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authorWilco Dijkstra <wdijkstr@arm.com>2018-04-03 16:28:03 +0100
committerWilco Dijkstra <wdijkstr@arm.com>2018-04-03 16:52:17 +0100
commit7a5640f23a797d3be38a78fb899903699c3aa5a0 (patch)
tree5d0dc9164a8001312f3211fd88b646399adcc4c7 /support/xpthread_create.c
parent19a8b9a300f2f1f0012aff0f2b70b09430f50d9e (diff)
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[PATCH 2/7] sin/cos slow paths: remove large range reduction
This patch removes the large range reduction code and defers to the huge range
reduction code.  The first level range reducer supports inputs up to 2^27,
which is way too large given that inputs for sin/cos are typically small
(< 10), and optimizing for a smaller range would give a significant speedup.

Input values above 2^27 are practically never used, so there is no reason for
supporting range reduction between 2^27 and 2^48.  Removing it significantly
simplifies code and enables further speedups.  There is about a 2.3x slowdown
in this range due to __branred being extremely slow  (a better algorithm could
easily more than double performance).

	* sysdeps/ieee754/dbl-64/s_sin.c (reduce_sincos_2): Remove function.
	(do_sincos_2): Likewise.
	(__sin): Remove middle range reduction case.
	(__cos): Likewise.
	* sysdeps/ieee754/dbl-64/s_sincos.c (__sincos): Remove middle range
	reduction case.
Diffstat (limited to 'support/xpthread_create.c')
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