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Add uniform variants of RNG functions to stdlib

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This commit is contained in:
Matt Pharr
2012-03-01 12:09:16 -08:00
parent f7937f1e4b
commit 7bf9c11822
1 changed files with 34 additions and 1 deletions
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35
stdlib.ispc
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@@ -3409,6 +3409,21 @@ static inline unsigned int random(varying RNGState * uniform state)
return (state->z1 ^ state->z2 ^ state->z3 ^ state->z4);
}
static inline uniform unsigned int random(uniform RNGState * uniform state)
{
uniform unsigned int b;
b = ((state->z1 << 6) ^ state->z1) >> 13;
state->z1 = ((state->z1 & 4294967294U) << 18) ^ b;
b = ((state->z2 << 2) ^ state->z2) >> 27;
state->z2 = ((state->z2 & 4294967288U) << 2) ^ b;
b = ((state->z3 << 13) ^ state->z3) >> 21;
state->z3 = ((state->z3 & 4294967280U) << 7) ^ b;
b = ((state->z4 << 3) ^ state->z4) >> 12;
state->z4 = ((state->z4 & 4294967168U) << 13) ^ b;
return (state->z1 ^ state->z2 ^ state->z3 ^ state->z4);
}
static inline float frandom(varying RNGState * uniform state)
{
unsigned int irand = random(state);
@@ -3416,6 +3431,13 @@ static inline float frandom(varying RNGState * uniform state)
return floatbits(0x3F800000 | irand)-1.0f;
}
static inline uniform float frandom(uniform RNGState * uniform state)
{
uniform unsigned int irand = random(state);
irand &= (1<<23)-1;
return floatbits(0x3F800000 | irand)-1.0f;
}
static inline uniform unsigned int __seed4(varying RNGState * uniform state,
uniform int start,
uniform unsigned int seed) {
@@ -3450,7 +3472,8 @@ static inline uniform unsigned int __seed4(varying RNGState * uniform state,
return seed;
}
static inline void seed_rng(varying RNGState * uniform state, uniform unsigned int seed) {
static inline void seed_rng(varying RNGState * uniform state,
uniform unsigned int seed) {
if (programCount == 1) {
state->z1 = seed;
state->z2 = seed ^ 0xbeeff00d;
@@ -3471,6 +3494,16 @@ static inline void seed_rng(varying RNGState * uniform state, uniform unsigned i
}
}
static inline void seed_rng(uniform RNGState * uniform state,
uniform unsigned int seed) {
state->z1 = seed;
state->z2 = seed ^ 0xbeeff00d;
state->z3 = ((seed & 0xffff) << 16) | (seed >> 16);
state->z4 = (((seed & 0xff) << 24) | ((seed & 0xff00) << 8) |
((seed & 0xff0000) >> 8) | (seed & 0xff000000) >> 24);
}
static inline void fastmath() {
__fastmath();
}