*********************** FLOATING-POINT DATA ******************************* ASM32 floating-point data subroutines (C) Copyright 1994 Douglas Herr all rights reserved ASM32 recognizes two floating point formats: IEEE-standard single- precision, and IEEE-standard double-precision. Single-precision floating point numbers are 4 bytes long, and are referred to as float4 or simply f4, while double-precision floating point numbers are 8 bytes long, which I describe as float8 or f8. This is the format used by the Intel 80x87 math coprocessors. 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� ABSF4: absolute value of float4 number Source: absf4.asm Call with: DS:[EBX] pointing to 4-byte real number Returns: number converted to absolute value Uses: flags Example: include model.inc extrn absf4:near include dataseg.inc f4 dd -123.456 @curseg ends include codeseg.inc . . . lea ebx,f4 ; point to 4-byte real number call absf4 ; convert to absolute value 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� ABSF8: absolute value of float8 number Source: absf8.asm Call with: DS:[EBX] pointing to 8-byte real number Returns: number converted to absolute value Uses: flags Example: include model.inc extrn absf8:near include dataseg.inc f8 dd -123.456789 @curseg ends include codeseg.inc . . . lea bx,f8 ; point to 8-byte real number call absf8 ; convert to absolute value 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� ADDF4: add two float4 numbers Source: addf4.asm 80x87 not required; no OS dependancies Call with: DS:[ESI] pointing to number0, ES:[EDI] pointing to number1 both numbers must be float4 numbers in IEEE format Returns: if CF = 0, number0 is replaced by the sum if CF = 1, the sum would result in an overflow or underflow; neither number is changed Uses: flags Example: include model.inc extrn addf4:near include dataseg.inc number0 dd 123.456 number1 dd -67.4 include codeseg.inc . . . push ds pop es ; ES = DS lea esi,number0 lea edi,number1 call addf4 ; note that this can be used for subtraction by changing the sign ; of one of the numbers. ; ; changing the sign is trivial: if DS:[ESI] points to a float4 number, ; the sign is changed with ; ; xor byte ptr 3[esi],10000000b 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� ADDF8: add two float8 numbers Source: addf8.asm 80x87 not required; no OS dependancies Call with: DS:[ESI] pointing to number0, ES:[EDI] pointing to number1 both numbers must be float8 numbers in IEEE format Returns: if CF = 0, number0 is replaced by the sum if CF = 1, the sum would result in an overflow or underflow; neither number is changed Uses: CF Example: include model.inc extrn addf8:near include dataseg.inc number0 dq 123.456e16 number1 dq -67.407865 include codeseg.inc . . . push ds pop es ; ES = DS lea esi,number0 lea edi,number1 call addf4 ; note that this can be used for subtraction by changing the sign ; of one of the numbers. ; ; changing the sign is trivial: if DS:[ESI] points to a float8 number, ; the sign is changed with ; ; xor byte ptr 7[esi],10000000b 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� CMPF4: compare two float4 numbers Source: cmpf4.asm CMPF8: compare two float8 numbers Source: cmpf8.asm 80x87 NOT required Call with: ESI pointing to number 0 EDI pointing to number 1 Returns: if ZF = 1, numbers are equal if SF = 1, number 1 is larger Uses: zero flag (ZF), sign flag (SF) Example: extrn cmpf4:near include dataseg.inc v0 dd 12.345 v1 dd 17.04 @curseg ends include codeseg.inc . . . lea esi,v0 ; point ESI to number 0 lea edi,v1 ; point EDI to number 1 call cmpf4 ; compare js number1 ; v1 is larger if SF = 1 je equal ; numbers identical if ZF = 1 ; otherwise v0 is larger 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� F4TOI2: copies the integer portion of a float4 number to AX Source: f4toi2.asm 80x87 not required Note: only the integer portion of the number is converted; decimals are truncated Call with: ESI pointing to a float4 number Returns: if CF = 0, AX = integer number if CF = 1, float4 number is too large (if positive) or is too small (if negtive) Uses: AX, CF; all other flags and registers are saved Example: extrn f4toi2:near include dataseg.inc float4 dd 1234.567 @curseg ends include codeseg.inc . . . lea esi,float4 call f4toi2 jc oops ; gotta fix something if error 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� F4TOI4: copies the long integer portion of a float4 number to EAX Source: f4toi4.asm 80x87 not required Note: only the integer portion of the number is converted; decimals are truncated Call with: ESI pointing to a float4 number Returns: if CF = 0, EAX = long integer number if CF = 1, float4 number is too large (if positive) or is too small (if negtive) Uses: EAX, CF; all other flags and registers are saved Example: extrn f4toi4:near include dataseg.inc float4 dd 1234.567 @curseg ends include codeseg.inc . . . lea esi,float4 call f4toi4 jc oops ; gotta fix something if error 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� I4TOF4: convert 4-byte integer to float4 IEEE format Source: i4tof4.asm 80x87 not required Call with: DS:[EBX] pointing to 4-byte buffer for float4 number EAX = signed integer number to convert Returns: converted number in float4 IEEE format at DS:[EBX] Uses: nothing; all registers and flags are saved Example: include model.inc extrn i4tof4:near include dataseg.inc float4 dd ? ; initial number undefined longint dd -123456789 include codeseg.inc . . . mov eax,longint ; signed integer lea ebx,float4 ; point to buffer for converted number call i4tof4 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� MAXF4, MAXF4b: find maximum value in single-precision real-number array Source: maxf4.asm MINF4, MINF4b: find minimum value in single-precision real-number array Source: minf4.asm 80x87 not required Call with: EDI pointing to array element at start of search ECX = number of array elements to search For maxf4b or minf4b, call with EBX = byte increment between array elements. Maxf4 and minf4 assume byte increment = 4. Returns: EAX = array element number with maximum or minimum value note that the offset of that number is EDI + (EAX shl 2). With maxf4b and minf4b, the offset of the number is EDI + (EAX * EBX). CF = 1 if called with ECX = 0. Uses: EAX, CF Example: extrn maxf4:near include dataseg.inc floatdata dd 1500 dup(0) @curseg ends include codeseg.inc ; program provides values for the array . . . lea edi,floatdata ; EDI points to the data array mov ecx,1500 ; search entire array call maxf4 ; returns with EAX = array element 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� MAXF8, MAXF8b: find maximum value in double-precision real-number array Source: maxf8.asm MINF8, MINF8b: find minimum value in double-precision real-number array Source: minf8.asm 80x87 not required Call with: EDI pointing to array element at start of search ECX = number of array elements to search For maxf8b or minf8b, call with EBX = byte increment between array elements. Maxf8 and minf8 assume byte increment = 8. Returns: EAX = array element number with maximum or minimum value note that the offset of that number is EDI + (EAX shl 3) With maxf8b and minf8b, the offset of the number is EDI + (EAX * EBX). CF = 1 if called with ECX = 0. Uses: EAX, CF Example: extrn maxf8:near include dataseg.inc floatdata dq 1500 dup(0) @curseg ends include codeseg.inc ; program provides values for the array . . . lea edi,floatdata ; EDI points to the data array mov ecx,1500 ; search entire array call maxf8 ; returns with EAX = array element shl eax,3 add edi,eax ; EDI points to maximum value 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� MULF4: multiplies two float4 numbers Source: mulf4.asm 80x87 not required Call with: DS:[ESI] pointing to number0, ES:[EDI] pointing to number1 Returns: if CF = 0, no error; product replaces number0 at DS:[ESI] if CF = 1, the product is either zero or infinity (number0 is lost) Uses: CF; all other flags and registers are saved Example: include model.inc extrn mulf4:near include dataseg.inc number0 dd 1.234 number1 dd 0.5 @curseg ends include codeseg.inc . . . push ds pop es lea esi,number0 lea edi,number1 call mulf4 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� SCALEF4: scale a float4 number by an integer power of 2 Source: scalef4.asm SCALEF8: scale a float8 number by an integer power of 2 Source: scalef8.asm 80x87 not required; no OS dependancies Call with: DS:[ESI] pointing to the float4 data AL = scale factor (may be positive or negative) Returns: CF = 0 if success: number was properly scaled CF = 1 if error: resulting number would have overflowed number unchanged in this case Uses: CF; all other flags and all registers saved Example: include model.inc include codeseg.inc . . . lea esi,float4data mov al,3 ; scale by (2^3) effectively multiplies by 8 call scalef4 jc oops ; take remedial action if error 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� SORTF4HI: sort an array of single-precision real numbers, highest first Source: sortf4hi.asm SORTF4LO: sort an array of single-precision real numbers, lowest first Source: sortf4lo.asm 80x87 not required Call with: ES:[EDI] pointing to the first of the array elements to be sorted, ECX = number of array elements Returns: nothing Uses: nothing; all registers and flags are saved Example: extrn sortf4hi:near include dataseg.inc floatdata dd 1500 dup(0) @curseg ends include codeseg.inc ; program provides values for the array . . lea edi,floatdata push ds pop es mov ecx,1500 ; sort entire array call sortf4hi ; highest number first 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� SORTF8HI: sort an array of double-precision real numbers, highest first Source: sortf8hi.asm SORTF8LO: sort an array of double-precision real numbers, lowest first Source: sortf8lo.asm 80x87 not required Call with: ES:[EDI] pointing to the first of the array elements to be sorted, ECX = number of array elements Returns: nothing Uses: nothing; all registers and flags are saved Example: extrn sortf8hi:near include dataseg.inc floatdata dq 1500 dup(?) @curseg ends include codeseg.inc ; program provides values for the array . . lea edi,floatdata push ds pop es mov ecx,1500 ; sort entire array call sortf8hi ; highest value first