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glibc/math/test-fpucw-ieee.c

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Fix static-binary lazy FPU context allocation Long ago static startup did not parse the auxiliary vector and therefore could not get at any `AT_FPUCW' tag to check whether upon FPU context allocation the kernel would use a FPU control word setting different to that provided by the `__fpu_control' variable. Static startup therefore always initialized the FPU control word, forcing immediate FPU context allocation even for binaries that otherwise never used the FPU. As from GIT commit f8f900ecb9096ec47f5b7bb7626e29223c69061a static startup supports parsing the auxiliary vector, so now it can avoid explicit initialization of the FPU control word, just as can dynamic startup, in the usual case where the setting written to the FPU control word would be the same as the kernel uses. This defers FPU context allocation until the binary itself actually pokes at the FPU. Note that the `AT_FPUCW' tag is usually absent from the auxiliary vector in which case _FPU_DEFAULT is assumed to be the kernel default.
2013-09-09 21:36:57 +00:00
/* FPU control word overridden initialization test.
Copyright (C) 2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
test-fpucw-ieee: Don't use _FPU_IEEE if not defined Not all architectures define this value, and if they don't, just let the test run the same as test-fpucw, with __fpu_control set to _FPU_DEFAULT explicitly.
2013-11-18 18:27:09 +00:00
#ifdef _FPU_IEEE
/* Some architectures don't have _FPU_IEEE. */
# define FPU_CONTROL _FPU_IEEE
#endif
Fix static-binary lazy FPU context allocation Long ago static startup did not parse the auxiliary vector and therefore could not get at any `AT_FPUCW' tag to check whether upon FPU context allocation the kernel would use a FPU control word setting different to that provided by the `__fpu_control' variable. Static startup therefore always initialized the FPU control word, forcing immediate FPU context allocation even for binaries that otherwise never used the FPU. As from GIT commit f8f900ecb9096ec47f5b7bb7626e29223c69061a static startup supports parsing the auxiliary vector, so now it can avoid explicit initialization of the FPU control word, just as can dynamic startup, in the usual case where the setting written to the FPU control word would be the same as the kernel uses. This defers FPU context allocation until the binary itself actually pokes at the FPU. Note that the `AT_FPUCW' tag is usually absent from the auxiliary vector in which case _FPU_DEFAULT is assumed to be the kernel default.
2013-09-09 21:36:57 +00:00
#include "test-fpucw.c"
/* Preempt the library's definition of `__fpu_control'. */
test-fpucw-ieee: Don't use _FPU_IEEE if not defined Not all architectures define this value, and if they don't, just let the test run the same as test-fpucw, with __fpu_control set to _FPU_DEFAULT explicitly.
2013-11-18 18:27:09 +00:00
fpu_control_t __fpu_control = FPU_CONTROL;
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