On 04/11/15 09:45, Jiong Wang wrote: > As discussed at the bugzilla > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67305 > > neon_vector_mem_operand is broken. As the comments says > "/* Reject eliminable registers. */", the code block at the head > of this function which checks eliminable registers is designed to do > early reject only, there shouldn't be any early accept. > > If this code hunk doesn't reject the incoming rtx, then the rtx pattern > should still go through all default checks below. All other similar > functions, thumb1_legitimate_address_p, arm_coproc_mem_operand, > neon_struct_mem_operand etc are exactly follow this check flow. > > So as Jim Wilson commented on the bugzilla, instead of "return !strict", > we need to only do the check if strict be true, and only does rejection > which means return FALSE, for all other cases, we need to go through > those normal checks below. > > neon_vector_mem_operand is only used by several misalign pattern, I > guess that's why this bug is not exposed for long time. > > boostrap & regression OK on armv8 aarch32, ok for trunk? > > 2015-11-04 Jiong Wang <jiong.w...@arm.com> > Jim Wilson <wil...@gcc.gnu.org> > > gcc/ > PR target/67305 > * config/arm/arm.md (neon_vector_mem_operand): Return FALSE if strict > be true and eliminable registers mentioned. >
This has been lurking for a long time ... Sorry about the delay in reviewing. This is OK for trunk regards Ramana > > neon-mem.patch > > > diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c > index 87e55e9..7fbf897 100644 > --- a/gcc/config/arm/arm.c > +++ b/gcc/config/arm/arm.c > @@ -12957,14 +12957,14 @@ neon_vector_mem_operand (rtx op, int type, bool > strict) > rtx ind; > > /* Reject eliminable registers. */ > - if (! (reload_in_progress || reload_completed) > - && ( reg_mentioned_p (frame_pointer_rtx, op) > + if (strict && ! (reload_in_progress || reload_completed) > + && (reg_mentioned_p (frame_pointer_rtx, op) > || reg_mentioned_p (arg_pointer_rtx, op) > || reg_mentioned_p (virtual_incoming_args_rtx, op) > || reg_mentioned_p (virtual_outgoing_args_rtx, op) > || reg_mentioned_p (virtual_stack_dynamic_rtx, op) > || reg_mentioned_p (virtual_stack_vars_rtx, op))) > - return !strict; > + return FALSE; > > /* Constants are converted into offsets from labels. */ > if (!MEM_P (op)) >
