GCC memory consumption decreased by recent patch

gcctest@suse.de gcctest@suse.de
Sun Mar 6 08:09:00 GMT 2005


Hi,
Comparing memory consumption on compilation of combine.i and generate-3.4.ii I got:


comparing combine.c compilation at -O0 level:
    Overall memory needed: 24665k
    Peak memory use before GGC: 9359k
    Peak memory use after GGC: 8673k
    Maximum of released memory in single GGC run: 2865k
    Garbage: 41675k
    Leak: 6395k
    Overhead: 5772k
    GGC runs: 327

comparing combine.c compilation at -O1 level:
    Overall memory needed: 24509k -> 24513k
    Peak memory use before GGC: 8673k
    Peak memory use after GGC: 8093k
    Maximum of released memory in single GGC run: 2026k
    Garbage: 58556k
    Leak: 6756k
    Overhead: 9886k
    GGC runs: 500

comparing combine.c compilation at -O2 level:
    Overall memory needed: 29141k -> 29149k
    Peak memory use before GGC: 12671k
    Peak memory use after GGC: 12544k
    Maximum of released memory in single GGC run: 2533k
    Garbage: 78269k
    Leak: 6594k
    Overhead: 14170k
    GGC runs: 520

comparing combine.c compilation at -O3 level:
    Overall memory needed: 30813k -> 30817k
    Peak memory use before GGC: 12713k
    Peak memory use after GGC: 12544k
    Maximum of released memory in single GGC run: 3392k
    Garbage: 105878k
    Leak: 7189k
    Overhead: 19022k
    GGC runs: 582

comparing insn-attrtab.c compilation at -O0 level:
    Overall memory needed: 114212k
    Peak memory use before GGC: 74821k
    Peak memory use after GGC: 45494k
    Maximum of released memory in single GGC run: 39413k
    Garbage: 152830k
    Leak: 10984k
    Overhead: 19970k
    GGC runs: 273

comparing insn-attrtab.c compilation at -O1 level:
    Overall memory needed: 124600k
    Peak memory use before GGC: 78641k
    Peak memory use after GGC: 70036k
    Maximum of released memory in single GGC run: 40782k
    Garbage: 369270k
    Leak: 11361k
    Overhead: 71894k
    GGC runs: 398

comparing insn-attrtab.c compilation at -O2 level:
    Overall memory needed: 148936k
    Peak memory use before GGC: 97678k
    Peak memory use after GGC: 83497k
    Maximum of released memory in single GGC run: 39163k
    Garbage: 486952k
    Leak: 11252k
    Overhead: 87104k
    GGC runs: 342

comparing insn-attrtab.c compilation at -O3 level:
  Ovarall memory allocated via mmap and sbrk decreased from 147500k to 137824k, overall -7.02%
    Overall memory needed: 147500k -> 137824k
    Peak memory use before GGC: 97679k
    Peak memory use after GGC: 83499k
    Maximum of released memory in single GGC run: 39162k
    Garbage: 487762k
    Leak: 11287k
    Overhead: 87234k
    GGC runs: 348

comparing Gerald's testcase PR8361 compilation at -O0 level:
    Overall memory needed: 111952k
    Peak memory use before GGC: 87325k
    Peak memory use after GGC: 85900k
    Maximum of released memory in single GGC run: 19511k
    Garbage: 246370k
    Leak: 55513k
    Overhead: 43275k
    GGC runs: 366

comparing Gerald's testcase PR8361 compilation at -O1 level:
    Overall memory needed: 104041k -> 104033k
    Peak memory use before GGC: 86183k
    Peak memory use after GGC: 85119k
    Maximum of released memory in single GGC run: 18950k
    Garbage: 435088k
    Leak: 56863k
    Overhead: 65172k
    GGC runs: 513

comparing Gerald's testcase PR8361 compilation at -O2 level:
    Overall memory needed: 104249k
    Peak memory use before GGC: 86184k
    Peak memory use after GGC: 85119k
    Maximum of released memory in single GGC run: 18951k
    Garbage: 476277k
    Leak: 57427k
    Overhead: 74892k
    GGC runs: 569

comparing Gerald's testcase PR8361 compilation at -O3 level:
    Overall memory needed: 105353k
    Peak memory use before GGC: 87323k
    Peak memory use after GGC: 86199k
    Maximum of released memory in single GGC run: 19400k
    Garbage: 481450k
    Leak: 57631k
    Overhead: 75594k
    GGC runs: 557

Head of changelog is:

--- /usr/src/SpecTests/sandbox-britten-memory/x86_64/mem-result/ChangeLog	2005-03-06 01:49:48.000000000 +0000
+++ /usr/src/SpecTests/sandbox-britten-memory/gcc/gcc/ChangeLog	2005-03-06 07:09:27.000000000 +0000
@@ -1,3 +1,14 @@
+2005-03-06  Kazu Hirata  <kazu@cs.umass.edu>
+
+	* cse.c (fold_rtx_subreg, fold_rtx_mem): New.
+	(fold_rtx): Call fold_rtx_subreg and fold_rtx_mem to handle
+	SUBREG and MEM, respectively.
+
+2005-03-06  Kazu Hirata  <kazu@cs.umass.edu>
+
+	* fold-const.c (fold_binary): Avoid directly using the original
+	expression t as much as possible.
+
 2005-03-05  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* c-semantics.c (build_stmt): Use TYPE_P instead of

I am friendly script caring about memory consumption in GCC.  Please contact
jh@suse.cz if something is going wrong.

The results can be reproduced by building compiler with
--enable-gather-detailed-mem-stats targetting x86-64 and compiling preprocessed
combine.c or testcase from PR8632 with:

-fmem-report --param=ggc-min-heapsize=1024 --param=ggc-min-expand=1 -Ox -Q

The memory consumption summary appears in the dump after detailed listing of
the places they are allocated in.  Peak memory consumption is actually computed
by looking for maximal value in {GC XXXX -> YYYY} report.

Yours testing script.



More information about the Gcc-regression mailing list