Disallow 64b BLAS integers + 32b BLIS integers.

Details:
- Print an error message from configure if the user attempts to
  explicitly configure BLIS for simultaneous use of 64-bit integers in
  the BLAS API with 32-bit integers in the BLIS API.
- Added cpp macro conditional to bli_type_defs.h to mandate that BLIS
  integers be 64 bits if the BLAS integers are 64 bits. This and the
  above item take care of issue #274. Thanks to Devin Matthews and
  Jeff Hammond for suggesting these safeguards.
- Slight reorganization and relabeling (for clarity) of BLAS/CBLAS
  sections and BLIS integer size line of the testsuite configuration
  output.
- Very minor edits to docs/MixedDatatypes.md.

configure

@@ -193,7 +193,7 @@ print_usage()
 	echo "                 Disable (enabled by default) support for mixing the"
 	echo "                 storage domain and/or storage precision of matrix"
 	echo "                 operands for the gemm operation, as well as support"
-	echo "                 for computing in a precision different from one or."
+	echo "                 for computing in a precision different from one or"
 	echo "                 both of matrices A and B."
 	echo " "
 	echo "   --disable-mixed-dt-extra-mem, --enable-mixed-dt-extra-mem"
@@ -2620,18 +2620,25 @@ main()
 
 	# Report integer sizes.
 	if [ "x${int_type_size}" = "x32" ]; then
-		echo "${script_name}: the internal integer size is 32-bit."
+		echo "${script_name}: the BLIS API integer size is 32-bit."
 	elif [ "x${int_type_size}" = "x64" ]; then
-		echo "${script_name}: the internal integer size is 64-bit."
+		echo "${script_name}: the BLIS API integer size is 64-bit."
 	else
-		echo "${script_name}: the internal integer size is automatically determined."
+		echo "${script_name}: the BLIS API integer size is automatically determined."
 	fi
 	if [ "x${blas_int_type_size}" = "x32" ]; then
-		echo "${script_name}: the BLAS/CBLAS interface integer size is 32-bit."
+		echo "${script_name}: the BLAS/CBLAS API integer size is 32-bit."
 	elif [ "x${blas_int_type_size}" = "x64" ]; then
-		echo "${script_name}: the BLAS/CBLAS interface integer size is 64-bit."
+		echo "${script_name}: the BLAS/CBLAS API integer size is 64-bit."
 	else
-		echo "${script_name}: the BLAS/CBLAS interface integer size is automatically determined."
+		echo "${script_name}: the BLAS/CBLAS API integer size is automatically determined."
+	fi
+
+	# Disallow the simultaneous use of 64-bit integers in the BLAS and
+	# 32-bit integers in BLIS.
+	if [ "x${blas_int_type_size}" = "x64" -a "x${int_type_size}" = "x32" ]; then
+		echo "${script_name}: *** To avoid the possibility of truncation, we do not allow use of 64-bit integers in the BLAS API with 32-bit integers in BLIS. Please use a different configuration of integers."
+		exit 1
 	fi
 
 	# Check if a sandbox was given.

docs/MixedDatatypes.md

@@ -13,7 +13,7 @@
 
 This document serves as a guide to users interested in taking advantage of
 BLIS's support for performing the `gemm` operation on operands of differing
-types.
+datatypes (domain and/or precision).
 
 ## Categories of mixed datatypes
 
@@ -182,10 +182,9 @@ distribution.
 
 ## Known issues
 
-While BLIS implements 128 mixed-datatype combinations of `gemm`, there may be
-odd behavior in the current implementation that does not conform to the reader's
-expectations. Below is a list of issues that BLIS developers are aware of in
-the context of mixed-datatype `gemm`. If any of these issues poses a problem for
+There may be odd behavior in the current implementation of mixed-datatype `gemm`
+that does not conform to the reader's expectations. Below is a list of issues
+that BLIS developers are aware of. If any of these issues poses a problem for
 your application, please contact us by
 [opening an issue](https://github.com/flame/blis/issues).
 

frame/include/bli_type_defs.h

@@ -62,6 +62,17 @@
 
 // -- General-purpose integers --
 
+// If BLAS integers are 64 bits, mandate that BLIS integers also be 64 bits.
+// NOTE: This cpp guard will only meaningfully change BLIS's behavior on
+// systems where the BLIS integer size would have been automatically selected
+// to be 32 bits, since explicit selection of 32 bits is prohibited at
+// configure-time (and explicit or automatic selection of 64 bits is fine
+// and would have had the same result).
+#if BLIS_BLAS_INT_SIZE == 64
+  #undef  BLIS_INT_TYPE_SIZE
+  #define BLIS_INT_TYPE_SIZE 64
+#endif
+
 // Define integer types depending on what size integer was requested.
 #if   BLIS_INT_TYPE_SIZE == 32
 typedef           int32_t  gint_t;

testsuite/src/test_libblis.c

@@ -829,7 +829,7 @@ void libblis_test_output_params_struct( FILE* os, test_params_t* params )
 	libblis_test_fprintf_c( os, "\n" );
 	libblis_test_fprintf_c( os, "active sub-configuration       %s\n", bli_arch_string( bli_arch_query_id() ) );
 	libblis_test_fprintf_c( os, "\n" );
-	libblis_test_fprintf_c( os, "integer type size (bits)       %d\n", ( int )int_type_size );
+	libblis_test_fprintf_c( os, "BLIS integer type size (bits)  %d\n", ( int )int_type_size );
 	libblis_test_fprintf_c( os, "\n" );
 	libblis_test_fprintf_c( os, "SIMD number of registers       %d\n", ( int )bli_info_get_simd_num_registers() );
 	libblis_test_fprintf_c( os, "SIMD size (bytes)              %d\n", ( int )bli_info_get_simd_size() );
@@ -846,13 +846,11 @@ void libblis_test_output_params_struct( FILE* os, test_params_t* params )
 	libblis_test_fprintf_c( os, "  obj_t stride                 %d\n", ( int )bli_info_get_heap_stride_align_size() );
 	libblis_test_fprintf_c( os, "  pool block addr              %d\n", ( int )bli_info_get_pool_addr_align_size() );
 	libblis_test_fprintf_c( os, "\n" );
-	libblis_test_fprintf_c( os, "BLAS compatibility layer         \n" );
-	libblis_test_fprintf_c( os, "  enabled?                     %d\n", ( int )bli_info_get_enable_blas() );
+	libblis_test_fprintf_c( os, "BLAS/CBLAS compatibility layers  \n" );
+	libblis_test_fprintf_c( os, "  BLAS API enabled?            %d\n", ( int )bli_info_get_enable_blas() );
+	libblis_test_fprintf_c( os, "  CBLAS API enabled?           %d\n", ( int )bli_info_get_enable_cblas() );
 	libblis_test_fprintf_c( os, "  integer type size (bits)     %d\n", ( int )bli_info_get_blas_int_type_size() );
 	libblis_test_fprintf_c( os, "\n" );
-	libblis_test_fprintf_c( os, "CBLAS compatibility layer        \n" );
-	libblis_test_fprintf_c( os, "  enabled?                     %d\n", ( int )bli_info_get_enable_cblas() );
-	libblis_test_fprintf_c( os, "\n" );
 	libblis_test_fprintf_c( os, "libmemkind                       \n" );
 	libblis_test_fprintf_c( os, "  enabled?                     %d\n", ( int )bli_info_get_enable_memkind() );
 	libblis_test_fprintf_c( os, "\n" );