GCC memory consumption increased by recent patch!

gcctest@suse.de gcctest@suse.de
Thu Sep 30 18:17:00 GMT 2004


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: 25269k
    Peak memory use before GGC: 9345k
    Peak memory use after GGC: 8656k
    Maximum of released memory in single GGC run: 2939k
    Garbage: 43116k
    Leak: 6090k
    Overhead: 5694k
    GGC runs: 363

comparing combine.c compilation at -O1 level:
    Overall memory needed: 26689k
    Peak memory use before GGC: 9433k
    Peak memory use after GGC: 8869k
    Maximum of released memory in single GGC run: 2070k
    Garbage: 70529k
    Leak: 6673k
    Overhead: 11340k
    GGC runs: 578

comparing combine.c compilation at -O2 level:
    Overall memory needed: 29841k -> 29837k
    Peak memory use before GGC: 12772k
    Peak memory use after GGC: 12612k
    Maximum of released memory in single GGC run: 2596k
    Garbage: 85679k
    Leak: 6427k
    Overhead: 15887k
    GGC runs: 577

comparing combine.c compilation at -O3 level:
    Overall memory needed: 21428k
    Peak memory use before GGC: 13077k
    Peak memory use after GGC: 12725k
    Maximum of released memory in single GGC run: 3454k
    Garbage: 114508k
    Leak: 6930k
    Overhead: 20982k
    GGC runs: 643

comparing insn-attrtab.c compilation at -O0 level:
    Overall memory needed: 118920k
    Peak memory use before GGC: 79664k
    Peak memory use after GGC: 46309k
    Maximum of released memory in single GGC run: 43569k
    Garbage: 163567k
    Leak: 10644k
    Overhead: 20607k
    GGC runs: 307

comparing insn-attrtab.c compilation at -O1 level:
    Overall memory needed: 131960k
    Peak memory use before GGC: 91605k
    Peak memory use after GGC: 70898k
    Maximum of released memory in single GGC run: 42250k
    Garbage: 465895k
    Leak: 11075k
    Overhead: 74816k
    GGC runs: 462

comparing insn-attrtab.c compilation at -O2 level:
    Overall memory needed: 210308k
    Peak memory use before GGC: 107164k
    Peak memory use after GGC: 86457k
    Maximum of released memory in single GGC run: 36153k
    Garbage: 515187k
    Leak: 10957k
    Overhead: 82852k
    GGC runs: 384

comparing insn-attrtab.c compilation at -O3 level:
    Overall memory needed: 210312k
    Peak memory use before GGC: 107173k
    Peak memory use after GGC: 86466k
    Maximum of released memory in single GGC run: 36152k
    Garbage: 516075k
    Leak: 11011k
    Overhead: 83007k
    GGC runs: 392

comparing Gerald's testcase PR8361 compilation at -O0 level:
    Overall memory needed: 114040k -> 113448k
    Peak memory use before GGC: 90996k -> 90536k
    Peak memory use after GGC: 89745k -> 89158k
    Maximum of released memory in single GGC run: 20088k -> 20157k
    Garbage: 262282k -> 262109k
    Leak: 60274k -> 59481k
    Overhead: 47613k -> 47301k
    GGC runs: 374 -> 375

comparing Gerald's testcase PR8361 compilation at -O1 level:
  Overall memory allocated via mmap and sbrk increased from 105224k to 108032k, overall 2.67%
  Peak amount of GGC memory allocated before garbage collecting increased from 90057k to 95134k, overall 5.64%
    Overall memory needed: 105224k -> 108032k
    Peak memory use before GGC: 90057k -> 95134k
    Peak memory use after GGC: 88621k -> 88446k
    Maximum of released memory in single GGC run: 19790k -> 19483k
    Garbage: 594707k -> 594371k
    Leak: 62341k -> 61548k
    Overhead: 131018k -> 130696k
    GGC runs: 604 -> 605

comparing Gerald's testcase PR8361 compilation at -O2 level:
  Overall memory allocated via mmap and sbrk increased from 105660k to 108412k, overall 2.60%
  Peak amount of GGC memory allocated before garbage collecting increased from 90058k to 95135k, overall 5.64%
    Overall memory needed: 105660k -> 108412k
    Peak memory use before GGC: 90058k -> 95135k
    Peak memory use after GGC: 88622k -> 88446k
    Maximum of released memory in single GGC run: 19791k -> 19484k
    Garbage: 646939k -> 646890k
    Leak: 62893k -> 62100k
    Overhead: 153857k -> 153551k
    GGC runs: 635 -> 638

comparing Gerald's testcase PR8361 compilation at -O3 level:
    Overall memory needed: 107960k -> 105432k
    Peak memory use before GGC: 91626k -> 91094k
    Peak memory use after GGC: 90204k -> 89672k
    Maximum of released memory in single GGC run: 20194k -> 20199k
    Garbage: 682985k -> 682975k
    Leak: 63318k -> 62521k
    Overhead: 163188k -> 162879k
    GGC runs: 626

Head of changelog is:

--- /usr/src/SpecTests/sandbox-britten-memory/x86_64/mem-result/ChangeLog	2004-09-30 12:13:30.000000000 +0000
+++ /usr/src/SpecTests/sandbox-britten-memory/gcc/gcc/ChangeLog	2004-09-30 16:52:50.000000000 +0000
@@ -1,3 +1,16 @@
+2004-09-30  Diego Novillo  <dnovillo@redhat.com>
+
+	* tree-ssa-alias.c (collect_points_to_info_r): Move analysis of
+	expressions...
+	(add_pointed_to_expr): ... here.
+	Call add_pointed_to_expr for variables with DECL_INITIAL set.
+	* tree-dfa.c (add_referenced_var): Scan DECL_INITIAL of any
+	pointer variable, if set.
+
+2004-09-30  Kazu Hirata  <kazu@cs.umass.edu>
+
+	* config/sh/sh.c: Follow spelling conventions.
+
 2004-09-29  Richard Henderson  <rth@redhat.com>
 
 	* unwind-dw2.c (_Unwind_GetGR): Honor DWARF_ZERO_REG.
--- /usr/src/SpecTests/sandbox-britten-memory/x86_64/mem-result/ChangeLog.cp	2004-09-30 06:10:49.000000000 +0000
+++ /usr/src/SpecTests/sandbox-britten-memory/gcc/gcc/cp/ChangeLog	2004-09-30 16:52:51.000000000 +0000
@@ -1,3 +1,8 @@
+2004-09-30  Nathan Sidwell  <nathan@codesourcery.com>
+
+	* cp-tree.h (struct lang_decl): Shrink by reordering fields and
+	turning operator_code and fixed_offset into bitfields.
+
 2004-09-29  Joseph S. Myers  <jsm@polyomino.org.uk>
 
 	* decl.c (duplicate_decls): Merge TREE_DEPRECATED.

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.



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