ilog2(): inline functions if practical

For many (most?) targets these will be very small functions, so inline
them.  However, just in case make these external library functions.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 2 insertions, 184 deletions

diff --git a/nasmlib/ilog2.c b/nasmlib/ilog2.c
index 7f4624f5..cba22248 100644
--- a/nasmlib/ilog2.c
+++ b/nasmlib/ilog2.c
@@ -1,184 +1,2 @@
-/* ----------------------------------------------------------------------- *
- *
- *   Copyright 1996-2017 The NASM Authors - All Rights Reserved
- *   See the file AUTHORS included with the NASM distribution for
- *   the specific copyright holders.
- *
- *   Redistribution and use in source and binary forms, with or without
- *   modification, are permitted provided that the following
- *   conditions are met:
- *
- *   * Redistributions of source code must retain the above copyright
- *     notice, this list of conditions and the following disclaimer.
- *   * Redistributions in binary form must reproduce the above
- *     copyright notice, this list of conditions and the following
- *     disclaimer in the documentation and/or other materials provided
- *     with the distribution.
- *
- *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
- *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
- *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
- *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
- *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * ----------------------------------------------------------------------- */
-
-#include "compiler.h"
-#include "nasmlib.h"
-#include <limits.h>
-
-#define ROUND(v, a, w)                                  \
-    do {                                                \
-        if (v & (((UINT32_C(1) << w) - 1) << w)) {      \
-            a  += w;                                    \
-            v >>= w;                                    \
-        }                                               \
-    } while (0)
-
-
-#if defined(__GNUC__) && defined(__x86_64__)
-
-int ilog2_32(uint32_t v)
-{
-    int n;
-
-    __asm__("bsrl %1,%0"
-            : "=r" (n)
-            : "rm" (v), "0" (0));
-    return n;
-}
-
-#elif defined(__GNUC__) && defined(__i386__)
-
-int ilog2_32(uint32_t v)
-{
-    int n;
-
-#ifdef __i686__
-    __asm__("bsrl %1,%0 ; cmovz %2,%0\n"
-            : "=&r" (n)
-            : "rm" (v), "r" (0));
-#else
-    __asm__("bsrl %1,%0 ; jnz 1f ; xorl %0,%0\n"
-            "1:"
-            : "=&r" (n)
-            : "rm" (v));
-#endif
-     return n;
-}
-
-#elif defined(HAVE___BUILTIN_CLZ) && INT_MAX == 2147483647
-
-int ilog2_32(uint32_t v)
-{
-    if (!v)
-        return 0;
-
-    return __builtin_clz(v) ^ 31;
-}
-
-#elif defined(HAVE__BITSCANREVERSE)
-
-int ilog2_32(uint32_t v)
-{
-    unsigned long ix;
-    return _BitScanReverse(&ix, v) ? v : 0;
-}
-
-#else
-
-int ilog2_32(uint32_t v)
-{
-    int p = 0;
-
-    ROUND(v, p, 16);
-    ROUND(v, p,  8);
-    ROUND(v, p,  4);
-    ROUND(v, p,  2);
-    ROUND(v, p,  1);
-
-    return p;
-}
-
-#endif
-
-#if defined(__GNUC__) && defined(__x86_64__)
-
-int ilog2_64(uint64_t v)
-{
-    uint64_t n;
-
-    __asm__("bsrq %1,%0"
-            : "=r" (n)
-            : "rm" (v), "0" (UINT64_C(0)));
-    return n;
-}
-
-#elif defined(HAVE__BUILTIN_CLZLL) && LLONG_MAX == 9223372036854775807LL
-
-int ilog2_64(uint64_t v)
-{
-    if (!v)
-        return 0;
-
-    return __builtin_clzll(v) ^ 63;
-}
-
-#elif defined(HAVE__BITSCANREVERSE64)
-
-int ilog2_64(uint64_t v)
-{
-    unsigned long ix;
-    return _BitScanReverse64(&ix, v) ? ix : 0;
-}
-
-#else
-
-int ilog2_64(uint64_t vv)
-{
-    int p = 0;
-    uint32_t v;
-
-    v = vv >> 32;
-    if (v)
-        p += 32;
-    else
-        v = vv;
-
-    ROUND(v, p, 16);
-    ROUND(v, p,  8);
-    ROUND(v, p,  4);
-    ROUND(v, p,  2);
-    ROUND(v, p,  1);
-
-    return p;
-}
-
-#endif
-
-/*
- * v == 0 ? 0 : is_power2(x) ? ilog2_X(v) : -1
- */
-int alignlog2_32(uint32_t v)
-{
-    if (unlikely(v & (v-1)))
-        return -1;              /* invalid alignment */
-
-    return ilog2_32(v);
-}
-
-int alignlog2_64(uint64_t v)
-{
-    if (unlikely(v & (v-1)))
-        return -1;              /* invalid alignment */
-
-    return ilog2_64(v);
-}
+#define ILOG2_C
+#include "ilog2.h"