Changeset b391de in git for factory/int_intdiv.cc

Timestamp:

Apr 6, 1998, 2:06:48 PM (26 years ago)

Author:

Jens Schmidt <schmidt@…>

Branches:

(u'spielwiese', '91e5db82acc17434e4062bcfa44e6efa7d41fd30')

Children:

1d418066c3ae5964017d4db2d217ad8886378c2c

Parents:

2e61d1c36b49ff9e3b6689855597e8a149fb806a

Message:

***** merge from branch `factory-gcd' to main trunk


git-svn-id: file:///usr/local/Singular/svn/trunk@1336 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• factory/int_intdiv.cc (modified) (13 diffs)

factory/int_intdiv.cc

@@ -1 +1 @@
 /* emacs edit mode for this file is -*- C++ -*- */
-/* $Id: int_intdiv.cc,v 1.2 1998-03-17 15:57:00 schmidt Exp $ */
+/* $Id: int_intdiv.cc,v 1.3 1998-04-06 12:06:48 schmidt Exp $ */
 
 //{{{ docu
@@ -18 +18 @@
 #include "ftmpl_functions.h"
 
-#include "stdio.h"
-
 //{{{ InternalCF * InternalInteger::dividesame, dividecoeff ( InternalCF * c )
 // docu: see CanonicalForm::operator /()
@@ -75 +73 @@
             mpz_init_set_si( &n, intC );
             mpz_init_set( &d, &thempi );
-        }
-        else {
+        } else {
+            mpz_init_set( &n, &thempi );
             mpz_init_set_si( &d, intC );
-            mpz_init_set( &n, &thempi );
         }
         if ( deleteObject() ) delete this;
@@ -88 +85 @@
         int mpiSign = mpz_sgn( &thempi );
         if ( deleteObject() ) delete this;
-        if ( intC > 0 )
+        if ( intC >= 0 )
             return int2imm( 0 );
         else
@@ -123 +120 @@
             "type error: InternalInteger expected" );
 
+    if ( c == this ) {
+        if ( deleteObject() ) delete this;
+        return int2imm( 1 );
+    }
+
     if ( getRefCount() > 1 ) {
         deleteObject();
@@ -140 +142 @@
     ASSERT( ::is_imm( c ) == INTMARK,
             "type error: immediate integer expected" );
-    ASSERT( ! invert || imm2int( c ) == 0, "math error: c does not divide CO" );
+    ASSERT( invert || imm2int( c ) != 0,
+            "math error: divide by zero" );
+    ASSERT( ! invert || imm2int( c ) == 0,
+            "math error: c does not divide CO" );
 
     if ( invert ) {
@@ -165 +170 @@
 //}}}
 
-// we have to divide the immediate integer `c' by CO.
-// If `c' is positive, this is quite simple: we
-// simply return `c'.  If `c' is negative we return
-// abs(CO)-abs(`c').
-// we have to divide CO by the immediate integer `c'.
-// The remainder will be less than the absolute value of
-// `c', hence it will fit again into an immediate.
-
 //{{{ InternalCF * InternalInteger::modulosame, modulocoeff ( InternalCF * c )
 // docu: see CanonicalForm::operator %()
@@ -181 +178 @@
             "type error: InternalInteger expected" );
 
-    if ( cf_glob_switches.isOn( SW_RATIONAL ) || c == this ) {
+    if ( (c == this) || cf_glob_switches.isOn( SW_RATIONAL ) ) {
         if ( deleteObject() ) delete this;
         return int2imm( 0 );
@@ -211 +208 @@
     }
 
-    InternalCF * result;
-
     int intC = imm2int( c );
 
     if ( invert ) {
-        // calculate c % CO
-        if ( intC > 0 )
-            result = int2imm( intC );
-        else {
+        if ( intC >= 0 ) {
+            if ( deleteObject() ) delete this;
+            return c;
+        } else {
             // no checks for refCount == 1 are done.  It is not worth ...
             MP_INT mpiResult;
@@ -225 +220 @@
             mpz_abs( &mpiResult, &mpiResult );
             mpz_sub_ui( &mpiResult, &mpiResult, -intC );
-            result = uiNormalizeMPI( mpiResult );
-        }
-    } else {
-        // calculate CO % c
+            if ( deleteObject() ) delete this;
+            return uiNormalizeMPI( mpiResult );
+        }
+    } else {
         MP_INT dummy;
         mpz_init( &dummy );
-        result = int2imm( mpz_mod_ui( &dummy, &thempi, (intC > 0 ? intC : -intC) ) );
+        InternalCF * result = int2imm( mpz_mod_ui( &dummy, &thempi, tabs( intC ) ) );
         mpz_clear( &dummy );
-    }
-
-    // clean up
-    if ( deleteObject() ) delete this;
-    return result;
+        if ( deleteObject() ) delete this;
+        return result;
+    }
 }
 //}}}
@@ -261 +254 @@
 InternalInteger::divremsame ( InternalCF * c, InternalCF * & quot, InternalCF * & rem )
 {
-    if ( cf_glob_switches.isOn( SW_RATIONAL ) ) {
-        quot = copyObject();
-        quot = quot->dividesame( c );
-        rem = int2imm( 0 );
-    }
-    else  if ( c == this ) {
+    ASSERT( ! ::is_imm( c ) && c->levelcoeff() == IntegerDomain,
+            "type error: InternalInteger expected" );
+
+    if ( c == this ) {
         quot = int2imm( 1 );
         rem = int2imm( 0 );
-    }
-    else {
-        MP_INT q;
-        MP_INT r;
-        mpz_init( &q ); mpz_init( &r );
-        int signmpi = mpz_cmp_si( &thempi, 0 );
-        int signc = mpz_cmp_si( &MPI( c ), 0 );
-        if ( signmpi < 0 )
-            mpz_neg( &thempi, &thempi );
-        if ( signc < 0 )
-            mpz_neg( &MPI( c ), &MPI( c ) );
-        mpz_divmod( &q, &r, &thempi, &MPI( c ) );
-        if ( signmpi < 0 && mpz_cmp_si( &r, 0 ) != 0 ) {
-            mpz_sub( &r, &MPI( c ), &r );
-        }
-        if ( signmpi < 0 )
-            mpz_neg( &thempi, &thempi );
-        if ( signc < 0 )
-            mpz_neg( &MPI( c ), &MPI( c ) );
-        if ( signmpi < 0 && signc < 0 ) {
-            if ( mpz_cmp_si( &r, 0 ) != 0 )
-                mpz_add_ui( &q, &q, 1 );
-        }
-        else  if ( signc < 0 )
-            mpz_neg( &q, &q );
-        else  if ( signmpi < 0 ) {
-            mpz_neg( &q, &q );
-            if ( mpz_cmp_si( &r, 0 ) != 0 )
-                mpz_sub_ui( &q, &q, 1 );
-        }
-        if ( mpz_is_imm( &q ) )
-            quot = int2imm( mpz_get_si( &q ) );
-        else
-            quot = new InternalInteger( q );
-        if ( mpz_is_imm( &r ) )
-            rem = int2imm( mpz_get_si( &r ) );
-        else
-            rem = new InternalInteger( r );
-    }
+        return;
+    }
+
+    if ( cf_glob_switches.isOn( SW_RATIONAL ) ) {
+        MP_INT n, d;
+        mpz_init_set( &n, &thempi );
+        mpz_init_set( &d, &MPI( c ) );
+        InternalRational * result = new InternalRational( n, d );
+        quot = result->normalize_myself();
+        rem = int2imm( 0 );
+        return;
+    }
+
+    MP_INT q;
+    MP_INT r;
+    mpz_init( &q ); mpz_init( &r );
+    if ( mpz_sgn( &MPI( c ) ) > 0 )
+        mpz_fdiv_qr( &q, &r, &thempi, &MPI( c ) );
+    else
+        mpz_cdiv_qr( &q, &r, &thempi, &MPI( c ) );
+
+    quot = normalizeMPI( q );
+    rem = uiNormalizeMPI( r );
 }
 
@@ -313 +288 @@
 InternalInteger::divremcoeff ( InternalCF * c, InternalCF * & quot, InternalCF * & rem, bool invert )
 {
-    ASSERT( ::is_imm( c ) == INTMARK, "incompatible base coefficients" );
-
-    if ( cf_glob_switches.isOn( SW_RATIONAL ) ) {
-        quot = copyObject();
-        quot = quot->dividecoeff( c, invert );
+    ASSERT( ::is_imm( c ) == INTMARK,
+            "type error: immediate integer expected" );
+    ASSERT( invert || imm2int( c ) != 0,
+            "math error: divide by zero" );
+
+    int intC = imm2int( c );
+
+    if ( cf_glob_switches.isOn( SW_RATIONAL ) ) {
+        MP_INT n, d;
+        if ( invert ) {
+            mpz_init_set_si( &n, intC );
+            mpz_init_set( &d, &thempi );
+        } else {
+            mpz_init_set( &n, &thempi );
+            mpz_init_set_si( &d, intC );
+        }
+        InternalRational * result = new InternalRational( n, d );
+        quot = result->normalize_myself();
         rem = int2imm( 0 );
         return;
     }
-    quot = copyObject();
-    quot = quot->divcoeff( c, invert );
-    rem = copyObject();
-    rem = rem->modcoeff( c, invert );
-    return;
-    int cc = imm2int( c );
-    MP_INT q, r;
-    int signmpi = mpz_cmp_si( &thempi, 0 );
-    int signc = cc;
-
-    mpz_init( &q ); mpz_init( &r );
-    if ( signmpi < 0 )
-        mpz_neg( &thempi, &thempi );
-    if ( signc < 0 )
-        cc = -cc;
+
     if ( invert ) {
-        MP_INT ccc;
-        mpz_init_set_si( &ccc, cc );
-        mpz_divmod( &q, &r, &ccc, &thempi );
-        mpz_clear( &ccc );
-        if ( signc < 0 && signmpi < 0 ) {
-            if ( mpz_cmp_si( &r, 0 ) != 0 ) {
-                mpz_add_ui( &q, &q, 1 );
-                mpz_sub( &r, &thempi, &r );
-            }
-        }
-        else  if ( signc < 0 ) {
-            if ( mpz_cmp_si( &r, 0 ) != 0 ) {
-                mpz_add_ui( &q, &q, 1 );
-                mpz_neg( &q, &q );
-                mpz_sub( &r, &thempi, &r );
-            }
-        }
-        else  if ( signmpi < 0 )
+        if ( intC >= 0 ) {
+            rem = c;
+            quot = int2imm( 0 );
+        } else {
+            MP_INT mpiResult;
+            mpz_init_set( &mpiResult, &thempi );
+            mpz_abs( &mpiResult, &mpiResult );
+            mpz_sub_ui( &mpiResult, &mpiResult, -intC );
+            rem = uiNormalizeMPI( mpiResult );
+            quot = int2imm( -mpz_sgn( &thempi ) );
+        }
+    } else {
+        MP_INT q;
+        MP_INT dummy;
+        mpz_init( &q ); mpz_init( &dummy );
+        if ( intC > 0 ) {
+            rem = int2imm( mpz_fdiv_qr_ui( &q, &dummy, &thempi, intC ) );
+            quot = normalizeMPI( q );
+        } else {
+            rem = int2imm( mpz_fdiv_qr_ui( &q, &dummy, &thempi, -intC ) );
             mpz_neg( &q, &q );
-    }
-    else {
-        mpz_divmod_ui( &q, &r, &thempi, cc );
-        if ( signmpi < 0 && signc < 0 ) {
-            if ( mpz_cmp_si( &r, 0 ) != 0 ) {
-                mpz_add_ui( &q, &q, 1 );
-                mpz_neg( &r, &r );
-                mpz_add_ui( &r, &r, cc );
-            }
-        }
-        else  if ( signmpi < 0 ) {
-            if ( mpz_cmp_si( &r, 0 ) != 0 ) {
-                mpz_add_ui( &q, &q, 1 );
-                mpz_neg( &q, &q );
-                mpz_neg( &r, &r );
-                mpz_add_ui( &r, &r, cc );
-            }
-        }
-        else  if ( signc < 0 )
-            mpz_neg( &q, &q );
-    }
-    if ( signmpi < 0 )
-        mpz_neg( &thempi, &thempi );
-    if ( mpz_is_imm( &r ) ) {
-        rem = int2imm( mpz_get_si( &r ) );
-        mpz_clear( &r );
-    }
-    else
-        rem = new InternalInteger( r );
-    if ( mpz_is_imm( &q ) ) {
-        quot = int2imm( mpz_get_si( &q ) );
-        mpz_clear( &q );
-    }
-    else
-        quot = new InternalInteger( q );
+            quot = normalizeMPI( q );
+        }
+        mpz_clear( &dummy );
+    }
 }
 //}}}
@@ -406 +351 @@
 InternalInteger::divremcoefft ( InternalCF * c, InternalCF * & quot, InternalCF * & rem, bool invert )
 {
-    ASSERT( ::is_imm( c ) == INTMARK, "incompatible base coefficients" );
     divremcoeff( c, quot, rem, invert );
     return true;