[lld] r263150 - [ELF] - Fixed handling R_X86_64_DTPOFF64 relocation relaxation

[George Rimar via llvm-commits]

Author: grimar
Date: Thu Mar 10 12:57:17 2016
New Revision: 263150

URL: http://llvm.org/viewvc/llvm-project?rev=263150&view=rev
Log:
[ELF] - Fixed handling R_X86_64_DTPOFF64 relocation relaxation

R_X86_64_DTPOFF64 was not handled properly.
Next sample app was impossible to link before this patch:

~/pg/release/bin/clang -target x86_64-pc-linux testthread.cpp -c -g
~/pg/d+a/bin/ld.lld testthread.o 
"Unknown TLS optimization" (value was 17)

__thread int x = 0;
void _start() {
}

It works fine now.

Differential revision: http://reviews.llvm.org/D18039

Modified:
    lld/trunk/ELF/Target.cpp
    lld/trunk/test/ELF/tls-opt.s

Modified: lld/trunk/ELF/Target.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Target.cpp?rev=263150&r1=263149&r2=263150&view=diff
==============================================================================
--- lld/trunk/ELF/Target.cpp (original)
+++ lld/trunk/ELF/Target.cpp Thu Mar 10 12:57:17 2016
@@ -895,6 +895,9 @@ size_t X86_64TargetInfo::relaxTls(uint8_
   case R_X86_64_DTPOFF32:
     relocateOne(Loc, BufEnd, R_X86_64_TPOFF32, P, SA);
     return 0;
+  case R_X86_64_DTPOFF64:
+    write64le(Loc, SA - Out<ELF64LE>::TlsPhdr->p_memsz);
+    return 0;
   case R_X86_64_GOTTPOFF:
     relocateTlsIeToLe(Loc, BufEnd, P, SA);
     return 0;

Modified: lld/trunk/test/ELF/tls-opt.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/tls-opt.s?rev=263150&r1=263149&r2=263150&view=diff
==============================================================================
--- lld/trunk/test/ELF/tls-opt.s (original)
+++ lld/trunk/test/ELF/tls-opt.s Thu Mar 10 12:57:17 2016
@@ -35,6 +35,11 @@
 // DISASM-NEXT: 1109a: 48 8d 80 f8 ff ff ff                leaq -8(%rax), %rax
 // DISASM-NEXT: 110a1: 64 48 8b 04 25 00 00 00 00          movq %fs:0, %rax
 // DISASM-NEXT: 110aa: 48 8d 80 fc ff ff ff                leaq -4(%rax), %rax
+// LD to LE (2):
+// DISASM:      _DTPOFF64_1:
+// DISASM-NEXT: 110b1: f8
+// DISASM:      _DTPOFF64_2:
+// DISASM-NEXT: 110ba: fc
 
 .type tls0, at object
 .section .tbss,"awT", at nobits
@@ -91,3 +96,12 @@ _start:
  .word 0x6666
  rex64
  call __tls_get_addr at plt
+ 
+ //LD to LE (2):
+_DTPOFF64_1:
+ .quad tls0 at DTPOFF
+ nop
+
+_DTPOFF64_2:
+ .quad tls1 at DTPOFF
+ nop