1 2 #include <stdio.h> 3 4 typedef signed int Int; 5 typedef unsigned int UInt; 6 7 __attribute__((noinline)) UInt do_udiv32 ( UInt x, UInt y ) 8 { 9 UInt res; 10 __asm__ __volatile__( 11 "mov r9, %1 ; mov r10, %2 ; udiv r3,r9,r10 ; mov %0, r3" 12 : "=r"(res) : "r"(x), "r"(y) : "r3", "r9", "r10" 13 ); 14 return res; 15 } 16 17 __attribute__((noinline)) Int do_sdiv32 ( Int x, Int y ) 18 { 19 UInt res; 20 __asm__ __volatile__( 21 "mov r9, %1 ; mov r10, %2 ; sdiv r3,r9,r10 ; mov %0, r3" 22 : "=r"(res) : "r"(x), "r"(y) : "r3", "r9", "r10" 23 ); 24 return res; 25 } 26 27 void test ( UInt x, UInt y ) 28 { 29 UInt ru = do_udiv32(x,y); 30 Int rs = do_sdiv32(x,y); 31 printf( "%08x %08x -> u:%08x s:%08x\n", x, y, ru, (UInt)rs); 32 } 33 34 int main ( void ) 35 { 36 // Check basic operation 37 test( 500, 50 ); 38 test( 500, -50 ); 39 test( -500, 50 ); 40 test( -500, -50 ); 41 // Check for rounding towards zero 42 test( 100, 7 ); // 14.285 43 test( -100, 7 ); 44 test( 100, -7 ); 45 test( -100, -7 ); 46 // Division by zero produces zero 47 test( 1, 0 ); 48 test( 0, 0 ); 49 test( -1, 0 ); 50 test( 0x80000000, 0 ); 51 test( 0x7FFFFFFF, 0 ); 52 // Test signed range ends 53 test( 0x80000000, -1 ); // unrepresentable as signed 32 54 return 0; 55 } 56
