The patch from PR21412 is causing miscompilation of glibc. Anything that uses
libpthread is crashing in __libc_dl_error_tsd.
void ** __attribute__ ((const))
__libc_dl_error_tsd (void)
{
static __thread void *data;
return &data;
}
When compiled without the patch:
dl-tsd.os: file format elf64-ia64-little
Disassembly of section .text:
0000000000000000 <__libc_dl_error_tsd>:
0: 18 08 15 06 80 05 [MMB] alloc r33=ar.pfs,5,3,0
1: LTOFF_DTPMOD22 data.6704
6: e0 00 04 00 48 00 addl r14=0,r1
c: 00 00 00 20 nop.b 0x0
10: 01 10 01 02 00 21 [MII] mov r34=r1
16: 00 02 00 62 00 80 mov r32=b0
1c: 04 00 00 84 mov r36=r0;;
20: 1d 18 01 1c 18 10 [MFB] ld8 r35=[r14]
22: PCREL21B __tls_get_addr
26: 00 00 00 02 00 00 nop.f 0x0
2c: 08 00 00 50 br.call.sptk.many b0=20
<__libc_dl_error_tsd+0x20>;;
30: 08 08 00 44 00 21 [MMI] mov r1=r34
36: 20 00 20 00 42 00 mov r2=r8
3c: 00 0a 00 07 mov b0=r32
40: 0b 00 00 00 01 00 [MMI] nop.m 0x0;;
41: DTPREL22 data.6704
46: 20 00 08 00 48 00 addl r2=0,r2
4c: 10 02 aa 00 mov.i ar.pfs=r33;;
50: 11 00 00 00 01 00 [MIB] nop.m 0x0
56: 80 00 08 00 42 80 mov r8=r2
5c: 08 00 84 00 br.ret.sptk.many b0;;
When compiled with the patch:
dl-tsd.os: file format elf64-ia64-little
Disassembly of section .text:
0000000000000000 <__libc_dl_error_tsd>:
0: 08 08 15 06 80 05 [MMI] alloc r33=ar.pfs,5,3,0
1: LTOFF_DTPMOD22 data.6704
6: e0 00 04 00 48 00 addl r14=0,r1
c: 04 00 c4 00 mov r32=b0
10: 0b 10 01 02 00 21 [MMI] mov r34=r1;;
16: e0 00 38 30 20 80 ld8 r14=[r14]
1c: 04 00 00 84 mov r36=r0;;
20: 1d 18 01 1c 18 10 [MFB] ld8 r35=[r14]
22: PCREL21B __tls_get_addr
26: 00 00 00 02 00 00 nop.f 0x0
2c: 08 00 00 50 br.call.sptk.many b0=20
<__libc_dl_error_tsd+0x20>;;
30: 09 08 00 44 00 21 [MMI] mov r1=r34
36: 20 00 20 00 42 00 mov r2=r8
3c: 00 0a 00 07 mov b0=r32;;
40: 11 40 00 04 00 24 [MIB] addl r8=0,r2
40: DTPREL22 data.6704
46: 00 08 01 55 00 80 mov.i ar.pfs=r33
4c: 08 00 84 00 br.ret.sptk.many b0;;
The bad version has one indirection on r14 too much.
--
Summary: [4.0 regression] TLS reference miscompiled
Product: gcc
Version: 4.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: schwab at suse dot de
CC: gcc-bugs at gcc dot gnu dot org,rth at gcc dot gnu dot
org
GCC target triplet: ia64-linux
OtherBugsDependingO 21412
nThis:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21657
