mirror of
https://github.com/RetroPortingToolKit/psxrecomp
synced 2026-10-26 10:19:47 -04:00
Matthew Stanley
48 lines
2.1 KiB
C
48 lines
2.1 KiB
C
/* Exercise the production CRC gate beyond cache capacity, then change live
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* code and restore it. A bounded replacement cache must never inherit a
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* different occupant's successful page-generation result. */
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#include <assert.h>
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#include <stdint.h>
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#include <stdio.h>
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#include "crc32.h"
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#include "overlay_loader.h"
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#include "psx_memory.h"
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uint32_t g_psx_ram_size=0x200000, g_psx_ram_mask=0x1fffff;
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static uint8_t ram[0x200000];
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static uint32_t generation;
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static uint32_t ranges[65536][2];
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uint8_t *memory_get_ram_ptr(void) { return ram; }
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uint32_t overlay_watch_pagegen_sum(uint32_t p,uint32_t n) { (void)p;(void)n;return generation; }
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void overlay_watch_set_range(uint32_t p,uint32_t n) { (void)p;(void)n; }
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extern void overlay_loader_static_match_stats(uint64_t*,uint64_t*,uint64_t*);
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extern int psx_overlay_static_code_matches(const uint32_t*,uint32_t,uint32_t);
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int main(void) {
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const uint32_t good=crc32_update(0xffffffff,ram+0x10000,4)^0xffffffff;
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for(unsigned i=0;i<65536;i++) {
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ranges[i][0]=0x80010000; ranges[i][1]=4;
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assert(psx_overlay_static_code_matches(ranges[i],1,good));
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/* Cache negative occupants too; identical generations don't make
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* these mismatching fingerprints safe to execute. */
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assert(!psx_overlay_static_code_matches(ranges[i],1,good^1));
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}
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const uint32_t *hot=ranges[65535];
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assert(psx_overlay_static_code_matches(hot,1,good));
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uint64_t a,b,c,prev;
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overlay_loader_static_match_stats(&a,&b,&prev);
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for(unsigned i=0;i<10000;i++)
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assert(psx_overlay_static_code_matches(hot,1,good));
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overlay_loader_static_match_stats(&a,&b,&c);
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assert(c-prev==10000); /* A result remains cached after saturation. */
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ram[0x10000]=1; generation++;
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assert(!psx_overlay_static_code_matches(hot,1,good));
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ram[0x10000]=0; generation++;
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assert(psx_overlay_static_code_matches(hot,1,good));
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const uint32_t bad[]={0x801fffff,4};
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assert(!psx_overlay_static_code_matches(bad,1,good));
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assert(!psx_overlay_static_code_matches(ranges[0],0,good));
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puts("static cache saturation, eviction and code replacement passed");
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return 0;
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}
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