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re PR middle-end/87290 (Optimize signed x % pow2p == cst)

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PR middle-end/87290
	* expr.c (maybe_optimize_pow2p_mod_cmp): New function.
	(maybe_optimize_mod_cmp): Use it if integer_pow2p treeop1.

	* gcc.target/i386/pr87290.c: New test.
	* gcc.c-torture/execute/pr87290.c: New test.

Co-Authored-By: Kyrylo Tkachov <kyrylo.tkachov@arm.com>

From-SVN: r264261
This commit is contained in:
Jakub Jelinek 2018-09-13 09:42:55 +02:00 committed by Jakub Jelinek
parent 392750c53e
commit d51232fb3b
5 changed files with 208 additions and 2 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2018-09-13 Jakub Jelinek <jakub@redhat.com>
Kyrylo Tkachov <kyrylo.tkachov@arm.com>
PR middle-end/87290
* expr.c (maybe_optimize_pow2p_mod_cmp): New function.
(maybe_optimize_mod_cmp): Use it if integer_pow2p treeop1.
2018-09-13 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/87287

99
gcc/expr.c
View File

@ -11523,6 +11523,98 @@ mod_inv (const wide_int &a, const wide_int &b)
return x1;
}
/* Optimize x % C1 == C2 for signed modulo if C1 is a power of two and C2
is non-zero and C3 ((1<<(prec-1)) | (C1 - 1)):
for C2 > 0 to x & C3 == C2
for C2 < 0 to x & C3 == (C2 & C3). */
enum tree_code
maybe_optimize_pow2p_mod_cmp (enum tree_code code, tree *arg0, tree *arg1)
{
gimple *stmt = get_def_for_expr (*arg0, TRUNC_MOD_EXPR);
tree treeop0 = gimple_assign_rhs1 (stmt);
tree treeop1 = gimple_assign_rhs2 (stmt);
tree type = TREE_TYPE (*arg0);
scalar_int_mode mode;
if (!is_a <scalar_int_mode> (TYPE_MODE (type), &mode))
return code;
if (GET_MODE_BITSIZE (mode) != TYPE_PRECISION (type)
|| TYPE_PRECISION (type) <= 1
|| TYPE_UNSIGNED (type)
/* Signed x % c == 0 should have been optimized into unsigned modulo
earlier. */
|| integer_zerop (*arg1)
/* If c is known to be non-negative, modulo will be expanded as unsigned
modulo. */
|| get_range_pos_neg (treeop0) == 1)
return code;
/* x % c == d where d < 0 && d <= -c should be always false. */
if (tree_int_cst_sgn (*arg1) == -1
&& -wi::to_widest (treeop1) >= wi::to_widest (*arg1))
return code;
int prec = TYPE_PRECISION (type);
wide_int w = wi::to_wide (treeop1) - 1;
w |= wi::shifted_mask (0, prec - 1, true, prec);
tree c3 = wide_int_to_tree (type, w);
tree c4 = *arg1;
if (tree_int_cst_sgn (*arg1) == -1)
c4 = wide_int_to_tree (type, w & wi::to_wide (*arg1));
rtx op0 = expand_normal (treeop0);
treeop0 = make_tree (TREE_TYPE (treeop0), op0);
bool speed_p = optimize_insn_for_speed_p ();
do_pending_stack_adjust ();
location_t loc = gimple_location (stmt);
struct separate_ops ops;
ops.code = TRUNC_MOD_EXPR;
ops.location = loc;
ops.type = TREE_TYPE (treeop0);
ops.op0 = treeop0;
ops.op1 = treeop1;
ops.op2 = NULL_TREE;
start_sequence ();
rtx mor = expand_expr_real_2 (&ops, NULL_RTX, TYPE_MODE (ops.type),
EXPAND_NORMAL);
rtx_insn *moinsns = get_insns ();
end_sequence ();
unsigned mocost = seq_cost (moinsns, speed_p);
mocost += rtx_cost (mor, mode, EQ, 0, speed_p);
mocost += rtx_cost (expand_normal (*arg1), mode, EQ, 1, speed_p);
ops.code = BIT_AND_EXPR;
ops.location = loc;
ops.type = TREE_TYPE (treeop0);
ops.op0 = treeop0;
ops.op1 = c3;
ops.op2 = NULL_TREE;
start_sequence ();
rtx mur = expand_expr_real_2 (&ops, NULL_RTX, TYPE_MODE (ops.type),
EXPAND_NORMAL);
rtx_insn *muinsns = get_insns ();
end_sequence ();
unsigned mucost = seq_cost (muinsns, speed_p);
mucost += rtx_cost (mur, mode, EQ, 0, speed_p);
mucost += rtx_cost (expand_normal (c4), mode, EQ, 1, speed_p);
if (mocost <= mucost)
{
emit_insn (moinsns);
*arg0 = make_tree (TREE_TYPE (*arg0), mor);
return code;
}
emit_insn (muinsns);
*arg0 = make_tree (TREE_TYPE (*arg0), mur);
*arg1 = c4;
return code;
}
/* Attempt to optimize unsigned (X % C1) == C2 (or (X % C1) != C2).
If C1 is odd to:
(X - C2) * C3 <= C4 (or >), where
@ -11561,8 +11653,6 @@ maybe_optimize_mod_cmp (enum tree_code code, tree *arg0, tree *arg1)
tree treeop1 = gimple_assign_rhs2 (stmt);
if (TREE_CODE (treeop0) != SSA_NAME
|| TREE_CODE (treeop1) != INTEGER_CST
/* x % pow2 is handled right already. */
|| integer_pow2p (treeop1)
/* Don't optimize the undefined behavior case x % 0;
x % 1 should have been optimized into zero, punt if
it makes it here for whatever reason;
@ -11572,6 +11662,11 @@ maybe_optimize_mod_cmp (enum tree_code code, tree *arg0, tree *arg1)
|| tree_int_cst_le (treeop1, *arg1))
return code;
/* Unsigned x % pow2 is handled right already, for signed
modulo handle it in maybe_optimize_pow2p_mod_cmp. */
if (integer_pow2p (treeop1))
return maybe_optimize_pow2p_mod_cmp (code, arg0, arg1);
tree type = TREE_TYPE (*arg0);
scalar_int_mode mode;
if (!is_a <scalar_int_mode> (TYPE_MODE (type), &mode))

7
gcc/testsuite/ChangeLog
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@ -1,3 +1,10 @@
2018-09-13 Jakub Jelinek <jakub@redhat.com>
Kyrylo Tkachov <kyrylo.tkachov@arm.com>
PR middle-end/87290
* gcc.target/i386/pr87290.c: New test.
* gcc.c-torture/execute/pr87290.c: New test.
2018-09-13 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/87287

63
gcc/testsuite/gcc.c-torture/execute/pr87290.c Normal file
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@ -0,0 +1,63 @@
/* PR middle-end/87290 */
int c;
__attribute__((noipa)) void
f0 (void)
{
c++;
}
__attribute__((noipa)) int
f1 (int x)
{
return x % 16 == 13;
}
__attribute__((noipa)) int
f2 (int x)
{
return x % 16 == -13;
}
__attribute__((noipa)) void
f3 (int x)
{
if (x % 16 == 13)
f0 ();
}
__attribute__((noipa)) void
f4 (int x)
{
if (x % 16 == -13)
f0 ();
}
int
main ()
{
int i, j;
for (i = -30; i < 30; i++)
{
if (f1 (13 + i * 16) != (i >= 0) || f2 (-13 + i * 16) != (i <= 0))
__builtin_abort ();
f3 (13 + i * 16);
if (c != (i >= 0))
__builtin_abort ();
f4 (-13 + i * 16);
if (c != 1 + (i == 0))
__builtin_abort ();
for (j = 1; j < 16; j++)
{
if (f1 (13 + i * 16 + j) || f2 (-13 + i * 16 + j))
__builtin_abort ();
f3 (13 + i * 16 + j);
f4 (-13 + i * 16 + j);
}
if (c != 1 + (i == 0))
__builtin_abort ();
c = 0;
}
return 0;
}

34
gcc/testsuite/gcc.target/i386/pr87290.c Normal file
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@ -0,0 +1,34 @@
/* PR middle-end/87290 */
/* { dg-do compile } */
/* { dg-options "-O2 -masm=att" } */
/* { dg-final { scan-assembler-times "and\[^\n\r]*-2147483633" 4 } } */
/* { dg-final { scan-assembler-times "\t\\\$13," 2 } } */
/* { dg-final { scan-assembler-times "\t\\\$-2147483645," 2 } } */
void f0 (void);
int
f1 (int x)
{
return x % 16 == 13;
}
int
f2 (int x)
{
return x % 16 == -13;
}
void
f3 (int x)
{
if (x % 16 == 13)
f0 ();
}
void
f4 (int x)
{
if (x % 16 == -13)
f0 ();
}