hg/stx-libbasic: comparison LargeInteger.st

equal deleted inserted replaced

-:cdf2971ca4a4
+:5d75e2de262b
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
 "
 "{ Package: 'stx:libbasic' }"
 Integer subclass:#LargeInteger
 	instanceVariableNames:'sign digitByteArray'
 	classVariableNames:''
 "
 this is the common case, subtracting a SmallInteger.
 Use a special method for this case ...
 "
 ((numberClass := aNumber class) == SmallInteger) ifTrue:[
-	sign > 0 ifTrue:[
+sign > 0 ifTrue:[
-	    aNumber > 0 ifTrue:[
+aNumber > 0 ifTrue:[
-		^ self absFastMinus:aNumber sign:1
+^ self absFastMinus:aNumber sign:1
-	    ].
+].
-	    ^ self absFastPlus:aNumber sign:1
+^ self absFastPlus:aNumber sign:1
-	].
+].
-	aNumber > 0 ifTrue:[
+aNumber > 0 ifTrue:[
-	    ^ self absFastPlus:aNumber sign:-1
+^ self absFastPlus:aNumber sign:-1
-	].
+].
-	^ self absFastMinus:aNumber sign:-1
+^ self absFastMinus:aNumber sign:-1
 ].
 "
 if the argument is not a largeInteger, coerce
 "
 (numberClass == self class) ifFalse:[
-	^ self retry:#- coercing:aNumber
+^ self retry:#- coercing:aNumber
 ].
 otherSign := aNumber sign.
 (sign > 0) ifTrue:[
-	"I am positive"
+"I am positive"
-	(otherSign > 0) ifTrue:[
+(otherSign > 0) ifTrue:[
-	    "+large - +large"
+"+large - +large"
-	    ^ self absMinus:aNumber sign:1
+^ self absMinus:aNumber sign:1
-	].
+].
-	(otherSign < 0) ifTrue:[
+(otherSign < 0) ifTrue:[
-	    "+large - -large"
+"+large - -large"
-	    ^ self absPlus:aNumber sign:1
+^ self absPlus:aNumber sign:1
-	].
+].
-	"should not happen"
+"should not happen"
-	^ self
+^ self
 ].
 "I am negative"
 (otherSign > 0) ifTrue:[
-	"-large - +large"
+"-large - +large"
-	^ self absPlus:aNumber sign:-1
+^ self absPlus:aNumber sign:-1
 ].
 (otherSign < 0) ifTrue:[
-	"-large - -large"
+"-large - -large"
-	^ self absMinus:aNumber sign:-1
+^ self absMinus:aNumber sign:-1
 ].
 ^ self
 "
 12345678901234567890 - 0
 len1 := digitByteArray size.
 otherDigitByteArray := aLargeInteger digitBytes.
 len2 := otherDigitByteArray size.
 len1 > len2 ifTrue:[
-	lResult := len1
+lResult := len1
 ] ifFalse:[
-	lResult := (len1 max: len2) + 1.
+lResult := (len1 max: len2) + 1.
 ].
 result := self class basicNew numberOfDigits:lResult.
 result sign:newSign.
 resultDigitByteArray := result digitBytes.
 OBJ _digitByteArray = __INST(digitByteArray);
 if (__isByteArray(_digitByteArray)
 && __isByteArray(otherDigitByteArray)
 && __isByteArray(resultDigitByteArray)) {
-	int __len1 = __intVal(len1);
+int __len1 = __intVal(len1);
-	int __len2 = __intVal(len2);
+int __len2 = __intVal(len2);
-	int __minLen = __len1 < __len2 ? __len1 : __len2;
+int __minLen = __len1 < __len2 ? __len1 : __len2;
-	int __index, __borrow = 0;
+int __index, __borrow = 0;
-	INT __diff;
+INT __diff;
-	unsigned char *__myDigits, *__otherDigits, *__resultDigits;
+unsigned char *__myDigits, *__otherDigits, *__resultDigits;
-	ok = true;
+ok = true;
-	__resultDigits = __ByteArrayInstPtr(resultDigitByteArray)->ba_element;
+__resultDigits = __ByteArrayInstPtr(resultDigitByteArray)->ba_element;
-	__otherDigits = __ByteArrayInstPtr(otherDigitByteArray)->ba_element;
+__otherDigits = __ByteArrayInstPtr(otherDigitByteArray)->ba_element;
-	__myDigits = __ByteArrayInstPtr(_digitByteArray)->ba_element;
+__myDigits = __ByteArrayInstPtr(_digitByteArray)->ba_element;
-	__index = 1;
+__index = 1;
 #if defined(__LSBFIRST__)
 # if __POINTER_SIZE__ == 8
-	/*
+/*
-	 * subtract int-wise
+* subtract int-wise
-	 */
+*/
-	while ((__index+3) <= __minLen) {
+while ((__index+3) <= __minLen) {
-	    /* do not make this into one expression - ask cg why */
+/* do not make this into one expression - ask cg why */
-	    __diff = ((unsigned int *)(__myDigits+__index-1))[0];
+__diff = ((unsigned int *)(__myDigits+__index-1))[0];
-	    __diff -= ((unsigned int *)(__otherDigits+__index-1))[0];
+__diff -= ((unsigned int *)(__otherDigits+__index-1))[0];
-	    __diff -= __borrow;
+__diff -= __borrow;
-	    if (__diff >= 0) {
+if (__diff >= 0) {
-		__borrow = 0;
+__borrow = 0;
-	    } else {
+} else {
-		__borrow = 1;
+__borrow = 1;
-		/* __diff += 0x10000; */
+/* __diff += 0x10000; */
-	    }
+}
-	    ((unsigned int *)(__resultDigits+__index-1))[0] = __diff;
+((unsigned int *)(__resultDigits+__index-1))[0] = __diff;
-	    __index += 4;
+__index += 4;
-	}
+}
 # endif /* 64bit */
-	/*
+/*
-	 * subtract short-wise
+* subtract short-wise
-	 */
+*/
-	while (__index < __minLen) {   /* i.e. index+1 <= minLen */
+while (__index < __minLen) {   /* i.e. index+1 <= minLen */
-	    /* do not make this into one expression - ask cg why */
+/* do not make this into one expression - ask cg why */
-	    __diff = ((unsigned short *)(__myDigits+__index-1))[0];
+__diff = ((unsigned short *)(__myDigits+__index-1))[0];
-	    __diff -= ((unsigned short *)(__otherDigits+__index-1))[0];
+__diff -= ((unsigned short *)(__otherDigits+__index-1))[0];
-	    __diff -= __borrow;
+__diff -= __borrow;
-	    if (__diff >= 0) {
+if (__diff >= 0) {
-		__borrow = 0;
+__borrow = 0;
-	    } else {
+} else {
-		__borrow = 1;
+__borrow = 1;
-		/* __diff += 0x10000; */
+/* __diff += 0x10000; */
-	    }
+}
-	    ((unsigned short *)(__resultDigits+__index-1))[0] = __diff;
+((unsigned short *)(__resultDigits+__index-1))[0] = __diff;
-	    __index += 2;
+__index += 2;
-	}
+}
-	if (__index == __minLen) {
+if (__index == __minLen) {
-	    /* one of the operands has odd length - cannot continue short-wise */
+/* one of the operands has odd length - cannot continue short-wise */
-	} else {
+} else {
-	    if (__len1 > __len2) {
+if (__len1 > __len2) {
-		while (__index < __len1) {
+while (__index < __len1) {
-		    /* do not make this into one expression - ask cg why */
+/* do not make this into one expression - ask cg why */
-		    __diff = ((unsigned short *)(__myDigits+__index-1))[0];
+__diff = ((unsigned short *)(__myDigits+__index-1))[0];
-		    __diff -= __borrow;
+__diff -= __borrow;
-		    if (__diff >= 0) {
+if (__diff >= 0) {
-			__borrow = 0;
+__borrow = 0;
-			((unsigned short *)(__resultDigits+__index-1))[0] = __diff;
+((unsigned short *)(__resultDigits+__index-1))[0] = __diff;
-			__index += 2;
+__index += 2;
-			/* copy over rest */
+/* copy over rest */
-			while (__index < __len1) {
+while (__index < __len1) {
-			    ((unsigned short *)(__resultDigits+__index-1))[0] = ((unsigned short *)(__myDigits+__index-1))[0];
+((unsigned short *)(__resultDigits+__index-1))[0] = ((unsigned short *)(__myDigits+__index-1))[0];
-			    __index+=2;
+__index+=2;
-			}
+}
-			if (__index <= __len1) {
+if (__index <= __len1) {
-			    __resultDigits[__index-1] = __myDigits[__index-1];
+__resultDigits[__index-1] = __myDigits[__index-1];
-			    __index++;
+__index++;
-			}
+}
-			break;
+break;
-		    }
+}
-		    __borrow = 1;
+__borrow = 1;
-		    /* __diff += 0x10000; */
+/* __diff += 0x10000; */
-		    ((unsigned short *)(__resultDigits+__index-1))[0] = __diff;
+((unsigned short *)(__resultDigits+__index-1))[0] = __diff;
-		    __index += 2;
+__index += 2;
-		}
+}
-	    } else {
+} else {
-		if (__len2 > __len1) {
+if (__len2 > __len1) {
-		    while (__index < __len2) {
+while (__index < __len2) {
-			/* do not make this into one expression - ask cg why */
+/* do not make this into one expression - ask cg why */
-			__diff = 0;
+__diff = 0;
-			__diff -= ((unsigned short *)(__otherDigits+__index-1))[0];
+__diff -= ((unsigned short *)(__otherDigits+__index-1))[0];
-			__diff -= __borrow;
+__diff -= __borrow;
-			if (__diff >= 0) {
+if (__diff >= 0) {
-			    __borrow = 0;
+__borrow = 0;
-			} else {
+} else {
-			    __borrow = 1;
+__borrow = 1;
-			    /* __diff += 0x10000; */
+/* __diff += 0x10000; */
-			}
+}
-			((unsigned short *)(__resultDigits+__index-1))[0] = __diff;
+((unsigned short *)(__resultDigits+__index-1))[0] = __diff;
-			__index += 2;
+__index += 2;
-		    }
+}
-		}
+}
-	    }
+}
-	}
+}
 #endif
-	/*
+/*
-	 * subtract byte-wise
+* subtract byte-wise
-	 */
+*/
-	while (__index <= __minLen) {
+while (__index <= __minLen) {
-	    /* do not make this into one expression - ask cg why */
+/* do not make this into one expression - ask cg why */
-	    __diff = __myDigits[__index-1];
+__diff = __myDigits[__index-1];
-	    __diff -= __otherDigits[__index-1];
+__diff -= __otherDigits[__index-1];
-	    __diff -= __borrow;
+__diff -= __borrow;
-	    if (__diff >= 0) {
+if (__diff >= 0) {
-		__borrow = 0;
+__borrow = 0;
-	    } else {
+} else {
-		__borrow = 1;
+__borrow = 1;
-		/* __diff += 0x100; */
+/* __diff += 0x100; */
-	    }
+}
-	    __resultDigits[__index-1] = __diff;
+__resultDigits[__index-1] = __diff;
-	    __index++;
+__index++;
-	}
+}
-	if (__len1 > __len2) {
+if (__len1 > __len2) {
-	    while (__index <= __len1) {
+while (__index <= __len1) {
-		/* do not make this into one expression - ask cg why */
+/* do not make this into one expression - ask cg why */
-		__diff = __myDigits[__index-1];
+__diff = __myDigits[__index-1];
-		__diff -= __borrow;
+__diff -= __borrow;
-		if (__diff >= 0) {
+if (__diff >= 0) {
-		    __borrow = 0;
+__borrow = 0;
-		    /* copy over rest */
+/* copy over rest */
-		    __resultDigits[__index-1] = __diff;
+__resultDigits[__index-1] = __diff;
-		    __index++;
+__index++;
-		    while (__index <= __len1) {
+while (__index <= __len1) {
-			__resultDigits[__index-1] = __myDigits[__index-1];
+__resultDigits[__index-1] = __myDigits[__index-1];
-			__index++;
+__index++;
-		    }
+}
-		    break;
+break;
-		}
+}
-		__borrow = 1;
+__borrow = 1;
-		/* __diff += 0x100; */
+/* __diff += 0x100; */
-		__resultDigits[__index-1] = __diff;
+__resultDigits[__index-1] = __diff;
-		__index++;
+__index++;
-	    }
+}
-	} else {
+} else {
-	    if (__len2 > __len1) {
+if (__len2 > __len1) {
-		while (__index <= __len2) {
+while (__index <= __len2) {
-		    /* do not make this into one expression - ask cg why */
+/* do not make this into one expression - ask cg why */
-		    __diff = 0;
+__diff = 0;
-		    __diff -= __otherDigits[__index-1];
+__diff -= __otherDigits[__index-1];
-		    __diff -= __borrow;
+__diff -= __borrow;
-		    if (__diff >= 0) {
+if (__diff >= 0) {
-			__borrow = 0;
+__borrow = 0;
-		    } else {
+} else {
-			__borrow = 1;
+__borrow = 1;
-			/* __diff += 0x100; */
+/* __diff += 0x100; */
-		    }
+}
-		    __resultDigits[__index-1] = __diff;
+__resultDigits[__index-1] = __diff;
-		    __index++;
+__index++;
-		}
+}
-	    }
+}
-	}
+}
-	borrow = __mkSmallInteger(__borrow);
+borrow = __mkSmallInteger(__borrow);
-	index = __mkSmallInteger(__index);
+index = __mkSmallInteger(__index);
-	lastDigit = __mkSmallInteger(__resultDigits[__intVal(lResult)-1]);
+lastDigit = __mkSmallInteger(__resultDigits[__intVal(lResult)-1]);
 }
 %}.
 ok == true ifFalse:[
-	index := 1.
+index := 1.
-	borrow := 0.
+borrow := 0.
-	done := false.
+done := false.
-	[done] whileFalse:[
+[done] whileFalse:[
-	    diff := borrow.
+diff := borrow.
-	    (index <= len1) ifTrue:[
+(index <= len1) ifTrue:[
-		diff := diff + (digitByteArray basicAt:index).
+diff := diff + (digitByteArray basicAt:index).
-		(index <= len2) ifTrue:[
+(index <= len2) ifTrue:[
-		    diff := diff - (otherDigitByteArray basicAt:index)
+diff := diff - (otherDigitByteArray basicAt:index)
-		]
+]
-	    ] ifFalse:[
+] ifFalse:[
-		(index <= len2) ifTrue:[
+(index <= len2) ifTrue:[
-		    diff := diff - (otherDigitByteArray basicAt:index)
+diff := diff - (otherDigitByteArray basicAt:index)
-		] ifFalse:[
+] ifFalse:[
-		    "end reached"
+"end reached"
-		    done := true
+done := true
-		]
+]
-	    ].
+].
-	    "/ workaround for
+"/ workaround for
-	    "/ gcc code generator bug
+"/ gcc code generator bug
-	    (diff >= 0) ifTrue:[
+(diff >= 0) ifTrue:[
-		borrow := 0
+borrow := 0
-	    ] ifFalse:[
+] ifFalse:[
-		borrow := -1.
+borrow := -1.
-		diff := diff + 16r100
+diff := diff + 16r100
-	    ].
+].
 "/        (diff < 0) ifTrue:[
 "/            borrow := -1.
 "/            diff := diff + 16r100
 "/        ] ifFalse:[
 "/            borrow := 0
 "/        ].
-	    resultDigitByteArray basicAt:index put:diff.
+resultDigitByteArray basicAt:index put:diff.
-	    index := index + 1
+index := index + 1
-	].
+].
-	lastDigit := resultDigitByteArray basicAt:lResult.
+lastDigit := resultDigitByteArray basicAt:lResult.
 ].
 (borrow ~~ 0) ifTrue:[
-	"/ must generate 255's complement
+"/ must generate 255's complement
-	result sign:-1.
+result sign:newSign negated.
-	[index <= lResult] whileTrue:[
+[index <= lResult] whileTrue:[
-	    resultDigitByteArray basicAt:index put:16rFF.
+resultDigitByteArray basicAt:index put:16rFF.
-	    index := index + 1.
+index := index + 1.
-	].
+].
-	index := lResult.
+index := lResult.
-	[index > 0] whileTrue:[
+[index > 0] whileTrue:[
-	    resultDigitByteArray basicAt:index put:(255 - (resultDigitByteArray at:index)).
+resultDigitByteArray basicAt:index put:(255 - (resultDigitByteArray at:index)).
-	    index := index - 1.
+index := index - 1.
-	].
+].
-	index := 1.
+index := 1.
-	carry := 1.
+carry := 1.
-	[carry ~~ 0] whileTrue:[
+[carry ~~ 0] whileTrue:[
-	    (index <= lResult) ifTrue:[
+(index <= lResult) ifTrue:[
-		carry := (resultDigitByteArray basicAt:index) + carry.
+carry := (resultDigitByteArray basicAt:index) + carry.
-	    ].
+].
-	    resultDigitByteArray basicAt:index put:(carry bitAnd:16rFF).
+resultDigitByteArray basicAt:index put:(carry bitAnd:16rFF).
-	    carry := carry bitShift:-8.
+carry := carry bitShift:-8.
-	    index := index + 1
+index := index + 1
-	].
+].
-	lastDigit := resultDigitByteArray basicAt:lResult.
+lastDigit := resultDigitByteArray basicAt:lResult.
 ].
 (lastDigit ~~ 0 and:[lResult > SmallInteger maxBytes]) ifTrue:[
-	^ result
+^ result
 ].
 ^ result compressed
 "Modified: 5.11.1996 / 14:09:25 / cg"
 !
 ! !
 !LargeInteger class methodsFor:'documentation'!
 version
-^ '$Header: /cvs/stx/stx/libbasic/LargeInteger.st,v 1.185 2007-01-19 00:03:12 stefan Exp $'
+^ '$Header: /cvs/stx/stx/libbasic/LargeInteger.st,v 1.186 2007-09-25 13:58:09 sr Exp $'
 ! !

changeset 10726	5d75e2de262b
parent 10342	58ce3aabaa4b
child 10728	ec5790d03608