Hi!
As discussed on IRC, this patch allows as to recognize more patterns as
memset, see the testcase for what it can do.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2013-04-04 Jakub Jelinek <ja...@redhat.com>
* tree-loop-distribution.c (generate_memset_builtin): Only handle
integer_all_onesp as -1 val if TYPE_PRECISION is equal to mode bitsize.
Use native_encode_expr if possible to compute val.
(classify_partition): Verify CONSTRUCTOR doesn't have any elts.
For QImode integers don't require anything about precision. Use
native_encode_expr to find out if the constant doesn't have repeated
bytes in it.
* gcc.dg/pr56837.c: New test.
--- gcc/tree-loop-distribution.c.jj 2013-04-04 15:03:28.000000000 +0200
+++ gcc/tree-loop-distribution.c 2013-04-04 16:52:40.139875453 +0200
@@ -331,11 +331,21 @@ generate_memset_builtin (struct loop *lo
|| real_zerop (val)
|| TREE_CODE (val) == CONSTRUCTOR)
val = integer_zero_node;
- else if (integer_all_onesp (val))
+ else if (integer_all_onesp (val)
+ && (TYPE_PRECISION (TREE_TYPE (val))
+ == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (val)))))
val = build_int_cst (integer_type_node, -1);
else
{
- if (TREE_CODE (val) == INTEGER_CST)
+ /* Handle constants like 0x15151515 and similarly
+ floating point constants etc. where all bytes are the same. */
+ unsigned char buf[64];
+ int len;
+ if (CHAR_BIT == 8
+ && BITS_PER_UNIT == 8
+ && (len = native_encode_expr (val, buf, sizeof (buf))) != 0)
+ val = build_int_cst (integer_type_node, buf[0]);
+ else if (TREE_CODE (val) == INTEGER_CST)
val = fold_convert (integer_type_node, val);
else if (!useless_type_conversion_p (integer_type_node, TREE_TYPE (val)))
{
@@ -944,16 +954,28 @@ classify_partition (loop_p loop, struct
if (!(integer_zerop (rhs)
|| real_zerop (rhs)
|| (TREE_CODE (rhs) == CONSTRUCTOR
- && !TREE_CLOBBER_P (rhs))
- || ((integer_all_onesp (rhs)
- || (INTEGRAL_TYPE_P (TREE_TYPE (rhs))
- && (TYPE_MODE (TREE_TYPE (rhs))
- == TYPE_MODE (unsigned_char_type_node))))
- /* For stores of a non-zero value require that the precision
- of the value matches its actual size. */
+ && !TREE_CLOBBER_P (rhs)
+ && CONSTRUCTOR_NELTS (rhs) == 0)
+ || (integer_all_onesp (rhs)
&& (TYPE_PRECISION (TREE_TYPE (rhs))
- == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (rhs)))))))
- return;
+ == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (rhs)))))
+ || (INTEGRAL_TYPE_P (TREE_TYPE (rhs))
+ && (TYPE_MODE (TREE_TYPE (rhs))
+ == TYPE_MODE (unsigned_char_type_node)))))
+ {
+ /* Handle constants like 0x15151515 and similarly
+ floating point constants etc. where all bytes are the same. */
+ unsigned char buf[64];
+ int i, len;
+ if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
+ return;
+ len = native_encode_expr (rhs, buf, sizeof (buf));
+ if (len == 0)
+ return;
+ for (i = 1; i < len; i++)
+ if (buf[i] != buf[0])
+ return;
+ }
if (TREE_CODE (rhs) == SSA_NAME
&& !SSA_NAME_IS_DEFAULT_DEF (rhs)
&& flow_bb_inside_loop_p (loop, gimple_bb (SSA_NAME_DEF_STMT (rhs))))
--- gcc/testsuite/gcc.dg/pr56837.c.jj 2013-04-04 17:37:58.458675152 +0200
+++ gcc/testsuite/gcc.dg/pr56837.c 2013-04-04 17:36:40.000000000 +0200
@@ -0,0 +1,67 @@
+/* Limit this test to selected targets with IEEE double, 8-byte long long,
+ supported 4x int vectors, 4-byte int. */
+/* { dg-do compile { target { i?86-*-* x86_64-*-* powerpc*-*-* } } } */
+/* { dg-options "-O3 -fdump-tree-optimized" } */
+/* { dg-additional-options "-msse2" { target ia32 } } */
+/* { dg-additional-options "-mvsx -maltivec" { target powerpc*-*-* } } */
+
+typedef int V __attribute__((__vector_size__ (16)));
+#define N 1024
+double d[N];
+long long int l[N];
+_Bool b[N];
+_Complex double c[N];
+V v[N];
+
+void
+fd (void)
+{
+ int i;
+ for (i = 0; i < N; i++)
+ d[i] = 747708026454360457216.0;
+}
+
+void
+fl (void)
+{
+ int i;
+ for (i = 0; i < N; i++)
+ l[i] = 0x7c7c7c7c7c7c7c7cULL;
+}
+
+void
+fb (void)
+{
+ int i;
+ for (i = 0; i < N; i++)
+ b[i] = 1;
+}
+
+void
+fc (void)
+{
+ int i;
+ for (i = 0; i < N; i++)
+ c[i] = 747708026454360457216.0 + 747708026454360457216.0i;
+}
+
+void
+fv (void)
+{
+ int i;
+ for (i = 0; i < N; i++)
+ v[i] = (V) { 0x12121212, 0x12121212, 0x12121212, 0x12121212 };
+}
+
+/* Look for
+ __builtin_memset (&d, 68, 8192);
+ __builtin_memset (&l, 124, 8192);
+ __builtin_memset (&b, 1, 1024);
+ __builtin_memset (&c, 68, 16384);
+ __builtin_memset (&v, 18, 16384); */
+/* { dg-final { scan-tree-dump-times "memset ..d, 68, 8192.;" 1 "optimized" }
} */
+/* { dg-final { scan-tree-dump-times "memset ..l, 124, 8192.;" 1 "optimized" }
} */
+/* { dg-final { scan-tree-dump-times "memset ..b, 1, 1024.;" 1 "optimized" } }
*/
+/* { dg-final { scan-tree-dump-times "memset ..c, 68, 16384.;" 1 "optimized" }
} */
+/* { dg-final { scan-tree-dump-times "memset ..v, 18, 16384.;" 1 "optimized" }
} */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
Jakub
