ELF/AMDGPU: Add support for R_AMDGPU_ABS32

[• tstellarAMD]

test/ELF/amdgpu-relocs-abs32.s

23 ↗

(On Diff #61701)

Is the full kernel_code_t definition required for this test?

[kzhuravl]

Rebase and update test

[ruiu]

ELF/Target.cpp

1425–1427

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[• rafael]

we don't use llc to test elf lld.

[kzhuravl]

Feedback + update test

[ruiu]

Verifying an entire dwarf file to test ABS32 relocations seems a bit overkill. Why don't you add a few lines to test/ELF/amdgpu-relocs.s?

[kzhuravl]

R_AMDGPU_ABS32 relocations are only generated for dwarf

[ruiu]

The fact that ABS32 is generated only for DWARF does not necessarily mean that you need to create a DWARF to verify the behavior of the relocation. I was trying to say was that the test is too big compared to the size of the feature that is testing; it mostly verifies the structure of DWARF rather than the relocation. A test for ABS32 can be written in a few lines.

[kzhuravl]

Update test

[ruiu]

Don't you want to verify the contents of .data section?

[kzhuravl]

Update test

[ruiu]

LGTM

ELF/Target.cpp

void AArch64TargetInfo::relaxTlsIeToLe(uint8_t *Loc, uint32_t Type,
   llvm_unreachable("invalid relocation for TLS IE to LE relaxation");
 }
 
 AMDGPUTargetInfo::AMDGPUTargetInfo() { GotRel = R_AMDGPU_ABS64; }
 
 void AMDGPUTargetInfo::relocateOne(uint8_t *Loc, uint32_t Type,
                                    uint64_t Val) const {
   switch (Type) {
   case R_AMDGPU_GOTPCREL:
   case R_AMDGPU_REL32:
+  case R_AMDGPU_ABS32:
     write32le(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:
+    return R_ABS;
   case R_AMDGPU_REL32:
     return R_PC;
   case R_AMDGPU_GOTPCREL:
     return R_GOT_PC;
   default:
     fatal("do not know how to handle relocation " + Twine(Type));
   }
 }

test/ELF/amdgpu-elf64-dwarf-relocs.ll

+; REQUIRES: amdgpu
+
+; RUN: llc -filetype=obj -mtriple=amdgcn--amdhsa -mcpu=fiji %s -o %t.o
+; RUN: ld.lld -shared %t.o -o %t.so
+; RUN: llvm-dwarfdump -debug-dump=info %t.so | FileCheck %s
+
+; CHECK: DW_AT_producer [DW_FORM_strp]   ( .debug_str[0x00000000] = "clang version 3.9.0 (trunk 274777)")
+; CHECK: DW_AT_name [DW_FORM_strp]       ( .debug_str[0x00000023] = "elf64-dwarf-relocs.cl")
+; CHECK: DW_AT_comp_dir [DW_FORM_strp]   ( .debug_str[0x00000039] = "/home/kzhuravl/Git/Lightning/temp")
+; CHECK: DW_AT_name [DW_FORM_strp]       ( .debug_str[0x0000005b] = "elf64_dwarf_relocs")
+; CHECK: DW_AT_decl_file [DW_FORM_data1] ("/home/kzhuravl/Git/Lightning/temp/elf64-dwarf-relocs.cl")
+
+; Function Attrs: norecurse nounwind readnone
+define amdgpu_kernel void @elf64_dwarf_relocs() local_unnamed_addr #0 !dbg !6 !kernel_arg_addr_space !2 !kernel_arg_access_qual !2 !kernel_arg_type !2 !kernel_arg_base_type !2 !kernel_arg_type_qual !2 {
+entry:
+  ret void, !dbg !9
+}
+
+attributes #0 = { norecurse nounwind readnone "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="fiji" "target-features"="+16-bit-insts,+s-memrealtime" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+!llvm.ident = !{!5}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.9.0 (trunk 274777)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "elf64-dwarf-relocs.cl", directory: "/home/kzhuravl/Git/Lightning/temp")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 2}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{!"clang version 3.9.0 (trunk 274777)"}
+!6 = distinct !DISubprogram(name: "elf64_dwarf_relocs", scope: !1, file: !1, line: 1, type: !7, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, variables: !2)
+!7 = !DISubroutineType(types: !8)
+!8 = !{null}
+!9 = !DILocation(line: 1, column: 35, scope: !6)