aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorBob Wilson <bob.wilson@acm.org>2005-03-29 00:26:00 +0000
committerBob Wilson <bob.wilson@acm.org>2005-03-29 00:26:00 +0000
commit7b1cc37781c2f9d9fad7553e8047c8da7c03b895 (patch)
tree45dd863b906c4996e07035032ecb9eccb256937b
parente78c98404ff015302e68446d05cfdbfa161efb08 (diff)
downloadgdb-7b1cc37781c2f9d9fad7553e8047c8da7c03b895.zip
gdb-7b1cc37781c2f9d9fad7553e8047c8da7c03b895.tar.gz
gdb-7b1cc37781c2f9d9fad7553e8047c8da7c03b895.tar.bz2
* config/tc-xtensa.c (do_align_targets): Update comment.
(xtensa_frob_label): Compute "freq" before possibly switching frags. Insert a LOOP_END frag before every loop target, and do not overload DESIRE_ALIGN_IF_TARGET frags with loop end information. (xg_assemble_vliw_tokens): Use do_align_targets. (xtensa_fix_target_frags): Remove code to convert a DESIRE_ALIGN_IF_TARGET frag to a LOOP_END frag when there is a negatable branch at the end of a loop. (frag_can_negate_branch): Delete.
-rw-r--r--gas/ChangeLog16
-rw-r--r--gas/config/tc-xtensa.c98
2 files changed, 37 insertions, 77 deletions
diff --git a/gas/ChangeLog b/gas/ChangeLog
index 3fef8de..f45d925 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,16 @@
+2005-03-28 Sterling Augustine <sterling@tensilica.com>
+ Bob Wilson <bob.wilson@acm.org>
+
+ * config/tc-xtensa.c (do_align_targets): Update comment.
+ (xtensa_frob_label): Compute "freq" before possibly switching frags.
+ Insert a LOOP_END frag before every loop target, and do not overload
+ DESIRE_ALIGN_IF_TARGET frags with loop end information.
+ (xg_assemble_vliw_tokens): Use do_align_targets.
+ (xtensa_fix_target_frags): Remove code to convert a
+ DESIRE_ALIGN_IF_TARGET frag to a LOOP_END frag when there is a
+ negatable branch at the end of a loop.
+ (frag_can_negate_branch): Delete.
+
2005-03-28 David Mosberger <davidm@hpl.hp.com>
H.J. Lu <hongjiu.lu@intel.com>
@@ -307,7 +320,8 @@
* configure: Regenerate.
* config/obj-vms.h, config/obj-vms.c, config/vms-conf.h: Remove.
-2005-03-10 Bob Wilson <bob.wilson@acm.org>
+2005-03-10 Sterling Augustine <sterling@tensilica.com>
+ Bob Wilson <bob.wilson@acm.org>
* config/tc-xtensa.c (finish_vinsn): Include the last instruction slot
when checking if xg_resolve_literals needs to be called.
diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
index 0bebbd0..907029f 100644
--- a/gas/config/tc-xtensa.c
+++ b/gas/config/tc-xtensa.c
@@ -1033,8 +1033,9 @@ use_transform (void)
static bfd_boolean
do_align_targets (void)
{
- /* After md_end, you should be checking frag by frag, rather
- than state directives. */
+ /* Do not use this function after md_end; just look at align_targets
+ instead. There is no target-align directive, so alignment is either
+ enabled for all frags or not done at all. */
assert (!past_xtensa_end);
return align_targets && use_transform ();
}
@@ -4525,7 +4526,7 @@ update_next_frag_state (fragS *fragP)
fragS *next_fragP = fragP->fr_next;
fragS *new_target = NULL;
- if (align_targets)
+ if (align_targets)
{
/* We are guaranteed there will be one of these... */
while (!(next_fragP->fr_type == rs_machine_dependent
@@ -5077,6 +5078,8 @@ xtensa_init_fix_data (fixS *x)
void
xtensa_frob_label (symbolS *sym)
{
+ float freq = get_subseg_target_freq (now_seg, now_subseg);
+
/* Since the label was already attached to a frag associated with the
previous basic block, it now needs to be reset to the current frag. */
symbol_set_frag (sym, frag_now);
@@ -5087,10 +5090,19 @@ xtensa_frob_label (symbolS *sym)
else
xtensa_add_insn_label (sym);
- if (symbol_get_tc (sym)->is_loop_target
- && (get_last_insn_flags (now_seg, now_subseg)
+ if (symbol_get_tc (sym)->is_loop_target)
+ {
+ if ((get_last_insn_flags (now_seg, now_subseg)
& FLAG_IS_BAD_LOOPEND) != 0)
- as_bad (_("invalid last instruction for a zero-overhead loop"));
+ as_bad (_("invalid last instruction for a zero-overhead loop"));
+
+ xtensa_set_frag_assembly_state (frag_now);
+ frag_var (rs_machine_dependent, 4, 4, RELAX_LOOP_END,
+ frag_now->fr_symbol, frag_now->fr_offset, NULL);
+
+ xtensa_set_frag_assembly_state (frag_now);
+ xtensa_move_labels (frag_now, 0, TRUE);
+ }
/* No target aligning in the absolute section. */
if (now_seg != absolute_section
@@ -5098,26 +5110,10 @@ xtensa_frob_label (symbolS *sym)
&& !is_unaligned_label (sym)
&& !generating_literals)
{
- float freq = get_subseg_target_freq (now_seg, now_subseg);
xtensa_set_frag_assembly_state (frag_now);
- /* The only time this type of frag grows is when there is a
- negatable branch that needs to be relaxed as the last
- instruction in a zero-overhead loop. Because alignment frags
- are so common, marking them all as possibly growing four
- bytes makes any worst-case analysis appear much worse than it
- is. So, we make fr_var not actually reflect the amount of
- memory allocated at the end of this frag, but rather the
- amount of memory this frag might grow. The "4, 0" below
- allocates four bytes at the end of the frag for room to grow
- if we need to relax a loop end with a NOP. Frags prior to
- this one might grow to align this one, but the frag itself
- won't grow unless it meets the condition above. */
-
-#define RELAX_LOOP_END_BYTES 4
-
frag_var (rs_machine_dependent,
- RELAX_LOOP_END_BYTES, (int) freq,
+ 0, (int) freq,
RELAX_DESIRE_ALIGN_IF_TARGET,
frag_now->fr_symbol, frag_now->fr_offset, NULL);
xtensa_set_frag_assembly_state (frag_now);
@@ -6937,7 +6933,7 @@ xg_assemble_vliw_tokens (vliw_insn *vinsn)
frag_now->fr_symbol, frag_now->fr_offset, NULL);
xtensa_set_frag_assembly_state (frag_now);
}
- else if (is_branch && align_targets)
+ else if (is_branch && do_align_targets ())
{
assert (finish_frag);
frag_var (rs_machine_dependent,
@@ -7064,11 +7060,7 @@ xtensa_cleanup_align_frags (void)
/* Re-process all of the fragments looking to convert all of the
RELAX_DESIRE_ALIGN_IF_TARGET fragments. If there is a branch
target in the next fragment, convert this to RELAX_DESIRE_ALIGN.
- If the next fragment starts with a loop target, AND the previous
- fragment can be expanded to negate the branch, convert this to a
- RELAX_LOOP_END. Otherwise, convert to a .fill 0. */
-
-static bfd_boolean frag_can_negate_branch (fragS *);
+ Otherwise, convert to a .fill 0. */
static void
xtensa_fix_target_frags (void)
@@ -7079,7 +7071,6 @@ xtensa_fix_target_frags (void)
so we walk over subsections instead of sections. */
for (frchP = frchain_root; frchP; frchP = frchP->frch_next)
{
- bfd_boolean prev_frag_can_negate_branch = FALSE;
fragS *fragP;
/* Walk over all of the fragments in a subsection. */
@@ -7088,61 +7079,16 @@ xtensa_fix_target_frags (void)
if (fragP->fr_type == rs_machine_dependent
&& fragP->fr_subtype == RELAX_DESIRE_ALIGN_IF_TARGET)
{
- if (next_frag_is_loop_target (fragP))
- {
- if (prev_frag_can_negate_branch)
- {
- fragP->fr_subtype = RELAX_LOOP_END;
- /* See the comment near the frag_var with a
- RELAX_DESIRE_ALIGN to see why we do this. */
- fragP->fr_var = RELAX_LOOP_END_BYTES;
- }
- else
- {
- if (next_frag_is_branch_target (fragP))
- fragP->fr_subtype = RELAX_DESIRE_ALIGN;
- else
- frag_wane (fragP);
- }
- }
- else if (next_frag_is_branch_target (fragP))
+ if (next_frag_is_branch_target (fragP))
fragP->fr_subtype = RELAX_DESIRE_ALIGN;
else
frag_wane (fragP);
}
- if (fragP->fr_fix != 0)
- prev_frag_can_negate_branch = FALSE;
- if (frag_can_negate_branch (fragP))
- prev_frag_can_negate_branch = TRUE;
}
}
}
-static bfd_boolean
-frag_can_negate_branch (fragS *fragP)
-{
- xtensa_isa isa = xtensa_default_isa;
- vliw_insn vinsn;
- int slot;
-
- if (fragP->fr_type != rs_machine_dependent
- || fragP->fr_subtype != RELAX_SLOTS)
- return FALSE;
-
- vinsn_from_chars (&vinsn, fragP->fr_opcode);
-
- for (slot = 0; slot < xtensa_format_num_slots (isa, vinsn.format); slot++)
- {
- if ((fragP->tc_frag_data.slot_subtypes[slot] == RELAX_IMMED)
- && xtensa_opcode_is_branch (isa, vinsn.slots[slot].opcode) == 1)
- return TRUE;
- }
-
- return FALSE;
-}
-
-
static bfd_boolean is_narrow_branch_guaranteed_in_range (fragS *, TInsn *);
static void