AMDGPU_ABS32:
+  case R_AMDGPU_ABS64:
     return R_ABS;
   case R_AMDGPU_REL32:
   case R_AMDGPU_REL32_LO:
   case R_AMDGPU_REL32_HI:
     return R_PC;
   case R_AMDGPU_GOTPCREL:
   case R_AMDGPU_GOTPCREL32_LO:
   case R_AMDGPU_GOTPCREL32_HI:

test/ELF/amdgpu-relocs.s

 # RUN: llvm-mc -filetype=obj -triple=amdgcn--amdhsa -mcpu=fiji %s -o %t.o
 # RUN: ld.lld -shared %t.o -o %t.so
 # RUN: llvm-readobj -r %t.so | FileCheck %s
 # RUN: llvm-objdump -s %t.so | FileCheck %s --check-prefix=OBJDUMP
 
 # REQUIRES: amdgpu
 
-  .text
 
 kernel0:
   s_mov_b32 s0, common_var0@GOTPCREL+4
   s_mov_b32 s0, common_var1@gotpcrel32@lo+4
   s_mov_b32 s0, common_var2@gotpcrel32@hi+4
 
   s_mov_b32 s0, global_var0@GOTPCREL+4
   s_mov_b32 s0, global_var1@gotpcrel32@lo+4
kernel0:
   .weak    weak_var2
   .weakref weakref_var0, weakref_alias_var0
   .weakref weakref_var1, weakref_alias_var1
   .weakref weakref_var2, weakref_alias_var2
   .local   local_var0
   .local   local_var1
   .local   local_var2
 
+# R_AMDGPU_ABS32:
 .section nonalloc, "w", @progbits
   .long var0, common_var2+4
   .long var1, common_var1+8
   .long var2, common_var0+12
 
+# R_AMDGPU_ABS64:
+.type ptr, @object
+.data
+  .globl ptr
+  .p2align 3
+ptr:
+  .quad temp
+  .size ptr, 8
+
 # The relocation for local_var{0, 1, 2} and var should be resolved by the
 # linker.
 # CHECK: Relocations [
 # CHECK: .rela.dyn {
 # CHECK-NEXT: R_AMDGPU_ABS64 common_var0 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 common_var1 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 common_var2 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 extern_var0 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 extern_var1 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 extern_var2 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 global_var0 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 global_var1 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 global_var2 0x0
+# CHECK-NEXT: R_AMDGPU_ABS64 temp 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 weak_var0 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 weak_var1 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 weak_var2 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 weakref_alias_var0 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 weakref_alias_var1 0x0
 # CHECK-NEXT: R_AMDGPU_ABS64 weakref_alias_var2 0x0
 # CHECK-NEXT: }
 # CHECK-NEXT: ]
 
 # OBJDUMP: Contents of section nonalloc:
-# OBJDUMP-NEXT: 0000 00000000 04380000 00000000 08340000
-# OBJDUMP-NEXT: 00000000 0c300000
+# OBJDUMP-NEXT: 0000 00000000 14380000 00000000 18340000
+# OBJDUMP-NEXT: 00000000 1c300000