Skip to content

R
riscv-gcc-1
Commit 328f4006 by Bernd Schmidt Committed by Bernd Schmidt
Options

Reformat load_mems slightly. 

From-SVN: r30618
parent 19a027a0
Showing with 140 additions and 137 deletions
gcc/ChangeLog
1999-11-22 Bernd Schmidt <bernds@cygnus.co.uk>
* loop.c (load_mems): Reformat slightly.
1999-11-22 Bruce Korb <autogen@linuxbox.com
* fixinc/mkfisinc.sh(i?86-*-linux): disable script, run fixincl exe
......
gcc/loop.c
......@@ -9715,165 +9715,164 @@ load_mems (scan_start, end, loop_top, start)
rtx p;
rtx label = NULL_RTX;
rtx end_label = NULL_RTX;
/* Nonzero if the next instruction may never be executed. */
int next_maybe_never = 0;
if (loop_mems_idx > 0)
{
/* Nonzero if the next instruction may never be executed. */
int next_maybe_never = 0;
if (loop_mems_idx == 0)
return;
/* Check to see if it's possible that some instructions in the
loop are never executed. */
for (p = next_insn_in_loop (scan_start, scan_start, end, loop_top);
p != NULL_RTX && !maybe_never;
p = next_insn_in_loop (p, scan_start, end, loop_top))
/* Check to see if it's possible that some instructions in the
loop are never executed. */
for (p = next_insn_in_loop (scan_start, scan_start, end, loop_top);
p != NULL_RTX && !maybe_never;
p = next_insn_in_loop (p, scan_start, end, loop_top))
{
if (GET_CODE (p) == CODE_LABEL)
maybe_never = 1;
else if (GET_CODE (p) == JUMP_INSN
/* If we enter the loop in the middle, and scan
around to the beginning, don't set maybe_never
for that. This must be an unconditional jump,
otherwise the code at the top of the loop might
never be executed. Unconditional jumps are
followed a by barrier then loop end. */
&& ! (GET_CODE (p) == JUMP_INSN
&& JUMP_LABEL (p) == loop_top
&& NEXT_INSN (NEXT_INSN (p)) == end
&& simplejump_p (p)))
{
if (GET_CODE (p) == CODE_LABEL)
maybe_never = 1;
else if (GET_CODE (p) == JUMP_INSN
/* If we enter the loop in the middle, and scan
around to the beginning, don't set maybe_never
for that. This must be an unconditional jump,
otherwise the code at the top of the loop might
never be executed. Unconditional jumps are
followed a by barrier then loop end. */
&& ! (GET_CODE (p) == JUMP_INSN
&& JUMP_LABEL (p) == loop_top
&& NEXT_INSN (NEXT_INSN (p)) == end
&& simplejump_p (p)))
{
if (!condjump_p (p))
/* Something complicated. */
maybe_never = 1;
else
/* If there are any more instructions in the loop, they
might not be reached. */
next_maybe_never = 1;
}
else if (next_maybe_never)
if (!condjump_p (p))
/* Something complicated. */
maybe_never = 1;
}
else
/* If there are any more instructions in the loop, they
might not be reached. */
next_maybe_never = 1;
}
else if (next_maybe_never)
maybe_never = 1;
}
/* Actually move the MEMs. */
for (i = 0; i < loop_mems_idx; ++i)
{
int written = 0;
rtx reg;
rtx mem = loop_mems[i].mem;
rtx mem_list_entry;
/* Actually move the MEMs. */
for (i = 0; i < loop_mems_idx; ++i)
if (MEM_VOLATILE_P (mem)
|| invariant_p (XEXP (mem, 0)) != 1)
/* There's no telling whether or not MEM is modified. */
loop_mems[i].optimize = 0;
/* Go through the MEMs written to in the loop to see if this
one is aliased by one of them. */
mem_list_entry = loop_store_mems;
while (mem_list_entry)
{
int written = 0;
rtx reg;
rtx mem = loop_mems[i].mem;
rtx mem_list_entry;
if (MEM_VOLATILE_P (mem)
|| invariant_p (XEXP (mem, 0)) != 1)
/* There's no telling whether or not MEM is modified. */
loop_mems[i].optimize = 0;
/* Go through the MEMs written to in the loop to see if this
one is aliased by one of them. */
mem_list_entry = loop_store_mems;
while (mem_list_entry)
if (rtx_equal_p (mem, XEXP (mem_list_entry, 0)))
written = 1;
else if (true_dependence (XEXP (mem_list_entry, 0), VOIDmode,
mem, rtx_varies_p))
{
if (rtx_equal_p (mem, XEXP (mem_list_entry, 0)))
written = 1;
else if (true_dependence (XEXP (mem_list_entry, 0), VOIDmode,
mem, rtx_varies_p))
{
/* MEM is indeed aliased by this store. */
loop_mems[i].optimize = 0;
break;
}
mem_list_entry = XEXP (mem_list_entry, 1);
/* MEM is indeed aliased by this store. */
loop_mems[i].optimize = 0;
break;
}
mem_list_entry = XEXP (mem_list_entry, 1);
}
/* If this MEM is written to, we must be sure that there
are no reads from another MEM that aliases this one. */
if (loop_mems[i].optimize && written)
{
int j;
/* If this MEM is written to, we must be sure that there
are no reads from another MEM that aliases this one. */
if (loop_mems[i].optimize && written)
{
int j;
for (j = 0; j < loop_mems_idx; ++j)
for (j = 0; j < loop_mems_idx; ++j)
{
if (j == i)
continue;
else if (true_dependence (mem,
VOIDmode,
loop_mems[j].mem,
rtx_varies_p))
{
if (j == i)
continue;
else if (true_dependence (mem,
VOIDmode,
loop_mems[j].mem,
rtx_varies_p))
{
/* It's not safe to hoist loop_mems[i] out of
the loop because writes to it might not be
seen by reads from loop_mems[j]. */
loop_mems[i].optimize = 0;
break;
}
/* It's not safe to hoist loop_mems[i] out of
the loop because writes to it might not be
seen by reads from loop_mems[j]. */
loop_mems[i].optimize = 0;
break;
}
}
}
if (maybe_never && may_trap_p (mem))
/* We can't access the MEM outside the loop; it might
cause a trap that wouldn't have happened otherwise. */
loop_mems[i].optimize = 0;
if (maybe_never && may_trap_p (mem))
/* We can't access the MEM outside the loop; it might
cause a trap that wouldn't have happened otherwise. */
loop_mems[i].optimize = 0;
if (!loop_mems[i].optimize)
/* We thought we were going to lift this MEM out of the
loop, but later discovered that we could not. */
continue;
if (!loop_mems[i].optimize)
/* We thought we were going to lift this MEM out of the
loop, but later discovered that we could not. */
continue;
/* Allocate a pseudo for this MEM. We set REG_USERVAR_P in
order to keep scan_loop from moving stores to this MEM
out of the loop just because this REG is neither a
user-variable nor used in the loop test. */
reg = gen_reg_rtx (GET_MODE (mem));
REG_USERVAR_P (reg) = 1;
loop_mems[i].reg = reg;
/* Now, replace all references to the MEM with the
corresponding pesudos. */
for (p = next_insn_in_loop (scan_start, scan_start, end, loop_top);
p != NULL_RTX;
p = next_insn_in_loop (p, scan_start, end, loop_top))
{
rtx_and_int ri;
ri.r = p;
ri.i = i;
for_each_rtx (&p, replace_loop_mem, &ri);
}
/* Allocate a pseudo for this MEM. We set REG_USERVAR_P in
order to keep scan_loop from moving stores to this MEM
out of the loop just because this REG is neither a
user-variable nor used in the loop test. */
reg = gen_reg_rtx (GET_MODE (mem));
REG_USERVAR_P (reg) = 1;
loop_mems[i].reg = reg;
/* Now, replace all references to the MEM with the
corresponding pesudos. */
for (p = next_insn_in_loop (scan_start, scan_start, end, loop_top);
p != NULL_RTX;
p = next_insn_in_loop (p, scan_start, end, loop_top))
{
rtx_and_int ri;
ri.r = p;
ri.i = i;
for_each_rtx (&p, replace_loop_mem, &ri);
}
if (!apply_change_group ())
/* We couldn't replace all occurrences of the MEM. */
loop_mems[i].optimize = 0;
else
{
rtx set;
if (! apply_change_group ())
/* We couldn't replace all occurrences of the MEM. */
loop_mems[i].optimize = 0;
else
{
rtx set;
/* Load the memory immediately before START, which is
the NOTE_LOOP_BEG. */
set = gen_move_insn (reg, mem);
emit_insn_before (set, start);
/* Load the memory immediately before START, which is
the NOTE_LOOP_BEG. */
set = gen_move_insn (reg, mem);
emit_insn_before (set, start);
if (written)
if (written)
{
if (label == NULL_RTX)
{
if (label == NULL_RTX)
{
/* We must compute the former
right-after-the-end label before we insert
the new one. */
end_label = next_label (end);
label = gen_label_rtx ();
emit_label_after (label, end);
}
/* Store the memory immediately after END, which is
the NOTE_LOOP_END. */
set = gen_move_insn (copy_rtx (mem), reg);
emit_insn_after (set, label);
/* We must compute the former
right-after-the-end label before we insert
the new one. */
end_label = next_label (end);
label = gen_label_rtx ();
emit_label_after (label, end);
}
if (loop_dump_stream)
{
fprintf (loop_dump_stream, "Hoisted regno %d %s from ",
REGNO (reg), (written ? "r/w" : "r/o"));
print_rtl (loop_dump_stream, mem);
fputc ('\n', loop_dump_stream);
}
/* Store the memory immediately after END, which is
the NOTE_LOOP_END. */
set = gen_move_insn (copy_rtx (mem), reg);
emit_insn_after (set, label);
}
if (loop_dump_stream)
{
fprintf (loop_dump_stream, "Hoisted regno %d %s from ",
REGNO (reg), (written ? "r/w" : "r/o"));
print_rtl (loop_dump_stream, mem);
fputc ('\n', loop_dump_stream);
}
}
}
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment