RE: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Thanks. All the best, Peixin -Original Message- From: Richard Sandiford [mailto:richard.sandif...@arm.com] Sent: Wednesday, August 19, 2020 5:56 PM To: qiaopeixin Cc: Christophe Lyon ; gcc-patches@gcc.gnu.org Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479] qiaopeixin writes: > Hi Richard, > > Thanks for the example. > > I remove the whole line "& && TREE_PUBLIC (fndecl)" and passed > bootstrap and deja tests. I add your provided example under > /gcc.target/aarch64, and the patch is attached. Thanks, pushed to master. Richard
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
qiaopeixin writes: > Hi Richard, > > Thanks for the example. > > I remove the whole line "& && TREE_PUBLIC (fndecl)" and passed > bootstrap and deja tests. I add your provided example under > /gcc.target/aarch64, and the patch is attached. Thanks, pushed to master. Richard
RE: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Hi Richard,
Thanks for the example.
I remove the whole line "& && TREE_PUBLIC (fndecl)" and passed bootstrap
and deja tests. I add your provided example under /gcc.target/aarch64, and the
patch is attached.
By the way, the new example also passed deja tests.
All the best,
Peixin
-Original Message-
From: Richard Sandiford [mailto:richard.sandif...@arm.com]
Sent: Wednesday, August 19, 2020 1:01 AM
To: qiaopeixin
Cc: Christophe Lyon ; gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value
[PR96479]
qiaopeixin writes:
> Hi Richard,
>
> Thanks for the review and explanation.
>
> The previous fix adding if condition of TARGET_FLOAT does crash glibc-2.29.
>
> I checked the past log of writing the function aarch64_init_cumulative_args,
> and did not find the reason why Alan Lawrence added TREE_PUBLIC (fndecl) as
> one condition for entering the function type check. Maybe Alan could clarify?
> I tried to delete TREE_PUBLIC (fndecl), which turns out could solve both the
> glibc problem and the previous ICE problem. A new fix is made as following,
> passed bootstrap and deja test. I believe this fix is reasonable, since the
> function type should be checked no matter if it has external linkage or not.
>
> The function aarch64_init_cumulative_args checks the function types and
> should catch the error that "-mgeneral-regs-only" is incompatible with the
> use of SIMD/FP registers. In the test case on PR96479, the function myfunc2
> returns one vector of 4 integers, while it is defined static type.
> TREE_PUBLIC (fndecl) is set as false and it prevents from entering if
> statement and checking function types. I delete "TREE_PUBLIC (fndecl)" so
> that gcc can catch the error through the function
> aarch64_init_cumulative_args now. The ICE on PR96479 can report the
> diagnostic error with this fix. The patch for the fix is attached as
> following:
>
> diff --git a/gcc/config/aarch64/aarch64.c
> b/gcc/config/aarch64/aarch64.c index b7f5bc76f1b..9ce83dce131 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -6017,7 +6017,7 @@ aarch64_init_cumulative_args (CUMULATIVE_ARGS
> *pcum,
>
>if (!silent_p
>&& !TARGET_FLOAT
> - && fndecl && TREE_PUBLIC (fndecl)
> + && fndecl
>&& fntype && fntype != error_mark_node)
> {
>const_tree type = TREE_TYPE (fntype);
I think the fndecl test is problematic too though. E.g. consider:
typedef int v4si __attribute__((vector_size(16)));
v4si (*foo) ();
void f (v4si *ptr) { *ptr = foo (); }
which ICEs for me even with the above.
I suggest we just remove the line and see whether anything breaks.
Thanks,
Richard
0001-AArch64-Remove-fndecl-TREE_PUBLIC-fndecl-in-aarch64_.patch
Description: 0001-AArch64-Remove-fndecl-TREE_PUBLIC-fndecl-in-aarch64_.patch
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
qiaopeixin writes:
> Hi Richard,
>
> Thanks for the review and explanation.
>
> The previous fix adding if condition of TARGET_FLOAT does crash glibc-2.29.
>
> I checked the past log of writing the function aarch64_init_cumulative_args,
> and did not find the reason why Alan Lawrence added TREE_PUBLIC (fndecl) as
> one condition for entering the function type check. Maybe Alan could clarify?
> I tried to delete TREE_PUBLIC (fndecl), which turns out could solve both the
> glibc problem and the previous ICE problem. A new fix is made as following,
> passed bootstrap and deja test. I believe this fix is reasonable, since the
> function type should be checked no matter if it has external linkage or not.
>
> The function aarch64_init_cumulative_args checks the function types and
> should catch the error that "-mgeneral-regs-only" is incompatible with the
> use of SIMD/FP registers. In the test case on PR96479, the function myfunc2
> returns one vector of 4 integers, while it is defined static type.
> TREE_PUBLIC (fndecl) is set as false and it prevents from entering if
> statement and checking function types. I delete "TREE_PUBLIC (fndecl)" so
> that gcc can catch the error through the function
> aarch64_init_cumulative_args now. The ICE on PR96479 can report the
> diagnostic error with this fix. The patch for the fix is attached as
> following:
>
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index b7f5bc76f1b..9ce83dce131 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -6017,7 +6017,7 @@ aarch64_init_cumulative_args (CUMULATIVE_ARGS *pcum,
>
>if (!silent_p
>&& !TARGET_FLOAT
> - && fndecl && TREE_PUBLIC (fndecl)
> + && fndecl
>&& fntype && fntype != error_mark_node)
> {
>const_tree type = TREE_TYPE (fntype);
I think the fndecl test is problematic too though. E.g. consider:
typedef int v4si __attribute__((vector_size(16)));
v4si (*foo) ();
void f (v4si *ptr) { *ptr = foo (); }
which ICEs for me even with the above.
I suggest we just remove the line and see whether anything breaks.
Thanks,
Richard
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
On Tue, 18 Aug 2020 at 05:38, qiaopeixin wrote:
>
> Hi Richard,
>
> Thanks for the review and explanation.
>
> The previous fix adding if condition of TARGET_FLOAT does crash glibc-2.29.
>
> I checked the past log of writing the function aarch64_init_cumulative_args,
> and did not find the reason why Alan Lawrence added TREE_PUBLIC (fndecl) as
> one condition for entering the function type check. Maybe Alan could clarify?
> I tried to delete TREE_PUBLIC (fndecl), which turns out could solve both the
> glibc problem and the previous ICE problem. A new fix is made as following,
> passed bootstrap and deja test. I believe this fix is reasonable, since the
> function type should be checked no matter if it has external linkage or not.
>
> The function aarch64_init_cumulative_args checks the function types and
> should catch the error that "-mgeneral-regs-only" is incompatible with the
> use of SIMD/FP registers. In the test case on PR96479, the function myfunc2
> returns one vector of 4 integers, while it is defined static type.
> TREE_PUBLIC (fndecl) is set as false and it prevents from entering if
> statement and checking function types. I delete "TREE_PUBLIC (fndecl)" so
> that gcc can catch the error through the function
> aarch64_init_cumulative_args now. The ICE on PR96479 can report the
> diagnostic error with this fix. The patch for the fix is attached as
> following:
>
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index b7f5bc76f1b..9ce83dce131 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -6017,7 +6017,7 @@ aarch64_init_cumulative_args (CUMULATIVE_ARGS *pcum,
>
>if (!silent_p
>&& !TARGET_FLOAT
> - && fndecl && TREE_PUBLIC (fndecl)
> + && fndecl
>&& fntype && fntype != error_mark_node)
> {
>const_tree type = TREE_TYPE (fntype);
>
> Christophe, thanks for your tests on glibc-2.29. With the above fix, I built
> glibc-2.29, and the previous error does not show up now. Could you please
> check if this fix works?
Hi,
I confirm this works OK for my testing (aarch64-linux-gnu and aarch64-elf)
Thanks,
Christophe
>
> Do you have any suggestions on this fix?
>
> All the best,
> Peixin
>
>
> -Original Message-----
> From: Richard Sandiford [mailto:richard.sandif...@arm.com]
> Sent: Thursday, August 13, 2020 8:19 PM
> To: Christophe Lyon
> Cc: qiaopeixin ; gcc-patches@gcc.gnu.org
> Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value
> [PR96479]
>
> Christophe Lyon writes:
> > On Thu, 13 Aug 2020 at 03:54, qiaopeixin wrote:
> >>
> >> Thanks for the review and commit.
> >>
> >> All the best,
> >> Peixin
> >>
> >> -Original Message-
> >> From: Richard Sandiford [mailto:richard.sandif...@arm.com]
> >> Sent: 2020年8月13日 0:25
> >> To: qiaopeixin
> >> Cc: gcc-patches@gcc.gnu.org
> >> Subject: Re: [PATCH] AArch64: Add if condition in
> >> aarch64_function_value [PR96479]
> >>
> >> qiaopeixin writes:
> >> > Hi,
> >> >
> >> > The test case vector-subscript-2.c in the gcc testsuit will report an
> >> > ICE in the expand pass since '-mgeneral-regs-only' is incompatible with
> >> > the use of V4SI mode. I propose to report the diagnostic information
> >> > instead of ICE, and the problem has been discussed on PR 96479.
> >> >
> >> > I attached the patch to solve the problem. Bootstrapped and tested on
> >> > aarch64-linux-gnu. Any suggestions?
> >>
> >> Thanks, pushed. I was initially sceptical because raising an error here
> >> and in aarch64_layout_arg is a hack. Both functions are just query
> >> functions and shouldn't have any side effects.
> >>
> >> The approach we took for FP modes seemed better: we define the FP move
> >> patterns unconditionally, and raise an error if we try to emit an FP move
> >> with !TARGET_FLOAT. This defers any error reporting until we actually try
> >> to generate code that depends on TARGET_FLOAT.
> >>
> >> But I guess SIMD stuff is different. There's no reason in principle why
> >> you can't use:
> >>
> >> unsigned short __attribute__((vector_size(8)))
> >>
> >> *within* a function with -mgeneral-regs-only. It would just need to be
> >> emulated, in the same way as for:
> >>
> >> unsigned short __attribute__((vector_size(4)))
> >>
>
RE: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Hi Richard,
Thanks for the review and explanation.
The previous fix adding if condition of TARGET_FLOAT does crash glibc-2.29.
I checked the past log of writing the function aarch64_init_cumulative_args,
and did not find the reason why Alan Lawrence added TREE_PUBLIC (fndecl) as one
condition for entering the function type check. Maybe Alan could clarify? I
tried to delete TREE_PUBLIC (fndecl), which turns out could solve both the
glibc problem and the previous ICE problem. A new fix is made as following,
passed bootstrap and deja test. I believe this fix is reasonable, since the
function type should be checked no matter if it has external linkage or not.
The function aarch64_init_cumulative_args checks the function types and should
catch the error that "-mgeneral-regs-only" is incompatible with the use of
SIMD/FP registers. In the test case on PR96479, the function myfunc2 returns
one vector of 4 integers, while it is defined static type. TREE_PUBLIC (fndecl)
is set as false and it prevents from entering if statement and checking
function types. I delete "TREE_PUBLIC (fndecl)" so that gcc can catch the error
through the function aarch64_init_cumulative_args now. The ICE on PR96479 can
report the diagnostic error with this fix. The patch for the fix is attached as
following:
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index b7f5bc76f1b..9ce83dce131 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -6017,7 +6017,7 @@ aarch64_init_cumulative_args (CUMULATIVE_ARGS *pcum,
if (!silent_p
&& !TARGET_FLOAT
- && fndecl && TREE_PUBLIC (fndecl)
+ && fndecl
&& fntype && fntype != error_mark_node)
{
const_tree type = TREE_TYPE (fntype);
Christophe, thanks for your tests on glibc-2.29. With the above fix, I built
glibc-2.29, and the previous error does not show up now. Could you please check
if this fix works?
Do you have any suggestions on this fix?
All the best,
Peixin
-Original Message-
From: Richard Sandiford [mailto:richard.sandif...@arm.com]
Sent: Thursday, August 13, 2020 8:19 PM
To: Christophe Lyon
Cc: qiaopeixin ; gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value
[PR96479]
Christophe Lyon writes:
> On Thu, 13 Aug 2020 at 03:54, qiaopeixin wrote:
>>
>> Thanks for the review and commit.
>>
>> All the best,
>> Peixin
>>
>> -Original Message-
>> From: Richard Sandiford [mailto:richard.sandif...@arm.com]
>> Sent: 2020年8月13日 0:25
>> To: qiaopeixin
>> Cc: gcc-patches@gcc.gnu.org
>> Subject: Re: [PATCH] AArch64: Add if condition in
>> aarch64_function_value [PR96479]
>>
>> qiaopeixin writes:
>> > Hi,
>> >
>> > The test case vector-subscript-2.c in the gcc testsuit will report an ICE
>> > in the expand pass since '-mgeneral-regs-only' is incompatible with the
>> > use of V4SI mode. I propose to report the diagnostic information instead
>> > of ICE, and the problem has been discussed on PR 96479.
>> >
>> > I attached the patch to solve the problem. Bootstrapped and tested on
>> > aarch64-linux-gnu. Any suggestions?
>>
>> Thanks, pushed. I was initially sceptical because raising an error here and
>> in aarch64_layout_arg is a hack. Both functions are just query functions
>> and shouldn't have any side effects.
>>
>> The approach we took for FP modes seemed better: we define the FP move
>> patterns unconditionally, and raise an error if we try to emit an FP move
>> with !TARGET_FLOAT. This defers any error reporting until we actually try
>> to generate code that depends on TARGET_FLOAT.
>>
>> But I guess SIMD stuff is different. There's no reason in principle why you
>> can't use:
>>
>> unsigned short __attribute__((vector_size(8)))
>>
>> *within* a function with -mgeneral-regs-only. It would just need to be
>> emulated, in the same way as for:
>>
>> unsigned short __attribute__((vector_size(4)))
>>
>> So it would be wrong to define the SIMD move patterns unconditionally and
>> raise an error there.
>>
>> So all in all, I agree this is the best we can do given the current
>> infrastructure.
>>
>
> Since this patch was committed my buildbot is broken for
> aarch64-linux-gnu because it now fails to build glibc-2.29:
> ../stdlib/bits/stdlib-float.h: In function 'atof':
> ../stdlib/bits/stdlib-float.h:26:1: error: '-mgeneral-regs-only' is
> incompatible with the use of floating-point types
Thanks for the heads-up. I've reverted the patch for now.
Looking mor
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Christophe Lyon writes:
> On Thu, 13 Aug 2020 at 03:54, qiaopeixin wrote:
>>
>> Thanks for the review and commit.
>>
>> All the best,
>> Peixin
>>
>> -Original Message-
>> From: Richard Sandiford [mailto:richard.sandif...@arm.com]
>> Sent: 2020年8月13日 0:25
>> To: qiaopeixin
>> Cc: gcc-patches@gcc.gnu.org
>> Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value
>> [PR96479]
>>
>> qiaopeixin writes:
>> > Hi,
>> >
>> > The test case vector-subscript-2.c in the gcc testsuit will report an ICE
>> > in the expand pass since '-mgeneral-regs-only' is incompatible with the
>> > use of V4SI mode. I propose to report the diagnostic information instead
>> > of ICE, and the problem has been discussed on PR 96479.
>> >
>> > I attached the patch to solve the problem. Bootstrapped and tested on
>> > aarch64-linux-gnu. Any suggestions?
>>
>> Thanks, pushed. I was initially sceptical because raising an error here and
>> in aarch64_layout_arg is a hack. Both functions are just query functions
>> and shouldn't have any side effects.
>>
>> The approach we took for FP modes seemed better: we define the FP move
>> patterns unconditionally, and raise an error if we try to emit an FP move
>> with !TARGET_FLOAT. This defers any error reporting until we actually try
>> to generate code that depends on TARGET_FLOAT.
>>
>> But I guess SIMD stuff is different. There's no reason in principle why you
>> can't use:
>>
>> unsigned short __attribute__((vector_size(8)))
>>
>> *within* a function with -mgeneral-regs-only. It would just need to be
>> emulated, in the same way as for:
>>
>> unsigned short __attribute__((vector_size(4)))
>>
>> So it would be wrong to define the SIMD move patterns unconditionally and
>> raise an error there.
>>
>> So all in all, I agree this is the best we can do given the current
>> infrastructure.
>>
>
> Since this patch was committed my buildbot is broken for
> aarch64-linux-gnu because it now fails to build glibc-2.29:
> ../stdlib/bits/stdlib-float.h: In function 'atof':
> ../stdlib/bits/stdlib-float.h:26:1: error: '-mgeneral-regs-only' is
> incompatible with the use of floating-point types
Thanks for the heads-up. I've reverted the patch for now.
Looking more closely, it seems like aarch64_init_cumulative_args
already tries to catch the problem that the patch was fixing:
if (!silent_p
&& !TARGET_FLOAT
&& fndecl && TREE_PUBLIC (fndecl)
&& fntype && fntype != error_mark_node)
{
const_tree type = TREE_TYPE (fntype);
machine_mode mode ATTRIBUTE_UNUSED; /* To pass pointer as argument. */
int nregs ATTRIBUTE_UNUSED; /* Likewise. */
if (aarch64_vfp_is_call_or_return_candidate (TYPE_MODE (type), type,
, , NULL, false))
aarch64_err_no_fpadvsimd (TYPE_MODE (type));
}
The only reason it doesn't work for the testcase is that TREE_PUBLIC
condition. TBH I'm not sure why it or the fndecl test is there:
this is just as problematic when calling via a function pointer
or when calling a static function.
Richard
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Hi, On Thu, 13 Aug 2020 at 03:54, qiaopeixin wrote: > > Thanks for the review and commit. > > All the best, > Peixin > > -Original Message- > From: Richard Sandiford [mailto:richard.sandif...@arm.com] > Sent: 2020年8月13日 0:25 > To: qiaopeixin > Cc: gcc-patches@gcc.gnu.org > Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value > [PR96479] > > qiaopeixin writes: > > Hi, > > > > The test case vector-subscript-2.c in the gcc testsuit will report an ICE > > in the expand pass since '-mgeneral-regs-only' is incompatible with the use > > of V4SI mode. I propose to report the diagnostic information instead of > > ICE, and the problem has been discussed on PR 96479. > > > > I attached the patch to solve the problem. Bootstrapped and tested on > > aarch64-linux-gnu. Any suggestions? > > Thanks, pushed. I was initially sceptical because raising an error here and > in aarch64_layout_arg is a hack. Both functions are just query functions and > shouldn't have any side effects. > > The approach we took for FP modes seemed better: we define the FP move > patterns unconditionally, and raise an error if we try to emit an FP move > with !TARGET_FLOAT. This defers any error reporting until we actually try to > generate code that depends on TARGET_FLOAT. > > But I guess SIMD stuff is different. There's no reason in principle why you > can't use: > > unsigned short __attribute__((vector_size(8))) > > *within* a function with -mgeneral-regs-only. It would just need to be > emulated, in the same way as for: > > unsigned short __attribute__((vector_size(4))) > > So it would be wrong to define the SIMD move patterns unconditionally and > raise an error there. > > So all in all, I agree this is the best we can do given the current > infrastructure. > Since this patch was committed my buildbot is broken for aarch64-linux-gnu because it now fails to build glibc-2.29: ../stdlib/bits/stdlib-float.h: In function 'atof': ../stdlib/bits/stdlib-float.h:26:1: error: '-mgeneral-regs-only' is incompatible with the use of floating-point types I haven't yet tried a more recent glibc version, not sure if 2.29 is considered obsolete? Christophe > Thanks, > Richard >
RE: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Thanks for the review and commit. All the best, Peixin -Original Message- From: Richard Sandiford [mailto:richard.sandif...@arm.com] Sent: 2020年8月13日 0:25 To: qiaopeixin Cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479] qiaopeixin writes: > Hi, > > The test case vector-subscript-2.c in the gcc testsuit will report an ICE in > the expand pass since '-mgeneral-regs-only' is incompatible with the use of > V4SI mode. I propose to report the diagnostic information instead of ICE, and > the problem has been discussed on PR 96479. > > I attached the patch to solve the problem. Bootstrapped and tested on > aarch64-linux-gnu. Any suggestions? Thanks, pushed. I was initially sceptical because raising an error here and in aarch64_layout_arg is a hack. Both functions are just query functions and shouldn't have any side effects. The approach we took for FP modes seemed better: we define the FP move patterns unconditionally, and raise an error if we try to emit an FP move with !TARGET_FLOAT. This defers any error reporting until we actually try to generate code that depends on TARGET_FLOAT. But I guess SIMD stuff is different. There's no reason in principle why you can't use: unsigned short __attribute__((vector_size(8))) *within* a function with -mgeneral-regs-only. It would just need to be emulated, in the same way as for: unsigned short __attribute__((vector_size(4))) So it would be wrong to define the SIMD move patterns unconditionally and raise an error there. So all in all, I agree this is the best we can do given the current infrastructure. Thanks, Richard
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
qiaopeixin writes: > Hi, > > The test case vector-subscript-2.c in the gcc testsuit will report an ICE in > the expand pass since '-mgeneral-regs-only' is incompatible with the use of > V4SI mode. I propose to report the diagnostic information instead of ICE, and > the problem has been discussed on PR 96479. > > I attached the patch to solve the problem. Bootstrapped and tested on > aarch64-linux-gnu. Any suggestions? Thanks, pushed. I was initially sceptical because raising an error here and in aarch64_layout_arg is a hack. Both functions are just query functions and shouldn't have any side effects. The approach we took for FP modes seemed better: we define the FP move patterns unconditionally, and raise an error if we try to emit an FP move with !TARGET_FLOAT. This defers any error reporting until we actually try to generate code that depends on TARGET_FLOAT. But I guess SIMD stuff is different. There's no reason in principle why you can't use: unsigned short __attribute__((vector_size(8))) *within* a function with -mgeneral-regs-only. It would just need to be emulated, in the same way as for: unsigned short __attribute__((vector_size(4))) So it would be wrong to define the SIMD move patterns unconditionally and raise an error there. So all in all, I agree this is the best we can do given the current infrastructure. Thanks, Richard
