This patch is okay with me if okay with the Release Managers. Thanks, David
On Wed, Jul 16, 2014 at 8:41 PM, Ulrich Weigand <uweig...@de.ibm.com> wrote: > Hello, > > this is the variant intended for the 4.8/4.9 branches of the patch: > https://gcc.gnu.org/ml/gcc-patches/2014-07/msg01072.html > > As discussed, it does *not* actually change ABI, but only warn when > encountering a situation where the ABI will change in a future GCC. > (Avoiding the specific term "GCC 4.10" here since I'm not certain > whether the next GCC release will in fact be called that ...) > > Tested on powerpc64-linux and powerpc64le-linux; also verified using > the ABI compat suite (against an unpatched GCC) that this patch does > not change the ABI. > > OK for 4.8/4.9 once the mainline patch is in? > > 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. Issue -Wpsabi warning if future GCC releases will use > different field alignment rules for this type. > * 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-4_9-branch/gcc/config/rs6000/rs6000-protos.h > =================================================================== > --- gcc-4_9-branch.orig/gcc/config/rs6000/rs6000-protos.h > +++ gcc-4_9-branch/gcc/config/rs6000/rs6000-protos.h > @@ -155,6 +155,7 @@ extern void rs6000_split_logical (rtx [] > > #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-4_9-branch/gcc/config/rs6000/rs6000.c > =================================================================== > --- gcc-4_9-branch.orig/gcc/config/rs6000/rs6000.c > +++ gcc-4_9-branch/gcc/config/rs6000/rs6000.c > @@ -5871,6 +5871,34 @@ rs6000_data_alignment (tree type, unsign > 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 will change in a future GCC > release", > + computed / BITS_PER_UNIT); > + } > + } > + /* GCC 4.8/4.9 Note: To avoid any ABI change on a release branch, we > + keep the special treatment of vector types, but warn if there will > + be differences in future GCC releases. */ > + return true; > + } > + > + 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-4_9-branch/gcc/config/rs6000/sysv4.h > =================================================================== > --- gcc-4_9-branch.orig/gcc/config/rs6000/sysv4.h > +++ gcc-4_9-branch/gcc/config/rs6000/sysv4.h > @@ -292,7 +292,7 @@ do { > \ > /* 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-4_9-branch/gcc/config/rs6000/linux64.h > =================================================================== > --- gcc-4_9-branch.orig/gcc/config/rs6000/linux64.h > +++ gcc-4_9-branch/gcc/config/rs6000/linux64.h > @@ -246,7 +246,7 @@ extern int dot_symbols; > /* 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-4_9-branch/gcc/config/rs6000/freebsd64.h > =================================================================== > --- gcc-4_9-branch.orig/gcc/config/rs6000/freebsd64.h > +++ gcc-4_9-branch/gcc/config/rs6000/freebsd64.h > @@ -367,7 +367,7 @@ extern int dot_symbols; > /* 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-4_9-branch/gcc/testsuite/gcc.c-torture/execute/20050316-1.x > =================================================================== > --- gcc-4_9-branch.orig/gcc/testsuite/gcc.c-torture/execute/20050316-1.x > +++ gcc-4_9-branch/gcc/testsuite/gcc.c-torture/execute/20050316-1.x > @@ -4,4 +4,5 @@ if { [check_effective_target_int16] } { > return 1 > } > > +set additional_flags "-Wno-psabi" > return 0; > Index: gcc-4_9-branch/gcc/testsuite/gcc.c-torture/execute/20050316-3.x > =================================================================== > --- /dev/null > +++ gcc-4_9-branch/gcc/testsuite/gcc.c-torture/execute/20050316-3.x > @@ -0,0 +1,2 @@ > +set additional_flags "-Wno-psabi" > +return 0 > Index: gcc-4_9-branch/gcc/testsuite/gcc.c-torture/execute/20050604-1.x > =================================================================== > --- gcc-4_9-branch.orig/gcc/testsuite/gcc.c-torture/execute/20050604-1.x > +++ gcc-4_9-branch/gcc/testsuite/gcc.c-torture/execute/20050604-1.x > @@ -6,4 +6,5 @@ if { [istarget "i?86-*-*"] || [istarget > set additional_flags "-mno-mmx" > } > > +set additional_flags "-Wno-psabi" > return 0 > Index: gcc-4_9-branch/gcc/testsuite/gcc.c-torture/execute/pr23135.x > =================================================================== > --- /dev/null > +++ gcc-4_9-branch/gcc/testsuite/gcc.c-torture/execute/pr23135.x > @@ -0,0 +1,2 @@ > +set additional_flags "-Wno-psabi" > +return 0 > Index: gcc-4_9-branch/gcc/testsuite/gcc.target/powerpc/ppc64-abi-warn-3.c > =================================================================== > --- /dev/null > +++ gcc-4_9-branch/gcc/testsuite/gcc.target/powerpc/ppc64-abi-warn-3.c > @@ -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 will change" } */ > + > -- > Dr. Ulrich Weigand > GNU/Linux compilers and toolchain > ulrich.weig...@de.ibm.com >
