| Message ID | 20110726090156.GD6925@davesworkthinkpad |
|---|---|
| State | New |
| Headers | show |
On 26 July 2011 10:01, Dr. David Alan Gilbert <david.gilbert@linaro.org> wrote: > Micahel K. Edwards points out in PR/48126 that the sync is in the wrong place > relative to the branch target of the compare, since the load could float > up beyond the ldrex. > > gcc/ > * config/arm/arm.c (arm_output_sync_loop): Move label before barier, > fixes PR/48126 s/barier/barrier. This is OK for trunk and appropriate release branches after due testing. Next time note that the Changelog entry should read - The PR number really shouldn't be a part of the actual log. PR target/48126 * config/arm/arm.c (arm_output_sync_loop): Move label before barrier. with appropriate formatting. Thanks, Ramana
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index 28be078..cee3471 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -23780,8 +23780,11 @@ arm_output_sync_loop (emit_f emit, } } - arm_process_output_memory_barrier (emit, NULL); + /* Note: label is before barrier so that in cmp failure case we still get + a barrier to stop subsequent loads floating upwards past the ldrex + pr/48126 */ arm_output_asm_insn (emit, 1, operands, "%sLSYB%%=:", LOCAL_LABEL_PREFIX); + arm_process_output_memory_barrier (emit, NULL); } static rtx
Micahel K. Edwards points out in PR/48126 that the sync is in the wrong place relative to the branch target of the compare, since the load could float up beyond the ldrex. gcc/ * config/arm/arm.c (arm_output_sync_loop): Move label before barier, fixes PR/48126