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Re: DFA scheduling bug?
Vladimir Makarov wrote:
>
> Dan Towner wrote:
> >
> > Hi all,
> >
> > I have encountered a problem with the DFA scheduler, for a 16-bit DSP
> > port of gcc, in which an invalid schedule is generated.
> >
>
> It is probably one of my patches. Could you sent me dump files before
> the insn scheduling and after that using -fsched-verbose=5. I'll look
> at that and try to fix it.
I can not reproduce the problem on other gcc ports. So could you try
the following patch. If it solves the problem, I'll submit it to public
gcc.
Thanks in advance,
Vlad
Index: sched-deps.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/sched-deps.c,v
retrieving revision 1.56
diff -c -p -r1.56 sched-deps.c
*** sched-deps.c 11 Mar 2003 09:17:38 -0000 1.56
--- sched-deps.c 27 Mar 2003 14:56:17 -0000
*************** static regset_head reg_pending_uses_head
*** 54,60 ****
static regset reg_pending_sets;
static regset reg_pending_clobbers;
static regset reg_pending_uses;
! static bool reg_pending_barrier;
/* To speed up the test for duplicate dependency links we keep a
record of dependencies created by add_dependence when the average
--- 54,68 ----
static regset reg_pending_sets;
static regset reg_pending_clobbers;
static regset reg_pending_uses;
!
! enum reg_pending_barrier_mode
! {
! NOT_A_BARRIER = 0,
! MOVE_BARRIER,
! TRUE_BARRIER
! };
!
! static enum reg_pending_barrier_mode reg_pending_barrier;
/* To speed up the test for duplicate dependency links we keep a
record of dependencies created by add_dependence when the average
*************** sched_analyze_2 (deps, x, insn)
*** 748,754 ****
mode. An insn should not be moved across this even if it only uses
pseudo-regs because it might give an incorrectly rounded result. */
if (code != ASM_OPERANDS || MEM_VOLATILE_P (x))
! reg_pending_barrier = true;
/* For all ASM_OPERANDS, we must traverse the vector of input operands.
We can not just fall through here since then we would be confused
--- 756,762 ----
mode. An insn should not be moved across this even if it only uses
pseudo-regs because it might give an incorrectly rounded result. */
if (code != ASM_OPERANDS || MEM_VOLATILE_P (x))
! reg_pending_barrier = TRUE_BARRIER;
/* For all ASM_OPERANDS, we must traverse the vector of input operands.
We can not just fall through here since then we would be confused
*************** sched_analyze_insn (deps, x, insn, loop_
*** 867,873 ****
sched_analyze_2 (deps, XEXP (link, 0), insn);
}
if (find_reg_note (insn, REG_SETJMP, NULL))
! reg_pending_barrier = true;
}
if (GET_CODE (insn) == JUMP_INSN)
--- 875,881 ----
sched_analyze_2 (deps, XEXP (link, 0), insn);
}
if (find_reg_note (insn, REG_SETJMP, NULL))
! reg_pending_barrier = MOVE_BARRIER;
}
if (GET_CODE (insn) == JUMP_INSN)
*************** sched_analyze_insn (deps, x, insn, loop_
*** 875,881 ****
rtx next;
next = next_nonnote_insn (insn);
if (next && GET_CODE (next) == BARRIER)
! reg_pending_barrier = true;
else
{
rtx pending, pending_mem;
--- 883,889 ----
rtx next;
next = next_nonnote_insn (insn);
if (next && GET_CODE (next) == BARRIER)
! reg_pending_barrier = TRUE_BARRIER;
else
{
rtx pending, pending_mem;
*************** sched_analyze_insn (deps, x, insn, loop_
*** 940,946 ****
|| INTVAL (XEXP (link, 0)) == NOTE_INSN_LOOP_END
|| INTVAL (XEXP (link, 0)) == NOTE_INSN_EH_REGION_BEG
|| INTVAL (XEXP (link, 0)) == NOTE_INSN_EH_REGION_END)
! reg_pending_barrier = true;
link = XEXP (link, 1);
}
--- 948,954 ----
|| INTVAL (XEXP (link, 0)) == NOTE_INSN_LOOP_END
|| INTVAL (XEXP (link, 0)) == NOTE_INSN_EH_REGION_BEG
|| INTVAL (XEXP (link, 0)) == NOTE_INSN_EH_REGION_END)
! reg_pending_barrier = MOVE_BARRIER;
link = XEXP (link, 1);
}
*************** sched_analyze_insn (deps, x, insn, loop_
*** 952,958 ****
where block boundaries fall. This is mighty confusing elsewhere.
Therefore, prevent such an instruction from being moved. */
if (can_throw_internal (insn))
! reg_pending_barrier = true;
/* Add dependencies if a scheduling barrier was found. */
if (reg_pending_barrier)
--- 960,966 ----
where block boundaries fall. This is mighty confusing elsewhere.
Therefore, prevent such an instruction from being moved. */
if (can_throw_internal (insn))
! reg_pending_barrier = MOVE_BARRIER;
/* Add dependencies if a scheduling barrier was found. */
if (reg_pending_barrier)
*************** sched_analyze_insn (deps, x, insn, loop_
*** 965,972 ****
{
struct deps_reg *reg_last = &deps->reg_last[i];
add_dependence_list (insn, reg_last->uses, REG_DEP_ANTI);
! add_dependence_list (insn, reg_last->sets, REG_DEP_ANTI);
! add_dependence_list (insn, reg_last->clobbers, REG_DEP_ANTI);
});
}
else
--- 973,984 ----
{
struct deps_reg *reg_last = &deps->reg_last[i];
add_dependence_list (insn, reg_last->uses, REG_DEP_ANTI);
! add_dependence_list
! (insn, reg_last->sets,
! reg_pending_barrier == TRUE_BARRIER ? 0 : REG_DEP_ANTI);
! add_dependence_list
! (insn, reg_last->clobbers,
! reg_pending_barrier == TRUE_BARRIER ? 0 : REG_DEP_ANTI);
});
}
else
*************** sched_analyze_insn (deps, x, insn, loop_
*** 976,985 ****
struct deps_reg *reg_last = &deps->reg_last[i];
add_dependence_list_and_free (insn, ®_last->uses,
REG_DEP_ANTI);
! add_dependence_list_and_free (insn, ®_last->sets,
! REG_DEP_ANTI);
! add_dependence_list_and_free (insn, ®_last->clobbers,
! REG_DEP_ANTI);
reg_last->uses_length = 0;
reg_last->clobbers_length = 0;
});
--- 988,999 ----
struct deps_reg *reg_last = &deps->reg_last[i];
add_dependence_list_and_free (insn, ®_last->uses,
REG_DEP_ANTI);
! add_dependence_list_and_free
! (insn, ®_last->sets,
! reg_pending_barrier == TRUE_BARRIER ? 0 : REG_DEP_ANTI);
! add_dependence_list_and_free
! (insn, ®_last->clobbers,
! reg_pending_barrier == TRUE_BARRIER ? 0 : REG_DEP_ANTI);
reg_last->uses_length = 0;
reg_last->clobbers_length = 0;
});
*************** sched_analyze_insn (deps, x, insn, loop_
*** 993,999 ****
}
flush_pending_lists (deps, insn, true, true);
! reg_pending_barrier = false;
}
else
{
--- 1007,1013 ----
}
flush_pending_lists (deps, insn, true, true);
! reg_pending_barrier = NOT_A_BARRIER;
}
else
{
*************** sched_analyze (deps, head, tail)
*** 1190,1196 ****
{
/* This is setjmp. Assume that all registers, not just
hard registers, may be clobbered by this call. */
! reg_pending_barrier = true;
}
else
{
--- 1204,1210 ----
{
/* This is setjmp. Assume that all registers, not just
hard registers, may be clobbered by this call. */
! reg_pending_barrier = MOVE_BARRIER;
}
else
{
*************** init_deps_global ()
*** 1505,1511 ****
reg_pending_sets = INITIALIZE_REG_SET (reg_pending_sets_head);
reg_pending_clobbers = INITIALIZE_REG_SET (reg_pending_clobbers_head);
reg_pending_uses = INITIALIZE_REG_SET (reg_pending_uses_head);
! reg_pending_barrier = false;
}
/* Free everything used by the dependency analysis code. */
--- 1519,1525 ----
reg_pending_sets = INITIALIZE_REG_SET (reg_pending_sets_head);
reg_pending_clobbers = INITIALIZE_REG_SET (reg_pending_clobbers_head);
reg_pending_uses = INITIALIZE_REG_SET (reg_pending_uses_head);
! reg_pending_barrier = NOT_A_BARRIER;
}
/* Free everything used by the dependency analysis code. */