target-i386: Simplify listflags() function

listflags() had lots of unnecessary complexity. Instead of printing to a
buffer that will be immediately printed, simply call the printing
function directly. Also, remove the fbits and flags arguments that were
always set to the same value. Also, there's no need to list the flags in
reverse order.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

target-i386/cpu.c

@@ -1911,34 +1911,19 @@ static void x86_cpu_parse_featurestr(CPUState *cs, char *features,
     }
 }
 
-/* generate a composite string into buf of all cpuid names in featureset
- * selected by fbits.  indicate truncation at bufsize in the event of overflow.
- * if flags, suppress names undefined in featureset.
+/* Print all cpuid feature names in featureset
  */
-static void listflags(char *buf, int bufsize, uint32_t fbits,
-                      const char **featureset, uint32_t flags)
-{
-    const char **p = &featureset[31];
-    char *q, *b, bit;
-    int nc;
-
-    b = 4 <= bufsize ? buf + (bufsize -= 3) - 1 : NULL;
-    *buf = '\0';
-    for (q = buf, bit = 31; fbits && bufsize; --p, fbits &= ~(1 << bit), --bit)
-        if (fbits & 1 << bit && (*p || !flags)) {
-            if (*p)
-                nc = snprintf(q, bufsize, "%s%s", q == buf ? "" : " ", *p);
-            else
-                nc = snprintf(q, bufsize, "%s[%d]", q == buf ? "" : " ", bit);
-            if (bufsize <= nc) {
-                if (b) {
-                    memcpy(b, "...", sizeof("..."));
-                }
-                return;
-            }
-            q += nc;
-            bufsize -= nc;
+static void listflags(FILE *f, fprintf_function print, const char **featureset)
+{
+    int bit;
+    bool first = true;
+
+    for (bit = 0; bit < 32; bit++) {
+        if (featureset[bit]) {
+            print(f, "%s%s", first ? "" : " ", featureset[bit]);
+            first = false;
         }
+    }
 }
 
 /* generate CPU information. */
@@ -1963,8 +1948,9 @@ void x86_cpu_list(FILE *f, fprintf_function cpu_fprintf)
     for (i = 0; i < ARRAY_SIZE(feature_word_info); i++) {
         FeatureWordInfo *fw = &feature_word_info[i];
 
-        listflags(buf, sizeof(buf), (uint32_t)~0, fw->feat_names, 1);
-        (*cpu_fprintf)(f, "  %s\n", buf);
+        (*cpu_fprintf)(f, "  ");
+        listflags(f, cpu_fprintf, fw->feat_names);
+        (*cpu_fprintf)(f, "\n");
     }
 }