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Use one active frag and one obstack per frag chain:

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* frags.c (frags): Variable deleted.
(frag_alloc): New function.
(frag_grow, frag_more, frag_variant, frag_now_fix, frag_append_1_char): Refer
to frchain_now->frch_obstack instead of frags variable.
(frag_new): Ditto.  Verify that frch_last and frag_now match on entry and exit,
and that old frag_now has non-zero type.  Replace "know" uses with "assert".
Use frag_alloc instead of mucking with obstack alignment.
* frags.h (frags): Declaration deleted.
* subsegs.h (struct frchain): Add new field frch_frag_now.
* subsegs.c (frchains, dummy_frag, absolute_frchain): New static variables.
(subsegs_begin): Initialize frchains obstack.  Under gcc, don't give it any
stricter alignment than frchainS structures need.  Do not initialize frags
obstack.  Set frag_now to point to dummy_obstack.  Initialize absolute_frchain.
(subseg_set_rest): Save and restore frag_now in frch_frag_now field of
frchainS.  Don't create new frags on section switch, and use frag_alloc when
creating a new frag chain.  For absolute section, set frchain_now to
absolute_frchain.  Verify that frch_last and frag_now match on entry and exit.
Initialize per-chain obstack, and under gcc, set required alignment to that
needed by fragS structure.
* write.c (chain_frchains_together_1): Verify fr_type is nonzero.

In one test case of Mike's (i386-linux, over 300K lines of .s code with lots
of stabs records), run time and memory use are reduced by about 1/3.

Might introduce some problems in cases that use the frag obstacks in unusual
ways.  Test suite does pass for i386-linux and sparc-solaris targets though.
This commit is contained in:
Ken Raeburn 1995-10-18 21:21:38 +00:00
parent 5a2846e3dd
commit d19dcb6715
1 changed files with 58 additions and 59 deletions
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117
gas/subsegs.c
View File

@ -29,6 +29,8 @@
frchainS *frchain_root, *frchain_now;
static struct obstack frchains;
#ifndef BFD_ASSEMBLER
#ifdef MANY_SEGMENTS
segment_info_type segment_info[SEG_MAXIMUM_ORDINAL];
@ -67,6 +69,10 @@ static segment_info_type *und_seg_info;
#endif /* BFD_ASSEMBLER */
static void subseg_set_rest PARAMS ((segT, subsegT));
static fragS dummy_frag;
static frchainS absolute_frchain;
void
subsegs_begin ()
@ -87,16 +93,17 @@ subsegs_begin ()
know (SEG_MAXIMUM_ORDINAL == SEG_REGISTER);
#endif
obstack_begin (&frchains, chunksize);
#if __GNUC__ >= 2
obstack_alignment_mask (&frchains) = __alignof__ (frchainS) - 1;
#endif
frchain_root = NULL;
frchain_now = NULL; /* Warn new_subseg() that we are booting. */
/* Fake up 1st frag. It won't be used=> is ok if obstack...
pads the end of it for alignment. */
frag_now = (fragS *) obstack_alloc (&frags, SIZEOF_STRUCT_FRAG);
memset (frag_now, 0, SIZEOF_STRUCT_FRAG);
frag_now = &dummy_frag;
#ifndef BFD_ASSEMBLER
/* This 1st frag will not be in any frchain.
We simply give subseg_new somewhere to scribble. */
now_subseg = 42; /* Lie for 1st call to subseg_new. */
#ifdef MANY_SEGMENTS
{
@ -117,6 +124,11 @@ subsegs_begin ()
#endif /* ! MANY_SEGMENTS */
#endif /* ! BFD_ASSEMBLER */
absolute_frchain.frch_seg = absolute_section;
absolute_frchain.frch_subseg = 0;
absolute_frchain.fix_root = absolute_frchain.fix_tail = 0;
absolute_frchain.frch_frag_now = &zero_address_frag;
absolute_frchain.frch_root = absolute_frchain.frch_last = &zero_address_frag;
}
/*
@ -137,6 +149,9 @@ subseg_change (seg, subseg)
now_seg = seg;
now_subseg = subseg;
if (now_seg == absolute_section)
return;
#ifdef BFD_ASSEMBLER
{
segment_info_type *seginfo;
@ -195,26 +210,29 @@ subseg_set_rest (seg, subseg)
register fragS *former_last_fragP;
register fragS *new_fragP;
if (frag_now) /* If not bootstrapping. */
{
frag_now->fr_fix = frag_now_fix ();
frag_wane (frag_now); /* Close off any frag in old subseg. */
}
/*
* It would be nice to keep an obstack for each subsegment, if we swap
* subsegments a lot. Hence we would have much fewer frag_wanes().
*/
{
obstack_finish (&frags);
/*
* If we don't do the above, the next object we put on obstack frags
* will appear to start at the fr_literal of the current frag.
* Also, above ensures that the next object will begin on a
* address that is aligned correctly for the engine that runs
* this program.
*/
}
mri_common_symbol = NULL;
if (frag_now && frchain_now)
frchain_now->frch_frag_now = frag_now;
assert (frchain_now == 0
|| now_seg == undefined_section
|| now_seg == absolute_section
|| frchain_now->frch_last == frag_now);
subseg_change (seg, (int) subseg);
if (seg == absolute_section)
{
frchain_now = &absolute_frchain;
frag_now = &zero_address_frag;
return;
}
assert (frchain_now == 0
|| now_seg == undefined_section
|| frchain_now->frch_last == frag_now);
/*
* Attempt to find or make a frchain for that sub seg.
* Crawl along chain of frchainSs, begins @ frchain_root.
@ -259,16 +277,22 @@ subseg_set_rest (seg, subseg)
/*
* This should be the only code that creates a frchainS.
*/
newP = (frchainS *) obstack_alloc (&frags, sizeof (frchainS));
newP->frch_root = 0;
extern fragS *frag_alloc ();
newP = (frchainS *) obstack_alloc (&frchains, sizeof (frchainS));
newP->frch_subseg = subseg;
newP->frch_seg = seg;
newP->frch_last = NULL;
#ifdef BFD_ASSEMBLER
newP->fix_root = NULL;
newP->fix_tail = NULL;
#endif
obstack_begin (&newP->frch_obstack, 5000);
#if __GNUC__ >= 2
obstack_alignment_mask (&newP->frch_obstack) = __alignof__ (fragS) - 1;
#endif
newP->frch_frag_now = frag_alloc (&newP->frch_obstack);
newP->frch_frag_now->fr_type = rs_fill;
newP->frch_root = newP->frch_last = newP->frch_frag_now;
*lastPP = newP;
newP->frch_next = frcP; /* perhaps NULL */
@ -278,37 +302,9 @@ subseg_set_rest (seg, subseg)
* Here with frcP pointing to the frchainS for subseg.
*/
frchain_now = frcP;
/*
* Make a fresh frag for the subsegment.
*/
/* We expect this to happen on a correct boundary since it was
proceeded by a obstack_done(). */
tmp = obstack_alignment_mask (&frags); /* JF disable alignment */
obstack_alignment_mask (&frags) = 0;
frag_now = (fragS *) obstack_alloc (&frags, SIZEOF_STRUCT_FRAG);
memset (frag_now, 0, SIZEOF_STRUCT_FRAG);
obstack_alignment_mask (&frags) = tmp;
/* But we want any more chars to come immediately after the
structure we just made. */
new_fragP = frag_now;
new_fragP->fr_next = NULL;
/*
* Append new frag to current frchain.
*/
former_last_fragP = frcP->frch_last;
if (former_last_fragP)
{
know (former_last_fragP->fr_next == NULL);
know (frchain_now->frch_root);
former_last_fragP->fr_next = new_fragP;
}
else
{
frcP->frch_root = new_fragP;
}
frcP->frch_last = new_fragP;
frag_now = frcP->frch_frag_now;
mri_common_symbol = NULL;
assert (frchain_now->frch_last == frag_now);
}
/*
@ -379,7 +375,10 @@ subseg_set (seg, subseg) /* begin assembly for a new sub-segment */
register subsegT subseg;
{
#ifndef MANY_SEGMENTS
know (seg == SEG_DATA || seg == SEG_TEXT || seg == SEG_BSS);
know (seg == SEG_DATA
|| seg == SEG_TEXT
|| seg == SEG_BSS
|| seg == SEG_ABSOLUTE);
#endif
if (seg != now_seg || subseg != now_subseg)