Hi, When x86-64 TLS support was added by:
http://gcc.gnu.org/ml/gcc-patches/2002-10/msg01262.html it didn't allow negative offset. Jakub, do you remember the reason for it? I tested this patch on Linux/x86-64 and used the new GCC to build glibc for x86-64 and x32. There are no regressions. OK to install? Thanks. H.J. ---- gcc/ 2012-09-02 H.J. Lu <hongjiu...@intel.com> PR target/54445 * config/i386/predicates.md (x86_64_immediate_operand): Allow negative offset for UNSPEC_DTPOFF/UNSPEC_NTPOFF. gcc/testsuite/ 2012-09-02 H.J. Lu <hongjiu...@intel.com> PR target/54445 * gcc.target/i386/pr54445-1.c: New file. * gcc.target/i386/pr54445-2.c: Likewise. diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md index 55e4b56..159594e 100644 --- a/gcc/config/i386/predicates.md +++ b/gcc/config/i386/predicates.md @@ -228,8 +228,7 @@ { case UNSPEC_DTPOFF: case UNSPEC_NTPOFF: - if (offset > 0 - && trunc_int_for_mode (offset, SImode) == offset) + if (trunc_int_for_mode (offset, SImode) == offset) return true; } break; diff --git a/gcc/testsuite/gcc.target/i386/pr54445-1.c b/gcc/testsuite/gcc.target/i386/pr54445-1.c new file mode 100644 index 0000000..72ef84e --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr54445-1.c @@ -0,0 +1,24 @@ +/* { dg-do run } */ +/* { dg-options "-O2" } */ + +__thread unsigned char tls_array[64]; + +unsigned char +__attribute__ ((noinline)) +tls_array_lookup_with_negative_constant(long long int position) { + return tls_array[position - 1]; +} + +int +main () +{ + int i; + + for (i = 0; i < sizeof (tls_array) / sizeof (tls_array[0]); i++) + tls_array[i] = i; + + for (i = 0; i < sizeof (tls_array) / sizeof (tls_array[0]); i++) + if (i != tls_array_lookup_with_negative_constant (i + 1)) + __builtin_abort (); + return 0; +} diff --git a/gcc/testsuite/gcc.target/i386/pr54445-2.c b/gcc/testsuite/gcc.target/i386/pr54445-2.c new file mode 100644 index 0000000..5151c13 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr54445-2.c @@ -0,0 +1,11 @@ +/* { dg-do compile { target { *-*-linux* && { ! { ia32 } } } } } */ +/* { dg-options "-O2 -fno-pic" } */ + +__thread unsigned char tls_array[64]; + +unsigned char +tls_array_lookup_with_negative_constant(long long int position) { + return tls_array[position - 1]; +} + +/* { dg-final { scan-assembler "mov(b|zbl)\[ \t\](%fs:)?tls_array@tpoff-1\\(%" } } */
