+2011-09-27 Andi Kleen <ak@linux.intel.com>
+ Jan Hubicka <jh@suse.cz>
+
+ * doc/invoke.texi (ffat-lto-objects): Document.
+ * toplev.c (compile_file): Do not output assembly when doing slim lto;
+ Output __gnu_slim_lto when doing slim lto.
+ * cgraphunit.c (ipa_passes): Do only analysis when producing slim lto.
+ (cgraph_optimize): Return early when doing slim lto.
+ * opts.c (finish_options): Complain about lack of linker plugin
+ when doing slim lto.
+ * common.opt (ffat-lto-objects): New.
+
2011-09-27 Richard Sandiford <richard.sandiford@linaro.org>
* ipa-inline-analysis.c (predicate_probability): Avoid comparison
-fcx-limited-range @gol
-fdata-sections -fdce -fdce -fdelayed-branch @gol
-fdelete-null-pointer-checks -fdse -fdevirtualize -fdse @gol
--fearly-inlining -fipa-sra -fexpensive-optimizations -ffast-math @gol
--ffinite-math-only -ffloat-store -fexcess-precision=@var{style} @gol
+-fearly-inlining -fipa-sra -fexpensive-optimizations -ffat-lto-objects @gol
+-ffast-math -ffinite-math-only -ffloat-store -fexcess-precision=@var{style} @gol
-fforward-propagate -ffp-contract=@var{style} -ffunction-sections @gol
-fgcse -fgcse-after-reload -fgcse-las -fgcse-lm -fgraphite-identity @gol
-fgcse-sm -fif-conversion -fif-conversion2 -findirect-inlining @gol
Enabled by default when LTO support in GCC is enabled and GCC was compiled
with a linker supporting plugins (GNU ld 2.21 or newer or gold).
+@item -ffat-lto-objects
+@opindex ffat-lto-objects
+Fat LTO objects are object files that contain both the intermediate language
+and the object code. This makes them useable for both LTO linking and normal
+linking. This option makes effect only with @option{-flto} and is ignored
+at linktime.
+
+@option{-fno-fat-lto-objects} improves compilation time over plain LTO, but
+requires the complete toolchain to be aware of LTO. It requires a linker with
+linker plugin support for basic functionality. Additionally, nm, ar and ranlib
+need to support linker plugins to allow a full-featured build environment
+(capable of building static libraries etc).
+
+The default is @option{-ffat-lto-objects} but this default is intended to
+change in future releases when linker plugin enabled environments become more
+common.
@item -fcompare-elim
@opindex fcompare-elim
After register allocation and post-register allocation instruction splitting,
return;
}
- varpool_assemble_pending_decls ();
- finish_aliases_2 ();
+ /* Compilation unit is finalized. When producing non-fat LTO object, we are
+ basically finished. */
+ if (in_lto_p || !flag_lto || flag_fat_lto_objects)
+ {
+ varpool_assemble_pending_decls ();
+ finish_aliases_2 ();
- /* Likewise for mudflap static object registrations. */
- if (flag_mudflap)
- mudflap_finish_file ();
+ /* Likewise for mudflap static object registrations. */
+ if (flag_mudflap)
+ mudflap_finish_file ();
- output_shared_constant_pool ();
- output_object_blocks ();
+ output_shared_constant_pool ();
+ output_object_blocks ();
- /* Write out any pending weak symbol declarations. */
- weak_finish ();
+ /* Write out any pending weak symbol declarations. */
+ weak_finish ();
- /* This must be at the end before unwind and debug info.
- Some target ports emit PIC setup thunks here. */
- targetm.asm_out.code_end ();
+ /* This must be at the end before unwind and debug info.
+ Some target ports emit PIC setup thunks here. */
+ targetm.asm_out.code_end ();
- /* Do dbx symbols. */
- timevar_push (TV_SYMOUT);
+ /* Do dbx symbols. */
+ timevar_push (TV_SYMOUT);
-#if defined DWARF2_DEBUGGING_INFO || defined DWARF2_UNWIND_INFO
- if (dwarf2out_do_frame ())
- dwarf2out_frame_finish ();
-#endif
+ #if defined DWARF2_DEBUGGING_INFO || defined DWARF2_UNWIND_INFO
+ if (dwarf2out_do_frame ())
+ dwarf2out_frame_finish ();
+ #endif
- (*debug_hooks->finish) (main_input_filename);
- timevar_pop (TV_SYMOUT);
+ (*debug_hooks->finish) (main_input_filename);
+ timevar_pop (TV_SYMOUT);
- /* Output some stuff at end of file if nec. */
+ /* Output some stuff at end of file if nec. */
- dw2_output_indirect_constants ();
+ dw2_output_indirect_constants ();
- /* Flush any pending external directives. */
- process_pending_assemble_externals ();
+ /* Flush any pending external directives. */
+ process_pending_assemble_externals ();
+ }
/* Emit LTO marker if LTO info has been previously emitted. This is
used by collect2 to determine whether an object file contains IL.
(unsigned HOST_WIDE_INT) 1,
(unsigned HOST_WIDE_INT) 1);
#endif
+ /* Let linker plugin know that this is a slim object and must be LTOed
+ even when user did not ask for it. */
+ if (!flag_fat_lto_objects)
+ {
+#if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
+ ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, NULL_TREE,
+ "__gnu_slim_lto",
+ (unsigned HOST_WIDE_INT) 1, 8);
+#elif defined ASM_OUTPUT_ALIGNED_COMMON
+ ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, "__gnu_slim_lto",
+ (unsigned HOST_WIDE_INT) 1, 8);
+#else
+ ASM_OUTPUT_COMMON (asm_out_file, "__gnu_slim_lto",
+ (unsigned HOST_WIDE_INT) 1,
+ (unsigned HOST_WIDE_INT) 1);
+#endif
+ }
}
/* Attach a special .ident directive to the end of the file to identify