* [PATCH] loongarch: ignore zero-size fields in calling convention
@ 2022-04-20 6:23 Xi Ruoyao
2022-04-25 5:57 ` Xi Ruoyao
0 siblings, 1 reply; 8+ messages in thread
From: Xi Ruoyao @ 2022-04-20 6:23 UTC (permalink / raw)
To: Xi Ruoyao via Gcc-patches; +Cc: Chenghua Xu, Lulu Cheng, Xuerui Wang
Currently, LoongArch ELF psABI is not clear on the handling of zero-
sized fields in aggregates arguments or return values [1]. The behavior
of GCC trunk is puzzling considering the following cases:
struct test1
{
double a[0];
float x;
};
struct test2
{
float a[0];
float x;
};
GCC trunk passes test1::x via GPR, but test2::x via FPR. I believe no
rational Homo Sapiens can understand (or even expect) this.
And, to make things even worse, test1 behaves differently in C and C++.
GCC trunk passes test1::x via GPR, but G++ trunk passes test1::x via
FPR.
I've write a paragraph about current GCC behavior for the psABI [2], but
I think it's cleaner to just ignore all zero-sized fields in the ABI.
This will require only a two-line change in GCC (this patch), and an
one-line change in the ABI doc.
If there is not any better idea I'd like to see this reviewed and
applied ASAP. If we finally have to apply this patch after GCC 12
release, we'll need to add a lot more boring code to emit a -Wpsabi
inform [3]. That will be an unnecessary burden for both us, and the
users using the compiler (as the compiler will spend CPU time only for
checking if a warning should be informed).
[1]:https://github.com/loongson/LoongArch-Documentation/issues/48
[2]:https://github.com/loongson/LoongArch-Documentation/pull/49
[3]:https://gcc.gnu.org/PR102024
gcc/
* config/loongarch/loongarch.cc
(loongarch_flatten_aggregate_field): Ignore empty fields for
RECORD_TYPE.
gcc/testsuite/
* gcc.target/loongarch/zero-size-field-pass.c: New test.
* gcc.target/loongarch/zero-size-field-ret.c: New test.
---
gcc/config/loongarch/loongarch.cc | 3 ++
.../loongarch/zero-size-field-pass.c | 30 +++++++++++++++++++
.../loongarch/zero-size-field-ret.c | 28 +++++++++++++++++
3 files changed, 61 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
index f22150a60cc..57e4d9f82ce 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -326,6 +326,9 @@ loongarch_flatten_aggregate_field (const_tree type,
for (tree f = TYPE_FIELDS (type); f; f = DECL_CHAIN (f))
if (TREE_CODE (f) == FIELD_DECL)
{
+ if (DECL_SIZE (f) && integer_zerop (DECL_SIZE (f)))
+ continue;
+
if (!TYPE_P (TREE_TYPE (f)))
return -1;
diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
new file mode 100644
index 00000000000..999dc913a71
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
@@ -0,0 +1,30 @@
+/* Test that LoongArch backend ignores zero-sized fields of aggregates in
+ argument passing. */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
+/* { dg-final { scan-assembler "\\\$f1" } } */
+
+struct test
+{
+ int empty1[0];
+ double empty2[0];
+ int : 0;
+ float x;
+ long empty3[0];
+ long : 0;
+ float y;
+ unsigned : 0;
+ char empty4[0];
+};
+
+extern void callee (struct test);
+
+void
+caller (void)
+{
+ struct test test;
+ test.x = 114;
+ test.y = 514;
+ callee (test);
+}
diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
new file mode 100644
index 00000000000..40137d97555
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
@@ -0,0 +1,28 @@
+/* Test that LoongArch backend ignores zero-sized fields of aggregates in
+ returning. */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
+/* { dg-final { scan-assembler-not "\\\$r4" } } */
+
+struct test
+{
+ int empty1[0];
+ double empty2[0];
+ int : 0;
+ float x;
+ long empty3[0];
+ long : 0;
+ float y;
+ unsigned : 0;
+ char empty4[0];
+};
+
+extern struct test callee (void);
+
+float
+caller (void)
+{
+ struct test test = callee ();
+ return test.x + test.y;
+}
--
2.36.0
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] loongarch: ignore zero-size fields in calling convention
2022-04-20 6:23 [PATCH] loongarch: ignore zero-size fields in calling convention Xi Ruoyao
@ 2022-04-25 5:57 ` Xi Ruoyao
2022-04-25 7:07 ` WANG Xuerui
2022-04-25 7:22 ` Lulu Cheng
0 siblings, 2 replies; 8+ messages in thread
From: Xi Ruoyao @ 2022-04-25 5:57 UTC (permalink / raw)
To: Xi Ruoyao via Gcc-patches; +Cc: Chenghua Xu, Lulu Cheng, Xuerui Wang
Ping.
Normally we shouldn't ping a patch after only a few days, but we're
running out of time to catch GCC 12 milestone. And once GCC 12 is
released the patch will become far more complicated for a psABI warning.
And please note that the ABI difference between GCC and G++ should be
considered a bug, and it has to be fixed anyway. If you don't like the
idea of this patch, please develop another solution and apply it *before
GCC 12*.
On Wed, 2022-04-20 at 14:23 +0800, Xi Ruoyao via Gcc-patches wrote:
> Currently, LoongArch ELF psABI is not clear on the handling of zero-
> sized fields in aggregates arguments or return values [1]. The behavior
> of GCC trunk is puzzling considering the following cases:
>
> struct test1
> {
> double a[0];
> float x;
> };
>
> struct test2
> {
> float a[0];
> float x;
> };
>
> GCC trunk passes test1::x via GPR, but test2::x via FPR. I believe no
> rational Homo Sapiens can understand (or even expect) this.
>
> And, to make things even worse, test1 behaves differently in C and C++.
> GCC trunk passes test1::x via GPR, but G++ trunk passes test1::x via
> FPR.
>
> I've write a paragraph about current GCC behavior for the psABI [2], but
> I think it's cleaner to just ignore all zero-sized fields in the ABI.
> This will require only a two-line change in GCC (this patch), and an
> one-line change in the ABI doc.
>
> If there is not any better idea I'd like to see this reviewed and
> applied ASAP. If we finally have to apply this patch after GCC 12
> release, we'll need to add a lot more boring code to emit a -Wpsabi
> inform [3]. That will be an unnecessary burden for both us, and the
> users using the compiler (as the compiler will spend CPU time only for
> checking if a warning should be informed).
>
> [1]:https://github.com/loongson/LoongArch-Documentation/issues/48
> [2]:https://github.com/loongson/LoongArch-Documentation/pull/49
> [3]:https://gcc.gnu.org/PR102024
>
> gcc/
>
> * config/loongarch/loongarch.cc
> (loongarch_flatten_aggregate_field): Ignore empty fields for
> RECORD_TYPE.
>
> gcc/testsuite/
>
> * gcc.target/loongarch/zero-size-field-pass.c: New test.
> * gcc.target/loongarch/zero-size-field-ret.c: New test.
> ---
> gcc/config/loongarch/loongarch.cc | 3 ++
> .../loongarch/zero-size-field-pass.c | 30 +++++++++++++++++++
> .../loongarch/zero-size-field-ret.c | 28 +++++++++++++++++
> 3 files changed, 61 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
> create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
>
> diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
> index f22150a60cc..57e4d9f82ce 100644
> --- a/gcc/config/loongarch/loongarch.cc
> +++ b/gcc/config/loongarch/loongarch.cc
> @@ -326,6 +326,9 @@ loongarch_flatten_aggregate_field (const_tree type,
> for (tree f = TYPE_FIELDS (type); f; f = DECL_CHAIN (f))
> if (TREE_CODE (f) == FIELD_DECL)
> {
> + if (DECL_SIZE (f) && integer_zerop (DECL_SIZE (f)))
> + continue;
> +
> if (!TYPE_P (TREE_TYPE (f)))
> return -1;
>
> diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
> new file mode 100644
> index 00000000000..999dc913a71
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
> @@ -0,0 +1,30 @@
> +/* Test that LoongArch backend ignores zero-sized fields of aggregates in
> + argument passing. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
> +/* { dg-final { scan-assembler "\\\$f1" } } */
> +
> +struct test
> +{
> + int empty1[0];
> + double empty2[0];
> + int : 0;
> + float x;
> + long empty3[0];
> + long : 0;
> + float y;
> + unsigned : 0;
> + char empty4[0];
> +};
> +
> +extern void callee (struct test);
> +
> +void
> +caller (void)
> +{
> + struct test test;
> + test.x = 114;
> + test.y = 514;
> + callee (test);
> +}
> diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
> new file mode 100644
> index 00000000000..40137d97555
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
> @@ -0,0 +1,28 @@
> +/* Test that LoongArch backend ignores zero-sized fields of aggregates in
> + returning. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
> +/* { dg-final { scan-assembler-not "\\\$r4" } } */
> +
> +struct test
> +{
> + int empty1[0];
> + double empty2[0];
> + int : 0;
> + float x;
> + long empty3[0];
> + long : 0;
> + float y;
> + unsigned : 0;
> + char empty4[0];
> +};
> +
> +extern struct test callee (void);
> +
> +float
> +caller (void)
> +{
> + struct test test = callee ();
> + return test.x + test.y;
> +}
--
Xi Ruoyao <xry111@mengyan1223.wang>
School of Aerospace Science and Technology, Xidian University
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] loongarch: ignore zero-size fields in calling convention
2022-04-25 5:57 ` Xi Ruoyao
@ 2022-04-25 7:07 ` WANG Xuerui
2022-04-25 7:22 ` Lulu Cheng
1 sibling, 0 replies; 8+ messages in thread
From: WANG Xuerui @ 2022-04-25 7:07 UTC (permalink / raw)
To: Xi Ruoyao, Xi Ruoyao via Gcc-patches; +Cc: Chenghua Xu, Lulu Cheng
On 4/25/22 13:57, Xi Ruoyao wrote:
> Ping.
>
> Normally we shouldn't ping a patch after only a few days, but we're
> running out of time to catch GCC 12 milestone. And once GCC 12 is
> released the patch will become far more complicated for a psABI warning.
>
> And please note that the ABI difference between GCC and G++ should be
> considered a bug, and it has to be fixed anyway. If you don't like the
> idea of this patch, please develop another solution and apply it *before
> GCC 12*.
>
> On Wed, 2022-04-20 at 14:23 +0800, Xi Ruoyao via Gcc-patches wrote:
>> Currently, LoongArch ELF psABI is not clear on the handling of zero-
>> sized fields in aggregates arguments or return values [1]. The behavior
>> of GCC trunk is puzzling considering the following cases:
>>
>> struct test1
>> {
>> double a[0];
>> float x;
>> };
>>
>> struct test2
>> {
>> float a[0];
>> float x;
>> };
>>
>> GCC trunk passes test1::x via GPR, but test2::x via FPR. I believe no
>> rational Homo Sapiens can understand (or even expect) this.
>>
>> And, to make things even worse, test1 behaves differently in C and C++.
>> GCC trunk passes test1::x via GPR, but G++ trunk passes test1::x via
>> FPR.
>>
>> I've write a paragraph about current GCC behavior for the psABI [2], but
>> I think it's cleaner to just ignore all zero-sized fields in the ABI.
>> This will require only a two-line change in GCC (this patch), and an
>> one-line change in the ABI doc.
>>
>> If there is not any better idea I'd like to see this reviewed and
>> applied ASAP. If we finally have to apply this patch after GCC 12
>> release, we'll need to add a lot more boring code to emit a -Wpsabi
>> inform [3]. That will be an unnecessary burden for both us, and the
>> users using the compiler (as the compiler will spend CPU time only for
>> checking if a warning should be informed).
>>
>> [1]:https://github.com/loongson/LoongArch-Documentation/issues/48
>> [2]:https://github.com/loongson/LoongArch-Documentation/pull/49
>> [3]:https://gcc.gnu.org/PR102024
>>
>> gcc/
>>
>> * config/loongarch/loongarch.cc
>> (loongarch_flatten_aggregate_field): Ignore empty fields for
>> RECORD_TYPE.
>>
>> gcc/testsuite/
>>
>> * gcc.target/loongarch/zero-size-field-pass.c: New test.
>> * gcc.target/loongarch/zero-size-field-ret.c: New test.
>> ---
>> gcc/config/loongarch/loongarch.cc | 3 ++
>> .../loongarch/zero-size-field-pass.c | 30 +++++++++++++++++++
>> .../loongarch/zero-size-field-ret.c | 28 +++++++++++++++++
>> 3 files changed, 61 insertions(+)
>> create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
>> create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
>>
Agreed; this is urgent. While I haven't personally got around to testing
this yet, I have looked at the linked LoongArch psABI spec change and
agree with the present approach.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] loongarch: ignore zero-size fields in calling convention
2022-04-25 5:57 ` Xi Ruoyao
2022-04-25 7:07 ` WANG Xuerui
@ 2022-04-25 7:22 ` Lulu Cheng
2022-04-27 6:57 ` Lulu Cheng
1 sibling, 1 reply; 8+ messages in thread
From: Lulu Cheng @ 2022-04-25 7:22 UTC (permalink / raw)
To: Xi Ruoyao, Xi Ruoyao via Gcc-patches; +Cc: Chenghua Xu, Xuerui Wang
This modification will cause the ABI to change, we are discussing solutions.
And we will give a conclusion at the latest tommorrow.
Thanks!
在 2022/4/25 下午1:57, Xi Ruoyao 写道:
> Ping.
>
> Normally we shouldn't ping a patch after only a few days, but we're
> running out of time to catch GCC 12 milestone. And once GCC 12 is
> released the patch will become far more complicated for a psABI warning.
>
> And please note that the ABI difference between GCC and G++ should be
> considered a bug, and it has to be fixed anyway. If you don't like the
> idea of this patch, please develop another solution and apply it *before
> GCC 12*.
>
> On Wed, 2022-04-20 at 14:23 +0800, Xi Ruoyao via Gcc-patches wrote:
>> Currently, LoongArch ELF psABI is not clear on the handling of zero-
>> sized fields in aggregates arguments or return values [1]. The behavior
>> of GCC trunk is puzzling considering the following cases:
>>
>> struct test1
>> {
>> double a[0];
>> float x;
>> };
>>
>> struct test2
>> {
>> float a[0];
>> float x;
>> };
>>
>> GCC trunk passes test1::x via GPR, but test2::x via FPR. I believe no
>> rational Homo Sapiens can understand (or even expect) this.
>>
>> And, to make things even worse, test1 behaves differently in C and C++.
>> GCC trunk passes test1::x via GPR, but G++ trunk passes test1::x via
>> FPR.
>>
>> I've write a paragraph about current GCC behavior for the psABI [2], but
>> I think it's cleaner to just ignore all zero-sized fields in the ABI.
>> This will require only a two-line change in GCC (this patch), and an
>> one-line change in the ABI doc.
>>
>> If there is not any better idea I'd like to see this reviewed and
>> applied ASAP. If we finally have to apply this patch after GCC 12
>> release, we'll need to add a lot more boring code to emit a -Wpsabi
>> inform [3]. That will be an unnecessary burden for both us, and the
>> users using the compiler (as the compiler will spend CPU time only for
>> checking if a warning should be informed).
>>
>> [1]:https://github.com/loongson/LoongArch-Documentation/issues/48
>> [2]:https://github.com/loongson/LoongArch-Documentation/pull/49
>> [3]:https://gcc.gnu.org/PR102024
>>
>> gcc/
>>
>> * config/loongarch/loongarch.cc
>> (loongarch_flatten_aggregate_field): Ignore empty fields for
>> RECORD_TYPE.
>>
>> gcc/testsuite/
>>
>> * gcc.target/loongarch/zero-size-field-pass.c: New test.
>> * gcc.target/loongarch/zero-size-field-ret.c: New test.
>> ---
>> gcc/config/loongarch/loongarch.cc | 3 ++
>> .../loongarch/zero-size-field-pass.c | 30 +++++++++++++++++++
>> .../loongarch/zero-size-field-ret.c | 28 +++++++++++++++++
>> 3 files changed, 61 insertions(+)
>> create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
>> create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
>>
>> diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
>> index f22150a60cc..57e4d9f82ce 100644
>> --- a/gcc/config/loongarch/loongarch.cc
>> +++ b/gcc/config/loongarch/loongarch.cc
>> @@ -326,6 +326,9 @@ loongarch_flatten_aggregate_field (const_tree type,
>> for (tree f = TYPE_FIELDS (type); f; f = DECL_CHAIN (f))
>> if (TREE_CODE (f) == FIELD_DECL)
>> {
>> + if (DECL_SIZE (f) && integer_zerop (DECL_SIZE (f)))
>> + continue;
>> +
>> if (!TYPE_P (TREE_TYPE (f)))
>> return -1;
>>
>> diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
>> new file mode 100644
>> index 00000000000..999dc913a71
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
>> @@ -0,0 +1,30 @@
>> +/* Test that LoongArch backend ignores zero-sized fields of aggregates in
>> + argument passing. */
>> +
>> +/* { dg-do compile } */
>> +/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
>> +/* { dg-final { scan-assembler "\\\$f1" } } */
>> +
>> +struct test
>> +{
>> + int empty1[0];
>> + double empty2[0];
>> + int : 0;
>> + float x;
>> + long empty3[0];
>> + long : 0;
>> + float y;
>> + unsigned : 0;
>> + char empty4[0];
>> +};
>> +
>> +extern void callee (struct test);
>> +
>> +void
>> +caller (void)
>> +{
>> + struct test test;
>> + test.x = 114;
>> + test.y = 514;
>> + callee (test);
>> +}
>> diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
>> new file mode 100644
>> index 00000000000..40137d97555
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
>> @@ -0,0 +1,28 @@
>> +/* Test that LoongArch backend ignores zero-sized fields of aggregates in
>> + returning. */
>> +
>> +/* { dg-do compile } */
>> +/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
>> +/* { dg-final { scan-assembler-not "\\\$r4" } } */
>> +
>> +struct test
>> +{
>> + int empty1[0];
>> + double empty2[0];
>> + int : 0;
>> + float x;
>> + long empty3[0];
>> + long : 0;
>> + float y;
>> + unsigned : 0;
>> + char empty4[0];
>> +};
>> +
>> +extern struct test callee (void);
>> +
>> +float
>> +caller (void)
>> +{
>> + struct test test = callee ();
>> + return test.x + test.y;
>> +}
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] loongarch: ignore zero-size fields in calling convention
2022-04-25 7:22 ` Lulu Cheng
@ 2022-04-27 6:57 ` Lulu Cheng
2022-04-27 11:45 ` [PATCH v2] " Xi Ruoyao
0 siblings, 1 reply; 8+ messages in thread
From: Lulu Cheng @ 2022-04-27 6:57 UTC (permalink / raw)
To: Xi Ruoyao, Xi Ruoyao via Gcc-patches; +Cc: Chenghua Xu, Xuerui Wang
>>> gcc/
>>>
>>> * config/loongarch/loongarch.cc
>>> (loongarch_flatten_aggregate_field): Ignore empty fields for
>>> RECORD_TYPE.
>>>
>>> gcc/testsuite/
>>>
>>> * gcc.target/loongarch/zero-size-field-pass.c: New test.
>>> * gcc.target/loongarch/zero-size-field-ret.c: New test.
>>> ---
>>> gcc/config/loongarch/loongarch.cc | 3 ++
>>> .../loongarch/zero-size-field-pass.c | 30
>>> +++++++++++++++++++
>>> .../loongarch/zero-size-field-ret.c | 28 +++++++++++++++++
>>> 3 files changed, 61 insertions(+)
>>> create mode 100644
>>> gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
>>> create mode 100644
>>> gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
>>>
>>> diff --git a/gcc/config/loongarch/loongarch.cc
>>> b/gcc/config/loongarch/loongarch.cc
>>> index f22150a60cc..57e4d9f82ce 100644
>>> --- a/gcc/config/loongarch/loongarch.cc
>>> +++ b/gcc/config/loongarch/loongarch.cc
>>> @@ -326,6 +326,9 @@ loongarch_flatten_aggregate_field (const_tree type,
>>> for (tree f = TYPE_FIELDS (type); f; f = DECL_CHAIN (f))
>>> if (TREE_CODE (f) == FIELD_DECL)
>>> {
>>> + if (DECL_SIZE (f) && integer_zerop (DECL_SIZE (f)))
>>> + continue;
>>> +
I think the modification should be below.
>>> if (!TYPE_P (TREE_TYPE (f)))
>>> return -1;
Thanks!
Lulu Cheng
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v2] loongarch: ignore zero-size fields in calling convention
2022-04-27 6:57 ` Lulu Cheng
@ 2022-04-27 11:45 ` Xi Ruoyao
2022-04-27 11:53 ` Lulu Cheng
2022-04-28 1:24 ` Lulu Cheng
0 siblings, 2 replies; 8+ messages in thread
From: Xi Ruoyao @ 2022-04-27 11:45 UTC (permalink / raw)
To: Lulu Cheng, Xi Ruoyao via Gcc-patches; +Cc: Chenghua Xu, Xuerui Wang
On Wed, 2022-04-27 at 14:57 +0800, Lulu Cheng wrote:
> I think the modification should be below.
> > >
> > > > if (!TYPE_P (TREE_TYPE (f)))
> > > > return -1;
I think (!TYPE_P (TREE_TYPE (f)) will never be true (the code handling
calling convention of other ports does not has this check). But "first
thing first" so I'll move the change below this for now.
gcc/
* config/loongarch/loongarch.cc
(loongarch_flatten_aggregate_field): Ignore empty fields for
RECORD_TYPE.
gcc/testsuite/
* gcc.target/loongarch/zero-size-field-pass.c: New test.
* gcc.target/loongarch/zero-size-field-ret.c: New test.
---
gcc/config/loongarch/loongarch.cc | 3 ++
.../loongarch/zero-size-field-pass.c | 30 +++++++++++++++++++
.../loongarch/zero-size-field-ret.c | 28 +++++++++++++++++
3 files changed, 61 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
index f22150a60cc..80046b64006 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -329,6 +329,9 @@ loongarch_flatten_aggregate_field (const_tree type,
if (!TYPE_P (TREE_TYPE (f)))
return -1;
+ if (DECL_SIZE (f) && integer_zerop (DECL_SIZE (f)))
+ continue;
+
HOST_WIDE_INT pos = offset + int_byte_position (f);
n = loongarch_flatten_aggregate_field (TREE_TYPE (f), fields, n,
pos);
diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
new file mode 100644
index 00000000000..999dc913a71
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
@@ -0,0 +1,30 @@
+/* Test that LoongArch backend ignores zero-sized fields of aggregates in
+ argument passing. */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
+/* { dg-final { scan-assembler "\\\$f1" } } */
+
+struct test
+{
+ int empty1[0];
+ double empty2[0];
+ int : 0;
+ float x;
+ long empty3[0];
+ long : 0;
+ float y;
+ unsigned : 0;
+ char empty4[0];
+};
+
+extern void callee (struct test);
+
+void
+caller (void)
+{
+ struct test test;
+ test.x = 114;
+ test.y = 514;
+ callee (test);
+}
diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
new file mode 100644
index 00000000000..40137d97555
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
@@ -0,0 +1,28 @@
+/* Test that LoongArch backend ignores zero-sized fields of aggregates in
+ returning. */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
+/* { dg-final { scan-assembler-not "\\\$r4" } } */
+
+struct test
+{
+ int empty1[0];
+ double empty2[0];
+ int : 0;
+ float x;
+ long empty3[0];
+ long : 0;
+ float y;
+ unsigned : 0;
+ char empty4[0];
+};
+
+extern struct test callee (void);
+
+float
+caller (void)
+{
+ struct test test = callee ();
+ return test.x + test.y;
+}
--
2.36.0
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] loongarch: ignore zero-size fields in calling convention
2022-04-27 11:45 ` [PATCH v2] " Xi Ruoyao
@ 2022-04-27 11:53 ` Lulu Cheng
2022-04-28 1:24 ` Lulu Cheng
1 sibling, 0 replies; 8+ messages in thread
From: Lulu Cheng @ 2022-04-27 11:53 UTC (permalink / raw)
To: Xi Ruoyao, Xi Ruoyao via Gcc-patches; +Cc: Chenghua Xu, Xuerui Wang
OK!
在 2022/4/27 下午7:45, Xi Ruoyao 写道:
> On Wed, 2022-04-27 at 14:57 +0800, Lulu Cheng wrote:
>
>> I think the modification should be below.
>>>>> if (!TYPE_P (TREE_TYPE (f)))
>>>>> return -1;
> I think (!TYPE_P (TREE_TYPE (f)) will never be true (the code handling
> calling convention of other ports does not has this check). But "first
> thing first" so I'll move the change below this for now.
>
> gcc/
>
> * config/loongarch/loongarch.cc
> (loongarch_flatten_aggregate_field): Ignore empty fields for
> RECORD_TYPE.
>
> gcc/testsuite/
>
> * gcc.target/loongarch/zero-size-field-pass.c: New test.
> * gcc.target/loongarch/zero-size-field-ret.c: New test.
> ---
> gcc/config/loongarch/loongarch.cc | 3 ++
> .../loongarch/zero-size-field-pass.c | 30 +++++++++++++++++++
> .../loongarch/zero-size-field-ret.c | 28 +++++++++++++++++
> 3 files changed, 61 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
> create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
>
> diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
> index f22150a60cc..80046b64006 100644
> --- a/gcc/config/loongarch/loongarch.cc
> +++ b/gcc/config/loongarch/loongarch.cc
> @@ -329,6 +329,9 @@ loongarch_flatten_aggregate_field (const_tree type,
> if (!TYPE_P (TREE_TYPE (f)))
> return -1;
>
> + if (DECL_SIZE (f) && integer_zerop (DECL_SIZE (f)))
> + continue;
> +
> HOST_WIDE_INT pos = offset + int_byte_position (f);
> n = loongarch_flatten_aggregate_field (TREE_TYPE (f), fields, n,
> pos);
> diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
> new file mode 100644
> index 00000000000..999dc913a71
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
> @@ -0,0 +1,30 @@
> +/* Test that LoongArch backend ignores zero-sized fields of aggregates in
> + argument passing. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
> +/* { dg-final { scan-assembler "\\\$f1" } } */
> +
> +struct test
> +{
> + int empty1[0];
> + double empty2[0];
> + int : 0;
> + float x;
> + long empty3[0];
> + long : 0;
> + float y;
> + unsigned : 0;
> + char empty4[0];
> +};
> +
> +extern void callee (struct test);
> +
> +void
> +caller (void)
> +{
> + struct test test;
> + test.x = 114;
> + test.y = 514;
> + callee (test);
> +}
> diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
> new file mode 100644
> index 00000000000..40137d97555
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
> @@ -0,0 +1,28 @@
> +/* Test that LoongArch backend ignores zero-sized fields of aggregates in
> + returning. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
> +/* { dg-final { scan-assembler-not "\\\$r4" } } */
> +
> +struct test
> +{
> + int empty1[0];
> + double empty2[0];
> + int : 0;
> + float x;
> + long empty3[0];
> + long : 0;
> + float y;
> + unsigned : 0;
> + char empty4[0];
> +};
> +
> +extern struct test callee (void);
> +
> +float
> +caller (void)
> +{
> + struct test test = callee ();
> + return test.x + test.y;
> +}
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] loongarch: ignore zero-size fields in calling convention
2022-04-27 11:45 ` [PATCH v2] " Xi Ruoyao
2022-04-27 11:53 ` Lulu Cheng
@ 2022-04-28 1:24 ` Lulu Cheng
1 sibling, 0 replies; 8+ messages in thread
From: Lulu Cheng @ 2022-04-28 1:24 UTC (permalink / raw)
To: Xi Ruoyao, Xi Ruoyao via Gcc-patches; +Cc: Chenghua Xu, Xuerui Wang
I have pushed upstream. Thanks. Lulu Cheng
在 2022/4/27 下午7:45, Xi Ruoyao 写道:
> On Wed, 2022-04-27 at 14:57 +0800, Lulu Cheng wrote:
>
>> I think the modification should be below.
>>>>> if (!TYPE_P (TREE_TYPE (f)))
>>>>> return -1;
> I think (!TYPE_P (TREE_TYPE (f)) will never be true (the code handling
> calling convention of other ports does not has this check). But "first
> thing first" so I'll move the change below this for now.
>
> gcc/
>
> * config/loongarch/loongarch.cc
> (loongarch_flatten_aggregate_field): Ignore empty fields for
> RECORD_TYPE.
>
> gcc/testsuite/
>
> * gcc.target/loongarch/zero-size-field-pass.c: New test.
> * gcc.target/loongarch/zero-size-field-ret.c: New test.
> ---
> gcc/config/loongarch/loongarch.cc | 3 ++
> .../loongarch/zero-size-field-pass.c | 30 +++++++++++++++++++
> .../loongarch/zero-size-field-ret.c | 28 +++++++++++++++++
> 3 files changed, 61 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
> create mode 100644 gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
>
> diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
> index f22150a60cc..80046b64006 100644
> --- a/gcc/config/loongarch/loongarch.cc
> +++ b/gcc/config/loongarch/loongarch.cc
> @@ -329,6 +329,9 @@ loongarch_flatten_aggregate_field (const_tree type,
> if (!TYPE_P (TREE_TYPE (f)))
> return -1;
>
> + if (DECL_SIZE (f) && integer_zerop (DECL_SIZE (f)))
> + continue;
> +
> HOST_WIDE_INT pos = offset + int_byte_position (f);
> n = loongarch_flatten_aggregate_field (TREE_TYPE (f), fields, n,
> pos);
> diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
> new file mode 100644
> index 00000000000..999dc913a71
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-pass.c
> @@ -0,0 +1,30 @@
> +/* Test that LoongArch backend ignores zero-sized fields of aggregates in
> + argument passing. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
> +/* { dg-final { scan-assembler "\\\$f1" } } */
> +
> +struct test
> +{
> + int empty1[0];
> + double empty2[0];
> + int : 0;
> + float x;
> + long empty3[0];
> + long : 0;
> + float y;
> + unsigned : 0;
> + char empty4[0];
> +};
> +
> +extern void callee (struct test);
> +
> +void
> +caller (void)
> +{
> + struct test test;
> + test.x = 114;
> + test.y = 514;
> + callee (test);
> +}
> diff --git a/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
> new file mode 100644
> index 00000000000..40137d97555
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/zero-size-field-ret.c
> @@ -0,0 +1,28 @@
> +/* Test that LoongArch backend ignores zero-sized fields of aggregates in
> + returning. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mdouble-float -mabi=lp64d" } */
> +/* { dg-final { scan-assembler-not "\\\$r4" } } */
> +
> +struct test
> +{
> + int empty1[0];
> + double empty2[0];
> + int : 0;
> + float x;
> + long empty3[0];
> + long : 0;
> + float y;
> + unsigned : 0;
> + char empty4[0];
> +};
> +
> +extern struct test callee (void);
> +
> +float
> +caller (void)
> +{
> + struct test test = callee ();
> + return test.x + test.y;
> +}
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2022-04-28 1:24 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-04-20 6:23 [PATCH] loongarch: ignore zero-size fields in calling convention Xi Ruoyao
2022-04-25 5:57 ` Xi Ruoyao
2022-04-25 7:07 ` WANG Xuerui
2022-04-25 7:22 ` Lulu Cheng
2022-04-27 6:57 ` Lulu Cheng
2022-04-27 11:45 ` [PATCH v2] " Xi Ruoyao
2022-04-27 11:53 ` Lulu Cheng
2022-04-28 1:24 ` Lulu Cheng
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