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>

1 files changed, 10 insertions, 24 deletions

diff --git a/lib/hexdump.c b/lib/hexdump.c
index a61cb6b1f011..4af53f73c7cc 100644
--- 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];