From: Bernd Edlinger <bernd.edlinger@hotmail.de>
To: Kyrill Tkachov <kyrylo.tkachov@foss.arm.com>,
Richard Biener <rguenther@suse.de>
Cc: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>,
Richard Earnshaw <richard.earnshaw@arm.com>,
Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>,
Eric Botcazou <ebotcazou@adacore.com>, Jeff Law <law@redhat.com>,
Jakub Jelinek <jakub@redhat.com>
Subject: Re: [PATCH] Sanitizing the middle-end interface to the back-end for strict alignment
Date: Wed, 28 Aug 2019 11:50:00 -0000 [thread overview]
Message-ID: <AM6PR10MB25661FB67616EA66FCE66224E4A30@AM6PR10MB2566.EURPRD10.PROD.OUTLOOK.COM> (raw)
In-Reply-To: <52c7ef9f-9fa2-6126-abf3-dc48c1a2d580@foss.arm.com>
[-- Attachment #1: Type: text/plain, Size: 2245 bytes --]
On 8/27/19 11:25 AM, Kyrill Tkachov wrote:
> Hi Bernd,
>
> On 8/15/19 8:47 PM, Bernd Edlinger wrote:
>> Hi,
>>
>> this is the split out part from the "Fix not 8-byte aligned ldrd/strd on ARMv5 (PR 89544)"
>> which is sanitizing the middle-end interface to the back-end for strict alignment,
>> and a couple of bug-fixes that are necessary to survive boot-strap.
>> It is intended to be applied after the PR 89544 fix.
>>
>> I think it would be possible to change the default implementation of STACK_SLOT_ALIGNMENT
>> to make all stack variables always naturally aligned instead of doing that only
>> in assign_parm_setup_stack, but would still like to avoid changing too many things
>> that do not seem to have a problem. Since this would affect many targets, and more
>> kinds of variables that may probably not have a strict alignment problem.
>> But I am ready to take your advice though.
>>
>>
>> Boot-strapped and reg-tested on x86_64-pc-linux-gnu and arm-linux-gnueabihf
>> Is it OK for trunk?
>
> I'm not opposed to the checks but...
>
>
>>
>> Thanks
>> Bernd.
>>
>
> Index: gcc/config/arm/vec-common.md
> ===================================================================
> --- gcc/config/arm/vec-common.md (Revision 274531)
> +++ gcc/config/arm/vec-common.md (Arbeitskopie)
> @@ -26,6 +26,12 @@
> "TARGET_NEON
> || (TARGET_REALLY_IWMMXT && VALID_IWMMXT_REG_MODE (<MODE>mode))"
> {
> + gcc_checking_assert (!MEM_P (operands[0])
> + || MEM_ALIGN (operands[0])
> + >= GET_MODE_ALIGNMENT (<MODE>mode));
> + gcc_checking_assert (!MEM_P (operands[1])
> + || MEM_ALIGN (operands[1])
> + >= GET_MODE_ALIGNMENT (<MODE>mode));
> if (can_create_pseudo_p ())
> {
> if (!REG_P (operands[0]))
>
> ... can we please factor the (!MEM_P (operands[0]) || MEM_ALIGN (operands[0]) >= GET_MODE_ALIGNMENT (<MODE>mode)) checks into a common function and use that?
>
Sure, good idea. How about converting it to a predicate?
This creates 1:1 equivalent code to the open coded assertions.
Is it OK for trunk?
Thanks
Bernd.
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[-- Attachment #2: patch-strict-align.diff --]
[-- Type: text/x-patch; name="patch-strict-align.diff", Size: 8624 bytes --]
2019-08-15 Bernd Edlinger <bernd.edlinger@hotmail.de>
Richard Biener <rguenther@suse.de>
* expr.c (expand_assignment): Handle misaligned DECLs.
(expand_expr_real_1): Handle FUNCTION_DECL as unaligned.
* function.c (assign_parm_adjust_stack_rtl): Check movmisalign optab
too.
(assign_parm_setup_stack): Allocate properly aligned stack slots.
* varasm.c (build_constant_desc): Align constants of misaligned types.
* config/arm/predicates.md (aligned_operand): New predicate.
* config/arm/arm.md (movdi, movsi, movhi, movhf, movsf, movdf): Use
sligned_operand to check restrictions on memory addresses.
* config/arm/neon.md (movti, mov<VSTRUCT>, mov<VH>): Likewise.
* config/arm/vec-common.md (mov<VALL>): Likewise.
Index: gcc/config/arm/arm.md
===================================================================
--- gcc/config/arm/arm.md (revision 274946)
+++ gcc/config/arm/arm.md (working copy)
@@ -5231,6 +5231,8 @@
(match_operand:DI 1 "general_operand"))]
"TARGET_EITHER"
"
+ gcc_checking_assert (aligned_operand (operands[0], DImode));
+ gcc_checking_assert (aligned_operand (operands[1], DImode));
if (can_create_pseudo_p ())
{
if (!REG_P (operands[0]))
@@ -5407,6 +5409,8 @@
{
rtx base, offset, tmp;
+ gcc_checking_assert (aligned_operand (operands[0], SImode));
+ gcc_checking_assert (aligned_operand (operands[1], SImode));
if (TARGET_32BIT || TARGET_HAVE_MOVT)
{
/* Everything except mem = const or mem = mem can be done easily. */
@@ -5896,6 +5900,8 @@
(match_operand:HI 1 "general_operand"))]
"TARGET_EITHER"
"
+ gcc_checking_assert (aligned_operand (operands[0], HImode));
+ gcc_checking_assert (aligned_operand (operands[1], HImode));
if (TARGET_ARM)
{
if (can_create_pseudo_p ())
@@ -6305,6 +6311,8 @@
(match_operand:HF 1 "general_operand"))]
"TARGET_EITHER"
"
+ gcc_checking_assert (aligned_operand (operands[0], HFmode));
+ gcc_checking_assert (aligned_operand (operands[1], HFmode));
if (TARGET_32BIT)
{
if (MEM_P (operands[0]))
@@ -6369,6 +6377,8 @@
(match_operand:SF 1 "general_operand"))]
"TARGET_EITHER"
"
+ gcc_checking_assert (aligned_operand (operands[0], SFmode));
+ gcc_checking_assert (aligned_operand (operands[1], SFmode));
if (TARGET_32BIT)
{
if (MEM_P (operands[0]))
@@ -6464,6 +6474,8 @@
(match_operand:DF 1 "general_operand"))]
"TARGET_EITHER"
"
+ gcc_checking_assert (aligned_operand (operands[0], DFmode));
+ gcc_checking_assert (aligned_operand (operands[1], DFmode));
if (TARGET_32BIT)
{
if (MEM_P (operands[0]))
Index: gcc/config/arm/neon.md
===================================================================
--- gcc/config/arm/neon.md (revision 274946)
+++ gcc/config/arm/neon.md (working copy)
@@ -127,6 +127,8 @@
(match_operand:TI 1 "general_operand"))]
"TARGET_NEON"
{
+ gcc_checking_assert (aligned_operand (operands[0], TImode));
+ gcc_checking_assert (aligned_operand (operands[1], TImode));
if (can_create_pseudo_p ())
{
if (!REG_P (operands[0]))
@@ -139,6 +141,8 @@
(match_operand:VSTRUCT 1 "general_operand"))]
"TARGET_NEON"
{
+ gcc_checking_assert (aligned_operand (operands[0], <MODE>mode));
+ gcc_checking_assert (aligned_operand (operands[1], <MODE>mode));
if (can_create_pseudo_p ())
{
if (!REG_P (operands[0]))
@@ -151,6 +155,8 @@
(match_operand:VH 1 "s_register_operand"))]
"TARGET_NEON"
{
+ gcc_checking_assert (aligned_operand (operands[0], <MODE>mode));
+ gcc_checking_assert (aligned_operand (operands[1], <MODE>mode));
if (can_create_pseudo_p ())
{
if (!REG_P (operands[0]))
Index: gcc/config/arm/predicates.md
===================================================================
--- gcc/config/arm/predicates.md (revision 274946)
+++ gcc/config/arm/predicates.md (working copy)
@@ -697,3 +697,7 @@
(ior (and (match_code "symbol_ref")
(match_test "!arm_is_long_call_p (SYMBOL_REF_DECL (op))"))
(match_operand 0 "s_register_operand")))
+
+(define_special_predicate "aligned_operand"
+ (ior (not (match_code "mem"))
+ (match_test "MEM_ALIGN (op) >= GET_MODE_ALIGNMENT (mode)")))
Index: gcc/config/arm/vec-common.md
===================================================================
--- gcc/config/arm/vec-common.md (revision 274946)
+++ gcc/config/arm/vec-common.md (working copy)
@@ -26,6 +26,8 @@
"TARGET_NEON
|| (TARGET_REALLY_IWMMXT && VALID_IWMMXT_REG_MODE (<MODE>mode))"
{
+ gcc_checking_assert (aligned_operand (operands[0], <MODE>mode));
+ gcc_checking_assert (aligned_operand (operands[1], <MODE>mode));
if (can_create_pseudo_p ())
{
if (!REG_P (operands[0]))
Index: gcc/expr.c
===================================================================
--- gcc/expr.c (revision 274946)
+++ gcc/expr.c (working copy)
@@ -5001,9 +5001,10 @@ expand_assignment (tree to, tree from, bool nontem
/* Handle misaligned stores. */
mode = TYPE_MODE (TREE_TYPE (to));
if ((TREE_CODE (to) == MEM_REF
- || TREE_CODE (to) == TARGET_MEM_REF)
+ || TREE_CODE (to) == TARGET_MEM_REF
+ || DECL_P (to))
&& mode != BLKmode
- && !mem_ref_refers_to_non_mem_p (to)
+ && (DECL_P (to) || !mem_ref_refers_to_non_mem_p (to))
&& ((align = get_object_alignment (to))
< GET_MODE_ALIGNMENT (mode))
&& (((icode = optab_handler (movmisalign_optab, mode))
@@ -10795,6 +10796,14 @@ expand_expr_real_1 (tree exp, rtx target, machine_
MEM_VOLATILE_P (op0) = 1;
}
+ if (MEM_P (op0) && TREE_CODE (tem) == FUNCTION_DECL)
+ {
+ if (op0 == orig_op0)
+ op0 = copy_rtx (op0);
+
+ set_mem_align (op0, BITS_PER_UNIT);
+ }
+
/* In cases where an aligned union has an unaligned object
as a field, we might be extracting a BLKmode value from
an integer-mode (e.g., SImode) object. Handle this case
Index: gcc/function.c
===================================================================
--- gcc/function.c (revision 274946)
+++ gcc/function.c (working copy)
@@ -2807,8 +2807,10 @@ assign_parm_adjust_stack_rtl (struct assign_parm_d
stack slot, if we need one. */
if (stack_parm
&& ((GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm)
- && targetm.slow_unaligned_access (data->nominal_mode,
- MEM_ALIGN (stack_parm)))
+ && ((optab_handler (movmisalign_optab, data->nominal_mode)
+ != CODE_FOR_nothing)
+ || targetm.slow_unaligned_access (data->nominal_mode,
+ MEM_ALIGN (stack_parm))))
|| (data->nominal_type
&& TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
&& MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
@@ -3461,11 +3463,20 @@ assign_parm_setup_stack (struct assign_parm_data_a
int align = STACK_SLOT_ALIGNMENT (data->arg.type,
GET_MODE (data->entry_parm),
TYPE_ALIGN (data->arg.type));
+ if (align < (int)GET_MODE_ALIGNMENT (GET_MODE (data->entry_parm))
+ && ((optab_handler (movmisalign_optab,
+ GET_MODE (data->entry_parm))
+ != CODE_FOR_nothing)
+ || targetm.slow_unaligned_access (GET_MODE (data->entry_parm),
+ align)))
+ align = GET_MODE_ALIGNMENT (GET_MODE (data->entry_parm));
data->stack_parm
= assign_stack_local (GET_MODE (data->entry_parm),
GET_MODE_SIZE (GET_MODE (data->entry_parm)),
align);
+ align = MEM_ALIGN (data->stack_parm);
set_mem_attributes (data->stack_parm, parm, 1);
+ set_mem_align (data->stack_parm, align);
}
dest = validize_mem (copy_rtx (data->stack_parm));
Index: gcc/varasm.c
===================================================================
--- gcc/varasm.c (revision 274946)
+++ gcc/varasm.c (working copy)
@@ -47,6 +47,7 @@ along with GCC; see the file COPYING3. If not see
#include "stmt.h"
#include "expr.h"
#include "expmed.h"
+#include "optabs.h"
#include "output.h"
#include "langhooks.h"
#include "debug.h"
@@ -3386,7 +3387,15 @@ build_constant_desc (tree exp)
if (TREE_CODE (exp) == STRING_CST)
SET_DECL_ALIGN (decl, targetm.constant_alignment (exp, DECL_ALIGN (decl)));
else
- align_variable (decl, 0);
+ {
+ align_variable (decl, 0);
+ if (DECL_ALIGN (decl) < GET_MODE_ALIGNMENT (DECL_MODE (decl))
+ && ((optab_handler (movmisalign_optab, DECL_MODE (decl))
+ != CODE_FOR_nothing)
+ || targetm.slow_unaligned_access (DECL_MODE (decl),
+ DECL_ALIGN (decl))))
+ SET_DECL_ALIGN (decl, GET_MODE_ALIGNMENT (DECL_MODE (decl)));
+ }
/* Now construct the SYMBOL_REF and the MEM. */
if (use_object_blocks_p ())
next prev parent reply other threads:[~2019-08-28 9:38 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-10 12:51 [PATCHv2] Fix not 8-byte aligned ldrd/strd on ARMv5 (PR 89544) Bernd Edlinger
2019-03-19 14:01 ` [PING] " Bernd Edlinger
2019-03-21 11:26 ` Richard Biener
2019-03-22 17:47 ` Bernd Edlinger
2019-03-25 9:28 ` Richard Biener
2019-07-30 22:13 ` [PATCHv3] " Bernd Edlinger
2019-07-31 13:17 ` Richard Earnshaw (lists)
2019-08-01 11:19 ` Bernd Edlinger
2019-08-02 9:10 ` Richard Earnshaw (lists)
2019-08-02 13:11 ` Richard Biener
2019-08-02 19:01 ` Bernd Edlinger
2019-08-08 14:20 ` [PATCHv4] " Bernd Edlinger
2019-08-14 10:54 ` [PING] " Bernd Edlinger
2019-08-14 12:27 ` Richard Biener
2019-08-14 22:26 ` Bernd Edlinger
2019-08-15 8:58 ` Richard Biener
2019-08-15 12:38 ` Bernd Edlinger
2019-08-15 13:03 ` Richard Biener
2019-08-15 14:33 ` Richard Biener
2019-08-15 15:28 ` Bernd Edlinger
2019-08-15 17:42 ` Richard Biener
2019-08-15 21:19 ` [PATCHv5] " Bernd Edlinger
2019-08-20 5:38 ` Jeff Law
2019-08-20 15:04 ` John David Anglin
[not found] ` <0d39b64f-67d9-7857-cf4e-36f09c0dc15e@bell.net>
2019-08-20 16:03 ` Fwd: " Bernd Edlinger
2019-09-04 12:53 ` Richard Earnshaw (lists)
2019-09-04 13:29 ` Bernd Edlinger
2019-09-04 14:14 ` Richard Earnshaw (lists)
2019-09-04 15:00 ` Bernd Edlinger
2019-09-04 15:48 ` Richard Earnshaw (lists)
2019-09-05 9:21 ` Richard Earnshaw (lists)
2019-09-05 9:35 ` Bernd Edlinger
2019-09-06 10:15 ` Bernd Edlinger
2019-09-06 10:18 ` Richard Earnshaw (lists)
2019-08-15 21:27 ` [PATCH] Sanitizing the middle-end interface to the back-end for strict alignment Bernd Edlinger
2019-08-17 10:11 ` Bernd Edlinger
2019-08-23 0:01 ` Jeff Law
2019-08-23 0:05 ` Jeff Law
2019-08-23 15:15 ` [PING] " Bernd Edlinger
2019-08-27 10:07 ` Kyrill Tkachov
2019-08-28 11:50 ` Bernd Edlinger [this message]
2019-08-28 12:01 ` Kyrill Tkachov
2019-08-28 13:54 ` Christophe Lyon
2019-08-28 21:48 ` Bernd Edlinger
2019-08-29 9:09 ` Kyrill Tkachov
2019-08-29 10:00 ` Christophe Lyon
2019-08-29 22:57 ` Bernd Edlinger
2019-08-30 10:07 ` Kyrill Tkachov
2019-08-30 15:22 ` Christophe Lyon
2019-08-14 11:56 ` [PATCHv3] Fix not 8-byte aligned ldrd/strd on ARMv5 (PR 89544) Richard Biener
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