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riscv-gcc-1
Commit ecb75b7a by Michael Meissner Committed by Michael Meissner
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For regmove if we could not improve code by changing the source to the… 

For regmove if we could not improve code by changing the source to the destination, copy the source to the destination directly

From-SVN: r20427
parent 8e34149d
Showing with 163 additions and 13 deletions
gcc/ChangeLog
Thu Jun 11 14:50:02 1998 Michael Meissner <meissner@cygnus.com>
* regmove.c (regmove_optimize): If we can't replace the
destination in an insn that sets the source, generate an explicit
move of the source to the destination.
(copy_src_to_dest): New function.
(toplevel): Include basic-block.h
* Makefile.in (regmove.o): Add basic-block.h dependencies.
Thu Jun 11 10:30:09 1998 Dave Brolley <brolley@cygnus.com>
* toplev.c (lang_options): Add missing options (nostdinc, idirafter).
......
gcc/Makefile.in
......@@ -1461,7 +1461,7 @@ alias.o : alias.c $(CONFIG_H) system.h $(RTL_H) flags.h hard-reg-set.h regs.h \
insn-codes.h
regmove.o : regmove.c $(CONFIG_H) system.h $(RTL_H) insn-config.h \
insn-codes.h recog.h output.h reload.h regs.h hard-reg-set.h flags.h \
expr.h insn-flags.h
expr.h insn-flags.h $(BASIC_BLOCK_H)
$(SCHED_PREFIX)sched.o : $(SCHED_PREFIX)sched.c $(CONFIG_H) system.h $(RTL_H) \
$(BASIC_BLOCK_H) regs.h hard-reg-set.h flags.h insn-config.h insn-attr.h \
toplev.h
......
gcc/regmove.c
......@@ -43,11 +43,14 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "flags.h"
#include "expr.h"
#include "insn-flags.h"
#include "basic-block.h"
static int optimize_reg_copy_1 PROTO((rtx, rtx, rtx));
static void optimize_reg_copy_2 PROTO((rtx, rtx, rtx));
static void optimize_reg_copy_3 PROTO((rtx, rtx, rtx));
static rtx gen_add3_insn PROTO((rtx, rtx, rtx));
static void copy_src_to_dest PROTO((rtx, rtx, rtx, int));
static int *regmove_bb_head;
struct match {
int with[MAX_RECOG_OPERANDS];
......@@ -528,6 +531,98 @@ optimize_reg_copy_3 (insn, dest, src)
validate_replace_rtx (src, src_reg, insn);
}
/* If we were not able to update the users of src to use dest directly, try
instead moving the value to dest directly before the operation. */
void
copy_src_to_dest (insn, src, dest, loop_depth)
rtx insn;
rtx src;
rtx dest;
{
rtx seq;
rtx link;
rtx next;
rtx set;
rtx move_insn;
rtx *p_insn_notes;
rtx *p_move_notes;
int i;
int src_regno;
int dest_regno;
int bb;
int insn_uid;
int move_uid;
if (GET_CODE (src) == REG && GET_CODE (dest) == REG
&& (set = single_set (insn)) != NULL_RTX
&& !reg_mentioned_p (dest, SET_SRC (set))
&& validate_replace_rtx (src, dest, insn))
{
/* Generate the src->dest move. */
start_sequence ();
emit_move_insn (dest, src);
seq = gen_sequence ();
end_sequence ();
emit_insn_before (seq, insn);
move_insn = PREV_INSN (insn);
p_move_notes = &REG_NOTES (move_insn);
p_insn_notes = &REG_NOTES (insn);
/* Move any notes mentioning src to the move instruction */
for (link = REG_NOTES (insn); link != NULL_RTX; link = next)
{
next = XEXP (link, 1);
if (XEXP (link, 0) == src)
{
*p_move_notes = link;
p_move_notes = &XEXP (link, 1);
}
else
{
*p_insn_notes = link;
p_insn_notes = &XEXP (link, 1);
}
}
*p_move_notes = NULL_RTX;
*p_insn_notes = NULL_RTX;
/* Is the insn the head of a basic block? If so extend it */
insn_uid = INSN_UID (insn);
move_uid = INSN_UID (move_insn);
bb = regmove_bb_head[insn_uid];
if (bb >= 0)
{
basic_block_head[bb] = move_insn;
regmove_bb_head[insn_uid] = -1;
}
/* Update the various register tables. */
dest_regno = REGNO (dest);
REG_N_SETS (dest_regno) += loop_depth;
REG_N_REFS (dest_regno) += loop_depth;
REG_LIVE_LENGTH (dest_regno)++;
if (REGNO_FIRST_UID (dest_regno) == insn_uid)
REGNO_FIRST_UID (dest_regno) = move_uid;
src_regno = REGNO (src);
if (! find_reg_note (move_insn, REG_DEAD, src))
REG_LIVE_LENGTH (src_regno)++;
if (REGNO_FIRST_UID (src_regno) == insn_uid)
REGNO_FIRST_UID (src_regno) = move_uid;
if (REGNO_LAST_UID (src_regno) == insn_uid)
REGNO_LAST_UID (src_regno) = move_uid;
if (REGNO_LAST_NOTE_UID (src_regno) == insn_uid)
REGNO_LAST_NOTE_UID (src_regno) = move_uid;
}
}
/* Return whether REG is set in only one location, and is set to a
constant, but is set in a different basic block from INSN (an
instructions which uses REG). In this case REG is equivalent to a
......@@ -750,10 +845,16 @@ regmove_optimize (f, nregs, regmove_dump_file)
struct match match;
int pass;
int maxregnum = max_reg_num (), i;
rtx copy_src, copy_dst;
regno_src_regno = (int *)alloca (sizeof *regno_src_regno * maxregnum);
for (i = maxregnum; --i >= 0; ) regno_src_regno[i] = -1;
regmove_bb_head = (int *)alloca (sizeof (int) * (get_max_uid () + 1));
for (i = get_max_uid (); --i >= 0; ) regmove_bb_head[i] = -1;
for (i = 0; i < n_basic_blocks; i++)
regmove_bb_head[INSN_UID (basic_block_head[i])] = i;
/* A forward/backward pass. Replace output operands with input operands. */
loop_depth = 1;
......@@ -936,6 +1037,7 @@ regmove_optimize (f, nregs, regmove_dump_file)
{
int insn_code_number = find_matches (insn, &match);
int operand_number, match_number;
int success = 0;
if (insn_code_number < 0)
continue;
......@@ -946,13 +1048,14 @@ regmove_optimize (f, nregs, regmove_dump_file)
operand. If safe, then replace the source operand with the
dest operand in both instructions. */
copy_src = NULL_RTX;
copy_dst = NULL_RTX;
for (operand_number = 0;
operand_number < insn_n_operands[insn_code_number];
operand_number++)
{
rtx set, p, src, dst;
rtx src_note, dst_note;
int success = 0;
int num_calls = 0;
enum reg_class src_class, dst_class;
int length;
......@@ -1016,27 +1119,58 @@ regmove_optimize (f, nregs, regmove_dump_file)
|| CLASS_LIKELY_SPILLED_P (src_class))
&& (! reg_class_subset_p (dst_class, src_class)
|| CLASS_LIKELY_SPILLED_P (dst_class)))
continue;
if (! (src_note = find_reg_note (insn, REG_DEAD, src)))
continue;
{
if (!copy_src)
{
copy_src = src;
copy_dst = dst;
}
continue;
}
/* Can not modify an earlier insn to set dst if this insn
uses an old value in the source. */
if (reg_overlap_mentioned_p (dst, SET_SRC (set)))
continue;
{
if (!copy_src)
{
copy_src = src;
copy_dst = dst;
}
continue;
}
if (! (src_note = find_reg_note (insn, REG_DEAD, src)))
{
if (!copy_src)
{
copy_src = src;
copy_dst = dst;
}
continue;
}
if (regmove_dump_file)
fprintf (regmove_dump_file,
"Could fix operand %d of insn %d matching operand %d.\n",
operand_number, INSN_UID (insn), match_number);
/* If src is set once in a different basic block,
and is set equal to a constant, then do not use
it for this optimization, as this would make it
no longer equivalent to a constant. */
if (reg_is_remote_constant_p (src, insn, f))
continue;
if (reg_is_remote_constant_p (src, insn, f))
{
if (!copy_src)
{
copy_src = src;
copy_dst = dst;
}
continue;
}
if (regmove_dump_file)
fprintf (regmove_dump_file,
"Could fix operand %d of insn %d matching operand %d.\n",
operand_number, INSN_UID (insn), match_number);
/* Scan backward to find the first instruction that uses
the input operand. If the operand is set here, then
......@@ -1173,6 +1307,12 @@ regmove_optimize (f, nregs, regmove_dump_file)
break;
}
}
/* If we weren't able to replace any of the alternatives, try an
alternative appoach of copying the source to the destination. */
if (!success && copy_src != NULL_RTX)
copy_src_to_dest (insn, copy_src, copy_dst, loop_depth);
}
}
#endif /* REGISTER_CONSTRAINTS */
......
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