Optimization for automatic objects

Joachim Schoeberl js@jku.at
Thu Oct 23 23:12:00 GMT 2003


Hello,

I have compiled now with the tree-ssa-20020619-branch, the code got 
about twice as large.
Did I miss some switches ?
Is it too early to start experimenting with the tree-ssa compiler ?

thanks a lot,
Joachim


I called gcc as:

/opt/gccast/bin/gcc -S -O10 -fverbose-asm -fpeephole2 -fnew-ra 
-ftree-ccp -ftree-combine-temps -ftree-dce -ftree-copyprop 
-ftree-combine-temps -ftree-dominator-opts -ftree-pre 
-finline-limit=10000 -ftemplate-depth-99 testexpr6.cpp


The generated assembler file starts with:

# GNU C++ version 3.5-tree-ssa-cfg (merged from tree-ssa 20031001) 
(i686-pc-linux-gnu)
#    compiled by GNU C version 3.5-tree-ssa-cfg (merged from tree-ssa 
20031001).
# GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
# options passed:  -D_GNU_SOURCE -mtune=pentiumpro -auxbase -O10
# -fverbose-asm -fpeephole2 -fnew-ra -ftree-ccp -ftree-combine-temps
# -ftree-dce -ftree-copyprop -ftree-combine-temps -ftree-dominator-opts
# -ftree-pre -finline-limit=10000 -ftemplate-depth-99
# options enabled:  -feliminate-unused-debug-types -fdefer-pop
# -foptimize-sibling-calls -fcse-follow-jumps -fcse-skip-blocks
# -fexpensive-optimizations -fthread-jumps -fstrength-reduce
# -funswitch-loops -fpeephole -fforce-mem -ffunction-cse
# -fkeep-static-consts -fcaller-saves -fpcc-struct-return -fgcse -fgcse-lm
# -fgcse-sm -floop-optimize -fcrossjumping -fif-conversion -fif-conversion2
# -frerun-cse-after-loop -frerun-loop-opt -fdelete-null-pointer-checks
# -fschedule-insns2 -fsched-interblock -fsched-spec -fbranch-count-reg
# -freorder-blocks -freorder-functions -frename-registers -fcprop-registers
# -fcommon -fverbose-asm -fgnu-linker -fregmove -foptimize-register-move
# -fargument-alias -fstrict-aliasing -fmerge-constants
# -fzero-initialized-in-bss -fident -fpeephole2 -fguess-branch-probability
# -fmath-errno -ftrapping-math -fnew-ra -ftree-pre -ftree-ccp
# -ftree-copyprop -ftree-dce -ftree-dominator-opts -ftree-combine-temps
# -ftree-must-alias -m80387 -mhard-float -mno-soft-float -mieee-fp
# -mfp-ret-in-387 -maccumulate-outgoing-args -mno-red-zone
# -mtls-direct-seg-refs -mtune=pentiumpro -march=i386




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