mirror of
https://github.com/hrydgard/ppsspp.git
synced 2026-11-01 12:07:31 +01:00
Henrik RydgårdandClaude Opus 5.5
3880999ada
- sceHeapDeleteHeap never freed the heap's memory. Allocation failure returned -1 rather than a null pointer, and a near-4GB size wrapped. - The USB wait timeout resumed threads that were no longer waiting on USB, and UsbUpdateState resumed them too, and never rescheduled. - The Mersenne Twister drew from mt_[index_] with the index taken from guest memory. It's now taken modulo the state size. sceSfmt19937 checks its index, and that fill arrays are at least a state long, which the library writes regardless of the length it's given. - sceCccEncodeUTF16's surrogate test also caught U+F800 - U+FFFF, which includes the fullwidth forms. - sceAudioRoutingSetVolumeMode stored the routing mode. - A sample rate of 0 to sceAudioInput or the camera mic divided by zero, and a huge sample count sized a host buffer. sceP3daBridgeCore's sizes could wrap. sceRtc's tz offset could overflow tm_min. - Camera shutdown freed the frame buffer and config without the lock the capture thread uses. GPS data is set from the platform's location thread, so it's now locked too, and the satellite index is bounded. - A loop in the sys event handler list hung the unregister. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
86 lines
2.4 KiB
C++
86 lines
2.4 KiB
C++
#pragma once
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#include <cstdint>
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#include "Common/Swap.h"
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// George Marsaglia-style random number generator.
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class GMRng {
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public:
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GMRng() {
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m_w = 0x23E866ED;
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m_z = 0x80FD5AF2;
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}
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void Init(int seed) {
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m_w = seed ^ (seed << 16);
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if (!m_w) m_w = 1337;
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m_z = ~seed;
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if (!m_z) m_z = 31337;
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}
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uint32_t R32() {
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m_z = 36969 * (m_z & 65535) + (m_z >> 16);
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m_w = 18000 * (m_w & 65535) + (m_w >> 16);
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return (m_z << 16) + m_w;
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}
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uint64_t R64() {
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const uint32_t bottom = R32();
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const uint32_t top = R32();
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return ((uint64_t)top << 32) | bottom;
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}
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float F() {
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return (float)R32() / (float)(0xFFFFFFFF);
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}
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// public for easy save/load. Yes a bit ugly but better than moving DoState into native.
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uint32_t m_w;
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uint32_t m_z;
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};
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// Data must consist only of the index and the twister array. This matches the PSP
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// MT context exactly - see pspautotests hash/mt19937ctx, which records the whole 2500 byte
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// context off a real PSP: the counter sits at offset 0 and the 624 word array at offset 4,
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// already twisted once by the time Init returns.
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class MersenneTwister {
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public:
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MersenneTwister(uint32_t seed) : index_(0) {
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mt_[0] = seed;
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for (uint32_t i = 1; i < MT_SIZE; i++)
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mt_[i] = (1812433253UL * (mt_[i - 1] ^ (mt_[i - 1] >> 30)) + i);
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// The PSP twists during Init rather than lazily on the first draw, so a context that
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// has been seeded but not yet used already holds the twisted array.
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for (uint32_t i = 0; i < MT_SIZE; i++)
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twist(i);
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}
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uint32_t R32() {
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// Read first, then regenerate that word in place - done in index order this is the
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// same as twisting the whole array in one go, and it matches what hardware leaves
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// behind in the context after each draw.
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// The context can live in emulated memory, so don't trust the index.
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const uint32_t i = index_ % MT_SIZE;
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uint32_t y = mt_[i];
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twist(i);
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index_ = (i + 1) % MT_SIZE;
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y ^= y >> 11;
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y ^= (y << 7) & 2636928640UL;
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y ^= (y << 15) & 4022730752UL;
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y ^= y >> 18;
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return y;
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}
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private:
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enum {
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MT_SIZE = 624,
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};
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u32_le index_;
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u32_le mt_[MT_SIZE];
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void twist(uint32_t i) {
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// The low half has to come through the LOWER mask - masking both halves with
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// 0x80000000 makes this something other than MT19937, which is what it used to do.
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uint32_t y = (mt_[i] & 0x80000000) | (mt_[(i + 1) % MT_SIZE] & 0x7FFFFFFF);
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mt_[i] = mt_[(i + 397) % MT_SIZE] ^ (y >> 1);
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if (y & 1) mt_[i] = mt_[i] ^ 2567483615UL;
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}
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};
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