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From: Colin Paul Gloster <Colin_Paul_Gloster@ACM.org>
Newsgroups: comp.lang.ada
Subject: Re: Is there an Ada compiler whose
 Ada.Numerics.Generic_Elementary_Functions.Log(Base=>10,
 X=>variable) is efficient?
Date: Wed, 17 Feb 2010 10:25:03 +0000
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On Tue, 16 Feb 2010, Jeffrey R. Carter sent:

|------------------------------------------------------------------|
|"[..]                                                             |
|                                                                  |
|[..] when comparing execution times between Ada and a language    |
|like C++, it's important not to try to compare apples to lugnuts."|
|------------------------------------------------------------------|

Fair enough, but when I say Ada is better than C++ I am not comparing
an apple with an apple.

Anyway, as I mentioned in
news:alpine.LNX.2.00.1002161654110.21651@Bluewhite64.example.net
in response to Bill Findlay, G++ has produced much slower code than
GNAT (the GNATism is in standard Ada, merely the obvious way to do it
in standard Ada is different)...

gnatmake -O3 -ffast-math Logarithmic_Work_In_Ada_with_a_Findlay_loop_with_a_Parker_GNATism_compiled_by_GCC4.4.3_with_-ffast-math.adb -o Logarithmic_Work_In_Ada_with_a_Findlay_loop_with_a_Parker_GNATism_compiled_by_GCC4.4.3_with_-ffast-math

 time ./Logarithmic_Work_In_Ada_with_a_Findlay_loop_with_a_Parker_GNATism_compiled_by_GCC4.4.3_with_-ffast-math
 6.34086408606382E+08

real    0m14.434s
user    0m14.433s
sys     0m0.004s


g++ -O3 -ffast-math logarithmic_work_in_CPlusPlus_with_a_Findlay_loop.cc -o logarithmic_work_in_CPlusPlus_with_a_Findlay_loop_compiled_by_GCC4.4.3_with_-ffast-math

 time ./logarithmic_work_in_CPlusPlus_with_a_Findlay_loop_compiled_by_GCC4.4.3_with_-ffast-math
6.34086e+08
real    0m38.388s
user    0m38.390s
sys     0m0.000s