File 2968-Add-a-measure-1-point-for-range-10000.patch of Package erlang
From 08f343bed4f75bf345b04b4c1fac7e1026a50ab3 Mon Sep 17 00:00:00 2001
From: Raimo Niskanen <raimo@erlang.org>
Date: Thu, 12 May 2022 08:53:34 +0200
Subject: [PATCH 8/8] Add a measure/1 point for range 10000
The mwc59_raw generator's low 16 bits can be used in
truncated multiplication for this range, so measure the speed.
Rename measure/1 tags _mas to _tm because truncated multiplication
is a more generic name than multiply-and-shift.
---
lib/stdlib/test/rand_SUITE.erl | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)
diff --git a/lib/stdlib/test/rand_SUITE.erl b/lib/stdlib/test/rand_SUITE.erl
index 05dcd897c3..11722fd060 100644
--- a/lib/stdlib/test/rand_SUITE.erl
+++ b/lib/stdlib/test/rand_SUITE.erl
@@ -1172,7 +1172,25 @@ do_measure(Iterations) ->
Range = 10000,
fun (St0) ->
St1 = rand:mwc59(St0),
- %% Multiply-and-shift, slightly skewed
+ %% Truncated multiplication, slightly skewed
+ case
+ ((Range * (St1 band ((1 bsl 16)-1))) bsr 16)
+ + 1
+ of
+ R when is_integer(R), 0 < R, R =< Range ->
+ St1
+ end
+ end
+ end,
+ {mwc59,raw_tm}, Iterations,
+ TMarkUniformRange10000, OverheadUniformRange1000),
+ _ =
+ measure_1(
+ fun (_Mod, _State) ->
+ Range = 10000,
+ fun (St0) ->
+ St1 = rand:mwc59(St0),
+ %% Truncated multiplication, slightly skewed
case
((Range * rand:mwc59_value32(St1)) bsr 32)
+ 1
@@ -1182,7 +1200,7 @@ do_measure(Iterations) ->
end
end
end,
- {mwc59,value32_mas}, Iterations,
+ {mwc59,value32_tm}, Iterations,
TMarkUniformRange10000, OverheadUniformRange1000),
_ =
measure_1(
@@ -1190,7 +1208,7 @@ do_measure(Iterations) ->
Range = 10000, % 14 bits
fun (St0) ->
St1 = rand:mwc59(St0),
- %% Multiply-and-shift, slightly skewed
+ %% Truncated multiplication, slightly skewed
case
( (Range *
(rand:mwc59_value(St1) bsr 14) )
@@ -1202,7 +1220,7 @@ do_measure(Iterations) ->
end
end
end,
- {mwc59,value_mas}, Iterations,
+ {mwc59,value_tm}, Iterations,
TMarkUniformRange10000, OverheadUniformRange1000),
_ =
measure_1(
@@ -1210,7 +1228,7 @@ do_measure(Iterations) ->
Range = 10000,
fun (St0) ->
{V,St1} = rand:exsp_next(St0),
- %% Multiply-and-shift, slightly skewed
+ %% Truncated multiplication, slightly skewed
case
((Range * (V bsr 14)) bsr (58-14)) + 1
of
@@ -1219,7 +1237,7 @@ do_measure(Iterations) ->
end
end
end,
- {exsp,mas}, Iterations,
+ {exsp,tm}, Iterations,
TMarkUniformRange10000, OverheadUniformRange1000),
_ =
measure_1(
--
2.35.3
