On Mon, Dec 14, 2020 at 2:13 PM Jakub Jelinek <ja...@redhat.com> wrote:
>
> Hi!
>
> If somebody has -march=x86-64-v2 (or -v3 or -v4) in $CFLAGS, $CXXFLAGS etc.,
> then -m32 or -mabi=ms stops working.
> What is worse, if one configures gcc --with-arch-32=x86-64-v2 (or -v3 or -v4),
> then -mabi=ms stops working.
>
> I think that is a nightmare user experience. It is ok that x86-64-v[234]
> behave slightly different from other -march= options (in that they imply
> unless overridden -mtune=generic rather then -mtune= equal to the -march
> argument), but the error when one mixes it with -mabi=ms, or -m32 doesn't
> improve anything.
> It is true that the exact option set is only defined in the x86-64 psABI
> (IMHO that is a mistake too, we should copy that into the GCC documentation
> like we document it for any other -march= option), but there is no reason
> why that exact set of CPU features can't be used for other ABIs, it is just
> a set of CPU features. If we add micro-architecture levels to the 32-bit
> ABI (I doubt anyone wants to do that, but just hypothetically), then those
> micro-architecture levels wouldn't certainly be called x86-64-v* but perhaps
> i386-v*.
> In the tests, __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 can't be expected on -m32
> not because the CPU feature wouldn't be set, but because the instruction
> is 64-bit only and 32-bit code doesn't have __int128 etc. support.
>
> Ok for trunk if this passes full bootstrap/regtest?
>
> 2020-12-14 Jakub Jelinek <ja...@redhat.com>
>
> * config/i386/i386-options.c (ix86_option_override_internal): Don't
> error on -march=x86-64-v[234] with -m32 or -mabi=ms.
> * config.gcc: Don't reject --with-arch=x86-64-v[234] or
> --with-arch_32=x86-64-v[234].
> * doc/invoke.texi (-march=x86-64-v[234]): Document what the option
> does for other ABIs.
>
> * gcc.target/i386/x86-64-v2.c: Don't expect
> __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 to be defined with -m32.
> * gcc.target/i386/x86-64-v2-other.c: New test.
> * gcc.target/i386/x86-64-v2-msabi.c: New test.
> * gcc.target/i386/x86-64-v3.c: Fix a comment pasto. Don't expect
> __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 to be defined with -m32.
> * gcc.target/i386/x86-64-v3-other.c: New test.
> * gcc.target/i386/x86-64-v3-msabi.c: New test.
> * gcc.target/i386/x86-64-v4.c:Don't expect
> __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 to be defined with -m32.
> * gcc.target/i386/x86-64-v4-other.c: New test.
> * gcc.target/i386/x86-64-v4-msabi.c: New test.
LGTM, but please allow some time for HJ to comment.
Thanks,
Uros.
>
> --- gcc/config/i386/i386-options.c.jj 2020-12-08 15:43:46.641140657 +0100
> +++ gcc/config/i386/i386-options.c 2020-12-14 13:31:51.864733294 +0100
> @@ -2084,17 +2084,6 @@ ix86_option_override_internal (bool main
> return false;
> }
>
> - /* The feature-only micro-architecture levels that use
> - PTA_NO_TUNE are only defined for the x86-64 psABI. */
> - if ((processor_alias_table[i].flags & PTA_NO_TUNE) != 0
> - && (!TARGET_64BIT_P (opts->x_ix86_isa_flags)
> - || opts->x_ix86_abi != SYSV_ABI))
> - {
> - error (G_("%qs architecture level is only defined"
> - " for the x86-64 psABI"), opts->x_ix86_arch_string);
> - return false;
> - }
> -
> ix86_schedule = processor_alias_table[i].schedule;
> ix86_arch = processor_alias_table[i].processor;
>
> --- gcc/config.gcc.jj 2020-12-08 10:36:28.817303511 +0100
> +++ gcc/config.gcc 2020-12-14 14:00:27.571656138 +0100
> @@ -4517,10 +4517,8 @@ case "${target}" in
> case " $x86_64_archs " in
> *" ${val} "*)
> # Disallow x86-64-v* for
> --with-cpu=/--with-tune=
> - # or --with-arch= or
> --with-arch_32=
> - # It can be only specified in
> --with-arch_64=
> case "x$which$val" in
> -
> xcpu*x86-64-v*|xtune*x86-64-v*|xarchx86-64-v*|xarch_32x86-64-v*)
> +
> xcpu*x86-64-v*|xtune*x86-64-v*)
> echo "Unknown CPU
> given in --with-$which=$val." 1>&2
> exit 1
> ;;
> --- gcc/doc/invoke.texi.jj 2020-12-09 23:51:01.284558982 +0100
> +++ gcc/doc/invoke.texi 2020-12-14 13:36:45.523458639 +0100
> @@ -29778,8 +29778,9 @@ A generic CPU with 64-bit extensions.
> @itemx x86-64-v3
> @itemx x86-64-v4
> These choices for @var{cpu-type} select the corresponding
> -micro-architecture level from the x86-64 psABI. They are only available
> -when compiling for an x86-64 target that uses the System V psABI@.
> +micro-architecture level from the x86-64 psABI. On ABIs other than
> +the x86-64 psABI they select the same CPU features as the x86-64 psABI
> +documents for the particular micro-architecture level.
>
> Since these @var{cpu-type} values do not have a corresponding
> @option{-mtune} setting, using @option{-march} with these values enables
> --- gcc/testsuite/gcc.target/i386/x86-64-v2.c.jj 2020-10-12
> 12:30:34.327813333 +0200
> +++ gcc/testsuite/gcc.target/i386/x86-64-v2.c 2020-12-14 13:48:35.039554681
> +0100
> @@ -12,8 +12,10 @@
> #ifndef __SSE2__
> # error __SSE2__ not defined
> #endif
> -#ifndef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16
> -# error __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 not defined
> +#ifdef __x86_64__
> +# ifndef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16
> +# error __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 not defined
> +# endif
> #endif
> #ifndef __LAHF_SAHF__
> # error __LAHF_SAHF__ not defined
> --- gcc/testsuite/gcc.target/i386/x86-64-v2-other.c.jj 2020-12-14
> 13:46:04.355233294 +0100
> +++ gcc/testsuite/gcc.target/i386/x86-64-v2-other.c 2020-12-14
> 13:46:04.355233294 +0100
> @@ -0,0 +1,5 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=x86-64-v2" } */
> +
> +/* Verify -march=x86-64-v2 works even with -m32 or -mabi=ms. */
> +#include "x86-64-v2.c"
> --- gcc/testsuite/gcc.target/i386/x86-64-v2-msabi.c.jj 2020-12-14
> 13:46:04.356233283 +0100
> +++ gcc/testsuite/gcc.target/i386/x86-64-v2-msabi.c 2020-12-14
> 13:46:04.356233283 +0100
> @@ -0,0 +1,5 @@
> +/* { dg-do compile { target lp64 } } */
> +/* { dg-options "-mabi=ms -march=x86-64-v2" } */
> +
> +/* Verify -march=x86-64-v2 works even with -mabi=ms. */
> +#include "x86-64-v2.c"
> --- gcc/testsuite/gcc.target/i386/x86-64-v3.c.jj 2020-10-12
> 12:30:34.327813333 +0200
> +++ gcc/testsuite/gcc.target/i386/x86-64-v3.c 2020-12-14 13:48:53.391350247
> +0100
> @@ -1,7 +1,7 @@
> /* { dg-do compile { target { ! ia32 } } } */
> /* { dg-options "-mabi=sysv -march=x86-64-v3" } */
>
> -/* Verify that the CPU features required by x86-64-v4 are enabled. */
> +/* Verify that the CPU features required by x86-64-v3 are enabled. */
>
> #ifndef __MMX__
> # error __MMX__ not defined
> @@ -12,8 +12,10 @@
> #ifndef __SSE2__
> # error __SSE2__ not defined
> #endif
> -#ifndef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16
> -# error __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 not defined
> +#ifdef __x86_64__
> +# ifndef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16
> +# error __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 not defined
> +# endif
> #endif
> #ifndef __LAHF_SAHF__
> # error __LAHF_SAHF__ not defined
> --- gcc/testsuite/gcc.target/i386/x86-64-v3-other.c.jj 2020-12-14
> 13:46:04.355233294 +0100
> +++ gcc/testsuite/gcc.target/i386/x86-64-v3-other.c 2020-12-14
> 13:46:04.355233294 +0100
> @@ -0,0 +1,5 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=x86-64-v3" } */
> +
> +/* Verify -march=x86-64-v3 works even with -m32 or -mabi=ms. */
> +#include "x86-64-v3.c"
> --- gcc/testsuite/gcc.target/i386/x86-64-v3-msabi.c.jj 2020-12-14
> 13:46:04.355233294 +0100
> +++ gcc/testsuite/gcc.target/i386/x86-64-v3-msabi.c 2020-12-14
> 13:46:04.355233294 +0100
> @@ -0,0 +1,5 @@
> +/* { dg-do compile { target lp64 } } */
> +/* { dg-options "-mabi=ms -march=x86-64-v3" } */
> +
> +/* Verify -march=x86-64-v3 works even with -mabi=ms. */
> +#include "x86-64-v3.c"
> --- gcc/testsuite/gcc.target/i386/x86-64-v4.c.jj 2020-10-12
> 12:30:34.328813318 +0200
> +++ gcc/testsuite/gcc.target/i386/x86-64-v4.c 2020-12-14 13:49:09.620169461
> +0100
> @@ -12,8 +12,10 @@
> #ifndef __SSE2__
> # error __SSE2__ not defined
> #endif
> -#ifndef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16
> -# error __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 not defined
> +#ifdef __x86_64__
> +# ifndef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16
> +# error __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 not defined
> +# endif
> #endif
> #ifndef __LAHF_SAHF__
> # error __LAHF_SAHF__ not defined
> --- gcc/testsuite/gcc.target/i386/x86-64-v4-other.c.jj 2020-12-14
> 13:46:04.355233294 +0100
> +++ gcc/testsuite/gcc.target/i386/x86-64-v4-other.c 2020-12-14
> 13:46:04.355233294 +0100
> @@ -0,0 +1,5 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=x86-64-v4" } */
> +
> +/* Verify -march=x86-64-v4 works even with -m32 or -mabi=ms. */
> +#include "x86-64-v4.c"
> --- gcc/testsuite/gcc.target/i386/x86-64-v4-msabi.c.jj 2020-12-14
> 13:46:04.356233283 +0100
> +++ gcc/testsuite/gcc.target/i386/x86-64-v4-msabi.c 2020-12-14
> 13:46:04.356233283 +0100
> @@ -0,0 +1,5 @@
> +/* { dg-do compile { target lp64 } } */
> +/* { dg-options "-mabi=ms -march=x86-64-v4" } */
> +
> +/* Verify -march=x86-64-v4 works even with -mabi=ms. */
> +#include "x86-64-v4.c"
>
> Jakub
>
