[RFC][gomp4] Offloading patches (1/3): Add '-fopenmp_target' option

[Michael Zolotukhin]

Ping.

On 17 December 2013 15:35, Michael V. Zolotukhin
<michael.v.zolotukhin@gmail.com> wrote:
> Hi everybody,
>
> Here is a set of patches implementing one more piece of offloading support in
> GCC.  These three patches allow to build a host binary with target image and all
> tables embedded.  Along with patches for libgomp and libgomp plugin, which
> hopefully will be sent soon, that gives a functional and runnable executable (or
> DSO) with actual offloading to MIC.
>
> There is still a lot to do in this area, but this is the necessary basics - with
> this we could actually run offloaded code, produced fully by compiler.
>
> We would like to hear any feedback on these patches: what issues we should
> address first before commit (if any), how the patches fit OpenACC work, etc.
>
> Here is a patch 1/3: Add '-fopenmp_target' option This option tells lto1 to look
> for "*.target_lto*" sections instead of usual "*.lto*".  That option is passed
> to target compiler when we invoke it to build target image.
>
> Thanks,
> Michael
>
>
> ---
>  gcc/lto/lang.opt     |    4 ++++
>  gcc/lto/lto-object.c |    5 +++--
>  gcc/lto/lto.c        |    7 ++++++-
>  3 files changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/gcc/lto/lang.opt b/gcc/lto/lang.opt
> index 7a9aede..cd0098c 100644
> --- a/gcc/lto/lang.opt
> +++ b/gcc/lto/lang.opt
> @@ -40,4 +40,8 @@ fresolution=
>  LTO Joined
>  The resolution file
>
> +fopenmp_target
> +LTO Var(flag_openmp_target)
> +Run LTO infrastructure to read target-side bytecode and to build it.
> +
>  ; This comment is to ensure we retain the blank line above.
> diff --git a/gcc/lto/lto-object.c b/gcc/lto/lto-object.c
> index 19f10cc..64274f3 100644
> --- a/gcc/lto/lto-object.c
> +++ b/gcc/lto/lto-object.c
> @@ -59,6 +59,8 @@ struct lto_simple_object
>
>  static simple_object_attributes *saved_attributes;
>
> +extern const char *section_name_prefix;
> +
>  /* Initialize FILE, an LTO file object for FILENAME.  */
>
>  static void
> @@ -229,8 +231,7 @@ lto_obj_add_section (void *data, const char *name, off_t offset,
>    void **slot;
>    struct lto_section_list *list = loasd->list;
>
> -  if (strncmp (name, LTO_SECTION_NAME_PREFIX,
> -              strlen (LTO_SECTION_NAME_PREFIX)) != 0)
> +  if (strncmp (name, section_name_prefix, strlen (section_name_prefix)))
>      return 1;
>
>    new_name = xstrdup (name);
> diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
> index 0211437..dedf8a8 100644
> --- a/gcc/lto/lto.c
> +++ b/gcc/lto/lto.c
> @@ -49,6 +49,8 @@ along with GCC; see the file COPYING3.  If not see
>  #include "context.h"
>  #include "pass_manager.h"
>
> +extern const char *section_name_prefix;
> +
>  /* Vector to keep track of external variables we've seen so far.  */
>  vec<tree, va_gc> *lto_global_var_decls;
>
> @@ -2081,7 +2083,7 @@ lto_section_with_id (const char *name, unsigned HOST_WIDE_INT *id)
>  {
>    const char *s;
>
> -  if (strncmp (name, LTO_SECTION_NAME_PREFIX, strlen (LTO_SECTION_NAME_PREFIX)))
> +  if (strncmp (name, section_name_prefix, strlen (section_name_prefix)))
>      return 0;
>    s = strrchr (name, '.');
>    return s && sscanf (s, "." HOST_WIDE_INT_PRINT_HEX_PURE, id) == 1;
> @@ -2757,6 +2759,9 @@ read_cgraph_and_symbols (unsigned nfiles, const char **fnames)
>
>    timevar_push (TV_IPA_LTO_DECL_IN);
>
> +  if (flag_openmp_target)
> +    section_name_prefix = OMP_SECTION_NAME_PREFIX;
> +
>    real_file_decl_data
>      = decl_data = ggc_alloc_cleared_vec_lto_file_decl_data_ptr (nfiles + 1);
>    real_file_count = nfiles;
> --
> 1.7.1
>
>
>