From e98d8253b951e048c18dab5ea06a8bad5ebb522b Mon Sep 17 00:00:00 2001
From: Timo Teras <timo.teras@iki.fi>
Date: Tue, 14 Jul 2009 14:08:15 +0300
Subject: [PATCH] blob: add some likelyness to help compiler optimizations
---
src/apk_defines.h | 12 ++++++++++++
src/blob.c | 24 ++++++++++++------------
2 files changed, 24 insertions(+), 12 deletions(-)
diff --git a/src/apk_defines.h b/src/apk_defines.h
index 49ca9ebf984c..c8a3622f2a19 100644
--- a/src/apk_defines.h
+++ b/src/apk_defines.h
@@ -30,6 +30,18 @@
#define NULL 0L
#endif
+#if defined __GNUC__ && __GNUC__ == 2 && __GNUC_MINOR__ < 96
+#define __builtin_expect(x, expected_value) (x)
+#endif
+
+#ifndef likely
+#define likely(x) __builtin_expect((!!(x)),1)
+#endif
+
+#ifndef unlikely
+#define unlikely(x) __builtin_expect((!!(x)),0)
+#endif
+
#ifndef container_of
#define container_of(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
diff --git a/src/blob.c b/src/blob.c
index cbcb31221ad7..73d39ec45e89 100644
--- a/src/blob.c
+++ b/src/blob.c
@@ -142,9 +142,9 @@ int apk_blob_for_each_segment(apk_blob_t blob, const char *split,
static inline int dx(int c)
{
- if (c >= '0' && c <= '9')
+ if (likely(c >= '0' && c <= '9'))
return c - '0';
- if (c >= 'a' && c <= 'f')
+ if (likely(c >= 'a' && c <= 'f'))
return c - 'a' + 0xa;
if (c >= 'A' && c <= 'F')
return c - 'A' + 0xa;
@@ -153,10 +153,10 @@ static inline int dx(int c)
void apk_blob_push_blob(apk_blob_t *to, apk_blob_t literal)
{
- if (APK_BLOB_IS_NULL(*to))
+ if (unlikely(APK_BLOB_IS_NULL(*to)))
return;
- if (to->len < literal.len) {
+ if (unlikely(to->len < literal.len)) {
*to = APK_BLOB_NULL;
return;
}
@@ -191,10 +191,10 @@ void apk_blob_push_hexdump(apk_blob_t *to, apk_blob_t binary)
char *d;
int i;
- if (APK_BLOB_IS_NULL(*to))
+ if (unlikely(APK_BLOB_IS_NULL(*to)))
return;
- if (to->len < binary.len * 2) {
+ if (unlikely(to->len < binary.len * 2)) {
*to = APK_BLOB_NULL;
return;
}
@@ -209,9 +209,9 @@ void apk_blob_push_hexdump(apk_blob_t *to, apk_blob_t binary)
void apk_blob_pull_char(apk_blob_t *b, int expected)
{
- if (APK_BLOB_IS_NULL(*b))
+ if (unlikely(APK_BLOB_IS_NULL(*b)))
return;
- if (b->len < 1 || b->ptr[0] != expected) {
+ if (unlikely(b->len < 1 || b->ptr[0] != expected)) {
*b = APK_BLOB_NULL;
return;
}
@@ -244,18 +244,18 @@ void apk_blob_pull_hexdump(apk_blob_t *b, apk_blob_t to)
char *s, *d;
int i, r1, r2;
- if (APK_BLOB_IS_NULL(*b))
+ if (unlikely(APK_BLOB_IS_NULL(*b)))
return;
- if (to.len > b->len * 2)
+ if (unlikely(to.len > b->len * 2))
goto err;
for (i = 0, s = b->ptr, d = to.ptr; i < to.len; i++) {
r1 = dx(*(s++));
- if (r1 < 0)
+ if (unlikely(r1 < 0))
goto err;
r2 = dx(*(s++));
- if (r2 < 0)
+ if (unlikely(r2 < 0))
goto err;
*(d++) = (r1 << 4) + r2;
}
--
GitLab