Add an option to change the complex return type.

ifort apparently does not return complex numbers in registers as in C/C++ (or gfortran), but instead creates a "hidden" first parameter for the return value. The option --complex-return=gnu|intel has been added, as well as a guess based on a provided FC if not specified (otherwise default to gnu). This option affects the signatures of cdotc, cdotu, zdotc, and zdotu, and a single library cannot be used with both GNU and Intel Fortran compilers. Fixes #433.

build/bli_config.h.in

@@ -165,5 +165,11 @@
 #define BLIS_DISABLE_SHARED
 #endif
 
+#if @complex_return_intel@
+#define BLIS_ENABLE_COMPLEX_RETURN_INTEL
+#else
+#define BLIS_DISABLE_COMPLEX_RETURN_INTEL
+#endif
+
 
 #endif

configure

@@ -299,6 +299,15 @@ print_usage()
 	echo "                 when debugging certain configuration issues, and/or as"
 	echo "                 a sanity check to make sure these lists are constituted"
 	echo "                 as expected."
+    echo " "
+    echo "   --complex-return=gnu|intel"
+    echo " "
+    echo "                 Specify the way in which complex numbers are returned"
+    echo "                 from Fortran functions, either \"gnu\" (return in"
+    echo "                 registers) or \"intel\" (return via hidden argument)."
+    echo "                 If not specified and the environment variable FC is set,"
+    echo "                 attempt to determine the return type from the compiler."
+    echo "                 Otherwise, the default is \"gnu\"."
 	echo " "
 	echo "   -q, --quiet   Suppress informational output. By default, configure"
 	echo "                 is verbose. (NOTE: -q is not yet implemented)"
@@ -309,6 +318,7 @@ print_usage()
 	echo " "
 	echo "   CC            Specifies the C compiler to use."
 	echo "   CXX           Specifies the C++ compiler to use (sandbox only)."
+    echo "   FC            Specifies the Fortran compiler to use (only to determine --complex-return)."
 	echo "   RANLIB        Specifies the ranlib executable to use."
 	echo "   AR            Specifies the archiver to use."
 	echo "   CFLAGS        Specifies additional compiler flags to use (prepended)."
@@ -1954,6 +1964,7 @@ main()
 	enable_sup_handling='yes'
 	enable_memkind='' # The default memkind value is determined later on.
 	force_version='no'
+	complex_return='default'
 
 	# The sandbox flag and name.
 	sandbox_flag=''
@@ -2142,6 +2153,9 @@ main()
 						show-config-list)
 							show_config_list=1
 							;;
+				        complex-return=*)
+                            complex_return=${OPTARG#*=}
+                            ;;
 						*)
 							print_usage
 							;;
@@ -2996,7 +3010,49 @@ main()
 
 		enable_sandbox_01=0
 	fi
+
+	# Check the method used for returning complex numbers
+    if [ "x${complex_return}" = "xdefault" ]; then
+        if [ -n "${FC}" ]; then
+            # Determine the complex return type from the given Fortran compiler
+
+            # Query the full vendor version string output. This includes the
+            # version number along with (potentially) a bunch of other textual
+            # clutter.
+            # NOTE: This maybe should use merged stdout/stderr rather than only
+            # stdout. But it works for now.
+            vendor_string="$(${FC} --version 2>/dev/null)"
+
+            # Query the compiler "vendor" (ie: the compiler's simple name) and
+            # isolate the version number.
+            # The last part ({ read first rest ; echo $first ; }) is a workaround
+            # to OS X's egrep only returning the first match.
+            fc_vendor=$(echo "${vendor_string}" | egrep -o 'ifort|GNU' | { read first rest ; echo $first ; })
+
+            if [ "x${fc_vendor}" = "xifort" ]; then
+                complex_return='intel'
+            elif [ "x${fc_vendor}" = "xGNU" ]; then
+                complex_return='gnu'
+            else
+                echo "${script_name}: unable to determine Fortran compiler vendor!"
+                complex_return='gnu'
+            fi
+        else
+            complex_return='gnu'
+        fi
+    fi
+
+    if [ "x${complex_return}" = "xgnu"  ]; then
+        complex_return_intel01='0'
+    elif [ "x${complex_return}" = "xintel" ]; then
+        complex_return_intel01='1'
+	else
+        echo "${script_name}: unknown complex return type \"${complex_return}\"! Cannot continue."
+        echo "${script_name}: *** Acceptable values are \"gnu\" and \"intel\"."
+        exit 1
+	fi
 
+    echo "${script_name}: configuring complex return type as \"${complex_return}\"."
 
 	# Variables that may contain forward slashes, such as paths, need extra
 	# escaping when used in sed commands. We insert those extra escape
@@ -3165,7 +3221,8 @@ main()
 		| sed   -e "s/@enable_memkind@/${enable_memkind_01}/g" \
 		| sed   -e "s/@enable_pragma_omp_simd@/${enable_pragma_omp_simd_01}/g" \
 		| sed   -e "s/@enable_sandbox@/${enable_sandbox_01}/g" \
-		| sed   -e "s/@enable_shared@/${enable_shared_01}/g" \
+        | sed   -e "s/@enable_shared@/${enable_shared_01}/g" \
+        | sed   -e "s/@complex_return_intel@/${complex_return_intel01}/g" \
 		> "${bli_config_h_out_path}"
 
 

frame/compat/bla_dot.c

@@ -34,6 +34,7 @@
 
 #include "blis.h"
 
+#ifdef BLIS_ENABLE_BLAS
 
 //
 // Define BLAS-to-BLIS interfaces.
@@ -48,45 +49,103 @@ ftype PASTEF772(ch,blasname,chc) \
        const ftype*   y, const f77_int* incy  \
      ) \
 { \
-	dim_t  n0; \
-	ftype* x0; \
-	ftype* y0; \
-	inc_t  incx0; \
-	inc_t  incy0; \
-	ftype  rho; \
+    dim_t  n0; \
+    ftype* x0; \
+    ftype* y0; \
+    inc_t  incx0; \
+    inc_t  incy0; \
+    ftype  rho; \
 \
-	/* Initialize BLIS. */ \
-	bli_init_auto(); \
+    /* Initialize BLIS. */ \
+    bli_init_auto(); \
 \
-	/* Convert/typecast negative values of n to zero. */ \
-	bli_convert_blas_dim1( *n, n0 ); \
+    /* Convert/typecast negative values of n to zero. */ \
+    bli_convert_blas_dim1( *n, n0 ); \
 \
-	/* If the input increments are negative, adjust the pointers so we can
-	   use positive increments instead. */ \
-	bli_convert_blas_incv( n0, (ftype*)x, *incx, x0, incx0 ); \
-	bli_convert_blas_incv( n0, (ftype*)y, *incy, y0, incy0 ); \
+    /* If the input increments are negative, adjust the pointers so we can
+       use positive increments instead. */ \
+    bli_convert_blas_incv( n0, (ftype*)x, *incx, x0, incx0 ); \
+    bli_convert_blas_incv( n0, (ftype*)y, *incy, y0, incy0 ); \
 \
-	/* Call BLIS interface. */ \
-	PASTEMAC2(ch,blisname,BLIS_TAPI_EX_SUF) \
-	( \
-	  blis_conjx, \
-	  BLIS_NO_CONJUGATE, \
-	  n0, \
-	  x0, incx0, \
-	  y0, incy0, \
-	  &rho, \
-	  NULL, \
-	  NULL  \
-	); \
+    /* Call BLIS interface. */ \
+    PASTEMAC2(ch,blisname,BLIS_TAPI_EX_SUF) \
+    ( \
+      blis_conjx, \
+      BLIS_NO_CONJUGATE, \
+      n0, \
+      x0, incx0, \
+      y0, incy0, \
+      &rho, \
+      NULL, \
+      NULL  \
+    ); \
 \
-	/* Finalize BLIS. */ \
-	bli_finalize_auto(); \
+    /* Finalize BLIS. */ \
+    bli_finalize_auto(); \
 \
-	return rho; \
+    return rho; \
 }
 
-#ifdef BLIS_ENABLE_BLAS
-INSERT_GENTFUNCDOT_BLAS( dot, dotv )
+INSERT_GENTFUNCDOTR_BLAS( dot, dotv )
+
+#if BLIS_DISABLE_COMPLEX_RETURN_INTEL
+
+INSERT_GENTFUNCDOTC_BLAS( dot, dotv )
+
+#else
+
+// For the "intel" complex return type, use a hidden parameter to return the result
+#undef  GENTFUNCDOT
+#define GENTFUNCDOT( ftype, ch, chc, blis_conjx, blasname, blisname ) \
+\
+void PASTEF772(ch,blasname,chc) \
+     ( \
+       ftype*         rhop, \
+       const f77_int* n, \
+       const ftype*   x, const f77_int* incx, \
+       const ftype*   y, const f77_int* incy  \
+     ) \
+{ \
+    dim_t  n0; \
+    ftype* x0; \
+    ftype* y0; \
+    inc_t  incx0; \
+    inc_t  incy0; \
+    ftype  rho; \
+\
+    /* Initialize BLIS. */ \
+    bli_init_auto(); \
+\
+    /* Convert/typecast negative values of n to zero. */ \
+    bli_convert_blas_dim1( *n, n0 ); \
+\
+    /* If the input increments are negative, adjust the pointers so we can
+       use positive increments instead. */ \
+    bli_convert_blas_incv( n0, (ftype*)x, *incx, x0, incx0 ); \
+    bli_convert_blas_incv( n0, (ftype*)y, *incy, y0, incy0 ); \
+\
+    /* Call BLIS interface. */ \
+    PASTEMAC2(ch,blisname,BLIS_TAPI_EX_SUF) \
+    ( \
+      blis_conjx, \
+      BLIS_NO_CONJUGATE, \
+      n0, \
+      x0, incx0, \
+      y0, incy0, \
+      &rho, \
+      NULL, \
+      NULL  \
+    ); \
+\
+    /* Finalize BLIS. */ \
+    bli_finalize_auto(); \
+\
+    *rhop = rho; \
+}
+
+INSERT_GENTFUNCDOTC_BLAS( dot, dotv )
+
+#endif
 
 
 // -- "Black sheep" dot product function definitions --

frame/include/bli_gentfunc_macro_defs.h

@@ -74,19 +74,35 @@ GENTFUNCCO( scomplex, float,  c, s, blasname, blisname ) \
 GENTFUNCCO( dcomplex, double, z, d, blasname, blisname )
 
 
-// -- Basic one-operand macro with conjugation (used only for dot, ger) --
+// -- Basic one-operand macro with conjugation (real funcs only, used only for dot, ger) --
 
 
-#define INSERT_GENTFUNCDOT_BLAS( blasname, blisname ) \
+#define INSERT_GENTFUNCDOTR_BLAS( blasname, blisname ) \
 \
 GENTFUNCDOT( float,    s,  , BLIS_NO_CONJUGATE, blasname, blisname ) \
-GENTFUNCDOT( double,   d,  , BLIS_NO_CONJUGATE, blasname, blisname ) \
+GENTFUNCDOT( double,   d,  , BLIS_NO_CONJUGATE, blasname, blisname )
+
+
+// -- Basic one-operand macro with conjugation (complex funcs only, used only for dot, ger) --
+
+
+#define INSERT_GENTFUNCDOTC_BLAS( blasname, blisname ) \
+\
 GENTFUNCDOT( scomplex, c, c, BLIS_CONJUGATE,    blasname, blisname ) \
 GENTFUNCDOT( scomplex, c, u, BLIS_NO_CONJUGATE, blasname, blisname ) \
 GENTFUNCDOT( dcomplex, z, c, BLIS_CONJUGATE,    blasname, blisname ) \
 GENTFUNCDOT( dcomplex, z, u, BLIS_NO_CONJUGATE, blasname, blisname )
 
 
+// -- Basic one-operand macro with conjugation (used only for dot, ger) --
+
+
+#define INSERT_GENTFUNCDOT_BLAS( blasname, blisname ) \
+\
+INSERT_GENTFUNCDOTR_BLAS( blasname, blisname ) \
+INSERT_GENTFUNCDOTC_BLAS( blasname, blisname )
+
+
 // -- Basic one-operand macro with real projection --