On 6 October 2011 18:52, Dr. David Alan Gilbert <david.gilb...@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. > > PR target/48126 > > * config/arm/arm.c (arm_output_sync_loop): Move label before barrier
> > diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c > index 5161439..6e7105a 100644 > --- a/gcc/config/arm/arm.c > +++ b/gcc/config/arm/arm.c > @@ -24214,8 +24214,11 @@ 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 > OK. Ramana
