hashrate: Remove some extra units and allow 4 digits

to keep current X11 output (sample: 2950.01 kH/s)

ccminer.cpp

@@ -528,7 +528,7 @@ static void calc_diff(struct work *work, int known)
 
 static int share_result(int result, const char *reason)
 {
-	char s[345];
+	char s[32] = { 0 };
 	double hashrate = 0.;
 
 	pthread_mutex_lock(&stats_lock);
@@ -542,8 +542,8 @@ static int share_result(int result, const char *reason)
 
 	global_hashrate = llround(hashrate);
 
-	sprintf(s, hashrate >= 1e6 ? "%.0f" : "%.2f", 1e-3 * hashrate);
-	applog(LOG_NOTICE, "accepted: %lu/%lu (%.2f%%), %s khash/s %s",
+	format_hashrate(hashrate, s);
+	applog(LOG_NOTICE, "accepted: %lu/%lu (%.2f%%), %s %s",
 			accepted_count,
 			accepted_count + rejected_count,
 			100. * accepted_count / (accepted_count + rejected_count),

util.cpp

@@ -175,54 +175,31 @@ void get_defconfig_path(char *out, size_t bufsize, char *argv0)
 
 void format_hashrate(double hashrate, char *output)
 {
-	char prefix;
+	char prefix = '\0';
 
-	if (hashrate < 1e3)
-		prefix = ' ';
-	else if (hashrate < 1e6)
-	{
+	if (hashrate < 10000) {
+		// nop
+	}
+	else if (hashrate < 1e7) {
 		prefix = 'k';
 		hashrate *= 1e-3;
 	}
-	else if (hashrate < 1e9)
-	{
+	else if (hashrate < 1e10) {
 		prefix = 'M';
 		hashrate *= 1e-6;
 	}
-	else if (hashrate < 1e12)
-	{
+	else if (hashrate < 1e13) {
 		prefix = 'G';
 		hashrate *= 1e-9;
 	}
-	else if (hashrate < 1e15)
-	{
+	else {
 		prefix = 'T';
 		hashrate *= 1e-12;
 	}
-	else if (hashrate < 1e18)
-	{
-		prefix = 'P';
-		hashrate *= 1e-15;
-	}
-	else if (hashrate < 1e21)
-	{
-		prefix = 'E';
-		hashrate *= 1e-18;
-	}
-	else if (hashrate < 1e24)
-	{
-		prefix = 'Z';
-		hashrate *= 1e-21;
-	}
-	else
-	{
-		prefix = 'Y';
-		hashrate *= 1e-24;
-	}
 
 	sprintf(
 		output,
-		prefix == ' ' ? "%.0f%cH/s" : "%.2f %cH/s",
+		prefix ? "%.2f %cH/s" : "%.2f H/s%c",
 		hashrate, prefix
 	);
 }