1 2 #include <stdlib.h> 3 4 int main ( void ) 5 { 6 int* x3 = malloc(3); float f, *f3 = malloc(3); 7 int* x4 = malloc(4); double d, *d7 = malloc(7); 8 int* x5 = malloc(5); long long int lli, *lli7 = malloc(7); 9 int* x6 = malloc(6); char c, *c0 = malloc(0); 10 int* x7 = malloc(7); short int s, *s1 = malloc(1); 11 int x; 12 int* y4 = malloc(4); 13 int* y5 = malloc(5); 14 int* y6 = malloc(6); 15 int* y7 = malloc(7); 16 17 #define ADDB(ptr, n) ((int*)(((unsigned long)(ptr)) + (n))) 18 19 // All these overrun by a single byte; the reads are happening at 20 // different alignments. 21 x = * ADDB(x3,0); // ok if --partial-loads-ok=yes 22 x = * ADDB(x4,1); 23 x = * ADDB(x5,2); 24 x = * ADDB(x6,3); 25 x = * ADDB(x7,4); // ok if --partial-loads-ok=yes 26 27 // These are fine 28 x = * ADDB(y4,0); 29 x = * ADDB(y5,1); 30 x = * ADDB(y6,2); 31 x = * ADDB(y7,3); 32 33 // These are all bad, at different points along 34 x = * ADDB(x3,-1); // before 35 x = * ADDB(x3, 0); // inside // ok if --partial-loads-ok=yes ... 36 x = * ADDB(x3, 1); // inside // ... but only on 32 bit platforms 37 x = * ADDB(x3, 2); // inside // ... ditto 38 x = * ADDB(x3, 3); // after 39 40 // These are all bad 41 f = * f3; // ok if --partial-loads-ok=yes // ... ditto 42 d = * d7; 43 lli = * lli7; // ok if --partial-loads-ok=yes see XXX below 44 c = * c0; 45 s = * s1; 46 47 return 0; 48 } 49 50 /* Note re XXX, this gives different behaviour on 32 and 64 bit 51 platforms, because on 64-bit it's one load whereas as on 32 bit 52 platforms it's necessarily 2 32-bit loads, and the first one is OK. */ 53
