* [RFC, rs6000, v2] Fix alignment of non-Altivec vector struct fields
@ 2014-07-14 19:01 Ulrich Weigand
2014-07-14 19:22 ` Ulrich Weigand
2014-07-15 8:32 ` Richard Biener
0 siblings, 2 replies; 5+ messages in thread
From: Ulrich Weigand @ 2014-07-14 19:01 UTC (permalink / raw)
To: gcc-patches; +Cc: dje.gcc
Hello,
this is an attempt to update the prior patch:
https://gcc.gnu.org/ml/gcc-patches/2014-07/msg00635.html
to add a -Wpsabi note as discussed.
However, this is causing a bit of difficulties. First of all, the warning
triggers in a larger number of tests -- which was probably to be expected
since a number of tests in the suite explicitly work on GCC vectors defined
using various vector_size values, and any size except 16 will result in the
warning. Note that the warning gets issued at the site of definition of
the structure type -- it does not have to be used in a function call.
More problematic is that this new warning causes four tests to fail
(it's actually 38 new FAILS since each of the tests fails in multiple
optimization levels):
FAIL: gcc.c-torture/execute/20050316-1.c compilation
gcc.c-torture/execute/20050316-1.c:53:9: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
FAIL: gcc.c-torture/execute/20050316-3.c compilation
gcc.c-torture/execute/20050316-3.c:26:9: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
FAIL: gcc.c-torture/execute/20050604-1.c compilation
gcc.c-torture/execute/20050604-1.c:12:1: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
FAIL: gcc.c-torture/execute/pr23135.c compilation
gcc.c-torture/execute/pr23135.c:20:1: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
Unfortunately, while most of the tests in the suite use the dg-test
framework which ignores "note" messages, the gcc.c-torture/execute
tests still use the old "torture" test framework, which does *not*.
(Also, in the old framework you cannot even add dg-... commands to
ignore those messages for a certain test, or add a -Wno-psabi option.)
Therefore, I'm not proposing to commit this patch as-is, but would
like to ask for feedback on how to best proceed with this.
One option might be to move the affected tests to the dg-test framework.
Or else we might decide we don't actually need a warning for this change,
since it only affects GCC synthetic vectors, where we might not have made
strict ABI guarantees anyway ...
Thoughts?
Bye,
Ulrich
gcc/ChangeLog:
* config/rs6000/rs6000-protos.h (rs6000_special_adjust_field_align_p):
Add prototype.
* config/rs6000/rs6000.c (rs6000_special_adjust_field_align_p): New
function.
* config/rs6000/sysv4.h (ADJUST_FIELD_ALIGN): Call it.
* config/rs6000/linux64.h (ADJUST_FIELD_ALIGN): Likewise.
* config/rs6000/freebsd64.h (ADJUST_FIELD_ALIGN): Likewise.
gcc/testsuite/ChangeLog:
* gcc.target/powerpc/ppc64-abi-warn-3.c: New test.
Index: gcc/config/rs6000/rs6000-protos.h
===================================================================
--- gcc/config/rs6000/rs6000-protos.h (revision 212147)
+++ gcc/config/rs6000/rs6000-protos.h (working copy)
@@ -155,6 +155,7 @@
#ifdef TREE_CODE
extern unsigned int rs6000_data_alignment (tree, unsigned int, enum data_align);
+extern bool rs6000_special_adjust_field_align_p (tree, unsigned int);
extern unsigned int rs6000_special_round_type_align (tree, unsigned int,
unsigned int);
extern unsigned int darwin_rs6000_special_round_type_align (tree, unsigned int,
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 212147)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -5878,6 +5878,32 @@
return align;
}
+/* Previous GCC releases forced all vector types to have 16-byte alignment. */
+
+bool
+rs6000_special_adjust_field_align_p (tree field, unsigned int computed)
+{
+ if (TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (field)) == VECTOR_TYPE)
+ {
+ if (computed != 128)
+ {
+ static bool warned;
+ if (!warned && warn_psabi)
+ {
+ warned = true;
+ inform (input_location,
+ "the layout of aggregates containing vectors with"
+ " %d-byte alignment has changed in GCC 4.10",
+ computed / BITS_PER_UNIT);
+ }
+ }
+ /* In current GCC there is no special case. */
+ return false;
+ }
+
+ return false;
+}
+
/* AIX increases natural record alignment to doubleword if the first
field is an FP double while the FP fields remain word aligned. */
Index: gcc/config/rs6000/sysv4.h
===================================================================
--- gcc/config/rs6000/sysv4.h (revision 212147)
+++ gcc/config/rs6000/sysv4.h (working copy)
@@ -292,7 +292,7 @@
/* An expression for the alignment of a structure field FIELD if the
alignment computed in the usual way is COMPUTED. */
#define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
- ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
+ (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
? 128 : COMPUTED)
#undef BIGGEST_FIELD_ALIGNMENT
Index: gcc/config/rs6000/linux64.h
===================================================================
--- gcc/config/rs6000/linux64.h (revision 212147)
+++ gcc/config/rs6000/linux64.h (working copy)
@@ -246,7 +246,7 @@
/* PowerPC64 Linux word-aligns FP doubles when -malign-power is given. */
#undef ADJUST_FIELD_ALIGN
#define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
- ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
+ (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
? 128 \
: (TARGET_64BIT \
&& TARGET_ALIGN_NATURAL == 0 \
Index: gcc/config/rs6000/freebsd64.h
===================================================================
--- gcc/config/rs6000/freebsd64.h (revision 212147)
+++ gcc/config/rs6000/freebsd64.h (working copy)
@@ -367,7 +367,7 @@
/* PowerPC64 Linux word-aligns FP doubles when -malign-power is given. */
#undef ADJUST_FIELD_ALIGN
#define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
- ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
+ (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
? 128 \
: (TARGET_64BIT \
&& TARGET_ALIGN_NATURAL == 0 \
Index: gcc/testsuite/gcc.target/powerpc/ppc64-abi-warn-3.c
===================================================================
--- /dev/null
+++ gcc/testsuite/gcc.target/powerpc/ppc64-abi-warn-3.c (revision 0)
@@ -0,0 +1,9 @@
+/* { dg-do compile { target { powerpc*-*-linux* && lp64 } } } */
+/* { dg-require-effective-target powerpc_altivec_ok } */
+/* { dg-options "-maltivec" } */
+
+struct test
+ {
+ int a __attribute__((vector_size (8)));
+ }; /* { dg-message "note: the layout of aggregates containing vectors with 8-byte alignment has changed" } */
+
--
Dr. Ulrich Weigand
GNU/Linux compilers and toolchain
Ulrich.Weigand@de.ibm.com
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC, rs6000, v2] Fix alignment of non-Altivec vector struct fields
2014-07-14 19:01 [RFC, rs6000, v2] Fix alignment of non-Altivec vector struct fields Ulrich Weigand
@ 2014-07-14 19:22 ` Ulrich Weigand
2014-07-15 8:32 ` Richard Biener
1 sibling, 0 replies; 5+ messages in thread
From: Ulrich Weigand @ 2014-07-14 19:22 UTC (permalink / raw)
To: gcc-patches; +Cc: dje.gcc
[ Sorry, re-sending with fixed email address. ]
Hello,
this is an attempt to update the prior patch:
https://gcc.gnu.org/ml/gcc-patches/2014-07/msg00635.html
to add a -Wpsabi note as discussed.
However, this is causing a bit of difficulties. First of all, the warning
triggers in a larger number of tests -- which was probably to be expected
since a number of tests in the suite explicitly work on GCC vectors defined
using various vector_size values, and any size except 16 will result in the
warning. Note that the warning gets issued at the site of definition of
the structure type -- it does not have to be used in a function call.
More problematic is that this new warning causes four tests to fail
(it's actually 38 new FAILS since each of the tests fails in multiple
optimization levels):
FAIL: gcc.c-torture/execute/20050316-1.c compilation
gcc.c-torture/execute/20050316-1.c:53:9: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
FAIL: gcc.c-torture/execute/20050316-3.c compilation
gcc.c-torture/execute/20050316-3.c:26:9: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
FAIL: gcc.c-torture/execute/20050604-1.c compilation
gcc.c-torture/execute/20050604-1.c:12:1: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
FAIL: gcc.c-torture/execute/pr23135.c compilation
gcc.c-torture/execute/pr23135.c:20:1: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
Unfortunately, while most of the tests in the suite use the dg-test
framework which ignores "note" messages, the gcc.c-torture/execute
tests still use the old "torture" test framework, which does *not*.
(Also, in the old framework you cannot even add dg-... commands to
ignore those messages for a certain test, or add a -Wno-psabi option.)
Therefore, I'm not proposing to commit this patch as-is, but would
like to ask for feedback on how to best proceed with this.
One option might be to move the affected tests to the dg-test framework.
Or else we might decide we don't actually need a warning for this change,
since it only affects GCC synthetic vectors, where we might not have made
strict ABI guarantees anyway ...
Thoughts?
Bye,
Ulrich
gcc/ChangeLog:
* config/rs6000/rs6000-protos.h (rs6000_special_adjust_field_align_p):
Add prototype.
* config/rs6000/rs6000.c (rs6000_special_adjust_field_align_p): New
function.
* config/rs6000/sysv4.h (ADJUST_FIELD_ALIGN): Call it.
* config/rs6000/linux64.h (ADJUST_FIELD_ALIGN): Likewise.
* config/rs6000/freebsd64.h (ADJUST_FIELD_ALIGN): Likewise.
gcc/testsuite/ChangeLog:
* gcc.target/powerpc/ppc64-abi-warn-3.c: New test.
Index: gcc/config/rs6000/rs6000-protos.h
===================================================================
--- gcc/config/rs6000/rs6000-protos.h (revision 212147)
+++ gcc/config/rs6000/rs6000-protos.h (working copy)
@@ -155,6 +155,7 @@
#ifdef TREE_CODE
extern unsigned int rs6000_data_alignment (tree, unsigned int, enum data_align);
+extern bool rs6000_special_adjust_field_align_p (tree, unsigned int);
extern unsigned int rs6000_special_round_type_align (tree, unsigned int,
unsigned int);
extern unsigned int darwin_rs6000_special_round_type_align (tree, unsigned int,
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 212147)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -5878,6 +5878,32 @@
return align;
}
+/* Previous GCC releases forced all vector types to have 16-byte alignment. */
+
+bool
+rs6000_special_adjust_field_align_p (tree field, unsigned int computed)
+{
+ if (TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (field)) == VECTOR_TYPE)
+ {
+ if (computed != 128)
+ {
+ static bool warned;
+ if (!warned && warn_psabi)
+ {
+ warned = true;
+ inform (input_location,
+ "the layout of aggregates containing vectors with"
+ " %d-byte alignment has changed in GCC 4.10",
+ computed / BITS_PER_UNIT);
+ }
+ }
+ /* In current GCC there is no special case. */
+ return false;
+ }
+
+ return false;
+}
+
/* AIX increases natural record alignment to doubleword if the first
field is an FP double while the FP fields remain word aligned. */
Index: gcc/config/rs6000/sysv4.h
===================================================================
--- gcc/config/rs6000/sysv4.h (revision 212147)
+++ gcc/config/rs6000/sysv4.h (working copy)
@@ -292,7 +292,7 @@
/* An expression for the alignment of a structure field FIELD if the
alignment computed in the usual way is COMPUTED. */
#define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
- ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
+ (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
? 128 : COMPUTED)
#undef BIGGEST_FIELD_ALIGNMENT
Index: gcc/config/rs6000/linux64.h
===================================================================
--- gcc/config/rs6000/linux64.h (revision 212147)
+++ gcc/config/rs6000/linux64.h (working copy)
@@ -246,7 +246,7 @@
/* PowerPC64 Linux word-aligns FP doubles when -malign-power is given. */
#undef ADJUST_FIELD_ALIGN
#define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
- ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
+ (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
? 128 \
: (TARGET_64BIT \
&& TARGET_ALIGN_NATURAL == 0 \
Index: gcc/config/rs6000/freebsd64.h
===================================================================
--- gcc/config/rs6000/freebsd64.h (revision 212147)
+++ gcc/config/rs6000/freebsd64.h (working copy)
@@ -367,7 +367,7 @@
/* PowerPC64 Linux word-aligns FP doubles when -malign-power is given. */
#undef ADJUST_FIELD_ALIGN
#define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
- ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
+ (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
? 128 \
: (TARGET_64BIT \
&& TARGET_ALIGN_NATURAL == 0 \
Index: gcc/testsuite/gcc.target/powerpc/ppc64-abi-warn-3.c
===================================================================
--- /dev/null
+++ gcc/testsuite/gcc.target/powerpc/ppc64-abi-warn-3.c (revision 0)
@@ -0,0 +1,9 @@
+/* { dg-do compile { target { powerpc*-*-linux* && lp64 } } } */
+/* { dg-require-effective-target powerpc_altivec_ok } */
+/* { dg-options "-maltivec" } */
+
+struct test
+ {
+ int a __attribute__((vector_size (8)));
+ }; /* { dg-message "note: the layout of aggregates containing vectors with 8-byte alignment has changed" } */
+
--
Dr. Ulrich Weigand
GNU/Linux compilers and toolchain
Ulrich.Weigand@de.ibm.com
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC, rs6000, v2] Fix alignment of non-Altivec vector struct fields
2014-07-14 19:01 [RFC, rs6000, v2] Fix alignment of non-Altivec vector struct fields Ulrich Weigand
2014-07-14 19:22 ` Ulrich Weigand
@ 2014-07-15 8:32 ` Richard Biener
2014-07-15 15:29 ` Ulrich Weigand
1 sibling, 1 reply; 5+ messages in thread
From: Richard Biener @ 2014-07-15 8:32 UTC (permalink / raw)
To: Ulrich Weigand; +Cc: GCC Patches, dje.gcc
On Mon, Jul 14, 2014 at 8:55 PM, Ulrich Weigand <uweigand@de.ibm.com> wrote:
> Hello,
>
> this is an attempt to update the prior patch:
> https://gcc.gnu.org/ml/gcc-patches/2014-07/msg00635.html
> to add a -Wpsabi note as discussed.
>
> However, this is causing a bit of difficulties. First of all, the warning
> triggers in a larger number of tests -- which was probably to be expected
> since a number of tests in the suite explicitly work on GCC vectors defined
> using various vector_size values, and any size except 16 will result in the
> warning. Note that the warning gets issued at the site of definition of
> the structure type -- it does not have to be used in a function call.
>
> More problematic is that this new warning causes four tests to fail
> (it's actually 38 new FAILS since each of the tests fails in multiple
> optimization levels):
>
> FAIL: gcc.c-torture/execute/20050316-1.c compilation
> gcc.c-torture/execute/20050316-1.c:53:9: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
> FAIL: gcc.c-torture/execute/20050316-3.c compilation
> gcc.c-torture/execute/20050316-3.c:26:9: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
> FAIL: gcc.c-torture/execute/20050604-1.c compilation
> gcc.c-torture/execute/20050604-1.c:12:1: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
> FAIL: gcc.c-torture/execute/pr23135.c compilation
> gcc.c-torture/execute/pr23135.c:20:1: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
>
> Unfortunately, while most of the tests in the suite use the dg-test
> framework which ignores "note" messages, the gcc.c-torture/execute
> tests still use the old "torture" test framework, which does *not*.
> (Also, in the old framework you cannot even add dg-... commands to
> ignore those messages for a certain test, or add a -Wno-psabi option.)
>
> Therefore, I'm not proposing to commit this patch as-is, but would
> like to ask for feedback on how to best proceed with this.
>
> One option might be to move the affected tests to the dg-test framework.
> Or else we might decide we don't actually need a warning for this change,
> since it only affects GCC synthetic vectors, where we might not have made
> strict ABI guarantees anyway ...
>
> Thoughts?
> cat gcc/testsuite/gcc.c-torture/execute/pr38151.x
set additional_flags "-Wno-psabi"
return 0
> Bye,
> Ulrich
>
>
> gcc/ChangeLog:
>
> * config/rs6000/rs6000-protos.h (rs6000_special_adjust_field_align_p):
> Add prototype.
> * config/rs6000/rs6000.c (rs6000_special_adjust_field_align_p): New
> function.
> * config/rs6000/sysv4.h (ADJUST_FIELD_ALIGN): Call it.
> * config/rs6000/linux64.h (ADJUST_FIELD_ALIGN): Likewise.
> * config/rs6000/freebsd64.h (ADJUST_FIELD_ALIGN): Likewise.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/powerpc/ppc64-abi-warn-3.c: New test.
>
>
>
> Index: gcc/config/rs6000/rs6000-protos.h
> ===================================================================
> --- gcc/config/rs6000/rs6000-protos.h (revision 212147)
> +++ gcc/config/rs6000/rs6000-protos.h (working copy)
> @@ -155,6 +155,7 @@
>
> #ifdef TREE_CODE
> extern unsigned int rs6000_data_alignment (tree, unsigned int, enum data_align);
> +extern bool rs6000_special_adjust_field_align_p (tree, unsigned int);
> extern unsigned int rs6000_special_round_type_align (tree, unsigned int,
> unsigned int);
> extern unsigned int darwin_rs6000_special_round_type_align (tree, unsigned int,
> Index: gcc/config/rs6000/rs6000.c
> ===================================================================
> --- gcc/config/rs6000/rs6000.c (revision 212147)
> +++ gcc/config/rs6000/rs6000.c (working copy)
> @@ -5878,6 +5878,32 @@
> return align;
> }
>
> +/* Previous GCC releases forced all vector types to have 16-byte alignment. */
> +
> +bool
> +rs6000_special_adjust_field_align_p (tree field, unsigned int computed)
> +{
> + if (TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (field)) == VECTOR_TYPE)
> + {
> + if (computed != 128)
> + {
> + static bool warned;
> + if (!warned && warn_psabi)
> + {
> + warned = true;
> + inform (input_location,
> + "the layout of aggregates containing vectors with"
> + " %d-byte alignment has changed in GCC 4.10",
> + computed / BITS_PER_UNIT);
> + }
> + }
> + /* In current GCC there is no special case. */
> + return false;
> + }
> +
> + return false;
> +}
> +
> /* AIX increases natural record alignment to doubleword if the first
> field is an FP double while the FP fields remain word aligned. */
>
> Index: gcc/config/rs6000/sysv4.h
> ===================================================================
> --- gcc/config/rs6000/sysv4.h (revision 212147)
> +++ gcc/config/rs6000/sysv4.h (working copy)
> @@ -292,7 +292,7 @@
> /* An expression for the alignment of a structure field FIELD if the
> alignment computed in the usual way is COMPUTED. */
> #define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
> - ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
> + (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
> ? 128 : COMPUTED)
>
> #undef BIGGEST_FIELD_ALIGNMENT
> Index: gcc/config/rs6000/linux64.h
> ===================================================================
> --- gcc/config/rs6000/linux64.h (revision 212147)
> +++ gcc/config/rs6000/linux64.h (working copy)
> @@ -246,7 +246,7 @@
> /* PowerPC64 Linux word-aligns FP doubles when -malign-power is given. */
> #undef ADJUST_FIELD_ALIGN
> #define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
> - ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
> + (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
> ? 128 \
> : (TARGET_64BIT \
> && TARGET_ALIGN_NATURAL == 0 \
> Index: gcc/config/rs6000/freebsd64.h
> ===================================================================
> --- gcc/config/rs6000/freebsd64.h (revision 212147)
> +++ gcc/config/rs6000/freebsd64.h (working copy)
> @@ -367,7 +367,7 @@
> /* PowerPC64 Linux word-aligns FP doubles when -malign-power is given. */
> #undef ADJUST_FIELD_ALIGN
> #define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
> - ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
> + (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
> ? 128 \
> : (TARGET_64BIT \
> && TARGET_ALIGN_NATURAL == 0 \
> Index: gcc/testsuite/gcc.target/powerpc/ppc64-abi-warn-3.c
> ===================================================================
> --- /dev/null
> +++ gcc/testsuite/gcc.target/powerpc/ppc64-abi-warn-3.c (revision 0)
> @@ -0,0 +1,9 @@
> +/* { dg-do compile { target { powerpc*-*-linux* && lp64 } } } */
> +/* { dg-require-effective-target powerpc_altivec_ok } */
> +/* { dg-options "-maltivec" } */
> +
> +struct test
> + {
> + int a __attribute__((vector_size (8)));
> + }; /* { dg-message "note: the layout of aggregates containing vectors with 8-byte alignment has changed" } */
> +
> --
> Dr. Ulrich Weigand
> GNU/Linux compilers and toolchain
> Ulrich.Weigand@de.ibm.com
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC, rs6000, v2] Fix alignment of non-Altivec vector struct fields
2014-07-15 8:32 ` Richard Biener
@ 2014-07-15 15:29 ` Ulrich Weigand
2014-07-18 18:21 ` David Edelsohn
0 siblings, 1 reply; 5+ messages in thread
From: Ulrich Weigand @ 2014-07-15 15:29 UTC (permalink / raw)
To: Richard Biener; +Cc: GCC Patches, dje.gcc
Richard Biener wrote:
> On Mon, Jul 14, 2014 at 8:55 PM, Ulrich Weigand <uweigand@de.ibm.com> wrote:
> > Hello,
> >
> > this is an attempt to update the prior patch:
> > https://gcc.gnu.org/ml/gcc-patches/2014-07/msg00635.html
> > to add a -Wpsabi note as discussed.
> >
> > However, this is causing a bit of difficulties. First of all, the warning
> > triggers in a larger number of tests -- which was probably to be expected
> > since a number of tests in the suite explicitly work on GCC vectors defined
> > using various vector_size values, and any size except 16 will result in the
> > warning. Note that the warning gets issued at the site of definition of
> > the structure type -- it does not have to be used in a function call.
> >
> > More problematic is that this new warning causes four tests to fail
> > (it's actually 38 new FAILS since each of the tests fails in multiple
> > optimization levels):
> >
> > FAIL: gcc.c-torture/execute/20050316-1.c compilation
> > gcc.c-torture/execute/20050316-1.c:53:9: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
> > FAIL: gcc.c-torture/execute/20050316-3.c compilation
> > gcc.c-torture/execute/20050316-3.c:26:9: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
> > FAIL: gcc.c-torture/execute/20050604-1.c compilation
> > gcc.c-torture/execute/20050604-1.c:12:1: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
> > FAIL: gcc.c-torture/execute/pr23135.c compilation
> > gcc.c-torture/execute/pr23135.c:20:1: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
> >
> > Unfortunately, while most of the tests in the suite use the dg-test
> > framework which ignores "note" messages, the gcc.c-torture/execute
> > tests still use the old "torture" test framework, which does *not*.
> > (Also, in the old framework you cannot even add dg-... commands to
> > ignore those messages for a certain test, or add a -Wno-psabi option.)
> >
> > Therefore, I'm not proposing to commit this patch as-is, but would
> > like to ask for feedback on how to best proceed with this.
> >
> > One option might be to move the affected tests to the dg-test framework.
> > Or else we might decide we don't actually need a warning for this change,
> > since it only affects GCC synthetic vectors, where we might not have made
> > strict ABI guarantees anyway ...
> >
> > Thoughts?
>
> cat gcc/testsuite/gcc.c-torture/execute/pr38151.x
> set additional_flags "-Wno-psabi"
> return 0
Ah, I had forgotten about the .x files. Thanks!
Here's a version with the -Wno-psabi added to the .x files. This now
passes regression testing.
OK for mainline?
Bye,
Ulrich
gcc/ChangeLog:
* config/rs6000/rs6000-protos.h (rs6000_special_adjust_field_align_p):
Add prototype.
* config/rs6000/rs6000.c (rs6000_special_adjust_field_align_p): New
function.
* config/rs6000/sysv4.h (ADJUST_FIELD_ALIGN): Call it.
* config/rs6000/linux64.h (ADJUST_FIELD_ALIGN): Likewise.
* config/rs6000/freebsd64.h (ADJUST_FIELD_ALIGN): Likewise.
gcc/testsuite/ChangeLog:
* gcc.target/powerpc/ppc64-abi-warn-3.c: New test.
* gcc.c-torture/execute/20050316-1.x: Add -Wno-psabi.
* gcc.c-torture/execute/20050604-1.x: Add -Wno-psabi.
* gcc.c-torture/execute/20050316-3.x: New file. Add -Wno-psabi.
* gcc.c-torture/execute/pr23135.x: Likewise.
Index: gcc/config/rs6000/rs6000-protos.h
===================================================================
--- gcc/config/rs6000/rs6000-protos.h (revision 212147)
+++ gcc/config/rs6000/rs6000-protos.h (working copy)
@@ -155,6 +155,7 @@
#ifdef TREE_CODE
extern unsigned int rs6000_data_alignment (tree, unsigned int, enum data_align);
+extern bool rs6000_special_adjust_field_align_p (tree, unsigned int);
extern unsigned int rs6000_special_round_type_align (tree, unsigned int,
unsigned int);
extern unsigned int darwin_rs6000_special_round_type_align (tree, unsigned int,
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 212147)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -5878,6 +5878,32 @@
return align;
}
+/* Previous GCC releases forced all vector types to have 16-byte alignment. */
+
+bool
+rs6000_special_adjust_field_align_p (tree field, unsigned int computed)
+{
+ if (TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (field)) == VECTOR_TYPE)
+ {
+ if (computed != 128)
+ {
+ static bool warned;
+ if (!warned && warn_psabi)
+ {
+ warned = true;
+ inform (input_location,
+ "the layout of aggregates containing vectors with"
+ " %d-byte alignment has changed in GCC 4.10",
+ computed / BITS_PER_UNIT);
+ }
+ }
+ /* In current GCC there is no special case. */
+ return false;
+ }
+
+ return false;
+}
+
/* AIX increases natural record alignment to doubleword if the first
field is an FP double while the FP fields remain word aligned. */
Index: gcc/config/rs6000/sysv4.h
===================================================================
--- gcc/config/rs6000/sysv4.h (revision 212147)
+++ gcc/config/rs6000/sysv4.h (working copy)
@@ -292,7 +292,7 @@
/* An expression for the alignment of a structure field FIELD if the
alignment computed in the usual way is COMPUTED. */
#define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
- ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
+ (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
? 128 : COMPUTED)
#undef BIGGEST_FIELD_ALIGNMENT
Index: gcc/config/rs6000/linux64.h
===================================================================
--- gcc/config/rs6000/linux64.h (revision 212147)
+++ gcc/config/rs6000/linux64.h (working copy)
@@ -246,7 +246,7 @@
/* PowerPC64 Linux word-aligns FP doubles when -malign-power is given. */
#undef ADJUST_FIELD_ALIGN
#define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
- ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
+ (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
? 128 \
: (TARGET_64BIT \
&& TARGET_ALIGN_NATURAL == 0 \
Index: gcc/config/rs6000/freebsd64.h
===================================================================
--- gcc/config/rs6000/freebsd64.h (revision 212147)
+++ gcc/config/rs6000/freebsd64.h (working copy)
@@ -367,7 +367,7 @@
/* PowerPC64 Linux word-aligns FP doubles when -malign-power is given. */
#undef ADJUST_FIELD_ALIGN
#define ADJUST_FIELD_ALIGN(FIELD, COMPUTED) \
- ((TARGET_ALTIVEC && TREE_CODE (TREE_TYPE (FIELD)) == VECTOR_TYPE) \
+ (rs6000_special_adjust_field_align_p ((FIELD), (COMPUTED)) \
? 128 \
: (TARGET_64BIT \
&& TARGET_ALIGN_NATURAL == 0 \
Index: gcc/testsuite/gcc.target/powerpc/ppc64-abi-warn-3.c
===================================================================
--- /dev/null
+++ gcc/testsuite/gcc.target/powerpc/ppc64-abi-warn-3.c (revision 0)
@@ -0,0 +1,9 @@
+/* { dg-do compile { target { powerpc*-*-linux* && lp64 } } } */
+/* { dg-require-effective-target powerpc_altivec_ok } */
+/* { dg-options "-maltivec" } */
+
+struct test
+ {
+ int a __attribute__((vector_size (8)));
+ }; /* { dg-message "note: the layout of aggregates containing vectors with 8-byte alignment has changed" } */
+
Index: gcc/testsuite/gcc.c-torture/execute/pr23135.x
===================================================================
--- /dev/null
+++ gcc/testsuite/gcc.c-torture/execute/pr23135.x (revision 0)
@@ -0,0 +1,2 @@
+set additional_flags "-Wno-psabi"
+return 0
Index: gcc/testsuite/gcc.c-torture/execute/20050316-1.x
===================================================================
--- gcc/testsuite/gcc.c-torture/execute/20050316-1.x (revision 212147)
+++ gcc/testsuite/gcc.c-torture/execute/20050316-1.x (working copy)
@@ -4,4 +4,5 @@
return 1
}
+set additional_flags "-Wno-psabi"
return 0;
Index: gcc/testsuite/gcc.c-torture/execute/20050316-3.x
===================================================================
--- /dev/null
+++ gcc/testsuite/gcc.c-torture/execute/20050316-3.x (revision 0)
@@ -0,0 +1,2 @@
+set additional_flags "-Wno-psabi"
+return 0
Index: gcc/testsuite/gcc.c-torture/execute/20050604-1.x
===================================================================
--- gcc/testsuite/gcc.c-torture/execute/20050604-1.x (revision 212147)
+++ gcc/testsuite/gcc.c-torture/execute/20050604-1.x (working copy)
@@ -6,4 +6,5 @@
set additional_flags "-mno-mmx"
}
+set additional_flags "-Wno-psabi"
return 0
--
Dr. Ulrich Weigand
GNU/Linux compilers and toolchain
Ulrich.Weigand@de.ibm.com
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC, rs6000, v2] Fix alignment of non-Altivec vector struct fields
2014-07-15 15:29 ` Ulrich Weigand
@ 2014-07-18 18:21 ` David Edelsohn
0 siblings, 0 replies; 5+ messages in thread
From: David Edelsohn @ 2014-07-18 18:21 UTC (permalink / raw)
To: Ulrich Weigand; +Cc: Richard Biener, GCC Patches
On Tue, Jul 15, 2014 at 11:23 AM, Ulrich Weigand <uweigand@de.ibm.com> wrote:
> Richard Biener wrote:
>> On Mon, Jul 14, 2014 at 8:55 PM, Ulrich Weigand <uweigand@de.ibm.com> wrote:
>> > Hello,
>> >
>> > this is an attempt to update the prior patch:
>> > https://gcc.gnu.org/ml/gcc-patches/2014-07/msg00635.html
>> > to add a -Wpsabi note as discussed.
>> >
>> > However, this is causing a bit of difficulties. First of all, the warning
>> > triggers in a larger number of tests -- which was probably to be expected
>> > since a number of tests in the suite explicitly work on GCC vectors defined
>> > using various vector_size values, and any size except 16 will result in the
>> > warning. Note that the warning gets issued at the site of definition of
>> > the structure type -- it does not have to be used in a function call.
>> >
>> > More problematic is that this new warning causes four tests to fail
>> > (it's actually 38 new FAILS since each of the tests fails in multiple
>> > optimization levels):
>> >
>> > FAIL: gcc.c-torture/execute/20050316-1.c compilation
>> > gcc.c-torture/execute/20050316-1.c:53:9: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
>> > FAIL: gcc.c-torture/execute/20050316-3.c compilation
>> > gcc.c-torture/execute/20050316-3.c:26:9: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
>> > FAIL: gcc.c-torture/execute/20050604-1.c compilation
>> > gcc.c-torture/execute/20050604-1.c:12:1: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
>> > FAIL: gcc.c-torture/execute/pr23135.c compilation
>> > gcc.c-torture/execute/pr23135.c:20:1: note: the layout of aggregates containing vectors with 8-byte alignment has changed in GCC 4.10
>> >
>> > Unfortunately, while most of the tests in the suite use the dg-test
>> > framework which ignores "note" messages, the gcc.c-torture/execute
>> > tests still use the old "torture" test framework, which does *not*.
>> > (Also, in the old framework you cannot even add dg-... commands to
>> > ignore those messages for a certain test, or add a -Wno-psabi option.)
>> >
>> > Therefore, I'm not proposing to commit this patch as-is, but would
>> > like to ask for feedback on how to best proceed with this.
>> >
>> > One option might be to move the affected tests to the dg-test framework.
>> > Or else we might decide we don't actually need a warning for this change,
>> > since it only affects GCC synthetic vectors, where we might not have made
>> > strict ABI guarantees anyway ...
>> >
>> > Thoughts?
>>
>> cat gcc/testsuite/gcc.c-torture/execute/pr38151.x
>> set additional_flags "-Wno-psabi"
>> return 0
>
> Ah, I had forgotten about the .x files. Thanks!
>
> Here's a version with the -Wno-psabi added to the .x files. This now
> passes regression testing.
>
> OK for mainline?
>
> Bye,
> Ulrich
>
>
> gcc/ChangeLog:
>
> * config/rs6000/rs6000-protos.h (rs6000_special_adjust_field_align_p):
> Add prototype.
> * config/rs6000/rs6000.c (rs6000_special_adjust_field_align_p): New
> function.
> * config/rs6000/sysv4.h (ADJUST_FIELD_ALIGN): Call it.
> * config/rs6000/linux64.h (ADJUST_FIELD_ALIGN): Likewise.
> * config/rs6000/freebsd64.h (ADJUST_FIELD_ALIGN): Likewise.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/powerpc/ppc64-abi-warn-3.c: New test.
>
> * gcc.c-torture/execute/20050316-1.x: Add -Wno-psabi.
> * gcc.c-torture/execute/20050604-1.x: Add -Wno-psabi.
> * gcc.c-torture/execute/20050316-3.x: New file. Add -Wno-psabi.
> * gcc.c-torture/execute/pr23135.x: Likewise.
This patch is okay.
Thanks, David
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2014-07-18 17:28 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-07-14 19:01 [RFC, rs6000, v2] Fix alignment of non-Altivec vector struct fields Ulrich Weigand
2014-07-14 19:22 ` Ulrich Weigand
2014-07-15 8:32 ` Richard Biener
2014-07-15 15:29 ` Ulrich Weigand
2014-07-18 18:21 ` David Edelsohn
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).