hexdump: do a few calculations ahead

Instead of doing calculations in each case of different groupsize let's do
them beforehand.  While there, change the switch to an if-else-if
construction.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/hexdump.c b/lib/hexdump.c
index a61cb6b1f0119f95aeff9724d68e6dbd5b521304..4af53f73c7ccd4306d99adc5d41d115505bb9e5b 100644 (file)
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -103,6 +103,7 @@ void hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
                        bool ascii)
 {
        const u8 *ptr = buf;
+       int ngroups;
        u8 ch;
        int j, lx = 0;
        int ascii_column;
@@ -114,45 +115,33 @@ void hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
                goto nil;
        if (len > rowsize)              /* limit to one line at a time */
                len = rowsize;
+       if (!is_power_of_2(groupsize) || groupsize > 8)
+               groupsize = 1;
        if ((len % groupsize) != 0)     /* no mixed size output */
                groupsize = 1;
 
-       switch (groupsize) {
-       case 8: {
+       ngroups = len / groupsize;
+       ascii_column = rowsize * 2 + rowsize / groupsize + 1;
+       if (groupsize == 8) {
                const u64 *ptr8 = buf;
-               int ngroups = len / groupsize;
 
                for (j = 0; j < ngroups; j++)
                        lx += scnprintf(linebuf + lx, linebuflen - lx,
                                        "%s%16.16llx", j ? " " : "",
                                        (unsigned long long)*(ptr8 + j));
-               ascii_column = rowsize * 2 + rowsize / 8 + 2;
-               break;
-       }
-
-       case 4: {
+       } else if (groupsize == 4) {
                const u32 *ptr4 = buf;
-               int ngroups = len / groupsize;
 
                for (j = 0; j < ngroups; j++)
                        lx += scnprintf(linebuf + lx, linebuflen - lx,
                                        "%s%8.8x", j ? " " : "", *(ptr4 + j));
-               ascii_column = rowsize * 2 + rowsize / 4 + 2;
-               break;
-       }
-
-       case 2: {
+       } else if (groupsize == 2) {
                const u16 *ptr2 = buf;
-               int ngroups = len / groupsize;
 
                for (j = 0; j < ngroups; j++)
                        lx += scnprintf(linebuf + lx, linebuflen - lx,
                                        "%s%4.4x", j ? " " : "", *(ptr2 + j));
-               ascii_column = rowsize * 2 + rowsize / 2 + 2;
-               break;
-       }
-
-       default:
+       } else {
                for (j = 0; (j < len) && (lx + 3) <= linebuflen; j++) {
                        ch = ptr[j];
                        linebuf[lx++] = hex_asc_hi(ch);
@@ -161,14 +150,11 @@ void hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
                }
                if (j)
                        lx--;
-
-               ascii_column = 3 * rowsize + 2;
-               break;
        }
        if (!ascii)
                goto nil;
 
-       while (lx < (linebuflen - 1) && lx < (ascii_column - 1))
+       while (lx < (linebuflen - 1) && lx < ascii_column)
                linebuf[lx++] = ' ';
        for (j = 0; (j < len) && (lx + 2) < linebuflen; j++) {
                ch = ptr[j];