[PATCH] ICF: compare type attributes for gimple_call_fntypes.

[PATCH] ICF: compare type attributes for gimple_call_fntypes.

[Martin Liška]

[-- Attachment #1: Type: text/plain, Size: 768 bytes --]

Hi.

The patch compares type attributes for gimple_call_fntypes in IPA ICF.
Note that we were unable to find a generic function attribute that
can be used on a function type definition.

For a one which is allowed assume_aligned(16) I get affects_type_identity == false
which seems suspicious to me.

Note that we currently use comp_type_attributes in ICF for both variable and
function declarations.

Patch can bootstrap on x86_64-linux-gnu and survives regression tests.

Ready to be installed?
Thanks,
Martin

gcc/ChangeLog:

2020-04-02  Martin Liska  <mliska@suse.cz>

	PR ipa/94445
	* ipa-icf-gimple.c (func_checker::compare_gimple_call):
	  Compare type attributes for gimple_call_fntypes.
---
  gcc/ipa-icf-gimple.c | 4 ++++
  1 file changed, 4 insertions(+)



[-- Attachment #2: 0001-ICF-compare-type-attributes-for-gimple_call_fntypes.patch --]
[-- Type: text/x-patch, Size: 814 bytes --]

diff --git a/gcc/ipa-icf-gimple.c b/gcc/ipa-icf-gimple.c
index 3e5b2d4bd6d..fa02809defd 100644
--- a/gcc/ipa-icf-gimple.c
+++ b/gcc/ipa-icf-gimple.c
@@ -37,6 +37,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-eh.h"
 #include "builtins.h"
 #include "cfgloop.h"
+#include "attribs.h"
 
 #include "ipa-icf-gimple.h"
 
@@ -568,6 +569,9 @@ func_checker::compare_gimple_call (gcall *s1, gcall *s2)
       || (fntype1 && !types_compatible_p (fntype1, fntype2)))
     return return_false_with_msg ("call function types are not compatible");
 
+  if (fntype1 && fntype2 && comp_type_attributes (fntype1, fntype2) != 1)
+    return return_false_with_msg ("different fntype attributes");
+
   tree chain1 = gimple_call_chain (s1);
   tree chain2 = gimple_call_chain (s2);
   if ((chain1 && !chain2)

Re: [PATCH] ICF: compare type attributes for gimple_call_fntypes.

[Christophe Lyon]

On Thu, 2 Apr 2020 at 17:16, Martin Liška <mliska@suse.cz> wrote:
>
> Hi.
>
> The patch compares type attributes for gimple_call_fntypes in IPA ICF.
> Note that we were unable to find a generic function attribute that
> can be used on a function type definition.
>
> For a one which is allowed assume_aligned(16) I get affects_type_identity == false
> which seems suspicious to me.
>
> Note that we currently use comp_type_attributes in ICF for both variable and
> function declarations.
>
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>
> Ready to be installed?
> Thanks,
> Martin
>

Hi,

Thanks for the quick patch!

I confirm it fixes the problem I noticed on arm with the cmse-15.c for
-O2 and -O3.

However, the testcase still fails with -Os. I haven't looked at the
details, so it may be a different cause.

Thanks,

Christophe

> gcc/ChangeLog:
>
> 2020-04-02  Martin Liska  <mliska@suse.cz>
>
>         PR ipa/94445
>         * ipa-icf-gimple.c (func_checker::compare_gimple_call):
>           Compare type attributes for gimple_call_fntypes.
> ---
>   gcc/ipa-icf-gimple.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
>

Re: [PATCH] ICF: compare type attributes for gimple_call_fntypes.

[Richard Biener]

On Thu, Apr 2, 2020 at 5:16 PM Martin Liška <mliska@suse.cz> wrote:
>
> Hi.
>
> The patch compares type attributes for gimple_call_fntypes in IPA ICF.
> Note that we were unable to find a generic function attribute that
> can be used on a function type definition.
>
> For a one which is allowed assume_aligned(16) I get affects_type_identity == false
> which seems suspicious to me.
>
> Note that we currently use comp_type_attributes in ICF for both variable and
> function declarations.
>
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>
> Ready to be installed?

OK.

Richard.

> Thanks,
> Martin
>
> gcc/ChangeLog:
>
> 2020-04-02  Martin Liska  <mliska@suse.cz>
>
>         PR ipa/94445
>         * ipa-icf-gimple.c (func_checker::compare_gimple_call):
>           Compare type attributes for gimple_call_fntypes.
> ---
>   gcc/ipa-icf-gimple.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
>

Re: [PATCH] ICF: compare type attributes for gimple_call_fntypes.

[Martin Liška]

On 4/2/20 7:17 PM, Christophe Lyon wrote:
> On Thu, 2 Apr 2020 at 17:16, Martin Liška <mliska@suse.cz> wrote:
>>
>> Hi.
>>
>> The patch compares type attributes for gimple_call_fntypes in IPA ICF.
>> Note that we were unable to find a generic function attribute that
>> can be used on a function type definition.
>>
>> For a one which is allowed assume_aligned(16) I get affects_type_identity == false
>> which seems suspicious to me.
>>
>> Note that we currently use comp_type_attributes in ICF for both variable and
>> function declarations.
>>
>> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>>
>> Ready to be installed?
>> Thanks,
>> Martin
>>
> 
> Hi,
> 
> Thanks for the quick patch!

Hi.

Good!

> 
> I confirm it fixes the problem I noticed on arm with the cmse-15.c for
> -O2 and -O3.
> 
> However, the testcase still fails with -Os. I haven't looked at the
> details, so it may be a different cause.

I analyzed that slightly and there are still IPA ICF merged that happen
(this time valid transformations):

/home/marxin/Programming/gcc/gcc/testsuite/gcc.target/arm/cmse/cmse-15.c:14:5: optimized: Semantic equality hit:nonsecure0/4->nonsecure2/6
/home/marxin/Programming/gcc/gcc/testsuite/gcc.target/arm/cmse/cmse-15.c:14:5: optimized: Assembler symbol names:nonsecure0/4->nonsecure2/6

/home/marxin/Programming/gcc/gcc/testsuite/gcc.target/arm/cmse/cmse-15.c:33:5: optimized: Semantic equality hit:secure0/8->secure2/10
/home/marxin/Programming/gcc/gcc/testsuite/gcc.target/arm/cmse/cmse-15.c:33:5: optimized: Assembler symbol names:secure0/8->secure2/10

and with -Os nosecure2 -> mosecure0 call is not inlined bad again. That makes the scanning pattern to miss:

-Os version:
nonsecure2:
	@ args = 0, pretend = 0, frame = 0
	@ frame_needed = 0, uses_anonymous_args = 0
	@ link register save eliminated.
	b	nonsecure0

-O2 version:
nonsecure2:
	@ args = 0, pretend = 0, frame = 0
	@ frame_needed = 0, uses_anonymous_args = 0
	push	{r4, lr}
	lsrs	r0, r0, #1
	lsls	r0, r0, #1
	mov	r1, r0
	mov	r2, r0
	mov	r3, r0
	bl	__gnu_cmse_nonsecure_call

Martin

> 
> Thanks,
> 
> Christophe
> 
>> gcc/ChangeLog:
>>
>> 2020-04-02  Martin Liska  <mliska@suse.cz>
>>
>>          PR ipa/94445
>>          * ipa-icf-gimple.c (func_checker::compare_gimple_call):
>>            Compare type attributes for gimple_call_fntypes.
>> ---
>>    gcc/ipa-icf-gimple.c | 4 ++++
>>    1 file changed, 4 insertions(+)
>>
>>