1 // This artificial program runs a lot of code. The exact amount depends on 2 // the command line -- if an arg "0" is given, it does exactly 3 // the same amount of work, but using four times as much code. 4 // If an arg >= 1 is given, the amount of code is multiplied by this arg. 5 // 6 // It's a stress test for Valgrind's translation speed; natively the two 7 // modes run in about the same time (the I-cache effects aren't big enough 8 // to make a difference), but under Valgrind the one running more code is 9 // significantly slower due to the extra translation time. 10 11 #include <stdio.h> 12 #include <string.h> 13 #include <stdlib.h> 14 #include <assert.h> 15 #if defined(__mips__) 16 #include <asm/cachectl.h> 17 #include <sys/syscall.h> 18 #endif 19 #include "tests/sys_mman.h" 20 21 #define FN_SIZE 996 // Must be big enough to hold the compiled f() 22 #define N_LOOPS 20000 // Should be divisible by four 23 #define RATIO 4 // Ratio of code sizes between the two modes 24 25 int f(int x, int y) 26 { 27 int i; 28 for (i = 0; i < 5000; i++) { 29 switch (x % 8) { 30 case 1: y += 3; 31 case 2: y += x; 32 case 3: y *= 2; 33 default: y--; 34 } 35 } 36 return y; 37 } 38 39 int main(int argc, char* argv[]) 40 { 41 int h, i, sum1 = 0, sum2 = 0, sum3 = 0, sum4 = 0; 42 int n_fns, n_reps; 43 44 if (argc <= 1) { 45 // Mode 1: not so much code 46 n_fns = N_LOOPS / RATIO; 47 n_reps = RATIO; 48 printf("mode 1: "); 49 } else { 50 // Mode 2: lots of code 51 const int mul = atoi(argv[1]); 52 if (mul == 0) 53 n_fns = N_LOOPS; 54 else 55 n_fns = N_LOOPS * mul; 56 n_reps = 1; 57 printf("mode 1: "); 58 } 59 printf("%d copies of f(), %d reps\n", n_fns, n_reps); 60 61 char* a = mmap(0, FN_SIZE * n_fns, 62 PROT_EXEC|PROT_WRITE, 63 MAP_PRIVATE|MAP_ANONYMOUS, -1,0); 64 assert(a != (char*)MAP_FAILED); 65 66 // Make a whole lot of copies of f(). FN_SIZE is much bigger than f() 67 // will ever be (we hope). 68 for (i = 0; i < n_fns; i++) { 69 memcpy(&a[FN_SIZE*i], f, FN_SIZE); 70 } 71 72 #if defined(__mips__) 73 syscall(__NR_cacheflush, a, FN_SIZE * n_fns, ICACHE); 74 #endif 75 76 for (h = 0; h < n_reps; h += 1) { 77 for (i = 0; i < n_fns; i += 4) { 78 int(*f1)(int,int) = (void*)&a[FN_SIZE*(i+0)]; 79 int(*f2)(int,int) = (void*)&a[FN_SIZE*(i+1)]; 80 int(*f3)(int,int) = (void*)&a[FN_SIZE*(i+2)]; 81 int(*f4)(int,int) = (void*)&a[FN_SIZE*(i+3)]; 82 sum1 += f1(i+0, n_fns-i+0); 83 sum2 += f2(i+1, n_fns-i+1); 84 sum3 += f3(i+2, n_fns-i+2); 85 sum4 += f4(i+3, n_fns-i+3); 86 if (i % 1000 == 0) 87 printf("."); 88 } 89 } 90 printf("result = %d\n", sum1 + sum2 + sum3 + sum4); 91 return 0; 92 } 93
