From: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Date: Fri, 15 Jul 2016 00:23:31 +0000 (+0900)
Subject: mixer: remove alloca() from simple_add1()
X-Git-Tag: v1.1.2~16
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=c2a59624f124eafee1e441af248165b32fe515e3;p=alsa-lib.git

mixer: remove alloca() from simple_add1()

Both of alloca() and automatic variables keep storages on stack, while
the former generates more instructions than the latter. It's better to use
the latter if the size of storage is computable at pre-compile or compile
time; i.e. just for structures.

This commit obsolete usages of alloca() with automatic variables.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

diff --git a/src/mixer/simple_none.c b/src/mixer/simple_none.c
index 1ccccc42..68ab37eb 100644
--- a/src/mixer/simple_none.c
+++ b/src/mixer/simple_none.c
@@ -1419,18 +1419,17 @@ static int simple_add1(snd_mixer_class_t *class, const char *name,
 	snd_mixer_selem_id_t *id;
 	int new = 0;
 	int err;
-	snd_ctl_elem_info_t *info;
+	snd_ctl_elem_info_t info = {0};
 	selem_none_t *simple;
 	const char *name1;
 	snd_ctl_elem_type_t ctype;
 	unsigned long values;
 
-	snd_ctl_elem_info_alloca(&info);
-	err = snd_hctl_elem_info(helem, info);
+	err = snd_hctl_elem_info(helem, &info);
 	if (err < 0)
 		return err;
-	ctype = snd_ctl_elem_info_get_type(info);
-	values = snd_ctl_elem_info_get_count(info);
+	ctype = snd_ctl_elem_info_get_type(&info);
+	values = snd_ctl_elem_info_get_count(&info);
 	switch (type) {
 	case CTL_SINGLE:
 		if (ctype == SND_CTL_ELEM_TYPE_ENUMERATED)
@@ -1553,20 +1552,20 @@ static int simple_add1(snd_mixer_class_t *class, const char *name,
 		goto __error;
 	}
 	simple->ctls[type].elem = helem;
-	simple->ctls[type].type = snd_ctl_elem_info_get_type(info);
-	simple->ctls[type].inactive = snd_ctl_elem_info_is_inactive(info);
+	simple->ctls[type].type = snd_ctl_elem_info_get_type(&info);
+	simple->ctls[type].inactive = snd_ctl_elem_info_is_inactive(&info);
 	simple->ctls[type].values = values;
 	if ( (type == CTL_GLOBAL_ENUM) ||
 	     (type == CTL_PLAYBACK_ENUM) ||
 	     (type == CTL_CAPTURE_ENUM) ) {
 		simple->ctls[type].min = 0;
-		simple->ctls[type].max = snd_ctl_elem_info_get_items(info);
+		simple->ctls[type].max = snd_ctl_elem_info_get_items(&info);
 	} else {
 		if (ctype == SND_CTL_ELEM_TYPE_INTEGER) {
 			simple->ctls[type].min =
-					snd_ctl_elem_info_get_min(info);
+					snd_ctl_elem_info_get_min(&info);
 			simple->ctls[type].max =
-					snd_ctl_elem_info_get_max(info);
+					snd_ctl_elem_info_get_max(&info);
 		}
 	}
 	switch (type) {