Commit f5d2a381d1fb5f7def1c86c95d0c093e54e3aa67
1 parent
e553272d
performance boost (on P4 hosts at least, rdtsc is a _very_ bad random generator)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1892 c046a42c-6fe2-441c-8c8c-71466251a162
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6 additions
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3 deletions
hw/mips_r4k.c
| @@ -27,11 +27,14 @@ void cpu_mips_irqctrl_init (void) | @@ -27,11 +27,14 @@ void cpu_mips_irqctrl_init (void) | ||
| 27 | { | 27 | { |
| 28 | } | 28 | } |
| 29 | 29 | ||
| 30 | +/* XXX: do not use a global */ | ||
| 30 | uint32_t cpu_mips_get_random (CPUState *env) | 31 | uint32_t cpu_mips_get_random (CPUState *env) |
| 31 | { | 32 | { |
| 32 | - uint32_t now = qemu_get_clock(vm_clock); | ||
| 33 | - | ||
| 34 | - return now % (MIPS_TLB_NB - env->CP0_Wired) + env->CP0_Wired; | 33 | + static uint32_t seed = 0; |
| 34 | + uint32_t idx; | ||
| 35 | + seed = seed * 314159 + 1; | ||
| 36 | + idx = (seed >> 16) % (MIPS_TLB_NB - env->CP0_Wired) + env->CP0_Wired; | ||
| 37 | + return idx; | ||
| 35 | } | 38 | } |
| 36 | 39 | ||
| 37 | /* MIPS R4K timer */ | 40 | /* MIPS R4K timer */ |