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[PATCH] PR11706, optimize std::pow(T, int)

From: Richard Guenther <rguenth at tat dot physik dot uni-tuebingen dot de>
To: gcc-patches at gcc dot gnu dot org
Cc: libstdc++ at gcc dot gnu dot org
Date: Wed, 12 Jan 2005 16:11:13 +0100 (CET)
Subject: [PATCH] PR11706, optimize std::pow(T, int)

Hi!

This is a fix for the ages old PR11706 (or rather a work-around?).
cmath __pow_helper now recognizes constant (or small constant)
integer powers and dispatches to the appropriate gcc builtin in
these cases.  This makes the code for ::pow(x, 2), std::pow(x, 2)
and std::pow(x, 2.0) the same, likewise for exponents > 2 in case
of -ffast-math (even without -funroll-loops).

Ok for mainline?

Thanks,
Richard.


2005-01-12  Richard Guenther <richard.guenther@uni-tuebingen.de>

	PR11706
	* libstdc++-v3/include/c_std/std_cmath.h (__pow_helper):
	Specialize for (small) constant exponents.

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Follow-Ups:
- Re: [PATCH] PR11706, optimize std::pow(T, int)
  - From: Paolo Carlini

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