Changeset d3261710 for libcfa/src/bits

Timestamp:

Jan 20, 2022, 11:18:15 AM (4 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, ast-experimental, enum, forall-pointer-decay, master, pthread-emulation, qualifiedEnum

Children:

224916b

Parents:

6117fc0 (diff), 6a33e40 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

File:

• libcfa/src/bits/random.hfa (modified) (3 diffs)

libcfa/src/bits/random.hfa

@@ +1 @@
+// 
+// Cforall Version 1.0.0 Copyright (C) 2022 University of Waterloo
+// 
+// The contents of this file are covered under the licence agreement in the
+// file "LICENCE" distributed with Cforall.
+//
+// random.hfa -- 
+// 
+// Author           : Peter A. Buhr
+// Created On       : Fri Jan 14 07:18:11 2022
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Fri Jan 14 07:18:58 2022
+// Update Count     : 1
+// 
+
 #pragma once
 
 #include <stdint.h>
 
-// Pipelined to allow out-of-order overlap with reduced dependencies. Critically, return the current value, and compute
-// and store the next value.
+// Pipelined to allow out-of-order overlap with reduced dependencies. Critically, the current random state is returned
+// (copied), and then compute and store the next random value.
 
+#if defined(__SIZEOF_INT128__)
 //--------------------------------------------------
-#if defined(__SIZEOF_INT128__)
         static inline uint64_t lehmer64( __uint128_t & state ) {
                 __uint128_t ret = state;
@@ -50 +65 @@
 } xorwow__state_t;
 
-/* The state array must be initialized to not be all zero in the first four words */
+// The state array must be initialized to not be all zero in the first four words.
 static inline uint32_t xorwow( xorwow__state_t & state ) {
-        /* Algorithm "xorwow" from p. 5 of Marsaglia, "Xorshift RNGs" */
+        // Algorithm "xorwow" from p. 5 of Marsaglia, "Xorshift RNGs".
         uint32_t ret = state.a + state.counter;
         uint32_t t = state.d;
@@ -84 +99 @@
 #define D  (16_l64u)
 
+// Bi-directional LCG random-number generator
 static inline uint32_t LCGBI_fwd( uint64_t & state ) {
         state = (A * state + C) & (M - 1);