Mercurial > octave
comparison m4/octave_blas.m4 @ 31129:4dc326899f65
build: simplify BLAS library detection in configure (bug #62715)
* configure.ac: Replace calls to OCTAVE_BLAS_F77_FUNC with OCTAVE_BLAS.
* m4/octave_blas_f77_func.m4: Removed obsolete macro file.
* m4/octave_blas.m4: New file with OCTAVE_BLAS macro to detect BLAS library and
find size of integers in library.
* m4/module.mk: Add octave_blas.m4 to build system.
author | Rik <rik@octave.org> |
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date | Fri, 08 Jul 2022 21:38:05 -0700 |
parents | |
children | 1d61c36bb34a |
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31128:f8d3c0f035d0 | 31129:4dc326899f65 |
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1 dnl | |
2 dnl Check for BLAS libary and if valid determine integer size in library | |
3 dnl | |
4 AC_DEFUN([OCTAVE_BLAS], [ | |
5 AC_PREREQ(2.50) | |
6 dnl Call reference macro to find BLAS library | |
7 AX_BLAS | |
8 | |
9 if test "$cross_compiling" = yes ; then | |
10 dnl Assume generic 4-byte BLAS library exists when cross compiling | |
11 ax_blas_ok=yes | |
12 ax_cv_blas_integer_size=4 | |
13 AC_MSG_CHECKING([BLAS can be called from Fortran]) | |
14 AC_MSG_RESULT([yes assumed for cross compilation]) | |
15 elif test x"$ax_blas_ok" = xyes; then | |
16 save_octave_blas_f77_func_LIBS="$LIBS" | |
17 LIBS="$BLAS_LIBS $LIBS" | |
18 AC_LANG_PUSH(Fortran 77) | |
19 ## Check BLAS library integer size. | |
20 ## If it does not appear to be 8 bytes, we assume it is 4 bytes. | |
21 ## FIXME: this may fail with options like -ftrapping-math. | |
22 AC_CACHE_CHECK([BLAS library integer size], | |
23 [ax_cv_blas_integer_size], | |
24 [AC_RUN_IFELSE([AC_LANG_PROGRAM(,[[ | |
25 integer*8 two, n | |
26 integer*4 n2(2) | |
27 double precision d, a(1), b(1), ddot | |
28 equivalence (n, n2) | |
29 | |
30 a(1) = 1.0 | |
31 b(1) = 1.0 | |
32 | |
33 c Generate 2**32 + 1 in an 8-byte integer. Whether we have a big | |
34 c endian or little endian system, both 4-byte words of this value | |
35 c should be 1. | |
36 | |
37 two = 2 | |
38 n = (two ** 32) + 1 | |
39 | |
40 c Check that our expectation about the type conversions are correct. | |
41 | |
42 if (n2(1) .ne. 1 .or. n2(2) .ne. 1) then | |
43 print *, 'invalid assumption about integer type conversion' | |
44 stop 2 | |
45 endif | |
46 | |
47 * print *, n, n2(1), n2(2) | |
48 * print *, a(1), b(1) | |
49 | |
50 c DDOT will either see 1 or a large value for N. Since INCX and INCY | |
51 c are both 0, we will never increment the index, so A and B only need to | |
52 c have a single element. If N is interpreted as 1 (BLAS compiled with | |
53 c 4-byte integers) then the result will be 1. If N is interpreted as a | |
54 c large value (BLAS compiled with 8-byte integers) then the result will | |
55 c be the summation a(1)*b(1) 2^32+1 times. This will also take some | |
56 c time to compute, but at least for now it is the unusual case so we are | |
57 c much more likely to exit quickly after detecting that the BLAS library | |
58 c was compiled with 4-byte integers. | |
59 | |
60 d = ddot (n, a, 0, b, 0) | |
61 | |
62 * print *, a(1), b(1), d | |
63 | |
64 c Success (0 exit status) means we detected BLAS compiled with | |
65 c 8-byte integers. | |
66 | |
67 if (d .eq. 1.0) then | |
68 stop 1 | |
69 endif | |
70 | |
71 ]])], | |
72 ax_cv_blas_integer_size=8, | |
73 ax_cv_blas_integer_size=4) | |
74 ]) | |
75 | |
76 AC_LANG_POP(Fortran 77) | |
77 LIBS="$save_octave_blas_f77_func_LIBS" | |
78 fi | |
79 | |
80 ]) |