* stor-layout.c (round_up, round_down): Move ...

        * fold-const.c (round_up, round_down): ... here.  Use
        multiple_of_p to avoid any arithmetic at all.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@85848 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 70 insertions, 0 deletions

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 0b225c05e02..f7e90be6eaa 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -10678,4 +10678,74 @@ fold_ignored_result (tree t)
       }
 }
 
+/* Return the value of VALUE, rounded up to a multiple of DIVISOR.
+   This can only be applied to objects of a sizetype.  */
+
+tree
+round_up (tree value, int divisor)
+{
+  tree div, t;
+
+  if (divisor == 0)
+    abort ();
+  if (divisor == 1)
+    return value;
+
+  div = size_int_type (divisor, TREE_TYPE (value));
+
+  /* See if VALUE is already a multiple of DIVISOR.  If so, we don't
+     have to do anything.  */
+  if (multiple_of_p (TREE_TYPE (value), value, div))
+    return value;
+
+  /* If divisor is a power of two, simplify this to bit manipulation.  */
+  if (divisor == (divisor & -divisor))
+    {
+      t = size_int_type (divisor - 1, TREE_TYPE (value));
+      value = size_binop (PLUS_EXPR, value, t);
+      t = size_int_type (-divisor, TREE_TYPE (value));
+      value = size_binop (BIT_AND_EXPR, value, t);
+    }
+  else
+    {
+      value = size_binop (CEIL_DIV_EXPR, value, div);
+      value = size_binop (MULT_EXPR, value, div);
+    }
+
+  return value;
+}
+
+/* Likewise, but round down.  */
+
+tree
+round_down (tree value, int divisor)
+{
+  tree div, t;
+
+  if (divisor == 0)
+    abort ();
+  if (divisor == 1)
+    return value;
+
+  div = size_int_type (divisor, TREE_TYPE (value));
+
+  /* See if VALUE is already a multiple of DIVISOR.  If so, we don't
+     have to do anything.  */
+  if (multiple_of_p (TREE_TYPE (value), value, div))
+    return value;
+
+  /* If divisor is a power of two, simplify this to bit manipulation.  */
+  if (divisor == (divisor & -divisor))
+    {
+      t = size_int_type (-divisor, TREE_TYPE (value));
+      value = size_binop (BIT_AND_EXPR, value, t);
+    }
+  else
+    {
+      value = size_binop (FLOOR_DIV_EXPR, value, div);
+      value = size_binop (MULT_EXPR, value, div);
+    }
+
+  return value;
+}
 #include "gt-fold-const.h"