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kumquat-buildroot/package/binutils/2.24/910-xtensa-optimize-trampolines-relaxation.patch
Max Filippov af863a3bc0 binutils: fix xtensa gas trampolines regression 
xtensa trampolines relaxation optimization caused the following build
errors:
  Error: operand 1 of 'j' has out of range value '131643'
  Error: operand 1 of 'j' has out of range value '4294836162'
  Error: operand 1 of 'j' has out of range value '4294836072'

Extra condition 'abs (addr - trampaddr) < J_RANGE / 2' for trampoline
selection results in regressions: when relaxable jump is little longer
than J_RANGE so that single trampoline makes two new jumps, one longer
than J_RANGE / 2 and one shorter, correct trampoline cannot be found.

Drop that condition.

Upstream status: patch submitted.
Fix squashed into the optimization patch.
Fixes:
  http://autobuild.buildroot.net/results/5ba7d18262ce6a2dfd69db07d064a971267f1128/

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
2015-05-10 23:08:54 +02:00

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From cbe53e134d4c3a656880a906738ce19fdcd38e8b Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Fri, 1 May 2015 11:39:12 +0300
Subject: [PATCH] xtensa: optimize trampolines relaxation
Currently every fixup in the current segment is checked when relaxing
trampoline frag. This is very expensive. Make a searchable array of
fixups pointing at potentially oversized jumps at the beginning of every
relaxation pass and only check subset of this cache in the reach of
single jump from the trampoline frag currently being relaxed.
Original profile:
% time self children called name
-----------------------------------------
370.16 593.38 12283048/12283048 relax_segment
98.4 370.16 593.38 12283048 xtensa_relax_frag
58.91 269.26 2691463834/2699602236 xtensa_insnbuf_from_chars
68.35 68.17 811266668/813338977 S_GET_VALUE
36.85 29.51 2684369246/2685538060 xtensa_opcode_decode
28.34 8.84 2684369246/2685538060 xtensa_format_get_slot
12.39 5.94 2691463834/2699775044 xtensa_format_decode
0.03 4.60 4101109/4101109 relax_frag_for_align
0.18 1.76 994617/994617 relax_frag_immed
0.07 0.09 24556277/24851220 new_logical_line
0.06 0.00 12283048/14067410 as_where
0.04 0.00 7094588/15460506 xtensa_format_num_slots
0.00 0.00 1/712477 xtensa_insnbuf_alloc
-----------------------------------------
Same data, after optimization:
% time self children called name
-----------------------------------------
0.51 7.47 12283048/12283048 relax_segment
58.0 0.51 7.47 12283048 xtensa_relax_frag
0.02 4.08 4101109/4101109 relax_frag_for_align
0.18 1.39 994617/994617 relax_frag_immed
0.01 0.98 555/555 xtensa_cache_relaxable_fixups
0.21 0.25 7094588/16693271 xtensa_insnbuf_from_chars
0.06 0.12 24556277/24851220 new_logical_line
0.06 0.00 7094588/15460506 xtensa_format_num_slots
0.02 0.04 7094588/16866079 xtensa_format_decode
0.05 0.00 12283048/14067410 as_where
0.00 0.00 1/712477 xtensa_insnbuf_alloc
0.00 0.00 93808/93808 xtensa_find_first_cached_fixup
-----------------------------------------
2015-05-02 Max Filippov <jcmvbkbc@gmail.com>
gas/
* config/tc-xtensa.c (cached_fixupS, fixup_cacheS): New typedefs.
(struct cached_fixup, struct fixup_cache): New structures.
(fixup_order, xtensa_make_cached_fixup),
(xtensa_realloc_fixup_cache, xtensa_cache_relaxable_fixups),
(xtensa_find_first_cached_fixup, xtensa_delete_cached_fixup),
(xtensa_add_cached_fixup): New functions.
(xtensa_relax_frag): Cache fixups pointing at potentially
oversized jumps at the beginning of every relaxation pass. Only
check subset of this cache in the reach of single jump from the
trampoline frag currently being relaxed.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
Backported from: b76f99d702c3501ac320396ea06bc7f9237173c3
Changes to ChangeLog are dropped.
gas/config/tc-xtensa.c | 220 +++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 194 insertions(+), 26 deletions(-)
diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
index 3e85b69..31c0b6b 100644
--- a/gas/config/tc-xtensa.c
+++ b/gas/config/tc-xtensa.c
@@ -8785,6 +8785,154 @@ static long relax_frag_for_align (fragS *, long);
static long relax_frag_immed
(segT, fragS *, long, int, xtensa_format, int, int *, bfd_boolean);
+typedef struct cached_fixup cached_fixupS;
+struct cached_fixup
+{
+ int addr;
+ int target;
+ int delta;
+ fixS *fixP;
+};
+
+typedef struct fixup_cache fixup_cacheS;
+struct fixup_cache
+{
+ cached_fixupS *fixups;
+ unsigned n_fixups;
+ unsigned n_max;
+
+ segT seg;
+ fragS *first_frag;
+};
+
+static int fixup_order (const void *a, const void *b)
+{
+ const cached_fixupS *pa = a;
+ const cached_fixupS *pb = b;
+
+ if (pa->addr == pb->addr)
+ {
+ if (pa->target == pb->target)
+ {
+ if (pa->fixP->fx_r_type == pb->fixP->fx_r_type)
+ return 0;
+ return pa->fixP->fx_r_type < pb->fixP->fx_r_type ? -1 : 1;
+ }
+ return pa->target - pb->target;
+ }
+ return pa->addr - pb->addr;
+}
+
+static bfd_boolean xtensa_make_cached_fixup (cached_fixupS *o, fixS *fixP)
+{
+ xtensa_isa isa = xtensa_default_isa;
+ int addr = fixP->fx_frag->fr_address;
+ int target;
+ int delta;
+ symbolS *s = fixP->fx_addsy;
+ int slot;
+ xtensa_format fmt;
+ xtensa_opcode opcode;
+
+ if (fixP->fx_r_type < BFD_RELOC_XTENSA_SLOT0_OP ||
+ fixP->fx_r_type > BFD_RELOC_XTENSA_SLOT14_OP)
+ return FALSE;
+ target = S_GET_VALUE (s);
+ delta = target - addr;
+
+ if (abs(delta) < J_RANGE / 2)
+ return FALSE;
+
+ xtensa_insnbuf_from_chars (isa, trampoline_buf,
+ (unsigned char *) fixP->fx_frag->fr_literal +
+ fixP->fx_where, 0);
+ fmt = xtensa_format_decode (isa, trampoline_buf);
+ gas_assert (fmt != XTENSA_UNDEFINED);
+ slot = fixP->tc_fix_data.slot;
+ xtensa_format_get_slot (isa, fmt, slot, trampoline_buf, trampoline_slotbuf);
+ opcode = xtensa_opcode_decode (isa, fmt, slot, trampoline_slotbuf);
+ if (opcode != xtensa_j_opcode)
+ return FALSE;
+
+ o->addr = addr;
+ o->target = target;
+ o->delta = delta;
+ o->fixP = fixP;
+
+ return TRUE;
+}
+
+static void xtensa_realloc_fixup_cache (fixup_cacheS *cache, unsigned add)
+{
+ if (cache->n_fixups + add > cache->n_max)
+ {
+ cache->n_max = (cache->n_fixups + add) * 2;
+ cache->fixups = xrealloc (cache->fixups,
+ sizeof (*cache->fixups) * cache->n_max);
+ }
+}
+
+static void xtensa_cache_relaxable_fixups (fixup_cacheS *cache,
+ segment_info_type *seginfo)
+{
+ fixS *fixP;
+
+ cache->n_fixups = 0;
+
+ for (fixP = seginfo->fix_root; fixP ; fixP = fixP->fx_next)
+ {
+ xtensa_realloc_fixup_cache (cache, 1);
+
+ if (xtensa_make_cached_fixup (cache->fixups + cache->n_fixups, fixP))
+ ++cache->n_fixups;
+ }
+ qsort (cache->fixups, cache->n_fixups, sizeof (*cache->fixups), fixup_order);
+}
+
+static unsigned xtensa_find_first_cached_fixup (const fixup_cacheS *cache,
+ int addr)
+{
+ unsigned a = 0;
+ unsigned b = cache->n_fixups;
+
+ while (b - a > 1)
+ {
+ unsigned c = (a + b) / 2;
+
+ if (cache->fixups[c].addr < addr)
+ a = c;
+ else
+ b = c;
+ }
+ return a;
+}
+
+static void xtensa_delete_cached_fixup (fixup_cacheS *cache, unsigned i)
+{
+ memmove (cache->fixups + i, cache->fixups + i + 1,
+ (cache->n_fixups - i - 1) * sizeof (*cache->fixups));
+ --cache->n_fixups;
+}
+
+static bfd_boolean xtensa_add_cached_fixup (fixup_cacheS *cache, fixS *fixP)
+{
+ cached_fixupS o;
+ unsigned i;
+
+ if (!xtensa_make_cached_fixup (&o, fixP))
+ return FALSE;
+ xtensa_realloc_fixup_cache (cache, 1);
+ i = xtensa_find_first_cached_fixup (cache, o.addr);
+ if (i < cache->n_fixups)
+ {
+ ++i;
+ memmove (cache->fixups + i + 1, cache->fixups + i,
+ (cache->n_fixups - i) * sizeof (*cache->fixups));
+ }
+ cache->fixups[i] = o;
+ ++cache->n_fixups;
+ return TRUE;
+}
/* Return the number of bytes added to this fragment, given that the
input has been stretched already by "stretch". */
@@ -8896,35 +9044,42 @@ xtensa_relax_frag (fragS *fragP, long stretch, int *stretched_p)
case RELAX_TRAMPOLINE:
if (fragP->tc_frag_data.relax_seen)
{
- segment_info_type *seginfo = seg_info (now_seg);
- fragS *fP; /* The out-of-range jump. */
- fixS *fixP;
+ static fixup_cacheS fixup_cache;
+ segment_info_type *seginfo = seg_info (now_seg);
+ int trampaddr = fragP->fr_address + fragP->fr_fix;
+ int searchaddr = trampaddr < J_RANGE ? 0 : trampaddr - J_RANGE;
+ unsigned i;
+
+ if (now_seg != fixup_cache.seg ||
+ fragP == fixup_cache.first_frag ||
+ fixup_cache.first_frag == NULL)
+ {
+ xtensa_cache_relaxable_fixups (&fixup_cache, seginfo);
+ fixup_cache.seg = now_seg;
+ fixup_cache.first_frag = fragP;
+ }
/* Scan for jumps that will not reach. */
- for (fixP = seginfo->fix_root; fixP ; fixP = fixP->fx_next)
+ for (i = xtensa_find_first_cached_fixup (&fixup_cache, searchaddr);
+ i < fixup_cache.n_fixups; ++i)
+
{
- symbolS *s = fixP->fx_addsy;
- xtensa_opcode opcode;
- int target;
- int addr;
- int delta;
-
- if (fixP->fx_r_type < BFD_RELOC_XTENSA_SLOT0_OP ||
- fixP->fx_r_type > BFD_RELOC_XTENSA_SLOT14_OP)
- continue;
- xtensa_insnbuf_from_chars (isa, trampoline_buf,
- (unsigned char *) fixP->fx_frag->fr_literal + fixP->fx_where,
- 0);
- fmt = xtensa_format_decode (isa, trampoline_buf);
- gas_assert (fmt != XTENSA_UNDEFINED);
- slot = fixP->tc_fix_data.slot;
- xtensa_format_get_slot (isa, fmt, slot, trampoline_buf, trampoline_slotbuf);
- opcode = xtensa_opcode_decode (isa, fmt, slot, trampoline_slotbuf);
- if (opcode != xtensa_j_opcode)
+ fixS *fixP = fixup_cache.fixups[i].fixP;
+ int target = fixup_cache.fixups[i].target;
+ int addr = fixup_cache.fixups[i].addr;
+ int delta = fixup_cache.fixups[i].delta + stretch;
+
+ trampaddr = fragP->fr_address + fragP->fr_fix;
+
+ if (addr + J_RANGE < trampaddr)
continue;
- target = S_GET_VALUE (s);
- addr = fixP->fx_frag->fr_address;
- delta = target - addr + stretch;
+ if (addr > trampaddr + J_RANGE)
+ break;
+ if (abs (delta) < J_RANGE)
+ continue;
+
+ slot = fixP->tc_fix_data.slot;
+
if (delta > J_RANGE || delta < -1 * J_RANGE)
{ /* Found an out-of-range jump; scan the list of trampolines for the best match. */
struct trampoline_seg *ts = find_trampoline_seg (now_seg);
@@ -8978,14 +9133,13 @@ xtensa_relax_frag (fragS *fragP, long stretch, int *stretched_p)
}
if (tf->fragP == fragP)
{
- int trampaddr = fragP->fr_address + fragP->fr_fix;
-
if (abs (addr - trampaddr) < J_RANGE)
{ /* The trampoline is in range of original; fix it! */
fixS *newfixP;
int offset;
TInsn insn;
symbolS *lsym;
+ fragS *fP; /* The out-of-range jump. */
new_stretch += init_trampoline_frag (tf);
offset = fragP->fr_fix; /* Where to assemble the j insn. */
@@ -9009,10 +9163,20 @@ xtensa_relax_frag (fragS *fragP, long stretch, int *stretched_p)
newfixP->tc_fix_data.X_add_symbol = lsym;
newfixP->tc_fix_data.X_add_number = offset;
newfixP->tc_fix_data.slot = slot;
+
+ xtensa_delete_cached_fixup (&fixup_cache, i);
+ xtensa_add_cached_fixup (&fixup_cache, newfixP);
+
/* Move the fix-up from the original j insn to this one. */
fixP->fx_frag = fragP;
fixP->fx_where = fragP->fr_fix - 3;
fixP->tc_fix_data.slot = 0;
+
+ xtensa_add_cached_fixup (&fixup_cache, fixP);
+
+ /* re-do current fixup */
+ --i;
+
/* Adjust the jump around this trampoline (if present). */
if (tf->fixP != NULL)
{
@@ -9027,6 +9191,8 @@ xtensa_relax_frag (fragS *fragP, long stretch, int *stretched_p)
fragP->fr_subtype = 0;
/* Remove from the trampoline_list. */
prev->next = tf->next;
+ if (fragP == fixup_cache.first_frag)
+ fixup_cache.first_frag = NULL;
break;
}
}
--
1.8.1.4
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