invoke.texi: Update the options enabled at -O1, -O2, and -O3.
* doc/invoke.texi: Update the options enabled at -O1, -O2, and -O3. Update the documentation for -fgcse-sm, -fgcse-las, -ftree-pre, and -fthread-jumps. From-SVN: r94615
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2 changed files with 37 additions and 20 deletions
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@ -1,3 +1,9 @@
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2005-02-02 Steven Bosscher <stevenb@suse.de>
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* doc/invoke.texi: Update the options enabled at -O1, -O2,
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and -O3. Update the documentation for -fgcse-sm, -fgcse-las,
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-ftree-pre, and -fthread-jumps.
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2005-02-02 Richard Sandiford <rsandifo@redhat.com>
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PR tree-optimization/19578
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@ -4052,14 +4052,23 @@ compilation time.
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@option{-O} turns on the following optimization flags:
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@gccoptlist{-fdefer-pop @gol
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-fmerge-constants @gol
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-fthread-jumps @gol
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-fdelayed-branch @gol
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-fguess-branch-probability @gol
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-fcprop-registers @gol
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-floop-optimize @gol
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-fif-conversion @gol
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-fif-conversion2 @gol
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-fdelayed-branch @gol
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-fguess-branch-probability @gol
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-fcprop-registers}
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-ftree-ccp @gol
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-ftree-dce @gol
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-ftree-dom @gol
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-ftree-dse @gol
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-ftree-ter @gol
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-ftree-live_range_split @gol
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-ftree-sra @gol
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-ftree-copyrename @gol
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-ftree-fre @gol
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-ftree-ch @gol
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-fmerge-constants}
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@option{-O} also turns on @option{-fomit-frame-pointer} on machines
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where doing so does not interfere with debugging.
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@ -4074,25 +4083,27 @@ and the performance of the generated code.
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@option{-O2} turns on all optimization flags specified by @option{-O}. It
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also turns on the following optimization flags:
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@gccoptlist{-fforce-mem @gol
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@gccoptlist{-fthread-jumps @gol
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-fcrossjumping @gol
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-foptimize-sibling-calls @gol
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-fstrength-reduce @gol
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-fcse-follow-jumps -fcse-skip-blocks @gol
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-frerun-cse-after-loop -frerun-loop-opt @gol
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-fgcse -fgcse-lm -fgcse-sm -fgcse-las @gol
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-fdelete-null-pointer-checks @gol
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-fgcse -fgcse-lm @gol
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-fexpensive-optimizations @gol
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-fregmove @gol
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-fstrength-reduce @gol
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-frerun-cse-after-loop -frerun-loop-opt @gol
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-fcaller-saves @gol
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-fforce-mem @gol
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-fpeephole2 @gol
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-fschedule-insns -fschedule-insns2 @gol
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-fsched-interblock -fsched-spec @gol
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-fcaller-saves @gol
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-fpeephole2 @gol
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-freorder-blocks -freorder-functions @gol
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-fregmove @gol
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-fstrict-aliasing @gol
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-fdelete-null-pointer-checks @gol
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-freorder-blocks -freorder-functions @gol
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-funit-at-a-time @gol
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-falign-functions -falign-jumps @gol
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-falign-loops -falign-labels @gol
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-fcrossjumping}
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-ftree-pre}
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Please note the warning under @option{-fgcse} about
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invoking @option{-O2} on programs that use computed gotos.
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@ -4101,7 +4112,7 @@ invoking @option{-O2} on programs that use computed gotos.
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@opindex O3
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Optimize yet more. @option{-O3} turns on all optimizations specified by
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@option{-O2} and also turns on the @option{-finline-functions},
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@option{-fweb} and @option{-fgcse-after-reload} options.
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@option{-funswitch-loops} and @option{-fgcse-after-reload} options.
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@item -O0
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@opindex O0
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@ -4372,7 +4383,7 @@ so, the first branch is redirected to either the destination of the
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second branch or a point immediately following it, depending on whether
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the condition is known to be true or false.
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Enabled at levels @option{-O}, @option{-O2}, @option{-O3}, @option{-Os}.
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Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
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@item -fcse-follow-jumps
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@opindex fcse-follow-jumps
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@ -4436,7 +4447,7 @@ stores out of loops. When used in conjunction with @option{-fgcse-lm},
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loops containing a load/store sequence can be changed to a load before
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the loop and a store after the loop.
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Enabled by default when gcse is enabled.
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Not enabled at any optimization level.
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@item -fgcse-las
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@opindex fgcse-las
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@ -4444,7 +4455,7 @@ When @option{-fgcse-las} is enabled, the global common subexpression
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elimination pass eliminates redundant loads that come after stores to the
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same memory location (both partial and full redundancies).
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Enabled by default when gcse is enabled.
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Not enabled at any optimization level.
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@item -fgcse-after-reload
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@opindex fgcse-after-reload
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@ -4629,7 +4640,7 @@ Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
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@item -ftree-pre
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Perform Partial Redundancy Elimination (PRE) on trees. This flag is
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enabled by default at @option{-O} and higher.
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enabled by default at @option{-O2} and @option{-O3}.
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@item -ftree-fre
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Perform Full Redundancy Elimination (FRE) on trees. The difference
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