Re: [PATCH 2/2] if-to-switch conversion pass -- infrastructure

[Tom de Vries]

On 17/07/12 13:21, Tom de Vries wrote:
> attached patch implements an if-to-switch conversion tree pass
> pass_if_to_switch. I will follow up this email with an infrastructure patch 
> that
> provides double_int_popcount and popcount_hwi.

Bootstrapped and reg-tested (Ada inclusive) on x86_64, with pass_if_to_switch as
only client.

OK for trunk?

Thanks,
- Tom

2012-07-16  Tom de Vries  <t...@codesourcery.com>

        * double-int.h (double_int_popcount): New inline function.
        * hwint.c (popcount_hwi): New function.
        * hwint.h (popcount_hwi): Declare function.  New inline function.

Index: gcc/double-int.h
===================================================================
--- gcc/double-int.h (revision 189508)
+++ gcc/double-int.h (working copy)
@@ -284,6 +284,14 @@ double_int_equal_p (double_int cst1, dou
   return cst1.low == cst2.low && cst1.high == cst2.high;
 }
 
+/* Return number of set bits of CST.  */
+
+static inline int
+double_int_popcount (double_int cst)
+{
+  return popcount_hwi (cst.high) + popcount_hwi (cst.low);
+}
+
 
 /* Legacy interface with decomposed high/low parts.  */
 
Index: gcc/hwint.c
===================================================================
--- gcc/hwint.c (revision 189508)
+++ gcc/hwint.c (working copy)
@@ -107,6 +107,22 @@ ffs_hwi (unsigned HOST_WIDE_INT x)
   return 1 + floor_log2 (x & -x);
 }
 
+/* Return the number of set bits in X.  */
+
+int
+popcount_hwi (unsigned HOST_WIDE_INT x)
+{
+  int i, ret = 0;
+
+  for (i = 0; i < sizeof (x); i += 1)
+    {
+      ret += x & 1;
+      x >>= 1;
+    }
+
+  return ret;
+}
+
 #endif /* GCC_VERSION < 3004 */
 

Index: gcc/hwint.h
===================================================================
--- gcc/hwint.h (revision 189508)
+++ gcc/hwint.h (working copy)
@@ -179,6 +179,9 @@ extern int clz_hwi (unsigned HOST_WIDE_I
 extern int ctz_hwi (unsigned HOST_WIDE_INT x);
 extern int ffs_hwi (unsigned HOST_WIDE_INT x);
 
+/* Return the number of set bits in X.  */
+extern int popcount_hwi (unsigned HOST_WIDE_INT x);
+
 /* Return log2, or -1 if not exact.  */
 extern int exact_log2                  (unsigned HOST_WIDE_INT);
 
@@ -231,6 +234,18 @@ ffs_hwi (unsigned HOST_WIDE_INT x)
 # endif
 }
 
+static inline int
+popcount_hwi (unsigned HOST_WIDE_INT x)
+{
+# if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONG
+  return __builtin_popcountl (x);
+# elif HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONGLONG
+  return __builtin_popcountll (x);
+# else
+  return __builtin_popcount (x);
+# endif
+}
+
 static inline int
 floor_log2 (unsigned HOST_WIDE_INT x)
 {