From a4b6748cb5eaa6a9269f4437fc31230b893cd03a Mon Sep 17 00:00:00 2001
From: skywind3000 <skywind3000@163.com>
Date: Tue, 23 Jul 2019 14:20:31 +0800
Subject: [PATCH] new: meet armv7 bus alignment requirements fixed: ambiguous
 variable names.

---
 ikcp.c | 12 ++++++------
 ikcp.h | 13 ++++++++++++-
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/ikcp.c b/ikcp.c
index bb1a0c6..42e3a18 100644
--- a/ikcp.c
+++ b/ikcp.c
@@ -66,7 +66,7 @@ static inline const char *ikcp_decode8u(const char *p, unsigned char *c)
 /* encode 16 bits unsigned int (lsb) */
 static inline char *ikcp_encode16u(char *p, unsigned short w)
 {
-#if IWORDS_BIG_ENDIAN
+#if IWORDS_BIG_ENDIAN || IWORDS_MUST_ALIGN
 	*(unsigned char*)(p + 0) = (w & 255);
 	*(unsigned char*)(p + 1) = (w >> 8);
 #else
@@ -79,7 +79,7 @@ static inline char *ikcp_encode16u(char *p, unsigned short w)
 /* decode 16 bits unsigned int (lsb) */
 static inline const char *ikcp_decode16u(const char *p, unsigned short *w)
 {
-#if IWORDS_BIG_ENDIAN
+#if IWORDS_BIG_ENDIAN || IWORDS_MUST_ALIGN
 	*w = *(const unsigned char*)(p + 1);
 	*w = *(const unsigned char*)(p + 0) + (*w << 8);
 #else
@@ -92,7 +92,7 @@ static inline const char *ikcp_decode16u(const char *p, unsigned short *w)
 /* encode 32 bits unsigned int (lsb) */
 static inline char *ikcp_encode32u(char *p, IUINT32 l)
 {
-#if IWORDS_BIG_ENDIAN
+#if IWORDS_BIG_ENDIAN || IWORDS_MUST_ALIGN
 	*(unsigned char*)(p + 0) = (unsigned char)((l >>  0) & 0xff);
 	*(unsigned char*)(p + 1) = (unsigned char)((l >>  8) & 0xff);
 	*(unsigned char*)(p + 2) = (unsigned char)((l >> 16) & 0xff);
@@ -107,7 +107,7 @@ static inline char *ikcp_encode32u(char *p, IUINT32 l)
 /* decode 32 bits unsigned int (lsb) */
 static inline const char *ikcp_decode32u(const char *p, IUINT32 *l)
 {
-#if IWORDS_BIG_ENDIAN
+#if IWORDS_BIG_ENDIAN || IWORDS_MUST_ALIGN
 	*l = *(const unsigned char*)(p + 3);
 	*l = *(const unsigned char*)(p + 2) + (*l << 8);
 	*l = *(const unsigned char*)(p + 1) + (*l << 8);
@@ -741,7 +741,7 @@ void ikcp_parse_data(ikcpcb *kcp, IKCPSEG *newseg)
 //---------------------------------------------------------------------
 int ikcp_input(ikcpcb *kcp, const char *data, long size)
 {
-	IUINT32 una = kcp->snd_una;
+	IUINT32 prev_una = kcp->snd_una;
 	IUINT32 maxack = 0;
 	int flag = 0;
 
@@ -856,7 +856,7 @@ int ikcp_input(ikcpcb *kcp, const char *data, long size)
 		ikcp_parse_fastack(kcp, maxack);
 	}
 
-	if (_itimediff(kcp->snd_una, una) > 0) {
+	if (_itimediff(kcp->snd_una, prev_una) > 0) {
 		if (kcp->cwnd < kcp->rmt_wnd) {
 			IUINT32 mss = kcp->mss;
 			if (kcp->cwnd < kcp->ssthresh) {
diff --git a/ikcp.h b/ikcp.h
index 866d188..5652ae2 100644
--- a/ikcp.h
+++ b/ikcp.h
@@ -225,7 +225,7 @@ typedef struct IQUEUEHEAD iqueue_head;
 
 
 //---------------------------------------------------------------------
-// WORD ORDER
+// BYTE ORDER & ALIGNMENT
 //---------------------------------------------------------------------
 #ifndef IWORDS_BIG_ENDIAN
     #ifdef _BIG_ENDIAN_
@@ -248,6 +248,17 @@ typedef struct IQUEUEHEAD iqueue_head;
     #endif
 #endif
 
+#ifndef IWORDS_MUST_ALIGN
+	#if defined(__i386__) || defined(__i386) || defined(_i386_)
+		#define IWORDS_MUST_ALIGN 0
+	#elif defined(_M_IX86) || defined(_X86_) || defined(__x86_64__)
+		#define IWORDS_MUST_ALIGN 0
+	#elif defined(__amd64) || defined(__amd64__)
+		#define IWORDS_MUST_ALIGN 0
+	#else
+		#define IWORDS_MUST_ALIGN 1
+	#endif
+#endif
 
 
 //=====================================================================