General index file description

The general form of the index files are:

<Number of kernels>
<ID> <alpha> <beta> <incX> <incY> <source file> <author name>
 .
 .
<ID> <alpha> <beta> <incX> <incY> <source file> <author name>

Here's an explanation of these values:

• ID: Strictly positive ($>0$) integer which must be unique in the file (eg., two lines should not begin with the same ID). This ID is used to distinguish between kernels, so reusing one will result in confusion.
• ialpha: Integer flag describing special conditions of the scalar alpha. Possible values are:
  • 1: alpha = 1.0 (for complex, (1.0, 0.0))
  • -1: alpha = -1.0 (for complex, (-1.0, 0.0))
  • 0: For complex only, this flag means that the imaginary component is zero (i.e., scalar is actually real, not complex).
  • 2: or anything else, is assumed to mean that nothing special is known about the scalar.
• ibeta: Same as ialpha, but for second scalar.
• incX: Stride on the X vector your kernel is specialized for (eg., incX=1 means the kernel works only for X vectors with unit stride).
• incY: Vector stride for Y vector.
• source file: The name of the source file appearing in the BLAS subdir (eg, AXPY/myaxpy.c would mean an entry of myaxpy.c).
• author name: Name of the author, enclosed in double quotes.

For example, here is an example AXPY/dcases.dsc:

3
1  2  0  0 axpy1_x0y0.c       "R. Clint Whaley"
2  2  1  1 axpy1_x1y1.c       "R. Clint Whaley"
2 -1  1  1 axpy1_an1x1y1.c    "R. Clint Whaley"
<ID> <ialpha> <incX> <incY> <rout> <author> [\

So, to make this work, all three filenames mentioned above must appear in your AXPY/ subdir. The first kernel routine is the general case: general incX, incY, and alpha. The second specializes both vector increments to unit stride, but takes any alpha. Finally, the last routine specializes even further, with unit strides and requiring alpha be negative one. Note that all index files must contain at least one routine that handles the most general cases, and passes the tester.

If you need a particular compiler and flag combo to compile your kernel you end the line with a \, and put the compiler on the following line, and the flags on a line after that. So, if axpy_x1y1.c needed gcc, with -O1 -fschedule-insns -DGOODPERFORMANCE for flags, the above file would be changed to:

3
1  2  0  0 axpy1_x0y0.c       "R. Clint Whaley"
2  2  1  1 axpy1_x1y1.c       "R. Clint Whaley" \
gcc
-O1 -fschedule-insns -DGOODPERFORMANCE
2 -1  1  1 axpy1_an1x1y1.c    "R. Clint Whaley"
<ID> <ialpha> <incX> <incY> <rout> <author> [\