On April 26, 2020 2:26:26 PM GMT+02:00, Jakub Jelinek <ja...@redhat.com> wrote:
>Hi!
>
>This patch moves this optimization from fold-const.c to match.pd where
>it
>is actually much shorter to do and lets optimize even code not seen
>together
>in a single expression in the source, as the first step towards fixing
>the
>PR.
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for stage1?
OK.
Richard.
>2020-04-24 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/94718
> * fold-const.c (fold_binary_loc): Move (X & C) eqne (Y & C)
> -> (X ^ Y) & C eqne 0 optimization to ...
> * match.pd ((X & C) op (Y & C) into (X ^ Y) & C op 0): ... here.
>
> * gcc.dg/tree-ssa/pr94718-1.c: New test.
> * gcc.dg/tree-ssa/pr94718-2.c: New test.
>
>--- gcc/fold-const.c.jj 2020-04-23 19:50:11.693805797 +0200
>+++ gcc/fold-const.c 2020-04-24 18:34:04.245559495 +0200
>@@ -11631,50 +11631,6 @@ fold_binary_loc (location_t loc, enum tr
> return omit_one_operand_loc (loc, type, res, arg0);
> }
>
>- /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries.
> */
>- if (TREE_CODE (arg0) == BIT_AND_EXPR
>- && TREE_CODE (arg1) == BIT_AND_EXPR)
>- {
>- tree arg00 = TREE_OPERAND (arg0, 0);
>- tree arg01 = TREE_OPERAND (arg0, 1);
>- tree arg10 = TREE_OPERAND (arg1, 0);
>- tree arg11 = TREE_OPERAND (arg1, 1);
>- tree itype = TREE_TYPE (arg0);
>-
>- if (operand_equal_p (arg01, arg11, 0))
>- {
>- tem = fold_convert_loc (loc, itype, arg10);
>- tem = fold_build2_loc (loc, BIT_XOR_EXPR, itype, arg00, tem);
>- tem = fold_build2_loc (loc, BIT_AND_EXPR, itype, tem, arg01);
>- return fold_build2_loc (loc, code, type, tem,
>- build_zero_cst (itype));
>- }
>- if (operand_equal_p (arg01, arg10, 0))
>- {
>- tem = fold_convert_loc (loc, itype, arg11);
>- tem = fold_build2_loc (loc, BIT_XOR_EXPR, itype, arg00, tem);
>- tem = fold_build2_loc (loc, BIT_AND_EXPR, itype, tem, arg01);
>- return fold_build2_loc (loc, code, type, tem,
>- build_zero_cst (itype));
>- }
>- if (operand_equal_p (arg00, arg11, 0))
>- {
>- tem = fold_convert_loc (loc, itype, arg10);
>- tem = fold_build2_loc (loc, BIT_XOR_EXPR, itype, arg01, tem);
>- tem = fold_build2_loc (loc, BIT_AND_EXPR, itype, tem, arg00);
>- return fold_build2_loc (loc, code, type, tem,
>- build_zero_cst (itype));
>- }
>- if (operand_equal_p (arg00, arg10, 0))
>- {
>- tem = fold_convert_loc (loc, itype, arg11);
>- tem = fold_build2_loc (loc, BIT_XOR_EXPR, itype, arg01, tem);
>- tem = fold_build2_loc (loc, BIT_AND_EXPR, itype, tem, arg00);
>- return fold_build2_loc (loc, code, type, tem,
>- build_zero_cst (itype));
>- }
>- }
>-
> if (TREE_CODE (arg0) == BIT_XOR_EXPR
> && TREE_CODE (arg1) == BIT_XOR_EXPR)
> {
>--- gcc/match.pd.jj 2020-04-23 19:50:11.710805542 +0200
>+++ gcc/match.pd 2020-04-24 18:34:04.247559465 +0200
>@@ -4335,7 +4335,12 @@ (define_operator_list COND_TERNARY
> (simplify
> (cmp (convert? addr@0) integer_zerop)
> (if (tree_single_nonzero_warnv_p (@0, NULL))
>- { constant_boolean_node (cmp == NE_EXPR, type); })))
>+ { constant_boolean_node (cmp == NE_EXPR, type); }))
>+
>+ /* (X & C) op (Y & C) into (X ^ Y) & C op 0. */
>+ (simplify
>+ (cmp (bit_and:cs @0 @2) (bit_and:cs @1 @2))
>+ (cmp (bit_and (bit_xor @0 @1) @2) { build_zero_cst (TREE_TYPE (@2));
>})))
>
> /* If we have (A & C) == C where C is a power of 2, convert this into
> (A & C) != 0. Similarly for NE_EXPR. */
>--- gcc/testsuite/gcc.dg/tree-ssa/pr94718-1.c.jj 2020-04-24
>17:31:10.392472875 +0200
>+++ gcc/testsuite/gcc.dg/tree-ssa/pr94718-1.c 2020-04-24
>18:43:35.829119496 +0200
>@@ -0,0 +1,49 @@
>+/* PR tree-optimization/94718 */
>+/* { dg-do compile } */
>+/* { dg-options "-O2 -fno-ipa-icf -fdump-tree-optimized" } */
>+/* { dg-final { scan-tree-dump-times "= \[xy]_\[0-9]+\\\(D\\\) \\^
>\[xy]_\[0-9]+\\\(D\\\);" 6 "optimized" } } */
>+/* { dg-final { scan-tree-dump-times "\[0-9]+ < 0;" 6 "optimized" } }
>*/
>+
>+#define I (-__INT_MAX__ - 1)
>+
>+int
>+f1 (int x, int y)
>+{
>+ return (x & I) != (y & I);
>+}
>+
>+int
>+f2 (int x, int y)
>+{
>+ return (~x & I) != (~y & I);
>+}
>+
>+int
>+f3 (int x, int y)
>+{
>+ return ((x & I) ^ I) != ((y & I) ^ I);
>+}
>+
>+int
>+f4 (int x, int y)
>+{
>+ int s = (x & I);
>+ int t = (y & I);
>+ return s != t;
>+}
>+
>+int
>+f5 (int x, int y)
>+{
>+ int s = (~x & I);
>+ int t = (~y & I);
>+ return s != t;
>+}
>+
>+int
>+f6 (int x, int y)
>+{
>+ int s = ((x & I) ^ I);
>+ int t = ((y & I) ^ I);
>+ return s != t;
>+}
>--- gcc/testsuite/gcc.dg/tree-ssa/pr94718-2.c.jj 2020-04-24
>17:31:13.673424244 +0200
>+++ gcc/testsuite/gcc.dg/tree-ssa/pr94718-2.c 2020-04-24
>18:43:44.669988955 +0200
>@@ -0,0 +1,49 @@
>+/* PR tree-optimization/94718 */
>+/* { dg-do compile } */
>+/* { dg-options "-O2 -fno-ipa-icf -fdump-tree-optimized" } */
>+/* { dg-final { scan-tree-dump-times "= \[xy]_\[0-9]+\\\(D\\\) \\^
>\[xy]_\[0-9]+\\\(D\\\);" 6 "optimized" } } */
>+/* { dg-final { scan-tree-dump-times "\[0-9]+ >= 0;" 6 "optimized" } }
>*/
>+
>+#define I (-__INT_MAX__ - 1)
>+
>+int
>+f1 (int x, int y)
>+{
>+ return (x & I) == (y & I);
>+}
>+
>+int
>+f2 (int x, int y)
>+{
>+ return (~x & I) == (~y & I);
>+}
>+
>+int
>+f3 (int x, int y)
>+{
>+ return ((x & I) ^ I) == ((y & I) ^ I);
>+}
>+
>+int
>+f4 (int x, int y)
>+{
>+ int s = (x & I);
>+ int t = (y & I);
>+ return s == t;
>+}
>+
>+int
>+f5 (int x, int y)
>+{
>+ int s = (~x & I);
>+ int t = (~y & I);
>+ return s == t;
>+}
>+
>+int
>+f6 (int x, int y)
>+{
>+ int s = ((x & I) ^ I);
>+ int t = ((y & I) ^ I);
>+ return s == t;
>+}
>
> Jakub
