optimize ntohl etc. in terms of bswap functions

we can do this without violating the namespace now that they are
macros/inline functions rather than extern functions. the motivation
is that gcc was generating giant, slow, horrible code for the old
functions, and now generates a single byte-swapping instruction.

diff --git a/src/network/htonl.c b/src/network/htonl.c
index b21dace..6622d16 100644 (file)
--- a/src/network/htonl.c
+++ b/src/network/htonl.c
@@ -1,10 +1,8 @@
 #include <netinet/in.h>
+#include <byteswap.h>
 
 uint32_t htonl(uint32_t n)
 {
-       union {
-               uint8_t b[4];
-               uint32_t i;
-       } u = { { n>>24, n>>16, n>>8, n } };
-       return u.i;
+       union { int i; char c; } u = { 1 };
+       return u.c ? bswap_32(n) : n;
 }

diff --git a/src/network/htons.c b/src/network/htons.c
index 522504a..03a3a1d 100644 (file)
--- a/src/network/htons.c
+++ b/src/network/htons.c
@@ -1,10 +1,8 @@
 #include <netinet/in.h>
+#include <byteswap.h>
 
 uint16_t htons(uint16_t n)
 {
-       union {
-               uint8_t b[2];
-               uint16_t s;
-       } u = { { n>>8, n } };
-       return u.s;
+       union { int i; char c; } u = { 1 };
+       return u.c ? bswap_16(n) : n;
 }

diff --git a/src/network/ntohl.c b/src/network/ntohl.c
index 6437919..d6fce45 100644 (file)
--- a/src/network/ntohl.c
+++ b/src/network/ntohl.c
@@ -1,10 +1,8 @@
 #include <netinet/in.h>
+#include <byteswap.h>
 
 uint32_t ntohl(uint32_t n)
 {
-       union {
-               uint32_t i;
-               uint8_t b[4];
-       } u = { n };
-       return (u.b[0]<<24) | (u.b[1]<<16) | (u.b[2]<<8) | u.b[3];
+       union { int i; char c; } u = { 1 };
+       return u.c ? bswap_32(n) : n;
 }

diff --git a/src/network/ntohs.c b/src/network/ntohs.c
index 3544a47..745cef4 100644 (file)
--- a/src/network/ntohs.c
+++ b/src/network/ntohs.c
@@ -1,10 +1,8 @@
 #include <netinet/in.h>
+#include <byteswap.h>
 
 uint16_t ntohs(uint16_t n)
 {
-       union {
-               uint16_t s;
-               uint8_t b[2];
-       } u = { n };
-       return (u.b[0]<<8) | u.b[1];
+       union { int i; char c; } u = { 1 };
+       return u.c ? bswap_16(n) : n;
 }