https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114989
Bug ID: 114989
Summary: Compile time hog when building paml
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: sjames at gcc dot gnu.org
Target Milestone: ---
Created attachment 58130
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58130&action=edit
baseml.i
Noticed this while working on something unrelated, just felt it looked a bit
sluggish.
The source file is a bit complex, but it's also _not_ huge generated gunk,
which I think makes this a bit more interesting. I don't have older
non-checking compilers around to see if it's a regression, sorry.
```
# time gcc-13 baseml.i -c -O2
real 0m3.877s
user 0m3.755s
sys 0m0.087s
```
```
# gcc-13 baseml.i -c -O2 -ftime-report
Time variable usr sys wall
GGC
phase setup : 0.00 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
1819k ( 1%)
phase parsing : 0.09 ( 2%) 0.21 ( 34%) 0.31 ( 7%)
9507k ( 6%)
phase opt and generate : 3.59 ( 98%) 0.40 ( 66%) 4.01 ( 93%)
138M ( 93%)
dump files : 0.04 ( 1%) 0.01 ( 2%) 0.05 ( 1%)
0 ( 0%)
callgraph construction : 0.00 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
3240k ( 2%)
callgraph optimization : 0.00 ( 0%) 0.00 ( 0%) 0.02 ( 0%)
2592 ( 0%)
callgraph functions expansion : 3.16 ( 86%) 0.32 ( 52%) 3.50 ( 81%)
111M ( 75%)
callgraph ipa passes : 0.39 ( 11%) 0.07 ( 11%) 0.46 ( 11%)
14M ( 10%)
ipa function summary : 0.02 ( 1%) 0.00 ( 0%) 0.02 ( 0%)
1174k ( 1%)
ipa inlining heuristics : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
54k ( 0%)
ipa pure const : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
72k ( 0%)
ipa free inline summary : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
0 ( 0%)
cfg construction : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
580k ( 0%)
cfg cleanup : 0.08 ( 2%) 0.00 ( 0%) 0.08 ( 2%)
703k ( 0%)
trivially dead code : 0.02 ( 1%) 0.00 ( 0%) 0.02 ( 0%)
0 ( 0%)
df reaching defs : 0.03 ( 1%) 0.02 ( 3%) 0.03 ( 1%)
0 ( 0%)
df live regs : 0.13 ( 4%) 0.01 ( 2%) 0.14 ( 3%)
0 ( 0%)
df live&initialized regs : 0.02 ( 1%) 0.01 ( 2%) 0.06 ( 1%)
0 ( 0%)
df use-def / def-use chains : 0.04 ( 1%) 0.00 ( 0%) 0.01 ( 0%)
0 ( 0%)
df reg dead/unused notes : 0.08 ( 2%) 0.00 ( 0%) 0.05 ( 1%)
1648k ( 1%)
register information : 0.03 ( 1%) 0.00 ( 0%) 0.00 ( 0%)
0 ( 0%)
alias analysis : 0.02 ( 1%) 0.01 ( 2%) 0.05 ( 1%)
4296k ( 3%)
alias stmt walking : 0.10 ( 3%) 0.00 ( 0%) 0.15 ( 3%)
658k ( 0%)
register scan : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
24k ( 0%)
rebuild jump labels : 0.02 ( 1%) 0.00 ( 0%) 0.00 ( 0%)
0 ( 0%)
preprocessing : 0.02 ( 1%) 0.06 ( 10%) 0.11 ( 3%)
331k ( 0%)
lexical analysis : 0.03 ( 1%) 0.08 ( 13%) 0.13 ( 3%)
0 ( 0%)
parser (global) : 0.01 ( 0%) 0.01 ( 2%) 0.03 ( 1%)
2449k ( 2%)
parser function body : 0.03 ( 1%) 0.06 ( 10%) 0.04 ( 1%)
6620k ( 4%)
early inlining heuristics : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
41k ( 0%)
inline parameters : 0.02 ( 1%) 0.00 ( 0%) 0.01 ( 0%)
328k ( 0%)
tree gimplify : 0.02 ( 1%) 0.00 ( 0%) 0.02 ( 0%)
7063k ( 5%)
tree eh : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
29k ( 0%)
tree CFG construction : 0.01 ( 0%) 0.01 ( 2%) 0.02 ( 0%)
2159k ( 1%)
tree CFG cleanup : 0.03 ( 1%) 0.00 ( 0%) 0.04 ( 1%)
97k ( 0%)
tree tail merge : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
980k ( 1%)
tree VRP : 0.15 ( 4%) 0.00 ( 0%) 0.17 ( 4%)
4202k ( 3%)
tree Early VRP : 0.09 ( 2%) 0.01 ( 2%) 0.11 ( 3%)
1768k ( 1%)
tree copy propagation : 0.03 ( 1%) 0.00 ( 0%) 0.01 ( 0%)
108k ( 0%)
tree PTA : 0.13 ( 4%) 0.01 ( 2%) 0.04 ( 1%)
665k ( 0%)
tree SSA rewrite : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
2202k ( 1%)
tree SSA incremental : 0.02 ( 1%) 0.01 ( 2%) 0.00 ( 0%)
745k ( 0%)
tree operand scan : 0.01 ( 0%) 0.02 ( 3%) 0.03 ( 1%)
3714k ( 2%)
dominator optimization : 0.21 ( 6%) 0.02 ( 3%) 0.24 ( 6%)
3760k ( 2%)
backwards jump threading : 0.09 ( 2%) 0.01 ( 2%) 0.14 ( 3%)
837k ( 1%)
isolate eroneous paths : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
856 ( 0%)
tree CCP : 0.12 ( 3%) 0.01 ( 2%) 0.13 ( 3%)
924k ( 1%)
tree reassociation : 0.02 ( 1%) 0.00 ( 0%) 0.00 ( 0%)
46k ( 0%)
tree PRE : 0.10 ( 3%) 0.01 ( 2%) 0.14 ( 3%)
3693k ( 2%)
tree FRE : 0.15 ( 4%) 0.04 ( 7%) 0.16 ( 4%)
2644k ( 2%)
tree RPO VN : 0.01 ( 0%) 0.00 ( 0%) 0.02 ( 0%)
304k ( 0%)
tree code sinking : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
1562k ( 1%)
tree forward propagate : 0.00 ( 0%) 0.01 ( 2%) 0.08 ( 2%)
336k ( 0%)
tree conservative DCE : 0.03 ( 1%) 0.01 ( 2%) 0.04 ( 1%)
43k ( 0%)
tree aggressive DCE : 0.01 ( 0%) 0.01 ( 2%) 0.04 ( 1%)
682k ( 0%)
tree buildin call DCE : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
23k ( 0%)
tree DSE : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
204k ( 0%)
PHI merge : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
152k ( 0%)
tree loop invariant motion : 0.01 ( 0%) 0.01 ( 2%) 0.01 ( 0%)
86k ( 0%)
tree canonical iv : 0.00 ( 0%) 0.00 ( 0%) 0.03 ( 1%)
1120k ( 1%)
scev constant prop : 0.01 ( 0%) 0.01 ( 2%) 0.00 ( 0%)
222k ( 0%)
complete unrolling : 0.03 ( 1%) 0.00 ( 0%) 0.08 ( 2%)
3788k ( 2%)
tree vectorization : 0.02 ( 1%) 0.01 ( 2%) 0.02 ( 0%)
1974k ( 1%)
tree slp vectorization : 0.02 ( 1%) 0.03 ( 5%) 0.03 ( 1%)
9543k ( 6%)
tree loop distribution : 0.01 ( 0%) 0.01 ( 2%) 0.02 ( 0%)
981k ( 1%)
tree iv optimization : 0.05 ( 1%) 0.01 ( 2%) 0.05 ( 1%)
7110k ( 5%)
predictive commoning : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
799k ( 1%)
tree SSA uncprop : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
8640 ( 0%)
tree strlen optimization : 0.02 ( 1%) 0.00 ( 0%) 0.02 ( 0%)
477k ( 0%)
tree modref : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
272k ( 0%)
dominance frontiers : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
0 ( 0%)
dominance computation : 0.03 ( 1%) 0.00 ( 0%) 0.03 ( 1%)
0 ( 0%)
control dependences : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
0 ( 0%)
out of ssa : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
44k ( 0%)
expand vars : 0.00 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
1394k ( 1%)
expand : 0.03 ( 1%) 0.01 ( 2%) 0.01 ( 0%)
10M ( 7%)
forward prop : 0.11 ( 3%) 0.00 ( 0%) 0.06 ( 1%)
182k ( 0%)
CSE : 0.06 ( 2%) 0.00 ( 0%) 0.08 ( 2%)
406k ( 0%)
dead code elimination : 0.01 ( 0%) 0.00 ( 0%) 0.02 ( 0%)
0 ( 0%)
dead store elim1 : 0.01 ( 0%) 0.00 ( 0%) 0.02 ( 0%)
823k ( 1%)
dead store elim2 : 0.02 ( 1%) 0.00 ( 0%) 0.01 ( 0%)
1231k ( 1%)
loop init : 0.02 ( 1%) 0.00 ( 0%) 0.04 ( 1%)
10M ( 7%)
loop invariant motion : 0.00 ( 0%) 0.00 ( 0%) 0.02 ( 0%)
119k ( 0%)
loop unrolling : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
769k ( 1%)
loop fini : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
0 ( 0%)
CPROP : 0.05 ( 1%) 0.01 ( 2%) 0.06 ( 1%)
1971k ( 1%)
PRE : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
362k ( 0%)
CSE 2 : 0.03 ( 1%) 0.00 ( 0%) 0.07 ( 2%)
153k ( 0%)
branch prediction : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
1254k ( 1%)
combiner : 0.08 ( 2%) 0.02 ( 3%) 0.10 ( 2%)
4302k ( 3%)
if-conversion : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
470k ( 0%)
integrated RA : 0.27 ( 7%) 0.00 ( 0%) 0.22 ( 5%)
13M ( 9%)
LRA non-specific : 0.08 ( 2%) 0.00 ( 0%) 0.05 ( 1%)
1171k ( 1%)
LRA virtuals elimination : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
500k ( 0%)
LRA reload inheritance : 0.02 ( 1%) 0.00 ( 0%) 0.03 ( 1%)
186k ( 0%)
LRA create live ranges : 0.03 ( 1%) 0.00 ( 0%) 0.05 ( 1%)
152k ( 0%)
LRA hard reg assignment : 0.02 ( 1%) 0.00 ( 0%) 0.00 ( 0%)
0 ( 0%)
LRA rematerialization : 0.01 ( 0%) 0.01 ( 2%) 0.02 ( 0%)
288 ( 0%)
reload CSE regs : 0.04 ( 1%) 0.00 ( 0%) 0.10 ( 2%)
1630k ( 1%)
ree : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
90k ( 0%)
thread pro- & epilogue : 0.02 ( 1%) 0.00 ( 0%) 0.03 ( 1%)
584k ( 0%)
combine stack adjustments : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
0 ( 0%)
peephole 2 : 0.04 ( 1%) 0.00 ( 0%) 0.01 ( 0%)
425k ( 0%)
hard reg cprop : 0.02 ( 1%) 0.00 ( 0%) 0.02 ( 0%)
6720 ( 0%)
scheduling 2 : 0.16 ( 4%) 0.00 ( 0%) 0.19 ( 4%)
648k ( 0%)
machine dep reorg : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
464 ( 0%)
reorder blocks : 0.01 ( 0%) 0.00 ( 0%) 0.02 ( 0%)
727k ( 0%)
shorten branches : 0.02 ( 1%) 0.00 ( 0%) 0.01 ( 0%)
0 ( 0%)
final : 0.03 ( 1%) 0.00 ( 0%) 0.01 ( 0%)
2345k ( 2%)
tree if-combine : 0.01 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
40k ( 0%)
address lowering : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
20k ( 0%)
tree loop if-conversion : 0.04 ( 1%) 0.00 ( 0%) 0.02 ( 0%)
793k ( 1%)
access analysis : 0.02 ( 1%) 0.01 ( 2%) 0.02 ( 0%)
321k ( 0%)
rest of compilation : 0.07 ( 2%) 0.02 ( 3%) 0.08 ( 2%)
1036k ( 1%)
remove unused locals : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
0 ( 0%)
address taken : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
0 ( 0%)
repair loop structures : 0.00 ( 0%) 0.00 ( 0%) 0.01 ( 0%)
4056 ( 0%)
TOTAL : 3.68 0.61 4.32
149M
```
* gcc-13 -O0 takes 0.6s
* gcc-13 -O1 takes 2.2s
* clang 18.1.5 -O2 takes 0.3s.
```
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/13/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with:
/var/tmp/portage/sys-devel/gcc-13.2.1_p20240210/work/gcc-13-20240210/configure
--host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr
--bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/13
--includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/13/include
--datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/13
--mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/13/man
--infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/13/info
--with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/13/include/g++-v13
--disable-silent-rules --disable-dependency-tracking
--with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/13/python
--enable-objc-gc --enable-languages=c,c++,objc,obj-c++,fortran
--enable-obsolete --enable-secureplt --disable-werror --with-system-zlib
--enable-nls --without-included-gettext --disable-libunwind-exceptions
--enable-checking=release --with-bugurl=https://bugs.gentoo.org/
--with-pkgversion='Gentoo 13.2.1_p20240210 p14' --with-gcc-major-version-only
--enable-libstdcxx-time --enable-lto --disable-libstdcxx-pch --enable-shared
--enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu
--enable-multilib --with-multilib-list=m32,m64 --disable-fixed-point
--enable-targets=all --enable-libgomp --disable-libssp --disable-libada
--disable-cet --disable-systemtap --disable-valgrind-annotations
--disable-vtable-verify --disable-libvtv --without-zstd --with-isl
--disable-isl-version-check --enable-default-pie --enable-default-ssp
--disable-fixincludes
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 13.2.1 20240210 (Gentoo 13.2.1_p20240210 p14)
```
