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loop-invariant.c (pre_check_invariant_p): New function.

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2014-06-23  Zhenqiang Chen  <zhenqiang.chen@linaro.org>

	* loop-invariant.c (pre_check_invariant_p): New function.
	(find_invariant_insn): Call pre_check_invariant_p.

From-SVN: r211885
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Zhenqiang Chen 2014-06-23 02:47:54 +00:00 • committed by Zhenqiang Chen
parent 0001689b2e
commit 2c97f4728c
2 changed files with 40 additions and 1 deletions
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5
gcc/ChangeLog
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@ -1,3 +1,8 @@
2014-06-23 Zhenqiang Chen <zhenqiang.chen@linaro.org>
* loop-invariant.c (pre_check_invariant_p): New function.
(find_invariant_insn): Call pre_check_invariant_p.
2014-06-22 Richard Henderson <rth@redhat.com>
PR target/61565

36
gcc/loop-invariant.c
View file

@ -839,6 +839,39 @@ check_dependencies (rtx insn, bitmap depends_on)
return true;
}
/* Pre-check candidate DEST to skip the one which can not make a valid insn
during move_invariant_reg. SIMPLE is to skip HARD_REGISTER. */
static bool
pre_check_invariant_p (bool simple, rtx dest)
{
if (simple && REG_P (dest) && DF_REG_DEF_COUNT (REGNO (dest)) > 1)
{
df_ref use;
rtx ref;
unsigned int i = REGNO (dest);
struct df_insn_info *insn_info;
df_ref def_rec;
for (use = DF_REG_USE_CHAIN (i); use; use = DF_REF_NEXT_REG (use))
{
ref = DF_REF_INSN (use);
insn_info = DF_INSN_INFO_GET (ref);
FOR_EACH_INSN_INFO_DEF (def_rec, insn_info)
if (DF_REF_REGNO (def_rec) == i)
{
/* Multi definitions at this stage, most likely are due to
instruction constraints, which requires both read and write
on the same register. Since move_invariant_reg is not
powerful enough to handle such cases, just ignore the INV
and leave the chance to others. */
return false;
}
}
}
return true;
}
/* Finds invariant in INSN. ALWAYS_REACHED is true if the insn is always
executed. ALWAYS_EXECUTED is true if the insn is always executed,
unless the program ends due to a function call. */
@ -868,7 +901,8 @@ find_invariant_insn (rtx insn, bool always_reached, bool always_executed)
|| HARD_REGISTER_P (dest))
simple = false;
if (!may_assign_reg_p (SET_DEST (set))
if (!may_assign_reg_p (dest)
|| !pre_check_invariant_p (simple, dest)
|| !check_maybe_invariant (SET_SRC (set)))
return;