OpenE2K
/
gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

document -fno-guess-branch-probability option 

From-SVN: r39096
This commit is contained in:
Aldy Hernandez 2001-01-17 19:43:13 +00:00
parent 5f3aebeadf
commit 454d0cc7dd
2 changed files with 16 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
gcc/ChangeLog
View File

@ -1,9 +1,14 @@
2001-01-17 Aldy Hernandez <aldyh@redhat.com>
* invoke.texi (-fno-guess-branch-probability): New option.
Wed Jan 17 13:26:34 2001 Richard Kenner <kenner@vlsi1.ultra.nyu.edu> Wed Jan 17 13:26:34 2001 Richard Kenner <kenner@vlsi1.ultra.nyu.edu>
* combine.c (try_combine): Don't set i3_subst_into_i2 for * combine.c (try_combine): Don't set i3_subst_into_i2 for
case of making new double-word constant. case of making new double-word constant.
Revert last change: instead just test i3_subst_into_i2. Revert last change: instead just test i3_subst_into_i2.
>>>>>>> 1.9022
2001-01-17 Jakub Jelinek <jakub@redhat.com> 2001-01-17 Jakub Jelinek <jakub@redhat.com>
* config/i386/i386.md (cmpqi_minus_1): Use {b} for QImode operation. * config/i386/i386.md (cmpqi_minus_1): Use {b} for QImode operation.

12
gcc/invoke.texi
View File

@ -244,7 +244,8 @@ in the following sections.
-finline-functions -finline-limit=@var{n} -fkeep-inline-functions @gol -finline-functions -finline-limit=@var{n} -fkeep-inline-functions @gol
-fkeep-static-consts -fmove-all-movables @gol -fkeep-static-consts -fmove-all-movables @gol
-fno-default-inline -fno-defer-pop @gol -fno-default-inline -fno-defer-pop @gol
-fno-function-cse -fno-inline -fno-math-errno -fno-peephole @gol -fno-function-cse -fno-guess-branch-probability
-fno-inline -fno-math-errno -fno-peephole @gol
-fomit-frame-pointer -foptimize-register-move @gol -fomit-frame-pointer -foptimize-register-move @gol
-foptimize-sibling-calls -freduce-all-givs @gol -foptimize-sibling-calls -freduce-all-givs @gol
-fregmove -frename-registers @gol -fregmove -frename-registers @gol
@ -3123,6 +3124,15 @@ branch is mostly to take, the @samp{REG_BR_PROB} values are used to
exactly determine which path is taken more often. exactly determine which path is taken more often.
@end ifset @end ifset
@item -fno-guess-branch-probability
Sometimes gcc will opt to guess branch probabilities when none are
available from either profile directed feedback (@samp{-fprofile-arcs})
or @samp(__builtin_expect). In a hard real-time system, people don't
want different runs of the compiler to produce code that has different
behavior; minimizing non-determinism is of paramount import. This
switch allows users to reduce non-determinism, possibly at the expense
of inferior optimization.
@item -fstrict-aliasing @item -fstrict-aliasing
Allows the compiler to assume the strictest aliasing rules applicable to Allows the compiler to assume the strictest aliasing rules applicable to
the language being compiled. For C (and C++), this activates the language being compiled. For C (and C++), this activates