diff options
author | Per Bothner <per@bothner.com> | 2001-03-01 22:55:33 -0800 |
---|---|---|
committer | Per Bothner <bothner@gcc.gnu.org> | 2001-03-01 22:55:33 -0800 |
commit | c04278f74fd6b49f7a770ae51fd1dd0412989af7 (patch) | |
tree | 30e3d7caf1e4140d48d269c9d3049f16681a89ca /libjava/gnu | |
parent | d6edb99e92ed0d198857f104e81d98c57ad5d768 (diff) | |
download | gcc-c04278f74fd6b49f7a770ae51fd1dd0412989af7.zip gcc-c04278f74fd6b49f7a770ae51fd1dd0412989af7.tar.gz gcc-c04278f74fd6b49f7a770ae51fd1dd0412989af7.tar.bz2 |
Changes merged from Kawa's gnu.math.
* java/math/BigInteger.java
* gnu/gcj/math/MPN.java (rshift0): New method handles zero shift count.
(rshift(int[],int[],int,int): Removed - not needed.
(gcd): Use rshift0 rather than rshift.
* java/math/BigInteger.java (setShiftRight): Likewise.
(divide): Simplify by using rshift0.
(divide): Zero-extend results if high-order bit set.
From-SVN: r40177
Diffstat (limited to 'libjava/gnu')
-rw-r--r-- | libjava/gnu/gcj/math/MPN.java | 43 |
1 files changed, 23 insertions, 20 deletions
diff --git a/libjava/gnu/gcj/math/MPN.java b/libjava/gnu/gcj/math/MPN.java index fb947a5..879b173 100644 --- a/libjava/gnu/gcj/math/MPN.java +++ b/libjava/gnu/gcj/math/MPN.java @@ -1,4 +1,4 @@ -/* Copyright (C) 1999, 2000 Free Software Foundation +/* Copyright (C) 1999, 2000, 2001 Free Software Foundation This file is part of libgcj. @@ -481,7 +481,7 @@ public class MPN return xlen > ylen ? 1 : xlen < ylen ? -1 : cmp (x, y, xlen); } - /* Shift x[x_start:x_start+len-1]count bits to the "right" + /* Shift x[x_start:x_start+len-1] count bits to the "right" * (i.e. divide by 2**count). * Store the len least significant words of the result at dest. * The bits shifted out to the right are returned. @@ -506,6 +506,23 @@ public class MPN return retval; } + /* Shift x[x_start:x_start+len-1] count bits to the "right" + * (i.e. divide by 2**count). + * Store the len least significant words of the result at dest. + * OK if dest==x. + * Assumes: 0 <= count < 32 + * Same as rshift, but handles count==0 (and has no return value). + */ + public static void rshift0 (int[] dest, int[] x, int x_start, + int len, int count) + { + if (count > 0) + rshift(dest, x, x_start, len, count); + else + for (int i = 0; i < len; i++) + dest[i] = x[i + x_start]; + } + /** Return the long-truncated value of right shifting. * @param x a two's-complement "bignum" * @param len the number of significant words in x @@ -530,20 +547,6 @@ public class MPN return ((long)w1 << 32) | ((long)w0 & 0xffffffffL); } - /* Shift x[0:len-1]count bits to the "right" (i.e. divide by 2**count). - * Store the len least significant words of the result at dest. - * OK if dest==x. - * OK if count > 32 (but must be >= 0). - */ - public static void rshift (int[] dest, int[] x, int len, int count) - { - int word_count = count >> 5; - count &= 31; - rshift (dest, x, word_count, len, count); - while (word_count < len) - dest[word_count++] = 0; - } - /* Shift x[0:len-1] left by count bits, and store the len least * significant words of the result in dest[d_offset:d_offset+len-1]. * Return the bits shifted out from the most significant digit. @@ -624,8 +627,8 @@ public class MPN // Temporarily devide both x and y by 2**sh. len -= initShiftWords; - MPN.rshift (x, x, initShiftWords, len, initShiftBits); - MPN.rshift (y, y, initShiftWords, len, initShiftBits); + MPN.rshift0 (x, x, initShiftWords, len, initShiftBits); + MPN.rshift0 (y, y, initShiftWords, len, initShiftBits); int[] odd_arg; /* One of x or y which is odd. */ int[] other_arg; /* The other one can be even or odd. */ @@ -704,7 +707,7 @@ public class MPN } /** Calcaulte the Common Lisp "integer-length" function. - * Assumes input is canonicalized: len==IntNum.wordsNeeded(words,len) */ + * Assumes input is canonicalized: len==BigInteger.wordsNeeded(words,len) */ public static int intLength (int[] words, int len) { len--; @@ -712,7 +715,7 @@ public class MPN } /* DEBUGGING: - public static void dprint (IntNum x) + public static void dprint (BigInteger x) { if (x.words == null) System.err.print(Long.toString((long) x.ival & 0xffffffffL, 16)); |