match.pd: Add BIT_FIELD_REF canonicalizations and vector constructor simplifications.
authorRichard Biener <rguenther@suse.de>
Wed, 4 May 2016 12:37:56 +0000 (12:37 +0000)
committerRichard Biener <rguenth@gcc.gnu.org>
Wed, 4 May 2016 12:37:56 +0000 (12:37 +0000)
2016-05-04  Richard Biener  <rguenther@suse.de>

* match.pd: Add BIT_FIELD_REF canonicalizations and vector
constructor simplifications.
* fold-const.c (fold_ternary_loc): Remove duplicate functionality
here.

From-SVN: r235871

gcc/ChangeLog
gcc/fold-const.c
gcc/match.pd

index 272b1ed..623b269 100644 (file)
@@ -1,3 +1,10 @@
+2016-05-04  Richard Biener  <rguenther@suse.de>
+
+       * match.pd: Add BIT_FIELD_REF canonicalizations and vector
+       constructor simplifications.
+       * fold-const.c (fold_ternary_loc): Remove duplicate functionality
+       here.
+
 2016-05-04  Oleg Endo  <olegendo@gcc.gnu.org>
 
        * config/sh/predicates (post_inc_mem, pre_dec_mem): New predicates.
index 0004f78..416ec5d 100644 (file)
@@ -11719,9 +11719,7 @@ fold_ternary_loc (location_t loc, enum tree_code code, tree type,
       gcc_unreachable ();
 
     case BIT_FIELD_REF:
-      if ((TREE_CODE (arg0) == VECTOR_CST
-          || (TREE_CODE (arg0) == CONSTRUCTOR
-              && TREE_CODE (TREE_TYPE (arg0)) == VECTOR_TYPE))
+      if (TREE_CODE (arg0) == VECTOR_CST
          && (type == TREE_TYPE (TREE_TYPE (arg0))
              || (TREE_CODE (type) == VECTOR_TYPE
                  && TREE_TYPE (type) == TREE_TYPE (TREE_TYPE (arg0)))))
@@ -11749,88 +11747,32 @@ fold_ternary_loc (location_t loc, enum tree_code code, tree type,
                    vals[i] = VECTOR_CST_ELT (arg0, idx + i);
                  return build_vector (type, vals);
                }
-
-             /* Constructor elements can be subvectors.  */
-             unsigned HOST_WIDE_INT k = 1;
-             if (CONSTRUCTOR_NELTS (arg0) != 0)
-               {
-                 tree cons_elem = TREE_TYPE (CONSTRUCTOR_ELT (arg0, 0)->value);
-                 if (TREE_CODE (cons_elem) == VECTOR_TYPE)
-                   k = TYPE_VECTOR_SUBPARTS (cons_elem);
-               }
-
-             /* We keep an exact subset of the constructor elements.  */
-             if ((idx % k) == 0 && (n % k) == 0)
-               {
-                 if (CONSTRUCTOR_NELTS (arg0) == 0)
-                   return build_constructor (type, NULL);
-                 idx /= k;
-                 n /= k;
-                 if (n == 1)
-                   {
-                     if (idx < CONSTRUCTOR_NELTS (arg0))
-                       return CONSTRUCTOR_ELT (arg0, idx)->value;
-                     return build_zero_cst (type);
-                   }
-
-                 vec<constructor_elt, va_gc> *vals;
-                 vec_alloc (vals, n);
-                 for (unsigned i = 0;
-                      i < n && idx + i < CONSTRUCTOR_NELTS (arg0);
-                      ++i)
-                   CONSTRUCTOR_APPEND_ELT (vals, NULL_TREE,
-                                           CONSTRUCTOR_ELT
-                                             (arg0, idx + i)->value);
-                 return build_constructor (type, vals);
-               }
-             /* The bitfield references a single constructor element.  */
-             else if (idx + n <= (idx / k + 1) * k)
-               {
-                 if (CONSTRUCTOR_NELTS (arg0) <= idx / k)
-                   return build_zero_cst (type);
-                 else if (n == k)
-                   return CONSTRUCTOR_ELT (arg0, idx / k)->value;
-                 else
-                   return fold_build3_loc (loc, code, type,
-                     CONSTRUCTOR_ELT (arg0, idx / k)->value, op1,
-                     build_int_cst (TREE_TYPE (op2), (idx % k) * width));
-               }
            }
        }
 
-      /* A bit-field-ref that referenced the full argument can be stripped.  */
-      if (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
-         && TYPE_PRECISION (TREE_TYPE (arg0)) == tree_to_uhwi (arg1)
-         && integer_zerop (op2))
-       return fold_convert_loc (loc, type, arg0);
-
       /* On constants we can use native encode/interpret to constant
          fold (nearly) all BIT_FIELD_REFs.  */
       if (CONSTANT_CLASS_P (arg0)
          && can_native_interpret_type_p (type)
-         && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (arg0)))
-         /* This limitation should not be necessary, we just need to
-            round this up to mode size.  */
-         && tree_to_uhwi (op1) % BITS_PER_UNIT == 0
-         /* Need bit-shifting of the buffer to relax the following.  */
-         && tree_to_uhwi (op2) % BITS_PER_UNIT == 0)
+         && BITS_PER_UNIT == 8)
        {
          unsigned HOST_WIDE_INT bitpos = tree_to_uhwi (op2);
          unsigned HOST_WIDE_INT bitsize = tree_to_uhwi (op1);
-         unsigned HOST_WIDE_INT clen;
-         clen = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (arg0)));
-         /* ???  We cannot tell native_encode_expr to start at
-            some random byte only.  So limit us to a reasonable amount
-            of work.  */
-         if (clen <= 4096)
+         /* Limit us to a reasonable amount of work.  To relax the
+            other limitations we need bit-shifting of the buffer
+            and rounding up the size.  */
+         if (bitpos % BITS_PER_UNIT == 0
+             && bitsize % BITS_PER_UNIT == 0
+             && bitsize <= MAX_BITSIZE_MODE_ANY_MODE)
            {
-             unsigned char *b = XALLOCAVEC (unsigned char, clen);
-             unsigned HOST_WIDE_INT len = native_encode_expr (arg0, b, clen);
+             unsigned char b[MAX_BITSIZE_MODE_ANY_MODE / BITS_PER_UNIT];
+             unsigned HOST_WIDE_INT len
+               = native_encode_expr (arg0, b, bitsize / BITS_PER_UNIT,
+                                     bitpos / BITS_PER_UNIT);
              if (len > 0
-                 && len * BITS_PER_UNIT >= bitpos + bitsize)
+                 && len * BITS_PER_UNIT >= bitsize)
                {
-                 tree v = native_interpret_expr (type,
-                                                 b + bitpos / BITS_PER_UNIT,
+                 tree v = native_interpret_expr (type, b,
                                                  bitsize / BITS_PER_UNIT);
                  if (v)
                    return v;
index ee2aee3..55dd23c 100644 (file)
@@ -3229,3 +3229,99 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
                                 WARN_STRICT_OVERFLOW_COMPARISON);
        }
        (cmp @0 { res; })))))))))
+
+/* Canonicalizations of BIT_FIELD_REFs.  */
+
+(simplify
+ (BIT_FIELD_REF @0 @1 @2)
+ (switch
+  (if (TREE_CODE (TREE_TYPE (@0)) == COMPLEX_TYPE
+       && tree_int_cst_equal (@1, TYPE_SIZE (TREE_TYPE (TREE_TYPE (@0)))))
+   (switch
+    (if (integer_zerop (@2))
+     (view_convert (realpart @0)))
+    (if (tree_int_cst_equal (@2, TYPE_SIZE (TREE_TYPE (TREE_TYPE (@0)))))
+     (view_convert (imagpart @0)))))
+  (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
+       && INTEGRAL_TYPE_P (type)
+       /* A bit-field-ref that referenced the full argument can be stripped.  */
+       && ((compare_tree_int (@1, TYPE_PRECISION (TREE_TYPE (@0))) == 0
+           && integer_zerop (@2))
+          /* Low-parts can be reduced to integral conversions.
+             ???  The following doesn't work for PDP endian.  */
+          || (BYTES_BIG_ENDIAN == WORDS_BIG_ENDIAN
+              /* Don't even think about BITS_BIG_ENDIAN.  */
+              && TYPE_PRECISION (TREE_TYPE (@0)) % BITS_PER_UNIT == 0
+              && TYPE_PRECISION (type) % BITS_PER_UNIT == 0
+              && compare_tree_int (@2, (BYTES_BIG_ENDIAN
+                                        ? (TYPE_PRECISION (TREE_TYPE (@0))
+                                           - TYPE_PRECISION (type))
+                                        : 0)) == 0)))
+   (convert @0))))
+
+/* Simplify vector extracts.  */
+
+(simplify
+ (BIT_FIELD_REF CONSTRUCTOR@0 @1 @2)
+ (if (VECTOR_TYPE_P (TREE_TYPE (@0))
+      && (types_match (type, TREE_TYPE (TREE_TYPE (@0)))
+          || (VECTOR_TYPE_P (type)
+             && types_match (TREE_TYPE (type), TREE_TYPE (TREE_TYPE (@0))))))
+  (with
+   {
+     tree ctor = (TREE_CODE (@0) == SSA_NAME
+                 ? gimple_assign_rhs1 (SSA_NAME_DEF_STMT (@0)) : @0);
+     tree eltype = TREE_TYPE (TREE_TYPE (ctor));
+     unsigned HOST_WIDE_INT width = tree_to_uhwi (TYPE_SIZE (eltype));
+     unsigned HOST_WIDE_INT n = tree_to_uhwi (@1);
+     unsigned HOST_WIDE_INT idx = tree_to_uhwi (@2);
+   }
+   (if (n != 0
+       && (idx % width) == 0
+       && (n % width) == 0
+       && ((idx + n) / width) <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (ctor)))
+    (with
+     {
+       idx = idx / width;
+       n = n / width;
+       /* Constructor elements can be subvectors.  */
+       unsigned HOST_WIDE_INT k = 1;
+       if (CONSTRUCTOR_NELTS (ctor) != 0)
+         {
+           tree cons_elem = TREE_TYPE (CONSTRUCTOR_ELT (ctor, 0)->value);
+          if (TREE_CODE (cons_elem) == VECTOR_TYPE)
+            k = TYPE_VECTOR_SUBPARTS (cons_elem);
+        }
+     }
+     (switch
+      /* We keep an exact subset of the constructor elements.  */
+      (if ((idx % k) == 0 && (n % k) == 0)
+       (if (CONSTRUCTOR_NELTS (ctor) == 0)
+        { build_constructor (type, NULL); }
+       (with
+        {
+          idx /= k;
+          n /= k;
+        }
+        (if (n == 1)
+         (if (idx < CONSTRUCTOR_NELTS (ctor))
+          { CONSTRUCTOR_ELT (ctor, idx)->value; }
+          { build_zero_cst (type); })
+         {
+           vec<constructor_elt, va_gc> *vals;
+           vec_alloc (vals, n);
+           for (unsigned i = 0;
+                i < n && idx + i < CONSTRUCTOR_NELTS (ctor); ++i)
+             CONSTRUCTOR_APPEND_ELT (vals, NULL_TREE,
+                                     CONSTRUCTOR_ELT (ctor, idx + i)->value);
+           build_constructor (type, vals);
+         }))))
+      /* The bitfield references a single constructor element.  */
+      (if (idx + n <= (idx / k + 1) * k)
+       (switch
+        (if (CONSTRUCTOR_NELTS (ctor) <= idx / k)
+        { build_zero_cst (type); })
+       (if (n == k)
+        { CONSTRUCTOR_ELT (ctor, idx / k)->value; })
+       (BIT_FIELD_REF { CONSTRUCTOR_ELT (ctor, idx / k)->value; }
+                      @1 { bitsize_int ((idx % k) * width); })))))))))