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authorJan Hubicka <jh@suse.cz>2002-05-15 11:00:30 +0200
committerJan Hubicka <hubicka@gcc.gnu.org>2002-05-15 09:00:30 +0000
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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.texi29
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