replace memcpy with loop in LAGraph FastSV methods

DrTimothyAldenDavis · Oct 28, 2023 · 16f137a · 16f137a
1 parent 0cfb8c4
commit 16f137a
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Showing 2 changed files with 21 additions and 4 deletions.
diff --git a/LAGraph/experimental/algorithm/LG_CC_FastSV5.c b/LAGraph/experimental/algorithm/LG_CC_FastSV5.c
@@ -674,8 +674,17 @@ int LG_CC_FastSV5           // SuiteSparse:GraphBLAS method, with GxB extensions
         GrB_Index offset = 0 ;
         for (tid = 0 ; tid < nthreads ; tid++)
         {
-            memcpy (Tj + offset, Tj + Tp [range [tid]],
-                sizeof (GrB_Index) * count [tid]) ;
+
+//          memcpy (Tj + offset, Tj + Tp [range [tid]],
+//              sizeof (GrB_Index) * count [tid]) ;
+
+            GrB_Index *Tj_dest = Tj + offset ;
+            GrB_Index *Tj_src  = Tj + Tp [range [tid]] ;
+            for (int64_t k = 0 ; k < count [tid] ; k++)
+            {
+                Tj_dest [k] = Tj_src [k] ;
+            }
+
             offset += count [tid] ;
             count [tid] = offset - count [tid] ;
         }

diff --git a/LAGraph/src/algorithm/LG_CC_FastSV6.c b/LAGraph/src/algorithm/LG_CC_FastSV6.c
@@ -604,8 +604,16 @@ printf ("did prune T\n") ; fflush (stdout) ; fflush (stderr) ;
         nvals = 0 ;
         for (tid = 0 ; tid < nthreads ; tid++)
         {
-            memcpy (Tj + nvals, Tj + Tp [range [tid]],
-                sizeof (GrB_Index) * count [tid]) ;
+
+//          memcpy (Tj + nvals, Tj + Tp [range [tid]],
+//              sizeof (GrB_Index) * count [tid]) ;
+            GrB_Index *Tj_dest = Tj + nvals ;
+            GrB_Index *Tj_src  = Tj + Tp [range [tid]] ;
+            for (int64_t k = 0 ; k < count [tid] ; k++)
+            {
+                Tj_dest [k] = Tj_src [k] ;
+            }
+
             nvals += count [tid] ;
             count [tid] = nvals - count [tid] ;
         }