Re: [PATCH v2] testsuite: Add new target check for no_alignment_constraints
On Mon, Jun 27, 2022 at 8:09 PM Dimitar Dimitrov wrote:
>
> A few testcases were marked for avr target, which has no alignment
> requirements. But those tests in fact should filter for any
> target having __BIGGEST_ALIGNMENT__=1.
>
> A new effective target check is introduced: no_alignment_constraints.
> It checks whether __BIGGEST_ALIGNMENT__ is declared as 1.
>
> This change fixes the testsuite cases for PRU target. I don't have
> environment to test mm32c and cris targets, which also declare
> __BIGGEST_ALIGNMENT__=1.
>
> It was regression-tested on x86_64-pc-linux-gnu.
>
> The following two existing macros were considered, but they check for
> subtly different target behaviour:
> 1. non_strict_align
> If true, non-aligned access is permitted. But it also allows
> variables to be naturally aligned, which is not true for
> no_alignment_constraints.
>
> 2. default_packed
> Whether structures are packed by default is not necessarily
> the same as lacking constraints for non-aggregate types.
> For example, BIGGEST_FIELD_ALIGNMENT or ADJUST_FIELD_ALIGN
> could be defined for a target as something other than
> BIGGEST_ALIGNMENT.
OK.
Thanks,
Richard.
> gcc/ChangeLog:
>
> * doc/sourcebuild.texi: Document new no_alignment_constraints
> effective target check.
>
> gcc/testsuite/ChangeLog:
>
> * c-c++-common/Wcast-align.c: Silence warnings for targets with
> no_alignment_constraints.
> * gcc.dg/c11-align-4.c: Skip for no_alignment_constraints.
> * gcc.dg/strlenopt-10.c: Replace checks for avr with checks for
> any target with no_alignment_constraints.
> * gcc.dg/strlenopt-11.c: Ditto.
> * gcc.dg/strlenopt-13.c: Ditto.
> * lib/target-supports.exp
> (check_effective_target_no_alignment_constraints): New.
>
>
> Signed-off-by: Dimitar Dimitrov
> ---
> Changes since patch V1:
> - Documented the new check in gcc/doc/sourcebuild.texi.
>
> gcc/doc/sourcebuild.texi | 9 +
> gcc/testsuite/c-c++-common/Wcast-align.c | 4 ++--
> gcc/testsuite/gcc.dg/c11-align-4.c | 2 +-
> gcc/testsuite/gcc.dg/strlenopt-10.c | 6 +++---
> gcc/testsuite/gcc.dg/strlenopt-11.c | 14 +++---
> gcc/testsuite/gcc.dg/strlenopt-13.c | 16
> gcc/testsuite/lib/target-supports.exp| 13 +
> 7 files changed, 43 insertions(+), 21 deletions(-)
>
> diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
> index 3696a58fbf2..760ff9559a6 100644
> --- a/gcc/doc/sourcebuild.texi
> +++ b/gcc/doc/sourcebuild.texi
> @@ -2716,6 +2716,7 @@ Target supports @option{-branch-cost=N}.
> Target uses @code{__cxa_atexit}.
>
> @item default_packed
> +@anchor{default_packed}
> Target has packed layout of structure members by default.
>
> @item exceptions
> @@ -2786,6 +2787,14 @@ Target uses natural alignment (aligned to type size)
> for types of
> Target uses natural alignment (aligned to type size) for types of
> 64 bits or less.
>
> +@item no_alignment_constraints
> +Target defines __BIGGEST_ALIGNMENT__=1. Hence target imposes
> +no alignment constraints. This is similar, but not necessarily
> +the same as @ref{default_packed}. Although @code{BIGGEST_FIELD_ALIGNMENT}
> +defaults to @code{BIGGEST_ALIGNMENT} for most targets, it is possible
> +for a target to set those two with different values and have different
> +alignment constraints for aggregate and non-aggregate types.
> +
> @item noinit
> Target supports the @code{noinit} variable attribute.
>
> diff --git a/gcc/testsuite/c-c++-common/Wcast-align.c
> b/gcc/testsuite/c-c++-common/Wcast-align.c
> index c296c7fd249..1087b10fd99 100644
> --- a/gcc/testsuite/c-c++-common/Wcast-align.c
> +++ b/gcc/testsuite/c-c++-common/Wcast-align.c
> @@ -16,8 +16,8 @@ struct t { double x; } *q;
> void
> foo (void)
> {
> - y = (c *) x; /* { dg-warning "7:cast \[^\n\r]* required alignment of
> target type" } */
> - z = (d *) x; /* { dg-warning "7:cast \[^\n\r]* required alignment of
> target type" } */
> + y = (c *) x; /* { dg-warning "7:cast \[^\n\r]* required alignment of
> target type" "" { target { ! no_alignment_constraints } } } */
> + z = (d *) x; /* { dg-warning "7:cast \[^\n\r]* required alignment of
> target type" "" { target { ! no_alignment_constraints } } } */
>(long long *) p; /* { dg-bogus "alignment" } */
>(double *) q; /* { dg-bogus "alignment" } */
> }
> diff --git a/gcc/testsuite/gcc.dg/c11-align-4.c
> b/gcc/testsuite/gcc.dg/c11-align-4.c
> index 57f93ff05fc..eb9071b9149 100644
> --- a/gcc/testsuite/gcc.dg/c11-align-4.c
> +++ b/gcc/testsuite/gcc.dg/c11-align-4.c
> @@ -2,7 +2,7 @@
> are at least some alignment constraints). */
> /* { dg-do compile } */
> /* { dg-options "-std=c11 -pedantic-errors" } */
> -/* { dg-skip-if "no alignment constraints" { "avr-*-*" } } */
> +/* { dg-skip-if "no alignment constraints" { no_alignment_constraints } } */
>
>
[PATCH v2] testsuite: Add new target check for no_alignment_constraints
A few testcases were marked for avr target, which has no alignment
requirements. But those tests in fact should filter for any
target having __BIGGEST_ALIGNMENT__=1.
A new effective target check is introduced: no_alignment_constraints.
It checks whether __BIGGEST_ALIGNMENT__ is declared as 1.
This change fixes the testsuite cases for PRU target. I don't have
environment to test mm32c and cris targets, which also declare
__BIGGEST_ALIGNMENT__=1.
It was regression-tested on x86_64-pc-linux-gnu.
The following two existing macros were considered, but they check for
subtly different target behaviour:
1. non_strict_align
If true, non-aligned access is permitted. But it also allows
variables to be naturally aligned, which is not true for
no_alignment_constraints.
2. default_packed
Whether structures are packed by default is not necessarily
the same as lacking constraints for non-aggregate types.
For example, BIGGEST_FIELD_ALIGNMENT or ADJUST_FIELD_ALIGN
could be defined for a target as something other than
BIGGEST_ALIGNMENT.
gcc/ChangeLog:
* doc/sourcebuild.texi: Document new no_alignment_constraints
effective target check.
gcc/testsuite/ChangeLog:
* c-c++-common/Wcast-align.c: Silence warnings for targets with
no_alignment_constraints.
* gcc.dg/c11-align-4.c: Skip for no_alignment_constraints.
* gcc.dg/strlenopt-10.c: Replace checks for avr with checks for
any target with no_alignment_constraints.
* gcc.dg/strlenopt-11.c: Ditto.
* gcc.dg/strlenopt-13.c: Ditto.
* lib/target-supports.exp
(check_effective_target_no_alignment_constraints): New.
Signed-off-by: Dimitar Dimitrov
---
Changes since patch V1:
- Documented the new check in gcc/doc/sourcebuild.texi.
gcc/doc/sourcebuild.texi | 9 +
gcc/testsuite/c-c++-common/Wcast-align.c | 4 ++--
gcc/testsuite/gcc.dg/c11-align-4.c | 2 +-
gcc/testsuite/gcc.dg/strlenopt-10.c | 6 +++---
gcc/testsuite/gcc.dg/strlenopt-11.c | 14 +++---
gcc/testsuite/gcc.dg/strlenopt-13.c | 16
gcc/testsuite/lib/target-supports.exp| 13 +
7 files changed, 43 insertions(+), 21 deletions(-)
diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
index 3696a58fbf2..760ff9559a6 100644
--- a/gcc/doc/sourcebuild.texi
+++ b/gcc/doc/sourcebuild.texi
@@ -2716,6 +2716,7 @@ Target supports @option{-branch-cost=N}.
Target uses @code{__cxa_atexit}.
@item default_packed
+@anchor{default_packed}
Target has packed layout of structure members by default.
@item exceptions
@@ -2786,6 +2787,14 @@ Target uses natural alignment (aligned to type size) for
types of
Target uses natural alignment (aligned to type size) for types of
64 bits or less.
+@item no_alignment_constraints
+Target defines __BIGGEST_ALIGNMENT__=1. Hence target imposes
+no alignment constraints. This is similar, but not necessarily
+the same as @ref{default_packed}. Although @code{BIGGEST_FIELD_ALIGNMENT}
+defaults to @code{BIGGEST_ALIGNMENT} for most targets, it is possible
+for a target to set those two with different values and have different
+alignment constraints for aggregate and non-aggregate types.
+
@item noinit
Target supports the @code{noinit} variable attribute.
diff --git a/gcc/testsuite/c-c++-common/Wcast-align.c
b/gcc/testsuite/c-c++-common/Wcast-align.c
index c296c7fd249..1087b10fd99 100644
--- a/gcc/testsuite/c-c++-common/Wcast-align.c
+++ b/gcc/testsuite/c-c++-common/Wcast-align.c
@@ -16,8 +16,8 @@ struct t { double x; } *q;
void
foo (void)
{
- y = (c *) x; /* { dg-warning "7:cast \[^\n\r]* required alignment of target
type" } */
- z = (d *) x; /* { dg-warning "7:cast \[^\n\r]* required alignment of target
type" } */
+ y = (c *) x; /* { dg-warning "7:cast \[^\n\r]* required alignment of target
type" "" { target { ! no_alignment_constraints } } } */
+ z = (d *) x; /* { dg-warning "7:cast \[^\n\r]* required alignment of target
type" "" { target { ! no_alignment_constraints } } } */
(long long *) p; /* { dg-bogus "alignment" } */
(double *) q; /* { dg-bogus "alignment" } */
}
diff --git a/gcc/testsuite/gcc.dg/c11-align-4.c
b/gcc/testsuite/gcc.dg/c11-align-4.c
index 57f93ff05fc..eb9071b9149 100644
--- a/gcc/testsuite/gcc.dg/c11-align-4.c
+++ b/gcc/testsuite/gcc.dg/c11-align-4.c
@@ -2,7 +2,7 @@
are at least some alignment constraints). */
/* { dg-do compile } */
/* { dg-options "-std=c11 -pedantic-errors" } */
-/* { dg-skip-if "no alignment constraints" { "avr-*-*" } } */
+/* { dg-skip-if "no alignment constraints" { no_alignment_constraints } } */
#include
diff --git a/gcc/testsuite/gcc.dg/strlenopt-10.c
b/gcc/testsuite/gcc.dg/strlenopt-10.c
index ce959c34a80..6e2c2597b27 100644
--- a/gcc/testsuite/gcc.dg/strlenopt-10.c
+++ b/gcc/testsuite/gcc.dg/strlenopt-10.c
@@ -70,10 +70,10 @@ main ()
}
/* { dg-final { scan-tree-dump-times "str
