match: Simplify `(T1)(a bit_op (T2)b)` to `((T1)a bit_op b)` When b is T1 type and...

This adds the simpliciation of:
```
  <unnamed-signed:3> _1;

  _2 = (signed char) _1;
  _3 = _2 ^ -47;
  _4 = (<unnamed-signed:3>) _3;
```

to:
```
  <unnamed-signed:3> _n;
  _4 = _1 ^ -47;
```

This also fixes PR 122843 by optimizing out the xor such that we get:
```
  _1 = b.a;
  _21 = (<unnamed-signed:3>) t_23(D);
  // t_23 in the original testcase was 200 so this is reduced to 0
  _5 = _1 ^ _21;
  # .MEM_24 = VDEF <.MEM_13>
  b.a = _5;
```
And then there is no cast catch this pattern:
`(bit_xor (convert1? (bit_xor:c @0 @1)) (convert2? (bit_xor:c @0 @2)))`
As we get:
```
  _21 = (<unnamed-signed:3>) t_23(D);
  _5 = _1 ^ _21;
  _22 = (<unnamed-signed:3>) t_23(D);
  _7 = _5 ^ _22;
  _25 = (<unnamed-signed:3>) t_23(D);
  _8 = _7 ^ _25;
  _26 = (<unnamed-signed:3>) t_23(D);
  _9 = _7 ^ _26;
```
After unrolling and then fre will optimize away all of those xor.

Bootstrapped and tested on x86_64-linux-gnu.

	PR tree-optimization/122845
	PR tree-optimization/122843
gcc/ChangeLog:

	* match.pd (`(T1)(a bit_op (T2)b)`): Also
	simplify if T1 is the same type as b and T2 is wider
	type than T1.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/bitops-12.c: New test.
	* gcc.dg/tree-ssa/bitops-13.c: New test.
	* gcc.dg/store_merging_18.c: xfail store merging.

Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>

diff --git a/gcc/match.pd b/gcc/match.pd
index 08d0810e986502402b3e6b804489ba6b48647ede..c339762b90c4897d8acf599d247bc9af4cab34b8 100644 (file)
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2323,7 +2323,15 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
        && !POINTER_TYPE_P (TREE_TYPE (@0))
        && TREE_CODE (TREE_TYPE (@0)) != OFFSET_TYPE
        && TYPE_PRECISION (TREE_TYPE (@0)) > TYPE_PRECISION (type))
-   (bitop:type (convert @0) (convert @1)))))
+   (bitop:type (convert @0) (convert @1))
+   /* Similar as above, but the outer and inner most types match
+       and it was widening cast; replacing 2 casts with only one.  */
+   (if (GIMPLE
+        && INTEGRAL_TYPE_P (type)
+        && INTEGRAL_TYPE_P (TREE_TYPE (@0))
+        && types_match (type, TREE_TYPE (@0))
+        && TYPE_PRECISION (TREE_TYPE (@2)) > TYPE_PRECISION (type))
+    (bitop:type @0 (convert @1))))))
 
 (for bitop (bit_and bit_ior)
      rbitop (bit_ior bit_and)

diff --git a/gcc/testsuite/gcc.dg/store_merging_18.c b/gcc/testsuite/gcc.dg/store_merging_18.c
index fdff6b4d812178a32aeccc050c88315bde46c37b..546c17dc7c45a50d5a5af5e385b4096cdd34e457 100644 (file)
--- a/gcc/testsuite/gcc.dg/store_merging_18.c
+++ b/gcc/testsuite/gcc.dg/store_merging_18.c
@@ -1,7 +1,8 @@
 /* PR tree-optimization/83843 */
 /* { dg-do run } */
 /* { dg-options "-O2 -fno-tree-vectorize -fdump-tree-store-merging" } */
-/* { dg-final { scan-tree-dump-times "Merging successful" 3 "store-merging" { target { store_merge && { ! arm*-*-* } } } } } */
+/* xfailed after PR 122845, see PR 123541 ( */
+/* { dg-final { scan-tree-dump-times "Merging successful" 3 "store-merging" { target { store_merge && { ! arm*-*-* } } xfail *-*-* } } } */
 
 __attribute__((noipa)) void
 foo (unsigned char *buf, unsigned char *tab)

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bitops-12.c b/gcc/testsuite/gcc.dg/tree-ssa/bitops-12.c
new file mode 100644 (file)
index 0000000..50d8dc2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/bitops-12.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-optimized-raw" } */
+/* PR tree-optimization/122845 */
+
+struct s1
+{
+  signed f1:3;
+};
+struct s1 p;
+void f(void)
+{
+ p.f1 ^= -47;
+ p.f1 ^= -47;
+}
+
+/* There should be no gimple stmts left except for return.
+   That is the ^ has been optimized away.   */
+/* { dg-final { scan-tree-dump-not "gimple_assign <" "optimized"  } } */

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bitops-13.c b/gcc/testsuite/gcc.dg/tree-ssa/bitops-13.c
new file mode 100644 (file)
index 0000000..ecf6973
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/bitops-13.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-optimized-raw" } */
+/* PR tree-optimization/122845 */
+
+int f(signed char a, int  b)
+{
+  int aa = a;
+  int bb = b;
+  aa &= bb;
+  signed char t = aa;
+  aa = t;
+  aa &= bb;
+  t = aa;
+  return t;
+}
+
+/* There should be only 1 bit_and_expr left as both ands are the same. */
+/* { dg-final { scan-tree-dump-times "bit_and_expr, " 1 "optimized"  } } */