On Fri, Jun 24, 2022 at 08:58:49AM +0200, Richard Biener wrote:
> On Fri, Jun 24, 2022 at 2:34 AM Andrew Pinski via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> >
> > On Thu, Jun 23, 2022 at 2:24 PM Dimitar Dimitrov <dimi...@dinux.eu> 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.
> > >
> > > Alternative names I considered for the new macro are:
> > > - !natural_alignment_16
> > > - biggest_alignment_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 any variable alignment.
> > > For example, BIGGEST_FIELD_ALIGNMENT or ADJUST_FIELD_ALIGN
> > > could be defined for a target.
> > >
> > > Ok for trunk?
> >
> > How is no_alignment_constraints different from default_packed? I
> > suspect they have the same effect really.
>
> Different when non-aggregates are involved? Does default_packed
> also apply to scalar types?
It is my understanding that aggregates and scalars could have
different alignment constraints.
For example, consider the following target settings combination, which I
found in the vax backend:
#define BIGGEST_ALIGNMENT 32
#define BIGGEST_FIELD_ALIGNMENT 8
I made an experiment and hacked pru-unknonwn-elf with the above change.
This resulted in:
default_packed=1
no_alignment_constraints=0
>
> Btw, new effective targets should be documented in sourcebuild.texi
I'll fix and post a new version.
Thanks,
Dimitar
>
> Richard.
>
> > Thanks,
> > Andrew
> >
> > >
> > > Signed-off-by: Dimitar Dimitrov <dimi...@dinux.eu>
> > > ---
> > > 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 +++++++++++++
> > > 6 files changed, 34 insertions(+), 21 deletions(-)
> > >
> > > 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 <stddef.h>
> > >
> > > 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 "strlen \\(" 2 "strlen1" } } */
> > > -/* avr has BIGGEST_ALIGNMENT 8, allowing fold_builtin_memory_op
> > > +/* Some targets have BIGGEST_ALIGNMENT 8-bits, allowing
> > > fold_builtin_memory_op
> > > to expand the memcpy call at the end of fn2. */
> > > -/* { dg-final { scan-tree-dump-times "memcpy \\(" 8 "strlen1" { target {
> > > ! avr-*-* } } } } */
> > > -/* { dg-final { scan-tree-dump-times "memcpy \\(" 7 "strlen1" { target {
> > > avr-*-* } } } } */
> > > +/* { dg-final { scan-tree-dump-times "memcpy \\(" 8 "strlen1" { target {
> > > ! no_alignment_constraints } } } } */
> > > +/* { dg-final { scan-tree-dump-times "memcpy \\(" 7 "strlen1" { target {
> > > no_alignment_constraints} } } } */
> > > /* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen1" } } */
> > > /* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen1" } } */
> > > /* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen1" } } */
> > > diff --git a/gcc/testsuite/gcc.dg/strlenopt-11.c
> > > b/gcc/testsuite/gcc.dg/strlenopt-11.c
> > > index abd9faebed6..952de0730f1 100644
> > > --- a/gcc/testsuite/gcc.dg/strlenopt-11.c
> > > +++ b/gcc/testsuite/gcc.dg/strlenopt-11.c
> > > @@ -59,17 +59,17 @@ main ()
> > > }
> > >
> > > /* { dg-final { scan-tree-dump-times "strlen \\(" 3 "strlen1" } } */
> > > -/* avr has BIGGEST_ALIGNMENT 8, allowing fold_builtin_memory_op
> > > +/* Some targets have BIGGEST_ALIGNMENT 8-bits, allowing
> > > fold_builtin_memory_op
> > > to expand the memcpy call at the end of fn1. */
> > > -/* { dg-final { scan-tree-dump-times "memcpy \\(" 7 "strlen1" { target {
> > > ! avr-*-* } } } } */
> > > -/* { dg-final { scan-tree-dump-times "memcpy \\(" 6 "strlen1" { target {
> > > avr-*-* } } } } */
> > > +/* { dg-final { scan-tree-dump-times "memcpy \\(" 7 "strlen1" { target {
> > > ! no_alignment_constraints } } } } */
> > > +/* { dg-final { scan-tree-dump-times "memcpy \\(" 6 "strlen1" { target {
> > > no_alignment_constraints } } } } */
> > > /* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen1" } } */
> > > /* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen1" } } */
> > > /* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen1" } } */
> > > /* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen1" } } */
> > > /* Where the memcpy is expanded, the assignemts to elements of l are
> > > propagated. */
> > > -/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.0. = " 1 "strlen1" { target { ! avr-*-* } } }
> > > } */
> > > -/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.6. = " 1 "strlen1" { target { ! avr-*-* } } }
> > > } */
> > > -/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.9. = " 1 "strlen1" { target { ! avr-*-* } } }
> > > } */
> > > -/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;" 3 "strlen1" { target { avr-*-* } } } } */
> > > +/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.0. = " 1 "strlen1" { target { !
> > > no_alignment_constraints } } } } */
> > > +/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.6. = " 1 "strlen1" { target { !
> > > no_alignment_constraints } } } } */
> > > +/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.9. = " 1 "strlen1" { target { !
> > > no_alignment_constraints } } } } */
> > > +/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;" 3 "strlen1" { target { no_alignment_constraints } } } } */
> > > diff --git a/gcc/testsuite/gcc.dg/strlenopt-13.c
> > > b/gcc/testsuite/gcc.dg/strlenopt-13.c
> > > index 27ecc79c2d9..4c6d5266780 100644
> > > --- a/gcc/testsuite/gcc.dg/strlenopt-13.c
> > > +++ b/gcc/testsuite/gcc.dg/strlenopt-13.c
> > > @@ -56,18 +56,18 @@ main ()
> > > }
> > >
> > > /* { dg-final { scan-tree-dump-times "strlen \\(" 4 "strlen1" } } */
> > > -/* avr has BIGGEST_ALIGNMENT 8, allowing fold_builtin_memory_op
> > > +/* Some targets have BIGGEST_ALIGNMENT 8-bits, allowing
> > > fold_builtin_memory_op
> > > to expand the memcpy call at the end of fn1. */
> > > -/* { dg-final { scan-tree-dump-times "memcpy \\(" 7 "strlen1" { target {
> > > ! avr-*-* } } } } */
> > > -/* { dg-final { scan-tree-dump-times "memcpy \\(" 6 "strlen1" { target {
> > > avr-*-* } } } } */
> > > +/* { dg-final { scan-tree-dump-times "memcpy \\(" 7 "strlen1" { target {
> > > ! no_alignment_constraints } } } } */
> > > +/* { dg-final { scan-tree-dump-times "memcpy \\(" 6 "strlen1" { target {
> > > no_alignment_constraints } } } } */
> > > /* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen1" } } */
> > > /* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen1" } } */
> > > /* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen1" } } */
> > > /* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen1" } } */
> > > /* Where the memcpy is expanded, the assignemts to elements of l are
> > > propagated. */
> > > -/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.0. = " 1 "strlen1" { target { ! avr-*-* } } }
> > > } */
> > > -/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.1. = " 1 "strlen1" { target { ! avr-*-* } } }
> > > } */
> > > -/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.5. = " 1 "strlen1" { target { ! avr-*-* } } }
> > > } */
> > > -/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.6. = " 1 "strlen1" { target { ! avr-*-* } } }
> > > } */
> > > -/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;" 4 "strlen1" { target { avr-*-* } } } } */
> > > +/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.0. = " 1 "strlen1" { target { !
> > > no_alignment_constraints } } } } */
> > > +/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.1. = " 1 "strlen1" { target { !
> > > no_alignment_constraints } } } } */
> > > +/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.5. = " 1 "strlen1" { target { !
> > > no_alignment_constraints } } } } */
> > > +/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;\[\n\r\]* l.6. = " 1 "strlen1" { target { !
> > > no_alignment_constraints } } } } */
> > > +/* { dg-final { scan-tree-dump-times " _\[0-9\]* = strlen
> > > \\(\[^\n\r\]*;" 4 "strlen1" { target { no_alignment_constraints } } } } */
> > > diff --git a/gcc/testsuite/lib/target-supports.exp
> > > b/gcc/testsuite/lib/target-supports.exp
> > > index d1f4eb7641f..a86b151bb9e 100644
> > > --- a/gcc/testsuite/lib/target-supports.exp
> > > +++ b/gcc/testsuite/lib/target-supports.exp
> > > @@ -7541,6 +7541,19 @@ proc check_effective_target_vect_aligned_arrays {
> > > } {
> > > return $et_vect_aligned_arrays
> > > }
> > >
> > > +# Return 1 if the biggest alignment required by target is 1 *
> > > BITS_PER_UNIT.
> > > +# In such case the target does not impose any alignment constraints.
> > > +
> > > +proc check_effective_target_no_alignment_constraints { } {
> > > + return [check_runtime_nocache no_alignment_constraints {
> > > + int
> > > + main (void)
> > > + {
> > > + return __BIGGEST_ALIGNMENT__ == 1 ? 0 : 1;
> > > + }
> > > + }]
> > > +}
> > > +
> > > # Return 1 if types of size 32 bit or less are naturally aligned
> > > # (aligned to their type-size), 0 otherwise.
> > > #
> > > --
> > > 2.36.1
> > >
