[Bug debug/63623] Lots of functions get -fvar-tracking silently turned off unnecessarily

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63623

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
dwlocstat --tabulate=0.0:10,99
results on cc1plus bootstrapped --enable-checking=yes,rtl binaries before/after
the patch (in the tree without the patch I've applied the patch afterwards and
did make cc1plus in the gcc directory, so var-tracking.o in stage3 got rebuilt
again and thus the compared binaries contain exactly the same code, just
different debug info):

x86_64-linux cc1plus built without the patch:
cov%    samples    cumul
0.0    506230/38%    506230/38%
0..10    10327/0%    516557/39%
11..20    12390/0%    528947/39%
21..30    31265/2%    560212/42%
31..40    18775/1%    578987/43%
41..50    20631/1%    599618/45%
51..60    24921/1%    624539/47%
61..70    40959/3%    665498/50%
71..80    23771/1%    689269/52%
81..90    41771/3%    731040/55%
91..99    81667/6%    812707/61%
100    510564/38%    1323271/100%

x86_64-linux cc1plus built with the patch:
cov%    samples    cumul
0.0    382214/28%    382214/28%
0..10    13100/0%    395314/29%
11..20    14568/1%    409882/30%
21..30    33708/2%    443590/33%
31..40    21927/1%    465517/35%
41..50    23924/1%    489441/36%
51..60    28736/2%    518177/39%
61..70    45847/3%    564024/42%
71..80    29284/2%    593308/44%
81..90    52085/3%    645393/48%
91..99    99971/7%    745364/56%
100    577907/43%    1323271/100%

i686-linux cc1plus built without the patch:
cov%    samples    cumul
0.0    631348/48%    631348/48%
0..10    7764/0%    639112/48%
11..20    9690/0%    648802/49%
21..30    25036/1%    673838/51%
31..40    16113/1%    689951/52%
41..50    19753/1%    709704/54%
51..60    14563/1%    724267/55%
61..70    34093/2%    758360/58%
71..80    17450/1%    775810/59%
81..90    31339/2%    807149/61%
91..99    60368/4%    867517/66%
100    437548/33%    1305065/100%

i686-linux cc1plus built with the patch:
cov%    samples    cumul
0.0    377352/28%    377352/28%
0..10    16077/1%    393429/30%
11..20    15390/1%    408819/31%
21..30    31790/2%    440609/33%
31..40    23889/1%    464498/35%
41..50    29267/2%    493765/37%
51..60    22902/1%    516667/39%
61..70    45629/3%    562296/43%
71..80    29511/2%    591807/45%
81..90    50536/3%    642343/49%
91..99    93584/7%    735927/56%
100    569138/43%    1305065/100%

.debug_info/.debug_loc sizes in bytes:
x86_64-linux cc1plus without patch .debug_info 75411710, .debug_loc 75421077
x86_64-linux cc1plus with    patch .debug_info 78498790, .debug_loc 90530117
  i686-linux cc1plus without patch .debug_info 59921183, .debug_loc 37823166
  i686-linux cc1plus with    patch .debug_info 63009554, .debug_loc 59535100