+2016-01-11 Bernd Schmidt <bschmidt@redhat.com>
+ Kyrylo Tkachov <kyrylo.tkachov@arm.com>
+
+ PR rtl-optimization/68841
+ * ifcvt.c (struct noce_if_info): Add orig_x field.
+ (bbs_ok_for_cmove_arith): Add to_rename parameter.
+ Don't record conflicts on to_rename if it's present.
+ Allow memory destinations in sets.
+ (noce_try_cmove_arith): Call bbs_ok_for_cmove_arith even on simple
+ blocks, passing orig_x to the checks.
+ (noce_process_if_block): Set if_info->orig_x appropriately.
+
2016-01-11 Tom de Vries <tom@codesourcery.com>
PR tree-optimization/69069
/* The SET_DEST of INSN_A. */
rtx x;
+ /* The original set destination that the THEN and ELSE basic blocks finally
+ write their result to. */
+ rtx orig_x;
/* True if this if block is not canonical. In the canonical form of
if blocks, the THEN_BB is the block reached via the fallthru edge
from TEST_BB. For the noce transformations, we allow the symmetric
}
-/* Return true iff the registers that the insns in BB_A set do not
- get used in BB_B. */
+/* Return true iff the registers that the insns in BB_A set do not get
+ used in BB_B. If TO_RENAME is non-NULL then it is a location that will be
+ renamed later by the caller and so conflicts on it should be ignored
+ in this function. */
static bool
-bbs_ok_for_cmove_arith (basic_block bb_a, basic_block bb_b)
+bbs_ok_for_cmove_arith (basic_block bb_a, basic_block bb_b, rtx to_rename)
{
rtx_insn *a_insn;
bitmap bba_sets = BITMAP_ALLOC (®_obstack);
BITMAP_FREE (bba_sets);
return false;
}
-
/* Record all registers that BB_A sets. */
FOR_EACH_INSN_DEF (def, a_insn)
- bitmap_set_bit (bba_sets, DF_REF_REGNO (def));
+ if (!(to_rename && DF_REF_REG (def) == to_rename))
+ bitmap_set_bit (bba_sets, DF_REF_REGNO (def));
}
rtx_insn *b_insn;
}
/* Make sure this is a REG and not some instance
- of ZERO_EXTRACT or SUBREG or other dangerous stuff. */
- if (!REG_P (SET_DEST (sset_b)))
+ of ZERO_EXTRACT or SUBREG or other dangerous stuff.
+ If we have a memory destination then we have a pair of simple
+ basic blocks performing an operation of the form [addr] = c ? a : b.
+ bb_valid_for_noce_process_p will have ensured that these are
+ the only stores present. In that case [addr] should be the location
+ to be renamed. Assert that the callers set this up properly. */
+ if (MEM_P (SET_DEST (sset_b)))
+ gcc_assert (rtx_equal_p (SET_DEST (sset_b), to_rename));
+ else if (!REG_P (SET_DEST (sset_b)))
{
BITMAP_FREE (bba_sets);
return false;
}
}
- if (then_bb && else_bb && !a_simple && !b_simple
- && (!bbs_ok_for_cmove_arith (then_bb, else_bb)
- || !bbs_ok_for_cmove_arith (else_bb, then_bb)))
+ if (then_bb && else_bb
+ && (!bbs_ok_for_cmove_arith (then_bb, else_bb, if_info->orig_x)
+ || !bbs_ok_for_cmove_arith (else_bb, then_bb, if_info->orig_x)))
return FALSE;
start_sequence ();
/* Only operate on register destinations, and even then avoid extending
the lifetime of hard registers on small register class machines. */
orig_x = x;
+ if_info->orig_x = orig_x;
if (!REG_P (x)
|| (HARD_REGISTER_P (x)
&& targetm.small_register_classes_for_mode_p (GET_MODE (x))))