saner perf_atoll()

That loop in there is both anti-idiomatic *and* completely pointless.
strtoll() is there for purpose; use it and compare what's left with
acceptable suffices.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 30 insertions, 60 deletions

diff --git a/tools/perf/util/string.c b/tools/perf/util/string.c
index 2553e5b55b89..d87767f76903 100644
--- a/tools/perf/util/string.c
+++ b/tools/perf/util/string.c
@@ -9,78 +9,48 @@
  */
 s64 perf_atoll(const char *str)
 {
-        unsigned int i;
-        s64 length = -1, unit = 1;
+        s64 length;
+        char *p;
+        char c;
 
         if (!isdigit(str[0]))
                 goto out_err;
 
-        for (i = 1; i < strlen(str); i++) {
-                switch (str[i]) {
-                case 'B':
-                case 'b':
-                        break;
-                case 'K':
-                        if (str[i + 1] != 'B')
-                                goto out_err;
-                        else
-                                goto kilo;
-                case 'k':
-                        if (str[i + 1] != 'b')
-                                goto out_err;
-kilo:
-                        unit = K;
-                        break;
-                case 'M':
-                        if (str[i + 1] != 'B')
-                                goto out_err;
-                        else
-                                goto mega;
-                case 'm':
-                        if (str[i + 1] != 'b')
+        length = strtoll(str, &p, 10);
+        switch (c = *p++) {
+                case 'b': case 'B':
+                        if (*p)
                                 goto out_err;
-mega:
-                        unit = K * K;
+                case '\0':
+                        return length;
+                default:
+                        goto out_err;
+                /* two-letter suffices */
+                case 'k': case 'K':
+                        length <<= 10;
                         break;
-                case 'G':
-                        if (str[i + 1] != 'B')
-                                goto out_err;
-                        else
-                                goto giga;
-                case 'g':
-                        if (str[i + 1] != 'b')
-                                goto out_err;
-giga:
-                        unit = K * K * K;
+                case 'm': case 'M':
+                        length <<= 20;
                         break;
-                case 'T':
-                        if (str[i + 1] != 'B')
-                                goto out_err;
-                        else
-                                goto tera;
-                case 't':
-                        if (str[i + 1] != 'b')
-                                goto out_err;
-tera:
-                        unit = K * K * K * K;
+                case 'g': case 'G':
+                        length <<= 30;
                         break;
-                case '\0':      /* only specified figures */
-                        unit = 1;
+                case 't': case 'T':
+                        length <<= 40;
                         break;
-                default:
-                        if (!isdigit(str[i]))
-                                goto out_err;
-                        break;
-                }
         }
-
-        length = atoll(str) * unit;
-        goto out;
+        /* we want the cases to match */
+        if (islower(c)) {
+                if (strcmp(p, "b") != 0)
+                        goto out_err;
+        } else {
+                if (strcmp(p, "B") != 0)
+                        goto out_err;
+        }
+        return length;
 
 out_err:
-        length = -1;
-out:
-        return length;
+        return -1;
 }
 
 /*