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dnl Copyright (C) 2007, 2009-2023 Free Software Foundation, Inc. |
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dnl This file is free software; the Free Software Foundation |
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dnl gives unlimited permission to copy and/or distribute it, |
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dnl with or without modifications, as long as this notice is preserved. |
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dnl |
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dnl gl_CHECK_MATH_LIB (VARIABLE, EXPRESSION [, EXTRA-CODE]) |
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dnl |
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dnl Sets the shell VARIABLE according to the libraries needed by EXPRESSION |
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dnl to compile and link: to the empty string if no extra libraries are needed, |
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dnl to "-lm" if -lm is needed, or to "missing" if it does not compile and |
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dnl link either way. |
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dnl |
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dnl Example: gl_CHECK_MATH_LIB([ROUNDF_LIBM], [x = roundf (x);]) |
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AC_DEFUN([gl_CHECK_MATH_LIB], [ |
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save_LIBS=$LIBS |
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$1=missing |
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for libm in "" "-lm"; do |
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LIBS="$save_LIBS $libm" |
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AC_LINK_IFELSE([AC_LANG_PROGRAM([[ |
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$3 |
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double x;]], |
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[$2])], |
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[$1=$libm |
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break]) |
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done |
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LIBS=$save_LIBS |
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]) |
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