mirror of https://git.tukaani.org/xz.git
37 lines
1.1 KiB
Plaintext
37 lines
1.1 KiB
Plaintext
##### http://autoconf-archive.cryp.to/ax_c_arithmetic_rshift.html
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#
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# SYNOPSIS
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#
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# AX_C_ARITHMETIC_RSHIFT
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#
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# DESCRIPTION
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#
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# Checks if the right shift operation is arithmetic.
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#
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# This macro uses compile-time detection and so is cross-compile
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# ready.
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#
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# LAST MODIFICATION
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#
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# 2006-12-12
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#
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# COPYLEFT
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#
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# Copyright (c) 2006 YAMAMOTO Kengo <yamaken AT bp.iij4u.or.jp>
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#
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# Copying and distribution of this file, with or without
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# modification, are permitted in any medium without royalty provided
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# the copyright notice and this notice are preserved.
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AC_DEFUN([AX_C_ARITHMETIC_RSHIFT], [
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AC_CACHE_CHECK([whether right shift operation is arithmetic],
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[ax_cv_c_arithmetic_rshift],
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[AC_COMPILE_IFELSE([[int dummy[((-1 >> 1) < 0) ? 1 : -1];]],
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[ax_cv_c_arithmetic_rshift=yes],
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[ax_cv_c_arithmetic_rshift=no])])
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if test "x$ax_cv_c_arithmetic_rshift" = xyes; then
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AC_DEFINE([HAVE_ARITHMETIC_RSHIFT], [1],
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[Define to 1 if the right shift operation is arithmetic.])
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fi
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])
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