GCC memory consumption increased by recent patch!

Sun Sep 26 21:45:00 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: 24125k -> 24121k
    Peak memory use before GGC: 9296k
    Peak memory use after GGC: 8607k
    Maximum of released memory in single GGC run: 2870k
    Garbage: 42629k
    Leak: 6090k
    Overhead: 5588k
    GGC runs: 363

comparing combine.c compilation at -O1 level:
  Amount of produced GGC garbage increased from 69012k to 69180k, overall 0.24%
    Overall memory needed: 25585k
    Peak memory use before GGC: 9377k
    Peak memory use after GGC: 8800k
    Maximum of released memory in single GGC run: 2031k
    Garbage: 69012k -> 69180k
    Leak: 6674k
    Overhead: 11060k -> 11094k
    GGC runs: 575

comparing combine.c compilation at -O2 level:
  Amount of produced GGC garbage increased from 84129k to 84273k, overall 0.17%
    Overall memory needed: 28865k -> 28885k
    Peak memory use before GGC: 12772k
    Peak memory use after GGC: 12613k
    Maximum of released memory in single GGC run: 2525k
    Garbage: 84129k -> 84273k
    Leak: 6428k
    Overhead: 15609k -> 15636k
    GGC runs: 571

comparing combine.c compilation at -O3 level:
  Amount of produced GGC garbage increased from 112018k to 112175k, overall 0.14%
  Amount of memory still referenced at the end of compilation increased from 6913k to 6929k, overall 0.23%
    Overall memory needed: 20544k
    Peak memory use before GGC: 13044k
    Peak memory use after GGC: 12692k
    Maximum of released memory in single GGC run: 3362k
    Garbage: 112018k -> 112175k
    Leak: 6913k -> 6929k
    Overhead: 20652k -> 20684k
    GGC runs: 637

comparing insn-attrtab.c compilation at -O0 level:
    Overall memory needed: 116476k
    Peak memory use before GGC: 77101k
    Peak memory use after GGC: 45186k
    Maximum of released memory in single GGC run: 42129k
    Garbage: 159505k
    Leak: 10645k
    Overhead: 19805k
    GGC runs: 310

comparing insn-attrtab.c compilation at -O1 level:
  Amount of produced GGC garbage increased from 452514k to 453085k, overall 0.13%
    Overall memory needed: 133128k -> 133084k
    Peak memory use before GGC: 93162k
    Peak memory use after GGC: 71529k
    Maximum of released memory in single GGC run: 41234k
    Garbage: 452514k -> 453085k
    Leak: 11078k
    Overhead: 73596k -> 73707k
    GGC runs: 461

comparing insn-attrtab.c compilation at -O2 level:
    Overall memory needed: 207744k
    Peak memory use before GGC: 108725k
    Peak memory use after GGC: 87092k
    Maximum of released memory in single GGC run: 34490k
    Garbage: 502029k -> 502446k
    Leak: 11218k
    Overhead: 82991k -> 83073k
    GGC runs: 384

comparing insn-attrtab.c compilation at -O3 level:
    Overall memory needed: 207736k
    Peak memory use before GGC: 108726k
    Peak memory use after GGC: 87093k
    Maximum of released memory in single GGC run: 34491k
    Garbage: 503198k -> 503617k
    Leak: 11256k
    Overhead: 83387k -> 83469k
    GGC runs: 393

comparing Gerald's testcase PR8361 compilation at -O0 level:
    Overall memory needed: 115352k
    Peak memory use before GGC: 92231k
    Peak memory use after GGC: 90025k
    Maximum of released memory in single GGC run: 20139k
    Garbage: 265688k
    Leak: 60277k
    Overhead: 47198k
    GGC runs: 378

comparing Gerald's testcase PR8361 compilation at -O1 level:
    Overall memory needed: 109300k -> 109320k
    Peak memory use before GGC: 95751k
    Peak memory use after GGC: 88883k
    Maximum of released memory in single GGC run: 19570k
    Garbage: 594162k -> 594441k
    Leak: 62349k -> 62357k
    Overhead: 130957k -> 131029k
    GGC runs: 605

comparing Gerald's testcase PR8361 compilation at -O2 level:
    Overall memory needed: 110336k -> 110308k
    Peak memory use before GGC: 95751k
    Peak memory use after GGC: 88883k
    Maximum of released memory in single GGC run: 19569k
    Garbage: 646972k -> 647298k
    Leak: 62912k
    Overhead: 154222k -> 154283k
    GGC runs: 637 -> 638

comparing Gerald's testcase PR8361 compilation at -O3 level:
    Overall memory needed: 108020k -> 108024k
    Peak memory use before GGC: 91613k
    Peak memory use after GGC: 90197k
    Maximum of released memory in single GGC run: 20253k
    Garbage: 682382k -> 682712k
    Leak: 63341k -> 63333k
    Overhead: 163378k -> 163435k
    GGC runs: 626

Head of changelog is:

--- /usr/src/SpecTests/sandbox-britten-memory/x86_64/mem-result/ChangeLog	2004-09-26 06:56:20.000000000 +0000
+++ /usr/src/SpecTests/sandbox-britten-memory/gcc/gcc/ChangeLog	2004-09-26 18:52:33.000000000 +0000
@@ -1,3 +1,40 @@
+2004-09-26  Roger Sayle  <roger@eyesopen.com>
+	    Giovanni Bajo  <giovannibajo@gcc.gnu.org>
+
+	PR middle-end/17112
+	* stor-layout.c (compute_record_mode): For records with a single
+	field, only use the field's mode if its size matches what we'd
+	have choosen for the record ourselves.  This forces the use of
+	BLKmode for packed records that don't completely fill a mode.
+
+2004-09-26  Roger Sayle  <roger@eyesopen.com>
+
+	PR middle-end/17151
+	* combine.c (force_to_mode): Remove dubious early return test that
+	inhibits further optimization.
+
+2004-09-26  Kazu Hirata  <kazu@cs.umass.edu>
+
+	* profile.c: Fix a comment typo.
+
+2004-09-26  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>
+
+	PR bootstrap/17591
+	* tree-ssa-loop-im.c (for_each_index): Call callback for component_refs
+	with varying offset.
+	* tree-ssa-loop-ivopts.c (abnormal_ssa_name_p): New function.
+	(idx_contains_abnormal_ssa_name_p): Scan step and lower bound for
+	ARRAY_REFS.
+	(expr_invariant_in_loop_p): New function.
+	(idx_find_step): Handle step and lower bound for ARRAY_REFs.  Handle
+	component_ref_field_offset for COMPONENT_REFs.  Do not allow
+	ALIGN_INDIRECT_REFs and MISALIGNED_INDIRECT_REFs.
+	(add_address_candidates): Do not handle ALIGN_INDIRECT_REFs and
+	MISALIGNED_INDIRECT_REFs.
+	(idx_remove_ssa_names): Handle step and lower bound for ARRAY_REFs.
+	(rewrite_address_base): Do not handle ALIGN_INDIRECT_REFs and
+	MISALIGNED_INDIRECT_REFs.
+
 2004-09-26  Joseph S. Myers  <jsm@polyomino.org.uk>
 
 	PR c/11459

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.

