On 03/08/2015 03:59 AM, Alexander Monakov wrote:
GCC manual explains the behavior:
Most optimizations are only enabled if an -O level is set on the command
line. Otherwise they are disabled, even if individual optimization flags
are specified.
As a result, you can use -O1 and disable individual optimizations with
-fno-... instead.
Yes, but I've tried it both ways. Setting -O1 followed by a list of -f-no-...
options that should be the same as passing -O0 causes wine to segfault when run.
Setting -O0 allows wine to run.
Here's the full list of CFLAGS on a working -O0 run:
-I. -I../../include -D__WINESRC__ -D_REENTRANT -fPIC -Wall -pipe \
-fno-strict-aliasing -Wdeclaration-after-statement -Wempty-body
-Wignored-qualifiers \
-Wstrict-prototypes -Wtype-limits -Wunused-but-set-parameter -Wvla
-Wwrite-strings -Wpointer-arith \
-Wlogical-op -O0
Here's the full list on a broken -O1 run:
-I. -I../../include -D__WINESRC__ -D_REENTRANT -fPIC -Wall -pipe \
-fno-strict-aliasing -Wdeclaration-after-statement -Wempty-body
-Wignored-qualifiers \
-Wstrict-prototypes -Wtype-limits -Wunused-but-set-parameter -Wvla
-Wwrite-strings -Wpointer-arith \
-Wlogical-op -O1 -fno-branch-count-reg -fno-combine-stack-adjustments
-fno-compare-elim -fno-cprop-registers -fno-defer-pop -fno-forward-propagate
-fno-guess-branch-probability -fno-if-conversion2 -fno-if-conversion
-fno-inline-functions-called-once -fno-ipa-pure-const -fno-ipa-profile
-fno-ipa-reference -fno-merge-constants -fno-move-loop-invariants -fno-shrink-wrap
-fno-split-wide-types -fno-ssa-phiopt -fno-tree-bit-ccp -fno-tree-ccp -fno-tree-ch
-fno-tree-copy-prop -fno-tree-copyrename -fno-tree-dce -fno-tree-dominator-opts
-fno-tree-dse -fno-tree-fre -fno-tree-sink -fno-tree-slsr -fno-tree-sra
-fno-tree-pta -fno-tree-ter
Out of curiousity, where did you find the -Q --help=optimizers incantation?
I've always thought it's a rarer bit of knowledge than the -O flag behavior.
From the same documentation that you quoted.
Depending on the target and how GCC was configured, a slightly
different set of optimizations may be enabled at each -O level than
those listed here. You can invoke GCC with -Q --help=optimizers to find
out the exact set of optimizations that are enabled at each level.
Thanks,
Michael
