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flow.c (find_basic_blocks): Emit NOPs after normal calls in this function.

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Tue Oct 13 22:12:11 1998  Bernd Schmidt <crux@pool.informatik.rwth-aachen.de>
        * flow.c (find_basic_blocks): Emit NOPs after normal calls in this
        function.
        Compute max_uid_for_flow by calling get_max_uid after the scan.
        (find_basic_blocks_1): Don't emit NOPs here.

From-SVN: r23061
This commit is contained in:
Bernd Schmidt 1998-10-13 22:19:54 +00:00 committed by Richard Henderson
parent 56ee928168
commit 27249135f3
2 changed files with 35 additions and 47 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
Tue Oct 13 22:12:11 1998 Bernd Schmidt <crux@pool.informatik.rwth-aachen.de>
* flow.c (find_basic_blocks): Emit NOPs after normal calls in this
function.
Compute max_uid_for_flow by calling get_max_uid after the scan.
(find_basic_blocks_1): Don't emit NOPs here.
Tue Oct 13 22:05:49 1998 Richard Henderson <rth@cygnus.com>
* alias.c (base_alias_check): Accept new args for the modes of the

75
gcc/flow.c
View File

@ -311,18 +311,16 @@ find_basic_blocks (f, nregs, file)
register int i;
rtx nonlocal_label_list = nonlocal_label_rtx_list ();
int in_libcall_block = 0;
int extra_uids_for_flow = 0;
/* Count the basic blocks. Also find maximum insn uid value used. */
{
rtx prev_call = 0;
register RTX_CODE prev_code = JUMP_INSN;
register RTX_CODE code;
int eh_region = 0;
int call_had_abnormal_edge = 0;
max_uid_for_flow = 0;
for (insn = f, i = 0; insn; insn = NEXT_INSN (insn))
{
/* Track when we are inside in LIBCALL block. */
@ -331,44 +329,41 @@ find_basic_blocks (f, nregs, file)
in_libcall_block = 1;
code = GET_CODE (insn);
if (INSN_UID (insn) > max_uid_for_flow)
max_uid_for_flow = INSN_UID (insn);
if (code == CODE_LABEL)
i++;
else if (GET_RTX_CLASS (code) == 'i')
/* A basic block starts at label, or after something that can jump. */
if (code == CODE_LABEL
|| (GET_RTX_CLASS (code) == 'i'
&& (prev_code == JUMP_INSN
|| (prev_code == CALL_INSN && call_had_abnormal_edge)
|| prev_code == BARRIER)))
{
if (prev_code == JUMP_INSN || prev_code == BARRIER)
i++;
else if (prev_code == CALL_INSN)
i++;
/* If the previous insn was a call that did not create an
abnormal edge, we want to add a nop so that the CALL_INSN
itself is not at basic_block_end. This allows us to easily
distinguish between normal calls and those which create
abnormal edges in the flow graph. */
if (i > 0 && !call_had_abnormal_edge && prev_call != 0)
{
if (call_had_abnormal_edge)
i++;
else
{
/* Else this call does not force a new block to be
created. However, it may still be the end of a basic
block if it is followed by a CODE_LABEL or a BARRIER.
To disambiguate calls which force new blocks to be
created from those which just happen to be at the end
of a block we insert nops during find_basic_blocks_1
after calls which are the last insn in a block by
chance. We must account for such insns in
max_uid_for_flow. */
extra_uids_for_flow++;
}
rtx nop = gen_rtx_USE (VOIDmode, const0_rtx);
emit_insn_after (nop, prev_call);
}
}
/* We change the code of the CALL_INSN, so that it won't start a
new block. */
if (code == CALL_INSN && in_libcall_block)
code = INSN;
/* Record whether this call created an edge. */
if (code == CALL_INSN)
call_had_abnormal_edge = (nonlocal_label_list != 0 || eh_region);
/* Record whether this call created an edge. */
if (code == CALL_INSN)
{
prev_call = insn;
call_had_abnormal_edge = (nonlocal_label_list != 0 || eh_region);
}
else if (code != NOTE && code != BARRIER)
prev_call = 0;
if (code != NOTE)
prev_code = code;
@ -385,12 +380,12 @@ find_basic_blocks (f, nregs, file)
n_basic_blocks = i;
max_uid_for_flow = get_max_uid ();
#ifdef AUTO_INC_DEC
/* Leave space for insns life_analysis makes in some cases for auto-inc.
These cases are rare, so we don't need too much space. */
max_uid_for_flow += max_uid_for_flow / 10;
#endif
max_uid_for_flow += extra_uids_for_flow;
/* Allocate some tables that last till end of compiling this function
and some needed only in find_basic_blocks and life_analysis. */
@ -513,20 +508,6 @@ find_basic_blocks_1 (f, nonlocal_labels)
if (LABEL_PRESERVE_P (insn))
block_live[i] = 1;
}
/* If the previous insn was a call that did not create an
abnormal edge, we want to add a nop so that the CALL_INSN
itself is not at basic_block_end. This allows us to easily
distinguish between normal calls and those which create
abnormal edges in the flow graph. */
if (i > 0 && !call_had_abnormal_edge
&& GET_CODE (basic_block_end[i-1]) == CALL_INSN)
{
rtx nop = gen_rtx_USE (VOIDmode, const0_rtx);
nop = emit_insn_after (nop, basic_block_end[i-1]);
basic_block_end[i-1] = nop;
}
}
else if (GET_RTX_CLASS (code) == 'i')