Merge pull request #1971 from martin-frbg/trsm-threshold

Shift transition to multithreading towards larger matrix sizes

Author: martin-frbg

interface/trsm.c

@@ -81,6 +81,12 @@
 #endif
 #endif
 
+#ifndef COMPLEX
+#define SMP_FACTOR 256
+#else
+#define SMP_FACTOR 128
+#endif
+
 static int (*trsm[])(blas_arg_t *, BLASLONG *, BLASLONG *, FLOAT *, FLOAT *, BLASLONG) = {
 #ifndef TRMM
   TRSM_LNUU, TRSM_LNUN, TRSM_LNLU, TRSM_LNLN,
@@ -366,11 +372,15 @@ void CNAME(enum CBLAS_ORDER order,
   mode |= (trans << BLAS_TRANSA_SHIFT);
   mode |= (side  << BLAS_RSIDE_SHIFT);
 
-  if ( args.m < 2*GEMM_MULTITHREAD_THRESHOLD )
+/*
+  if ( args.m < 2 * GEMM_MULTITHREAD_THRESHOLD )
 	args.nthreads = 1;
   else
-	if ( args.n < 2*GEMM_MULTITHREAD_THRESHOLD )
+	if ( args.n < 2 * GEMM_MULTITHREAD_THRESHOLD )
 		args.nthreads = 1;
+*/
+  if ( args.m * args.n < SMP_FACTOR * GEMM_MULTITHREAD_THRESHOLD)
+	args.nthreads = 1;
   else
 	args.nthreads = num_cpu_avail(3);