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author | Jan Hubicka <jh@suse.cz> | 2002-05-15 11:00:30 +0200 |
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committer | Jan Hubicka <hubicka@gcc.gnu.org> | 2002-05-15 09:00:30 +0000 |
commit | 194734e9e5501f9a295212b91978eee396879cda (patch) | |
tree | 6dab9b09a4ebcfb309dc527384a3d4f4607f240d /gcc/doc/invoke.texi | |
parent | 61ad9a3472b5cafde230efd925bf9c8f61d6b65e (diff) | |
download | gcc-194734e9e5501f9a295212b91978eee396879cda.zip gcc-194734e9e5501f9a295212b91978eee396879cda.tar.gz gcc-194734e9e5501f9a295212b91978eee396879cda.tar.bz2 |
invoke.texi (-malign-double): Re-add lost warning.
* invoke.texi (-malign-double): Re-add lost warning.
* i386-protos.h (x86_output_mi_thunk): Declare.
* unix.h (ASM_OUTPUT_MI_THUNK): Move offline to ...
* i386.c (x86_output_mi_thunk): ... here; handle 64bits.
* dwarf2out.c (output_call_frame_info): Do not skip unwind info
when flag_asynchronous_unwind_tables is set.
* flags.h (flag_reorder_functions): Declare.
* function.c (prepare_function_start): Initialize frequnecy.
* params.def (HOT_BB_COUNT_FRACTION, HOT_BB_FREQUENCY_FRACTION): New paramters.
* Makefile.in (predict.o): Add dependency on target.h and params.h
* defaults.h (HOT_TEXT_SECTION_NAME,
UNLIKELY_EXECUTED_TEXT_SECTION_NAME): New macros.
* predict.c (choose_function_section): New function.
(estimate_bb_frequencies): Use it.
* toplev.c (flag_reorder_functions): New global variable.
(lang_independent_options): New.
(parse_options_and_default_flags): Set.
* varasm.c (assemble_start_function): Bypass functdion alignment
for never executed functions.
* invoke.texi (-freorder-blocks, -freorder-functions): Document.
(param hot-bb-count-fraction, hot-bb-frequency-fraction): New.
* tm.texi (HOT_TEXT_SECTION_NAME, UNLIKELY_EXECUTED_TEXT_SECTION_NAME):
Document.
Thu Jan 3 21:52:09 CET 2002 Jan Hubicka <jh@suse.cz>
* predict.c: Inlude profile.h
(MIN_COUNT): Rename to MIN_COUNT_FRACTION
(maybe_hot_bb_p, probably_cold_bb_p, probably_never_executed_bb_p):
Use the information about maximal counter in the program.
Thu Dec 20 22:14:00 CET 2001 Jan Hubicka <jh@suse.cz>
* basic-block.h (maybe_hot_bb_p, probably_cold_bb_p,
probably_never_executed_bb_p): New functions.
* cfgcleanup.c (outgoing_edges_match): Use them.
* predict.c (MIN_COUNT, MIN_FREQUENCY): New macros.
(maybe_hot_bb_p, probably_cold_bb_p,
probably_never_executed_bb_p): New functions.
* function.h (function): Add new field function_frequency.
* predict.c (compute_function_frequency): New function.
(estimate_probability): Call it.
From-SVN: r53478
Diffstat (limited to 'gcc/doc/invoke.texi')
-rw-r--r-- | gcc/doc/invoke.texi | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 001ab25..1190c97 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -278,6 +278,7 @@ in the following sections. -fomit-frame-pointer -foptimize-register-move @gol -foptimize-sibling-calls -fprefetch-loop-arrays @gol -freduce-all-givs -fregmove -frename-registers @gol +-freorder-blocks -freorder-functions @gol -frerun-cse-after-loop -frerun-loop-opt @gol -fschedule-insns -fschedule-insns2 @gol -fsingle-precision-constant -fssa -fssa-ccp -fssa-dce @gol @@ -3712,6 +3713,23 @@ non-determinism is of paramount import. This switch allows users to reduce non-determinism, possibly at the expense of inferior optimization. +@item -freorder-blocks +@opindex freorder-blocks +Reorder basic blocks in the compiled function in order to reduce number of +taken branches and improve code locality. + +@item -freorder-functions +@opindex freorder-functions +Reorder basic blocks in the compiled function in order to reduce number of +taken branches and improve code locality. This is implemented by using special +subsections @code{text.hot} for most frequently executed functions and +@code{text.unlikely} for unlikely executed functions. Reordering is done by +the linker so object file format must support named sections and linker must +place them in resonable way. + +Also profile feedback must be available in to make this option effective. See +@option{-fprofile-arcs} for details. + @item -fstrict-aliasing @opindex fstrict-aliasing Allows the compiler to assume the strictest aliasing rules applicable to @@ -3900,6 +3918,13 @@ The maximum number of instructions that a loop should have if that loop is unrolled, and if the loop is unrolled, it determines how many times the loop code is unrolled. +@item hot-bb-count-fraction +Select fraction of the maximal count of repetitions of basic block in program +given basic block needs to have to be considered hot. + +@item hot-bb-frequency-fraction +Select fraction of the maximal frequency of executions of basic block in +function given basic block needs to have to be considered hot @end table @end table @@ -7389,6 +7414,10 @@ boundary. Aligning @code{double} variables on a two word boundary will produce code that runs somewhat faster on a @samp{Pentium} at the expense of more memory. +@strong{Warning:} if you use the @samp{-malign-double} switch, +structures containing the above types will be aligned differently than +the published application binary interface specifications for the 386. + @item -m128bit-long-double @opindex m128bit-long-double Control the size of @code{long double} type. i386 application binary interface |