RS6000_PIC_OFFSET_TABLE_REGNUM isn't being set up for functions that don't need a constant pool but access __thread vars using __tls_get_addr. /* Fails with -m64 -mminimal-toc -fPIC */ static __thread int x; int foo (void) { return x; } This is the reason why powerpc64 has been getting lots of libjava failures since this libjava change: 2005-09-27 Tom Tromey <tromey@redhat.com>
Confirmed, This is a latent bug but shows up as testsuite regressions which is why I am marking it as a regression.
Actually, it's not that RS6000_PIC_OFFSET_TABLE_REGNUM isn't being set up, it's that RS6000_PIC_OFFSET_TABLE_REGNUM is wrongly being using for tls accesses. As currently implemented by gcc, powerpc tls uses x@got@tlsgd and similar. ie. we are expecting the linker to manage allocation of tls entries in the got rather than having gcc allocate them itself in toc sections. This means that powerpc64 should use r2 for tls always, even when -mminimal-toc. Testing the following fix. Index: gcc/config/rs6000/rs6000.c =================================================================== RCS file: /cvs/gcc/gcc/gcc/config/rs6000/rs6000.c,v retrieving revision 1.872 diff -u -p -r1.872 rs6000.c --- gcc/config/rs6000/rs6000.c 6 Oct 2005 22:58:59 -0000 1.872 +++ gcc/config/rs6000/rs6000.c 21 Oct 2005 05:02:57 -0000 @@ -2979,7 +2979,7 @@ rs6000_legitimize_tls_address (rtx addr, rtx r3, got, tga, tmp1, tmp2, eqv; if (TARGET_64BIT) - got = gen_rtx_REG (Pmode, TOC_REGISTER); + got = gen_rtx_REG (Pmode, 2); else { if (flag_pic == 1)
Subject: Bug 24465 CVSROOT: /cvs/gcc Module name: gcc Changes by: amodra@gcc.gnu.org 2005-10-21 07:33:30 Modified files: gcc : ChangeLog gcc/config/rs6000: rs6000.c Log message: PR target/24465 * config/rs6000/rs6000.c (rs6000_legitimize_tls_address): Always use r2 for 64-bit tls .got access. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.10197&r2=2.10198 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/config/rs6000/rs6000.c.diff?cvsroot=gcc&r1=1.872&r2=1.873
Subject: Bug 24465 CVSROOT: /cvs/gcc Module name: gcc Branch: gcc-4_0-branch Changes by: amodra@gcc.gnu.org 2005-10-21 07:36:56 Modified files: gcc : ChangeLog gcc/config/rs6000: rs6000.c Log message: PR target/24465 * config/rs6000/rs6000.c (rs6000_legitimize_tls_address): Always use r2 for 64-bit tls .got access. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=2.7592.2.475&r2=2.7592.2.476 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/config/rs6000/rs6000.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.788.2.11&r2=1.788.2.12
Subject: Bug 24465 CVSROOT: /cvs/gcc Module name: gcc Branch: gcc-3_4-branch Changes by: amodra@gcc.gnu.org 2005-10-21 07:48:26 Modified files: gcc : ChangeLog gcc/config/rs6000: rs6000.c Log message: PR target/24465 * config/rs6000/rs6000.c (rs6000_legitimize_tls_address): Always use r2 for 64-bit tls .got access. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=2.2326.2.925&r2=2.2326.2.926 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/config/rs6000/rs6000.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.576.2.46&r2=1.576.2.47
Fixed on all active branches