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Commit 1ffbaa3f by Richard Biener Committed by Richard Biener
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fold-const.c (fold_binary_loc): Move simplification of (X <<>> C1) & C2 ... 

2015-06-25  Richard Biener  <rguenther@suse.de>

	* fold-const.c (fold_binary_loc): Move simplification of
	(X <<>> C1) & C2 ...
	* match.pd: ... here.

	* gcc.dg/tree-ssa/pr52631.c: Disable forwprop.

From-SVN: r224943
parent 0cf094c0
Showing with 102 additions and 101 deletions
gcc/ChangeLog
2015-06-25 Richard Biener <rguenther@suse.de>
* fold-const.c (fold_binary_loc): Move simplification of
(X <<>> C1) & C2 ...
* match.pd: ... here.
2015-06-25 Eric Botcazou <ebotcazou@adacore.com>
* lto-streamer-out.c (DFS::hash_scc): Fix typos & formatting glitches.
......
gcc/fold-const.c
......@@ -11516,106 +11516,6 @@ fold_binary_loc (location_t loc,
return build_int_cst (type, residue & low);
}
/* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
(X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
if the new mask might be further optimized. */
if ((TREE_CODE (arg0) == LSHIFT_EXPR
|| TREE_CODE (arg0) == RSHIFT_EXPR)
&& TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
&& TREE_CODE (arg1) == INTEGER_CST
&& tree_fits_uhwi_p (TREE_OPERAND (arg0, 1))
&& tree_to_uhwi (TREE_OPERAND (arg0, 1)) > 0
&& (tree_to_uhwi (TREE_OPERAND (arg0, 1))
< TYPE_PRECISION (TREE_TYPE (arg0))))
{
unsigned int shiftc = tree_to_uhwi (TREE_OPERAND (arg0, 1));
unsigned HOST_WIDE_INT mask = TREE_INT_CST_LOW (arg1);
unsigned HOST_WIDE_INT newmask, zerobits = 0;
tree shift_type = TREE_TYPE (arg0);
if (TREE_CODE (arg0) == LSHIFT_EXPR)
zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
else if (TREE_CODE (arg0) == RSHIFT_EXPR
&& TYPE_PRECISION (TREE_TYPE (arg0))
== GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (arg0))))
{
prec = TYPE_PRECISION (TREE_TYPE (arg0));
tree arg00 = TREE_OPERAND (arg0, 0);
/* See if more bits can be proven as zero because of
zero extension. */
if (TREE_CODE (arg00) == NOP_EXPR
&& TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
{
tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
if (TYPE_PRECISION (inner_type)
== GET_MODE_PRECISION (TYPE_MODE (inner_type))
&& TYPE_PRECISION (inner_type) < prec)
{
prec = TYPE_PRECISION (inner_type);
/* See if we can shorten the right shift. */
if (shiftc < prec)
shift_type = inner_type;
/* Otherwise X >> C1 is all zeros, so we'll optimize
it into (X, 0) later on by making sure zerobits
is all ones. */
}
}
zerobits = ~(unsigned HOST_WIDE_INT) 0;
if (shiftc < prec)
{
zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
zerobits <<= prec - shiftc;
}
/* For arithmetic shift if sign bit could be set, zerobits
can contain actually sign bits, so no transformation is
possible, unless MASK masks them all away. In that
case the shift needs to be converted into logical shift. */
if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
&& prec == TYPE_PRECISION (TREE_TYPE (arg0)))
{
if ((mask & zerobits) == 0)
shift_type = unsigned_type_for (TREE_TYPE (arg0));
else
zerobits = 0;
}
}
/* ((X << 16) & 0xff00) is (X, 0). */
if ((mask & zerobits) == mask)
return omit_one_operand_loc (loc, type,
build_int_cst (type, 0), arg0);
newmask = mask | zerobits;
if (newmask != mask && (newmask & (newmask + 1)) == 0)
{
/* Only do the transformation if NEWMASK is some integer
mode's mask. */
for (prec = BITS_PER_UNIT;
prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
break;
if (prec < HOST_BITS_PER_WIDE_INT
|| newmask == ~(unsigned HOST_WIDE_INT) 0)
{
tree newmaskt;
if (shift_type != TREE_TYPE (arg0))
{
tem = fold_build2_loc (loc, TREE_CODE (arg0), shift_type,
fold_convert_loc (loc, shift_type,
TREE_OPERAND (arg0, 0)),
TREE_OPERAND (arg0, 1));
tem = fold_convert_loc (loc, type, tem);
}
else
tem = op0;
newmaskt = build_int_cst_type (TREE_TYPE (op1), newmask);
if (!tree_int_cst_equal (newmaskt, arg1))
return fold_build2_loc (loc, BIT_AND_EXPR, type, tem, newmaskt);
}
}
}
goto associate;
case RDIV_EXPR:
......
gcc/match.pd
......@@ -738,6 +738,97 @@ along with GCC; see the file COPYING3. If not see
&& wi::eq_p (wi::lshift (@0, cand), @2))
(cmp @1 { build_int_cst (TREE_TYPE (@1), cand); })))))
/* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
(X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
if the new mask might be further optimized. */
(for shift (lshift rshift)
(simplify
(bit_and (convert?@4 (shift@5 (convert1?@3 @0) INTEGER_CST@1)) INTEGER_CST@2)
(if (tree_nop_conversion_p (TREE_TYPE (@4), TREE_TYPE (@5))
&& TYPE_PRECISION (type) <= HOST_BITS_PER_WIDE_INT
&& tree_fits_uhwi_p (@1)
&& tree_to_uhwi (@1) > 0
&& tree_to_uhwi (@1) < TYPE_PRECISION (type))
(with
{
unsigned int shiftc = tree_to_uhwi (@1);
unsigned HOST_WIDE_INT mask = TREE_INT_CST_LOW (@2);
unsigned HOST_WIDE_INT newmask, zerobits = 0;
tree shift_type = TREE_TYPE (@3);
unsigned int prec;
if (shift == LSHIFT_EXPR)
zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
else if (shift == RSHIFT_EXPR
&& (TYPE_PRECISION (shift_type)
== GET_MODE_PRECISION (TYPE_MODE (shift_type))))
{
prec = TYPE_PRECISION (TREE_TYPE (@3));
tree arg00 = @0;
/* See if more bits can be proven as zero because of
zero extension. */
if (@3 != @0
&& TYPE_UNSIGNED (TREE_TYPE (@0)))
{
tree inner_type = TREE_TYPE (@0);
if ((TYPE_PRECISION (inner_type)
== GET_MODE_PRECISION (TYPE_MODE (inner_type)))
&& TYPE_PRECISION (inner_type) < prec)
{
prec = TYPE_PRECISION (inner_type);
/* See if we can shorten the right shift. */
if (shiftc < prec)
shift_type = inner_type;
/* Otherwise X >> C1 is all zeros, so we'll optimize
it into (X, 0) later on by making sure zerobits
is all ones. */
}
}
zerobits = ~(unsigned HOST_WIDE_INT) 0;
if (shiftc < prec)
{
zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
zerobits <<= prec - shiftc;
}
/* For arithmetic shift if sign bit could be set, zerobits
can contain actually sign bits, so no transformation is
possible, unless MASK masks them all away. In that
case the shift needs to be converted into logical shift. */
if (!TYPE_UNSIGNED (TREE_TYPE (@3))
&& prec == TYPE_PRECISION (TREE_TYPE (@3)))
{
if ((mask & zerobits) == 0)
shift_type = unsigned_type_for (TREE_TYPE (@3));
else
zerobits = 0;
}
}
}
/* ((X << 16) & 0xff00) is (X, 0). */
(if ((mask & zerobits) == mask)
{ build_int_cst (type, 0); })
(with { newmask = mask | zerobits; }
(if (newmask != mask && (newmask & (newmask + 1)) == 0)
(with
{
/* Only do the transformation if NEWMASK is some integer
mode's mask. */
for (prec = BITS_PER_UNIT;
prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
break;
}
(if (prec < HOST_BITS_PER_WIDE_INT
|| newmask == ~(unsigned HOST_WIDE_INT) 0)
(with
{ tree newmaskt = build_int_cst_type (TREE_TYPE (@2), newmask); }
(if (!tree_int_cst_equal (newmaskt, @2))
(if (shift_type != TREE_TYPE (@3)
&& single_use (@4) && single_use (@5))
(bit_and (convert (shift:shift_type (convert @3) @1)) { newmaskt; }))
(if (shift_type == TREE_TYPE (@3))
(bit_and @4 { newmaskt; }))))))))))))
/* Simplifications of conversions. */
/* Basic strip-useless-type-conversions / strip_nops. */
......
gcc/testsuite/ChangeLog
2015-06-25 Richard Biener <rguenther@suse.de>
* gcc.dg/tree-ssa/pr52631.c: Disable forwprop.
2015-06-25 Richard Sandiford <richard.sandiford@arm.com>
* gcc.target/aarch64/vect-add-sub-cond.c: New test.
......
gcc/testsuite/gcc.dg/tree-ssa/pr52631.c
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-fre1-details" } */
/* { dg-options "-O2 -fno-tree-forwprop -fdump-tree-fre1-details" } */
unsigned f(unsigned a)
{
......
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