https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86078

            Bug ID: 86078
           Summary: Documentation: missing param default values
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: web
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ptdrnvqd at 10mail dot org
  Target Milestone: ---

in
https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
or https://gcc.gnu.org/onlinedocs/gcc-5.5.0/gcc/Optimize-Options.html
or whatever number,
 the params section at the bottom does not link/reference
source-code e.g. https://github.com/gcc-mirror/gcc/blob/master/gcc/params.def
it contains max,min and default values, along with description, includes
default values not mentioned in documentation, along with disagreements

e.g.
sched-state-edge-prob-cutoff&selsched-insns-to-rename in docs(gcc6+) changes
name, err correction, but not reflected|updated in older doc versions

could this be automated/scripted (link to source-code) to reduce human errors?


missing default doc

max-crossjump-edges=100
max-delay-slot-insn-search=100
max-delay-slot-live-search=333
max-gcse-memory=50*1024*1024  (2015)
max-gcse-memory=128*1024*1024  (2018)
max-modulo-backtrack-attempts=40
iv-consider-all-candidates-bound=30(2015)
iv-consider-all-candidates-bound=40(2018)
iv-max-considered-uses=250
scev-max-expr-size=100
scev-max-expr-complexity=10
max-partial-antic-length=100
devirt-type-list-size(4.6),ipa-cp-value-list-size(4.7+)=8
max-slsr-cand-scan=50(4.8+)
ipa-max-agg-items=16(4.9+)
ipa-max-aa-steps=25000(5+)
max-ssa-name-query-depth=3(6+)
max-speculative-devirt-maydefs=50(6+)
max-stores-to-merge=64(7+)
dse-max-object-size=256(7+)


Not mentioned @docs except SourceCode 
max-tracked-strlens=10000


what impact do they have,
anyway to emit debug info to show whether compilation hit limits?

to generalize, for benchmarks should an average of params be used?

should gcc params better reflect the host-compile-machine instead of a
one-size-fits all (compiling on mobile|desktop|workstation|server, new|old)

another question: when compiling using link-time-optimization-LTO, 
since it's bunched into a single unit would it hit the limits sooner and should
it be compensated for against

any mechanism for compile more/less aggressively based on usage patters, how
much (CPU-time|usage/day) a program uses (relevance)

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