CSC373/406: Example: Floating Point [3/8]

file:float1.c [source]

00001: #include <stdio.h> 00002: #include <math.h> 00003: #include "show-bytes.c" 00004: 00005: int main() { 00006: float x; 00007: printf("Enter a floating point number\n"); 00008: scanf("%f", &x); 00009: printf("%f in 2's complement is ", x); 00010: show_bytes((byte_pointer) &x, sizeof x); 00011: printf("\n"); 00012: return 0; 00013: } 00014:

file:float2.c [source]

00001: #include <stdio.h> 00002: #include <math.h> 00003: #include "show-bytes.c" 00004: 00005: int main() { 00006: float v = 1.0, // 1.0 00007: w = 2.5, // 10.1 00008: x = 3.25, // 11.01 00009: y = 32.5; // 100000.1 00010: double z = 75.75; // 1001011.11 00011: float a = .5, 00012: b = 3./16.; 00013: int i=1; 00014: float c = *((float *) ((byte_pointer) &i)); 00015: float d = 10.0/0.0; 00016: float n1 = -1.0, 00017: n2 = -3.25; 00018: // float c = 0.00000011920928955078125; // smallest possible float 00019: 00020: printf("%f (1.0) = ", v); 00021: show_bytes((byte_pointer) &v, sizeof v); 00022: printf("\n"); 00023: 00024: printf("%f (10.1) = ", w); 00025: show_bytes((byte_pointer) &w, sizeof w); 00026: printf("\n"); 00027: 00028: printf("%f (11.01) = ", x); 00029: show_bytes((byte_pointer) &x, sizeof x); 00030: printf("\n"); 00031: 00032: printf("%f (100000.1) = ", y); 00033: show_bytes((byte_pointer) &y, sizeof y); 00034: printf("\n"); 00035: 00036: printf("%f (1001011.11) = ", z); 00037: show_bytes((byte_pointer) &z, sizeof z); 00038: printf("\n"); 00039: 00040: printf("%f (.1) = ", a); 00041: show_bytes((byte_pointer) &a, sizeof a); 00042: printf("\n"); 00043: 00044: printf("%f (.0011) = ", b); 00045: show_bytes((byte_pointer) &b, sizeof b); 00046: printf("\n"); 00047: 00048: printf("%1.50f (smallest possible float) = ", c); 00049: show_bytes((byte_pointer) &c, sizeof c); 00050: printf("\n"); 00051: 00052: printf("10.0/0.0 = %f =", d); 00053: show_bytes((byte_pointer) &d, sizeof d); 00054: printf("\n"); 00055: 00056: printf("%f (-1.0) = ", n1); 00057: show_bytes((byte_pointer) &n1, sizeof n1); 00058: printf("\n"); 00059: 00060: printf("%f (-11.01) = ", n2); 00061: show_bytes((byte_pointer) &n2, sizeof n2); 00062: printf("\n"); 00063: 00064: return 0; 00065: } 00066:

file:float-b2u.c [source]

00001: #include <stdio.h> 00002: #include <math.h> 00003: #include "show-bytes.c" 00004: 00005: unsigned int b2u(char *s) { 00006: unsigned int x=0; 00007: while (*s!='\0') { // while s not pointing to NULL 00008: if (*s!='1' && *s!='0') { s++; continue; } // skip non-digits 00009: x <<= 1; // shift left one bit 00010: if (*s=='1') { x++; } // add this bit 00011: s++; // advance s 00012: } 00013: return x; 00014: } 00015: int main() { 00016: double v; 00017: float f; 00018: float *p, *q; 00019: unsigned int x, y; 00020: 00021: p = (float *) &x; 00022: q = (float *) &y; 00023: 00024: v = 0; 00025: printf("%le = ", v); 00026: show_bytes((byte_pointer) &v, sizeof v); 00027: printf("\n\n"); 00028: 00029: v = HUGE_VAL; 00030: printf("%le = ", v); 00031: show_bytes((byte_pointer) &v, sizeof v); 00032: printf("\n\n"); 00033: 00034: v = -HUGE_VAL; 00035: printf("%le = ", v); 00036: show_bytes((byte_pointer) &v, sizeof v); 00037: printf("\n\n"); 00038: 00039: v = 15213; 00040: printf("%le = ", v); 00041: show_bytes((byte_pointer) &v, sizeof v); 00042: printf("\n\n"); 00043: 00044: f = 15213; 00045: printf("%e = ", f); 00046: show_bytes((byte_pointer) &f, sizeof f); 00047: printf("\n\n"); 00048: 00049: //x = b2u("111100001111"); 00050: //printf("%u = ", x); 00051: //show_bytes((byte_pointer) &x, sizeof x); 00052: //printf("\n\n"); 00053: 00054: // Pos and neg zero 00055: x = b2u("0 00000000 00000000000000000000000"); 00056: printf("%e = (+0)\n", *p); 00057: show_bytes((byte_pointer) p, sizeof (*p)); 00058: printf("\n\n"); 00059: 00060: y = b2u("1 00000000 00000000000000000000000"); 00061: printf("%e = (-0)\n", *q); 00062: show_bytes((byte_pointer) q, sizeof (*q)); 00063: printf("\n\n"); 00064: printf("(0)==(-0)? %d", x==y); 00065: printf("\n\n"); 00066: 00067: // Denormalized 00068: x = b2u("0 00000000 00000000000000000000001"); 00069: printf("%e = (0+epsilon)\n", *p); 00070: show_bytes((byte_pointer) p, sizeof (*p)); 00071: printf("\n\n"); 00072: 00073: x = b2u("0 00000000 11111111111111111111111"); 00074: printf("%e = (largest denorm)\n", *p); 00075: show_bytes((byte_pointer) p, sizeof (*p)); 00076: printf("\n\n"); 00077: 00078: // Normalized 00079: x = b2u("0 00000001 00000000000000000000000"); 00080: printf("%e = (smallest norm)\n", *p); 00081: show_bytes((byte_pointer) p, sizeof (*p)); 00082: printf("\n\n"); 00083: 00084: x = b2u("0 01111110 11111111111111111111111"); 00085: printf("%e = (1-epsilon)\n", *p); 00086: show_bytes((byte_pointer) p, sizeof (*p)); 00087: printf("\n\n"); 00088: 00089: x = b2u("0 01111111 00000000000000000000000"); 00090: printf("%e = (1)\n", *p); 00091: show_bytes((byte_pointer) p, sizeof (*p)); 00092: printf("\n\n"); 00093: 00094: x = b2u("0 11111110 11111111111111111111111"); 00095: printf("%e = (largest norm)\n", *p); 00096: show_bytes((byte_pointer) p, sizeof (*p)); 00097: printf("\n\n"); 00098: 00099: // Specials 00100: x = b2u("0 11111111 00000000000000000000000"); 00101: printf("%e = (+INFINTIY)\n", *p); 00102: show_bytes((byte_pointer) p, sizeof (*p)); 00103: printf("\n\n"); 00104: 00105: x = b2u("0 11111111 00000000000000000010000"); 00106: printf("%e = (NaN)\n", *p); 00107: show_bytes((byte_pointer) p, sizeof (*p)); 00108: printf("\n\n"); 00109: 00110: // Denormalized 00111: x = b2u("1 00000000 00000000000000000000001"); 00112: printf("%e = (0+epsilon)\n", *p); 00113: show_bytes((byte_pointer) p, sizeof (*p)); 00114: printf("\n\n"); 00115: 00116: x = b2u("1 00000000 11111111111111111111111"); 00117: printf("%e = (largest denorm)\n", *p); 00118: show_bytes((byte_pointer) p, sizeof (*p)); 00119: printf("\n\n"); 00120: 00121: // Normalized 00122: x = b2u("1 00000001 00000000000000000000000"); 00123: printf("%e = (smallest norm)\n", *p); 00124: show_bytes((byte_pointer) p, sizeof (*p)); 00125: printf("\n\n"); 00126: 00127: x = b2u("1 01111110 11111111111111111111111"); 00128: printf("%e = (1-epsilon)\n", *p); 00129: show_bytes((byte_pointer) p, sizeof (*p)); 00130: printf("\n\n"); 00131: 00132: x = b2u("1 01111111 00000000000000000000000"); 00133: printf("%e = (1)\n", *p); 00134: show_bytes((byte_pointer) p, sizeof (*p)); 00135: printf("\n\n"); 00136: 00137: x = b2u("1 11111110 11111111111111111111111"); 00138: printf("%e = (largest norm)\n", *p); 00139: show_bytes((byte_pointer) p, sizeof (*p)); 00140: printf("\n\n"); 00141: 00142: // Specials 00143: x = b2u("1 11111111 00000000000000000000000"); 00144: printf("%e = (-INFINTIY)\n", *p); 00145: show_bytes((byte_pointer) p, sizeof (*p)); 00146: printf("\n\n"); 00147: 00148: x = b2u("1 11111111 00000001000000000000000"); 00149: printf("%e = (NaN)\n", *p); 00150: show_bytes((byte_pointer) p, sizeof (*p)); 00151: printf("\n\n"); 00152: 00153: return 0; 00154: } 00155: