[llvm-commits] [test-suite] r105418 - /test-suite/trunk/MultiSource/Benchmarks/VersaBench/bmm/bmm.c

[Jakob Stoklund Olesen]

Author: stoklund
Date: Thu Jun  3 16:50:54 2010
New Revision: 105418

URL: http://llvm.org/viewvc/llvm-project?rev=105418&view=rev
Log:
Avoid undefined behaviour from signed overflows and shifts >= type size.
This makes ARM and X86 produce identical results.

Modified:
    test-suite/trunk/MultiSource/Benchmarks/VersaBench/bmm/bmm.c

Modified: test-suite/trunk/MultiSource/Benchmarks/VersaBench/bmm/bmm.c
URL: http://llvm.org/viewvc/llvm-project/test-suite/trunk/MultiSource/Benchmarks/VersaBench/bmm/bmm.c?rev=105418&r1=105417&r2=105418&view=diff
==============================================================================
--- test-suite/trunk/MultiSource/Benchmarks/VersaBench/bmm/bmm.c (original)
+++ test-suite/trunk/MultiSource/Benchmarks/VersaBench/bmm/bmm.c Thu Jun  3 16:50:54 2010
@@ -148,10 +148,10 @@
 
 
 /* Use Linear congruential PRNG */
-int my_rand_r(int *seedp)
+unsigned my_rand_r(unsigned *seedp)
 {
   /* Knuth & Lewis */
-  unsigned x = *seedp * 1664525 + 1013904223;
+  unsigned x = *seedp * 1664525u + 1013904223u;
   *seedp = x;
   return (x >> 16) & 0x7fff;
 }
@@ -159,11 +159,11 @@
 
 void init() {
   int   i,j;
-  int random_seed = 1;
+  unsigned random_seed = 1;
   for (i=0 ; i < SIZE ; i++) {
     for (j=0 ; j < SIZE; j++) {
-      a[i][j] = (my_rand_r(&random_seed) >> j-i) & 0xF;
-      b[i][j] = (my_rand_r(&random_seed) << i+j) & 0xF;
+      a[i][j] = (my_rand_r(&random_seed) >> ((j-i) & 31)) & 0xF;
+      b[i][j] = (my_rand_r(&random_seed) << ((i+j) & 31)) & 0xF;
     }
   }
 }