fix -O3 for sysvchecksum

2 files changed, 13 insertions, 10 deletions

diff --git a/src/hash/sysvchecksum.c b/src/hash/sysvchecksum.c
index 661ee8d..107a998 100644
--- a/src/hash/sysvchecksum.c
+++ b/src/hash/sysvchecksum.c
@@ -12,12 +12,15 @@ void sysvchecksum_update(uint8_t* aa, size_t len, struct sysvchecksum_hash* hash
     hash->check += aa[i];

 }

 

-uint32_t sysvchecksum_final(struct sysvchecksum_hash* hash){

-  uint32_t r = hash->check % (int)pow(2,16) + (hash->check % (int)pow(2,32)) / (int)pow(2,16);

-  return (r % (int)pow(2,16)) + r / (int)pow(2,16);

+uint16_t sysvchecksum_final(struct sysvchecksum_hash* hash){

+  //uint16_t r = hash->check % (int)pow(2,16) + (hash->check % (int)pow(2,32)) / (int)pow(2,16);

+  //return (r % (int)pow(2,16)) + (r / (int)pow(2,16));

+  //rewrote from https://github.com/cxmcc/unixsums/blob/master/sysvsum/sysvsum.go, pow breaks with clang -O3 somehow

+  uint32_t r = (hash->check & 0xffff) + (hash->check >> 16);

+  return r & 0xffff + (r >> 16);

 }

 

-uint32_t sysvchecksum(uint8_t* aa, size_t len){

+uint16_t sysvchecksum(uint8_t* aa, size_t len){

   struct sysvchecksum_hash a = sysvchecksum_init();

   sysvchecksum_update(aa, len, &a);

   return sysvchecksum_final(&a);

@@ -28,8 +31,8 @@ common_hash_init_update(sysvchecksum);
 

 int l_sysvchecksum_final(lua_State* L){

   struct sysvchecksum_hash* a = (struct sysvchecksum_hash*)lua_touserdata(L, 1);

-  uint32_t u = sysvchecksum_final(a);

-  char digest[32];

+  uint16_t u = sysvchecksum_final(a);

+  char digest[16];

   sprintf(digest,"%x",u);

   lua_pushstring(L, digest);

   return 1;

@@ -40,9 +43,9 @@ int l_sysvchecksum(lua_State* L){
   size_t len = 0;

   uint8_t* a = (uint8_t*)luaL_checklstring(L, 1, &len);

   

-  char digest[32];

+  char digest[16];

 

-  uint32_t u = sysvchecksum(a, len);

+  uint16_t u = sysvchecksum(a, len);

   sprintf(digest,"%x",u);

   lua_pushstring(L, digest);

 

diff --git a/src/hash/sysvchecksum.h b/src/hash/sysvchecksum.h
index 3414f7f..cae322d 100644
--- a/src/hash/sysvchecksum.h
+++ b/src/hash/sysvchecksum.h
@@ -7,8 +7,8 @@ struct sysvchecksum_hash {
 
 struct sysvchecksum_hash sysvchecksum_init();
 void sysvchecksum_update(uint8_t*, size_t, struct sysvchecksum_hash*);
-uint32_t sysvchecksum_final(struct sysvchecksum_hash*);
-uint32_t sysvchecksum(uint8_t*, size_t);
+uint16_t sysvchecksum_final(struct sysvchecksum_hash*);
+uint16_t sysvchecksum(uint8_t*, size_t);
 
 int l_sysvchecksum(lua_State*);
 int l_sysvchecksum_init(lua_State*);