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re PR target/41081 (redundant ZERO_EXTENDs)

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PR target/41081
	* fwprop.c (get_reg_use_in): Delete.
	(free_load_extend): New function.
	(forward_propagate_subreg): Use it.

From-SVN: r151221
This commit is contained in:
Alan Modra 2009-08-30 06:09:42 +00:00 committed by Alan Modra
parent d1eda1365c
commit e85122be92
2 changed files with 45 additions and 21 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2009-08-30 Alan Modra <amodra@bigpond.net.au>
PR target/41081
* fwprop.c (get_reg_use_in): Delete.
(free_load_extend): New function.
(forward_propagate_subreg): Use it.
2009-08-29 Kaz Kojima <kkojima@gcc.gnu.org>
* config.gcc (sh*-*-elf): Add superh stuff only for sh*-superh-elf.

59
gcc/fwprop.c
View File

@ -1014,24 +1014,54 @@ try_fwprop_subst (df_ref use, rtx *loc, rtx new_rtx, rtx def_insn, bool set_reg_
return ok;
}
#ifdef LOAD_EXTEND_OP
static df_ref
get_reg_use_in (rtx insn, rtx reg)
/* For the given single_set INSN, containing SRC known to be a
ZERO_EXTEND or SIGN_EXTEND of a register, return true if INSN
is redundant due to the register being set by a LOAD_EXTEND_OP
load from memory. */
static bool
free_load_extend (rtx src, rtx insn)
{
rtx reg;
df_ref *use_vec;
df_ref use, def;
reg = XEXP (src, 0);
#ifdef LOAD_EXTEND_OP
if (LOAD_EXTEND_OP (GET_MODE (reg)) != GET_CODE (src))
#endif
return false;
for (use_vec = DF_INSN_USES (insn); *use_vec; use_vec++)
{
df_ref use = *use_vec;
use = *use_vec;
if (!DF_REF_IS_ARTIFICIAL (use)
&& DF_REF_TYPE (use) == DF_REF_REG_USE
&& DF_REF_REG (use) == reg)
return use;
break;
}
return NULL;
if (!use)
return false;
def = get_def_for_use (use);
if (!def)
return false;
if (DF_REF_IS_ARTIFICIAL (def))
return false;
if (NONJUMP_INSN_P (DF_REF_INSN (def)))
{
rtx patt = PATTERN (DF_REF_INSN (def));
if (GET_CODE (patt) == SET
&& GET_CODE (SET_SRC (patt)) == MEM
&& rtx_equal_p (SET_DEST (patt), reg))
return true;
}
return false;
}
#endif
/* If USE is a subreg, see if it can be replaced by a pseudo. */
@ -1073,26 +1103,13 @@ forward_propagate_subreg (df_ref use, rtx def_insn, rtx def_set)
be removed due to it matching a LOAD_EXTEND_OP load from memory. */
else if (subreg_lowpart_p (use_reg))
{
#ifdef LOAD_EXTEND_OP
df_ref prev_use, prev_def;
#endif
use_insn = DF_REF_INSN (use);
src = SET_SRC (def_set);
if ((GET_CODE (src) == ZERO_EXTEND
|| GET_CODE (src) == SIGN_EXTEND)
&& REG_P (XEXP (src, 0))
&& GET_MODE (XEXP (src, 0)) == use_mode
#ifdef LOAD_EXTEND_OP
&& !(LOAD_EXTEND_OP (use_mode) == GET_CODE (src)
&& (prev_use = get_reg_use_in (def_insn, XEXP (src, 0))) != NULL
&& (prev_def = get_def_for_use (prev_use)) != NULL
&& !DF_REF_IS_ARTIFICIAL (prev_def)
&& NONJUMP_INSN_P (DF_REF_INSN (prev_def))
&& GET_CODE (PATTERN (DF_REF_INSN (prev_def))) == SET
&& GET_CODE (SET_SRC (PATTERN (DF_REF_INSN (prev_def)))) == MEM
&& rtx_equal_p (SET_DEST (PATTERN (DF_REF_INSN (prev_def))),
XEXP (src, 0)))
#endif
&& !free_load_extend (src, def_insn)
&& all_uses_available_at (def_insn, use_insn))
return try_fwprop_subst (use, DF_REF_LOC (use), XEXP (src, 0),
def_insn, false);