[pulse] lower max disjuncts to 20 and loop unrollings to 3

Summary:
This is ~2.5x wall clock faster, ~5x user time faster, and finds 98% of
the bugs. Not very scientific yet but seems better than the previous
non-scientific arbitrary default.

Reviewed By: ngorogiannis

Differential Revision: D14753494

fbshipit-source-id: b72cdd613

infer/man/man1/infer-full.txt

@@ -1381,10 +1381,10 @@ INTERNAL OPTIONS
 
        --pulse-max-disjuncts int
            Under-approximate after int disjunctions in the domain (default:
-           50)
+           20)
 
        --pulse-widen-threshold int
-           Under-approximate after int loop iterations (default: 5)
+           Under-approximate after int loop iterations (default: 3)
 
        --reactive-capture
            Activates: Compile source files only when required by analyzer

infer/src/base/Config.ml

@@ -1846,12 +1846,12 @@ and project_root =
 
 
 and pulse_max_disjuncts =
-  CLOpt.mk_int ~long:"pulse-max-disjuncts" ~default:50
+  CLOpt.mk_int ~long:"pulse-max-disjuncts" ~default:20
     "Under-approximate after $(i,int) disjunctions in the domain"
 
 
 and pulse_widen_threshold =
-  CLOpt.mk_int ~long:"pulse-widen-threshold" ~default:5
+  CLOpt.mk_int ~long:"pulse-widen-threshold" ~default:3
     "Under-approximate after $(i,int) loop iterations"