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BB boundary problem in regmove.c
- To: gcc-patches at gcc dot gnu dot org
- Subject: BB boundary problem in regmove.c
- From: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
- Date: Fri, 18 Aug 00 15:07:28 EDT
In quite a few places, regmove.c tries to determine if it is going outside
of a basic block. However, the test in the CALL_INSN case is not correct
since it ignores nonlocal_goto_handler_labels.
I made a function to test for this, added the missing test, and changed
all the code that tests to use the function.
This test is conservative, and necessarily so. Therefore, it would be nice
if somebody would rewrite this to use the BB data structures sometime.
In the meantime, I checked in the following:
Fri Aug 18 14:23:18 2000 Richard Kenner <kenner@vlsi1.ultra.nyu.edu>
* regmove.c (perhaps_ends_bb_p): New function.
(optimize_reg_copy_1, optimize_reg_copy_2): Call it.
(optimize_reg_copy_3, fixup_match_2, regmove_optimize): Likewise.
(fixup_match_1): Likewise.
(fixup_match_1, combine_stack_adjustments_for_block): Add casts to
avoid signed/unsigned warnings.
*** regmove.c 2000/08/04 20:28:05 1.89
--- regmove.c 2000/08/18 17:57:17
*************** Boston, MA 02111-1307, USA. */
*** 42,45 ****
--- 42,46 ----
#include "toplev.h"
+ static int perhaps_ends_bb_p PARAMS ((rtx));
static int optimize_reg_copy_1 PARAMS ((rtx, rtx, rtx));
static void optimize_reg_copy_2 PARAMS ((rtx, rtx, rtx));
*************** replacement_quality(reg)
*** 368,372 ****
--- 369,397 ----
return 2;
}
+
+ /* Return 1 if INSN might end a basic block. */
+
+ static int perhaps_ends_bb_p (insn)
+ rtx insn;
+ {
+ switch (GET_CODE (insn))
+ {
+ case CODE_LABEL:
+ case JUMP_INSN:
+ /* These always end a basic block. */
+ return 1;
+ case CALL_INSN:
+ /* A CALL_INSN might be the last insn of a basic block, if it is inside
+ an EH region or if there are nonlocal gotos. Note that this test is
+ very conservative. */
+ return flag_exceptions || nonlocal_goto_handler_labels;
+
+ default:
+ /* All others never end a basic block. */
+ return 0;
+ }
+ }
+
/* INSN is a copy from SRC to DEST, both registers, and SRC does not die
in INSN.
*************** optimize_reg_copy_1 (insn, dest, src)
*** 404,419 ****
for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
{
- if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN)
- break;
-
/* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start).
! A CALL_INSN might be the last insn of a basic block, if it is inside
! an EH region. There is no easy way to tell, so we just always break
! when we see a CALL_INSN if flag_exceptions is nonzero. */
! if (flag_exceptions && GET_CODE (p) == CALL_INSN)
break;
!
! if (! INSN_P (p))
continue;
--- 429,437 ----
for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
{
/* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start). */
! if (perhaps_ends_bb_p (p))
break;
! else if (! INSN_P (p))
continue;
*************** optimize_reg_copy_2 (insn, dest, src)
*** 589,604 ****
for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
{
- if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN)
- break;
-
/* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start).
! A CALL_INSN might be the last insn of a basic block, if it is inside
! an EH region. There is no easy way to tell, so we just always break
! when we see a CALL_INSN if flag_exceptions is nonzero. */
! if (flag_exceptions && GET_CODE (p) == CALL_INSN)
break;
!
! if (! INSN_P (p))
continue;
--- 607,615 ----
for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
{
/* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start). */
! if (perhaps_ends_bb_p (p))
break;
! else if (! INSN_P (p))
continue;
*************** optimize_reg_copy_3 (insn, dest, src)
*** 662,680 ****
return;
for (p = PREV_INSN (insn); p && ! reg_set_p (src_reg, p); p = PREV_INSN (p))
! {
! if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN)
! return;
!
! /* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start).
! A CALL_INSN might be the last insn of a basic block, if it is inside
! an EH region. There is no easy way to tell, so we just always break
! when we see a CALL_INSN if flag_exceptions is nonzero. */
! if (flag_exceptions && GET_CODE (p) == CALL_INSN)
! return;
- if (! INSN_P (p))
- continue;
- }
if (! p)
return;
--- 673,681 ----
return;
for (p = PREV_INSN (insn); p && ! reg_set_p (src_reg, p); p = PREV_INSN (p))
! /* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start). */
! if (perhaps_ends_bb_p (p))
! break;
if (! p)
return;
*************** fixup_match_2 (insn, dst, src, offset, r
*** 941,957 ****
rtx pset;
- if (GET_CODE (p) == CODE_LABEL
- || GET_CODE (p) == JUMP_INSN)
- break;
-
/* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start).
! A CALL_INSN might be the last insn of a basic block, if it is inside
! an EH region. There is no easy way to tell, so we just always break
! when we see a CALL_INSN if flag_exceptions is nonzero. */
! if (flag_exceptions && GET_CODE (p) == CALL_INSN)
break;
!
! if (! INSN_P (p))
continue;
--- 942,950 ----
rtx pset;
/* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start). */
! if (perhaps_ends_bb_p (p))
break;
! else if (! INSN_P (p))
continue;
*************** regmove_optimize (f, nregs, regmove_dump
*** 1371,1389 ****
rtx pset;
- if (GET_CODE (p) == CODE_LABEL
- || GET_CODE (p) == JUMP_INSN)
- break;
-
/* ??? We can't scan past the end of a basic block without
updating the register lifetime info
! (REG_DEAD/basic_block_live_at_start).
! A CALL_INSN might be the last insn of a basic block, if
! it is inside an EH region. There is no easy way to tell,
! so we just always break when we see a CALL_INSN if
! flag_exceptions is nonzero. */
! if (flag_exceptions && GET_CODE (p) == CALL_INSN)
break;
!
! if (! INSN_P (p))
continue;
--- 1364,1373 ----
rtx pset;
/* ??? We can't scan past the end of a basic block without
updating the register lifetime info
! (REG_DEAD/basic_block_live_at_start). */
! if (perhaps_ends_bb_p (p))
break;
! else if (! INSN_P (p))
continue;
*************** find_matches (insn, matchp)
*** 1594,1597 ****
--- 1578,1582 ----
If BACKWARD is nonzero, we have been called in a backward pass.
Return nonzero for success. */
+
static int
fixup_match_1 (insn, set, src, src_subreg, dst, backward, operand_number,
*************** fixup_match_1 (insn, set, src, src_subre
*** 1659,1674 ****
for (length = s_length = 0, p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
{
- if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN)
- break;
-
/* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start).
! A CALL_INSN might be the last insn of a basic block, if it is
! inside an EH region. There is no easy way to tell, so we just
! always break when we see a CALL_INSN if flag_exceptions is nonzero. */
! if (flag_exceptions && GET_CODE (p) == CALL_INSN)
break;
!
! if (! INSN_P (p))
continue;
--- 1644,1652 ----
for (length = s_length = 0, p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
{
/* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start). */
! if (perhaps_ends_bb_p (p))
break;
! else if (! INSN_P (p))
continue;
*************** fixup_match_1 (insn, set, src, src_subre
*** 1705,1731 ****
for (q = p; q; q = NEXT_INSN (q))
{
- if (GET_CODE (q) == CODE_LABEL || GET_CODE (q) == JUMP_INSN)
- {
- q = 0;
- break;
- }
-
/* ??? We can't scan past the end of a basic block without
updating the register lifetime info
! (REG_DEAD/basic_block_live_at_start).
! A CALL_INSN might be the last insn of a basic block, if
! it is inside an EH region. There is no easy way to tell,
! so we just always break when we see a CALL_INSN if
! flag_exceptions is nonzero. */
! if (flag_exceptions && GET_CODE (q) == CALL_INSN)
{
q = 0;
break;
}
!
! if (! INSN_P (q))
continue;
! if (reg_overlap_mentioned_p (src, PATTERN (q))
! || reg_set_p (src, q))
break;
}
--- 1683,1698 ----
for (q = p; q; q = NEXT_INSN (q))
{
/* ??? We can't scan past the end of a basic block without
updating the register lifetime info
! (REG_DEAD/basic_block_live_at_start). */
! if (perhaps_ends_bb_p (q))
{
q = 0;
break;
}
! else if (! INSN_P (q))
continue;
! else if (reg_overlap_mentioned_p (src, PATTERN (q))
! || reg_set_p (src, q))
break;
}
*************** fixup_match_1 (insn, set, src, src_subre
*** 1772,1777 ****
if (code != PLUS
&& (newconst < 0
! || (newconst
! >= GET_MODE_BITSIZE (GET_MODE (SET_SRC (set2))))))
break;
if (code == PLUS)
--- 1739,1745 ----
if (code != PLUS
&& (newconst < 0
! || ((unsigned HOST_WIDE_INT) newconst
! >= (GET_MODE_BITSIZE (GET_MODE
! (SET_SRC (set2)))))))
break;
if (code == PLUS)
*************** fixup_match_1 (insn, set, src, src_subre
*** 1880,1904 ****
for (q = PREV_INSN (insn); q; q = PREV_INSN(q))
{
- if (GET_CODE (q) == CODE_LABEL || GET_CODE (q) == JUMP_INSN)
- {
- q = 0;
- break;
- }
-
/* ??? We can't scan past the end of a basic block without
updating the register lifetime info
! (REG_DEAD/basic_block_live_at_start).
! A CALL_INSN might be the last insn of a basic block, if
! it is inside an EH region. There is no easy way to tell,
! so we just always break when we see a CALL_INSN if
! flag_exceptions is nonzero. */
! if (flag_exceptions && GET_CODE (q) == CALL_INSN)
{
q = 0;
break;
}
!
! if (! INSN_P (q))
continue;
s_length2++;
if (reg_set_p (src, q))
--- 1848,1862 ----
for (q = PREV_INSN (insn); q; q = PREV_INSN(q))
{
/* ??? We can't scan past the end of a basic block without
updating the register lifetime info
! (REG_DEAD/basic_block_live_at_start). */
! if (perhaps_ends_bb_p (q))
{
q = 0;
break;
}
! else if (! INSN_P (q))
continue;
+
s_length2++;
if (reg_set_p (src, q))
*************** fixup_match_1 (insn, set, src, src_subre
*** 1952,1975 ****
for (q = post_inc; (q = NEXT_INSN (q)); )
{
- if (GET_CODE (q) == CODE_LABEL || GET_CODE (q) == JUMP_INSN)
- break;
-
/* ??? We can't scan past the end of a basic block without updating
! the register lifetime info (REG_DEAD/basic_block_live_at_start).
! A CALL_INSN might be the last insn of a basic block, if it
! is inside an EH region. There is no easy way to tell so we
! just always break when we see a CALL_INSN if flag_exceptions
! is nonzero. */
! if (flag_exceptions && GET_CODE (q) == CALL_INSN)
break;
!
! if (! INSN_P (q))
continue;
! if (src != inc_dest && (reg_overlap_mentioned_p (src, PATTERN (q))
! || reg_set_p (src, q)))
break;
! if (reg_set_p (inc_dest, q))
break;
! if (reg_overlap_mentioned_p (inc_dest, PATTERN (q)))
{
try_auto_increment (q, post_inc,
--- 1910,1927 ----
for (q = post_inc; (q = NEXT_INSN (q)); )
{
/* ??? We can't scan past the end of a basic block without updating
! the register lifetime info
! (REG_DEAD/basic_block_live_at_start). */
! if (perhaps_ends_bb_p (q))
break;
! else if (! INSN_P (q))
continue;
! else if (src != inc_dest
! && (reg_overlap_mentioned_p (src, PATTERN (q))
! || reg_set_p (src, q)))
break;
! else if (reg_set_p (inc_dest, q))
break;
! else if (reg_overlap_mentioned_p (inc_dest, PATTERN (q)))
{
try_auto_increment (q, post_inc,
*************** fixup_match_1 (insn, set, src, src_subre
*** 1979,1982 ****
--- 1931,1935 ----
}
}
+
/* Move the death note for DST to INSN if it is used
there. */
*************** combine_stack_adjustments_for_block (bb)
*** 2388,2392 ****
there were any intervening uses of the stack pointer. */
if (memlist == NULL
! && last_sp_adjust == GET_MODE_SIZE (GET_MODE (dest))
&& GET_CODE (dest) == MEM
&& GET_CODE (XEXP (dest, 0)) == PRE_DEC
--- 2341,2346 ----
there were any intervening uses of the stack pointer. */
if (memlist == NULL
! && (last_sp_adjust
! == (HOST_WIDE_INT) GET_MODE_SIZE (GET_MODE (dest)))
&& GET_CODE (dest) == MEM
&& GET_CODE (XEXP (dest, 0)) == PRE_DEC