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Add inlining of the C99 math functions isinf/isnan/signbit/isfinite/isnormal/fpclassify using GCC built-ins when available. Since going through the PLT is expensive for these small functions, inlining results in major speedups (about 7x on Cortex-A57 for isinf). The GCC built-ins are not correct if signalling NaN support is required, and thus are turned off in that case (see GCC bug 66462). The test-snan.c tests sNaNs and so must be explicitly built with -fsignaling-nans. As a result of this many target overrides and the various __isnan/__finite inlines in math_private.h are no longer required. If agreed we could remove all this code and only keep the generic definition of isinf/etc which will use the builtin. Tested on AArch64. OK for commit? ChangeLog: 2015-06-15 Wilco Dijkstra <wdijkstr@arm.com> * math/Makefile: Build test-snan.c with -fsignaling-nans. * math/math.h (fpclassify): Use __builtin_fpclassify when available. (signbit): Use __builtin_signbit(f/l). (isfinite): Use__builtin_isfinite. (isnormal): Use __builtin_isnormal. (isnan): Use __builtin_isnan. (isinf): Use __builtin_isinf_sign.
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Enable-C99-math-inlines.txt
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