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-rw-r--r--arch/ia64/lib/carta_random.S54
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diff --git a/arch/ia64/lib/carta_random.S b/arch/ia64/lib/carta_random.S
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+/*
+ * Fast, simple, yet decent quality random number generator based on
+ * a paper by David G. Carta ("Two Fast Implementations of the
+ * `Minimal Standard' Random Number Generator," Communications of the
+ * ACM, January, 1990).
+ *
+ * Copyright (C) 2002 Hewlett-Packard Co
+ * David Mosberger-Tang <davidm@hpl.hp.com>
+ */
+
+#include <asm/asmmacro.h>
+
+#define a r2
+#define m r3
+#define lo r8
+#define hi r9
+#define t0 r16
+#define t1 r17
+#define seed r32
+
+GLOBAL_ENTRY(carta_random32)
+ movl a = (16807 << 16) | 16807
+ ;;
+ pmpyshr2.u t0 = a, seed, 0
+ pmpyshr2.u t1 = a, seed, 16
+ ;;
+ unpack2.l t0 = t1, t0
+ dep m = -1, r0, 0, 31
+ ;;
+ zxt4 lo = t0
+ shr.u hi = t0, 32
+ ;;
+ dep t0 = 0, hi, 15, 49 // t0 = (hi & 0x7fff)
+ ;;
+ shl t0 = t0, 16 // t0 = (hi & 0x7fff) << 16
+ shr t1 = hi, 15 // t1 = (hi >> 15)
+ ;;
+ add lo = lo, t0
+ ;;
+ cmp.gtu p6, p0 = lo, m
+ ;;
+(p6) and lo = lo, m
+ ;;
+(p6) add lo = 1, lo
+ ;;
+ add lo = lo, t1
+ ;;
+ cmp.gtu p6, p0 = lo, m
+ ;;
+(p6) and lo = lo, m
+ ;;
+(p6) add lo = 1, lo
+ br.ret.sptk.many rp
+END(carta_random32)