Update from gnulib.

4 files changed, 114 insertions, 44 deletions

diff --git a/gettext-runtime/intl/ChangeLog b/gettext-runtime/intl/ChangeLog
index 87af1145a..cb55f3a44 100644
--- a/gettext-runtime/intl/ChangeLog
+++ b/gettext-runtime/intl/ChangeLog
@@ -1,5 +1,11 @@
 2011-10-15  Bruno Haible  <bruno@clisp.org>
 
+	vasnprintf: Optimize bit search operation.
+	* vasnprintf.c (divide): Use optimizations from gnulib's
+	integer_length.c.
+
+2011-10-15  Bruno Haible  <bruno@clisp.org>
+
 	vasnprintf: Fix comments.
 	* vasnprintf.c (decode_long_double, decode_double): Fix comments.
 
diff --git a/gettext-runtime/intl/vasnprintf.c b/gettext-runtime/intl/vasnprintf.c
index 665d59953..c6676c0ab 100644
--- a/gettext-runtime/intl/vasnprintf.c
+++ b/gettext-runtime/intl/vasnprintf.c
@@ -552,32 +552,61 @@ divide (mpn_t a, mpn_t b, mpn_t *q)
       size_t s;
       {
         mp_limb_t msd = b_ptr[b_len - 1]; /* = b[n-1], > 0 */
-        s = 31;
-        if (msd >= 0x10000)
-          {
-            msd = msd >> 16;
-            s -= 16;
-          }
-        if (msd >= 0x100)
-          {
-            msd = msd >> 8;
-            s -= 8;
-          }
-        if (msd >= 0x10)
-          {
-            msd = msd >> 4;
-            s -= 4;
-          }
-        if (msd >= 0x4)
+        /* Determine s = GMP_LIMB_BITS - integer_length (msd).
+           Code copied from gnulib's integer_length.c.  */
+# if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+        s = __builtin_clz (msd);
+# else
+#  if defined DBL_EXPBIT0_WORD && defined DBL_EXPBIT0_BIT
+        if (GMP_LIMB_BITS <= DBL_MANT_BIT)
           {
-            msd = msd >> 2;
-            s -= 2;
+            /* Use 'double' operations.
+               Assumes an IEEE 754 'double' implementation.  */
+#   define DBL_EXP_MASK ((DBL_MAX_EXP - DBL_MIN_EXP) | 7)
+#   define DBL_EXP_BIAS (DBL_EXP_MASK / 2 - 1)
+#   define NWORDS \
+     ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
+            union { double value; unsigned int word[NWORDS]; } m;
+
+            /* Use a single integer to floating-point conversion.  */
+            m.value = msd;
+
+            s = GMP_LIMB_BITS
+                - (((m.word[DBL_EXPBIT0_WORD] >> DBL_EXPBIT0_BIT) & DBL_EXP_MASK)
+                   - DBL_EXP_BIAS);
           }
-        if (msd >= 0x2)
+        else
+#   undef NWORDS
+#  endif
           {
-            msd = msd >> 1;
-            s -= 1;
+            s = 31;
+            if (msd >= 0x10000)
+              {
+                msd = msd >> 16;
+                s -= 16;
+              }
+            if (msd >= 0x100)
+              {
+                msd = msd >> 8;
+                s -= 8;
+              }
+            if (msd >= 0x10)
+              {
+                msd = msd >> 4;
+                s -= 4;
+              }
+            if (msd >= 0x4)
+              {
+                msd = msd >> 2;
+                s -= 2;
+              }
+            if (msd >= 0x2)
+              {
+                msd = msd >> 1;
+                s -= 1;
+              }
           }
+# endif
       }
       /* 0 <= s < GMP_LIMB_BITS.
          Copy b, shifting it left by s bits.  */
diff --git a/gettext-runtime/libasprintf/ChangeLog b/gettext-runtime/libasprintf/ChangeLog
index da626d5a1..7032d0014 100644
--- a/gettext-runtime/libasprintf/ChangeLog
+++ b/gettext-runtime/libasprintf/ChangeLog
@@ -1,5 +1,11 @@
 2011-10-15  Bruno Haible  <bruno@clisp.org>
 
+	vasnprintf: Optimize bit search operation.
+	* vasnprintf.c (divide): Use optimizations from gnulib's
+	integer_length.c.
+
+2011-10-15  Bruno Haible  <bruno@clisp.org>
+
 	vasnprintf: Fix comments.
 	* vasnprintf.c (decode_long_double, decode_double): Fix comments.
 
diff --git a/gettext-runtime/libasprintf/vasnprintf.c b/gettext-runtime/libasprintf/vasnprintf.c
index 665d59953..c6676c0ab 100644
--- a/gettext-runtime/libasprintf/vasnprintf.c
+++ b/gettext-runtime/libasprintf/vasnprintf.c
@@ -552,32 +552,61 @@ divide (mpn_t a, mpn_t b, mpn_t *q)
       size_t s;
       {
         mp_limb_t msd = b_ptr[b_len - 1]; /* = b[n-1], > 0 */
-        s = 31;
-        if (msd >= 0x10000)
-          {
-            msd = msd >> 16;
-            s -= 16;
-          }
-        if (msd >= 0x100)
-          {
-            msd = msd >> 8;
-            s -= 8;
-          }
-        if (msd >= 0x10)
-          {
-            msd = msd >> 4;
-            s -= 4;
-          }
-        if (msd >= 0x4)
+        /* Determine s = GMP_LIMB_BITS - integer_length (msd).
+           Code copied from gnulib's integer_length.c.  */
+# if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+        s = __builtin_clz (msd);
+# else
+#  if defined DBL_EXPBIT0_WORD && defined DBL_EXPBIT0_BIT
+        if (GMP_LIMB_BITS <= DBL_MANT_BIT)
           {
-            msd = msd >> 2;
-            s -= 2;
+            /* Use 'double' operations.
+               Assumes an IEEE 754 'double' implementation.  */
+#   define DBL_EXP_MASK ((DBL_MAX_EXP - DBL_MIN_EXP) | 7)
+#   define DBL_EXP_BIAS (DBL_EXP_MASK / 2 - 1)
+#   define NWORDS \
+     ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
+            union { double value; unsigned int word[NWORDS]; } m;
+
+            /* Use a single integer to floating-point conversion.  */
+            m.value = msd;
+
+            s = GMP_LIMB_BITS
+                - (((m.word[DBL_EXPBIT0_WORD] >> DBL_EXPBIT0_BIT) & DBL_EXP_MASK)
+                   - DBL_EXP_BIAS);
           }
-        if (msd >= 0x2)
+        else
+#   undef NWORDS
+#  endif
           {
-            msd = msd >> 1;
-            s -= 1;
+            s = 31;
+            if (msd >= 0x10000)
+              {
+                msd = msd >> 16;
+                s -= 16;
+              }
+            if (msd >= 0x100)
+              {
+                msd = msd >> 8;
+                s -= 8;
+              }
+            if (msd >= 0x10)
+              {
+                msd = msd >> 4;
+                s -= 4;
+              }
+            if (msd >= 0x4)
+              {
+                msd = msd >> 2;
+                s -= 2;
+              }
+            if (msd >= 0x2)
+              {
+                msd = msd >> 1;
+                s -= 1;
+              }
           }
+# endif
       }
       /* 0 <= s < GMP_LIMB_BITS.
          Copy b, shifting it left by s bits.  */