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authorBob Wilson <bob.wilson@acm.org>2005-04-05 23:37:34 +0000
committerBob Wilson <bob.wilson@acm.org>2005-04-05 23:37:34 +0000
commit664df4e44e97b794808f2c46dc410cf9db98f7fa (patch)
treec404772707743832871ca009f47a5b759893142e /gas/config
parentd77b99c958c510564060def9a5de1b305e1b6382 (diff)
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* config/tc-xtensa.c (branch_align_power): New.
(xtensa_find_unaligned_branch_targets, get_aligned_diff, future_alignment_required): Use branch_align_power to check section alignment as well as xtensa_fetch_width when aligning branch targets.
Diffstat (limited to 'gas/config')
-rw-r--r--gas/config/tc-xtensa.c40
1 files changed, 32 insertions, 8 deletions
diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
index cb71425..c621a8c 100644
--- a/gas/config/tc-xtensa.c
+++ b/gas/config/tc-xtensa.c
@@ -448,6 +448,7 @@ static int total_frag_text_expansion (fragS *);
static int get_text_align_power (unsigned);
static int get_text_align_max_fill_size (int, bfd_boolean, bfd_boolean);
+static int branch_align_power (segT);
/* Helpers for xtensa_relax_frag(). */
@@ -4869,15 +4870,16 @@ xtensa_find_unaligned_branch_targets (bfd *abfd ATTRIBUTE_UNUSED,
if (frag->tc_frag_data.is_branch_target)
{
int op_size;
- addressT frag_addr;
+ addressT branch_align, frag_addr;
xtensa_format fmt;
xtensa_insnbuf_from_chars
(isa, insnbuf, (unsigned char *) frag->fr_literal, 0);
fmt = xtensa_format_decode (isa, insnbuf);
op_size = xtensa_format_length (isa, fmt);
- frag_addr = frag->fr_address % xtensa_fetch_width;
- if (frag_addr + op_size > xtensa_fetch_width)
+ branch_align = 1 << branch_align_power (sec);
+ frag_addr = frag->fr_address % branch_align;
+ if (frag_addr + op_size > branch_align)
as_warn_where (frag->fr_file, frag->fr_line,
_("unaligned branch target: %d bytes at 0x%lx"),
op_size, frag->fr_address);
@@ -8006,6 +8008,27 @@ get_text_align_fill_size (addressT address,
}
+static int
+branch_align_power (segT sec)
+{
+ /* If the Xtensa processor has a fetch width of 8 bytes, and the section
+ is aligned to at least an 8-byte boundary, then a branch target need
+ only fit within an 8-byte aligned block of memory to avoid a stall.
+ Otherwise, try to fit branch targets within 4-byte aligned blocks
+ (which may be insufficient, e.g., if the section has no alignment, but
+ it's good enough). */
+ if (xtensa_fetch_width == 8)
+ {
+ if (get_recorded_alignment (sec) >= 3)
+ return 3;
+ }
+ else
+ assert (xtensa_fetch_width == 4);
+
+ return 2;
+}
+
+
/* This will assert if it is not possible. */
static int
@@ -8156,6 +8179,7 @@ get_aligned_diff (fragS *fragP, addressT address, offsetT *max_diff)
bfd_boolean is_loop;
int align_power;
offsetT opt_diff;
+ addressT branch_align;
assert (fragP->fr_type == rs_machine_dependent);
switch (fragP->fr_subtype)
@@ -8164,13 +8188,13 @@ get_aligned_diff (fragS *fragP, addressT address, offsetT *max_diff)
target_size = next_frag_format_size (fragP);
if (target_size == XTENSA_UNDEFINED)
target_size = 3;
- align_power = get_text_align_power (xtensa_fetch_width);
+ align_power = branch_align_power (now_seg);
+ branch_align = 1 << align_power;
opt_diff = get_text_align_fill_size (address, align_power,
target_size, FALSE, FALSE);
- *max_diff = (opt_diff + xtensa_fetch_width
- - (target_size + ((address + opt_diff)
- % xtensa_fetch_width)));
+ *max_diff = (opt_diff + branch_align
+ - (target_size + ((address + opt_diff) % branch_align)));
assert (*max_diff >= opt_diff);
return opt_diff;
@@ -8583,7 +8607,7 @@ future_alignment_required (fragS *fragP, long stretch ATTRIBUTE_UNUSED)
address = find_address_of_next_align_frag
(&fragP, &glob_widens, &dnn, &dw, &glob_pad);
/* If there is a padable portion, then skip. */
- if (glob_pad || glob_widens >= (int) xtensa_fetch_width)
+ if (glob_pad || glob_widens >= (1 << branch_align_power (now_seg)))
break;
if (address)