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Fix strict aliasing violations 

The cast to char** is a violation of strict aliasing rules.
Compilers may generate incorrect code due to this issue.
Using memcpy to avoid the issue. Not expecting perf difference.
This commit is contained in:
Mahesh Madhav 2026-06-16 15:33:12 +00:00
parent 4c08da846a
commit cfd526afd0
2 changed files with 12 additions and 8 deletions
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6
src/aig/hop/hop.h
View File

@ -233,7 +233,7 @@ static inline Hop_Obj_t * Hop_ManFetchMemory( Hop_Man_t * p )
if ( p->pListFree == NULL ) if ( p->pListFree == NULL )
Hop_ManAddMemory( p ); Hop_ManAddMemory( p );
pTemp = p->pListFree; pTemp = p->pListFree;
p->pListFree = *((Hop_Obj_t **)pTemp); memcpy(&p->pListFree, pTemp, sizeof(Hop_Obj_t *));
memset( pTemp, 0, sizeof(Hop_Obj_t) ); memset( pTemp, 0, sizeof(Hop_Obj_t) );
if ( p->vObjs ) if ( p->vObjs )
{ {
@ -245,8 +245,8 @@ static inline Hop_Obj_t * Hop_ManFetchMemory( Hop_Man_t * p )
} }
static inline void Hop_ManRecycleMemory( Hop_Man_t * p, Hop_Obj_t * pEntry ) static inline void Hop_ManRecycleMemory( Hop_Man_t * p, Hop_Obj_t * pEntry )
{ {
pEntry->Type = AIG_NONE; // distinquishes dead node from live node pEntry->Type = AIG_NONE; // distinguishes dead node from live node
*((Hop_Obj_t **)pEntry) = p->pListFree; memcpy(pEntry, &p->pListFree, sizeof(Hop_Obj_t *));
p->pListFree = pEntry; p->pListFree = pEntry;
} }

14
src/aig/hop/hopMem.c
View File

@ -88,14 +88,16 @@ void Hop_ManStopMemory( Hop_Man_t * p )
***********************************************************************/ ***********************************************************************/
void Hop_ManAddMemory( Hop_Man_t * p ) void Hop_ManAddMemory( Hop_Man_t * p )
{ {
char * pMemory; Hop_Obj_t * pMemory;
char *PMemAlign = 0;
int i, nBytes; int i, nBytes;
assert( sizeof(Hop_Obj_t) <= 64 ); assert( sizeof(Hop_Obj_t) <= 64 );
assert( p->pListFree == NULL ); assert( p->pListFree == NULL );
// assert( (Hop_ManObjNum(p) & IVY_PAGE_MASK) == 0 ); // assert( (Hop_ManObjNum(p) & IVY_PAGE_MASK) == 0 );
// allocate new memory page // allocate new memory page
nBytes = sizeof(Hop_Obj_t) * (1<<IVY_PAGE_SIZE) + 64; nBytes = sizeof(Hop_Obj_t) * (1<<IVY_PAGE_SIZE) + 64;
pMemory = ABC_ALLOC( char, nBytes ); PMemAlign = PMemAlign + 64 - (((int)(ABC_PTRUINT_T)PMemAlign) & 63);
pMemory = (Hop_Obj_t *)PMemAlign;
Vec_PtrPush( p->vChunks, pMemory ); Vec_PtrPush( p->vChunks, pMemory );
// align memory at the 32-byte boundary // align memory at the 32-byte boundary
pMemory = pMemory + 64 - (((int)(ABC_PTRUINT_T)pMemory) & 63); pMemory = pMemory + 64 - (((int)(ABC_PTRUINT_T)pMemory) & 63);
@ -105,10 +107,12 @@ void Hop_ManAddMemory( Hop_Man_t * p )
p->pListFree = (Hop_Obj_t *)pMemory; p->pListFree = (Hop_Obj_t *)pMemory;
for ( i = 1; i <= IVY_PAGE_MASK; i++ ) for ( i = 1; i <= IVY_PAGE_MASK; i++ )
{ {
*((char **)pMemory) = pMemory + sizeof(Hop_Obj_t); Hop_Obj_t *NextPtr = pMemory + 1;
pMemory += sizeof(Hop_Obj_t); memcpy(pMemory, &NextPtr, sizeof(Hop_Obj_t *));
pMemory += 1;
} }
*((char **)pMemory) = NULL; Hop_Obj_t *NullPtr = NULL;
memcpy(pMemory, &NullPtr, sizeof(Hop_Obj_t *));
} }
//////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////