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authorKen Raeburn <raeburn@cygnus>1995-10-18 21:21:38 +0000
committerKen Raeburn <raeburn@cygnus>1995-10-18 21:21:38 +0000
commitd19dcb671529004ecd8a06e38a00d9b8fb380ccd (patch)
tree64a2968b947f759397dda90e1b9d9a4b81a52c30
parent5a2846e3ddb533ded11de37a3e17638d554b6894 (diff)
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Use one active frag and one obstack per frag chain:
* 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.
-rw-r--r--gas/subsegs.c115
1 files changed, 57 insertions, 58 deletions
diff --git a/gas/subsegs.c b/gas/subsegs.c
index e360d32..3280bcd 100644
--- a/gas/subsegs.c
+++ b/gas/subsegs.c
@@ -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. */
+ 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)
{
- frag_now->fr_fix = frag_now_fix ();
- frag_wane (frag_now); /* Close off any frag in old subseg. */
+ frchain_now = &absolute_frchain;
+ frag_now = &zero_address_frag;
+ return;
}
- /*
- * 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.
- */
- }
- subseg_change (seg, (int) subseg);
+
+ 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)