updated libquantum 0.2.1 source files

CHANGES

@@ -1,3 +1,15 @@
+libquantum 0.2.1:
+	- Completed GNU/Hurd and FreeBSD ports
+	- Added unbounded toffoli gate
+	- Changed hashing method to linear probing (breaks backward 
+	  compatibility)
+	- Optimized quantum_gate1 and gates using quantum_cexp
+	- Added a bit measurement function that does not remove the
+	  measured bit
+	- Corrected qft, added qft_inv and adjusted shor
+	- Corrected the implementation of the Walsh-Hadamard transform
+	- Supplied version information
+
 libquantum 0.2.0:
 	- Added Quantum Error Correction
 	- Included an Implementation of Grover's algorithm

INSTALL

@@ -1,4 +1,4 @@
-libquantum 0.2.0 installation guide
+libquantum 0.2.1 installation guide
 -----------------------------------
 
 Contents:
@@ -13,7 +13,7 @@ Contents:
 ---------------
 
 libquantum needs a C compiler with complex number support (C99
-prefered). A recent gcc (>=2.9.5) will do the job. Furthermore, the
+prefered). A recent gcc (>=2.95) will do the job. Furthermore, the
 host must support 64-bit integers, even if it is not a 64-bit machine.
 
 If you encounter any difficulties while building, installing or using
@@ -27,7 +27,7 @@ libquantum@enyo.de.
 As libquantum was created using autoconf and libtool, this step should
 not be a major problem. Simply extract the tarball to a directory:
 
-	tar xzvf libquantum-0.1.0.tar.gz
+	tar xzvf libquantum-0.2.1.tar.gz
 
 Next, run the configure script:
 

Makefile.in

@@ -26,44 +26,44 @@ SHELL=/bin/sh
 # Target directory prefix
 
 PREFIX=@prefix@
+EPREFIX=${PREFIX}
 
 # Other directories
 
-LIBDIR=${PREFIX}/lib
+LIBDIR=${EPREFIX}/lib
 INCLUDEDIR=${PREFIX}/include
 top_builddir=.
 
-# Release information
+# Version information
 
-MAJOR=0
+VERSION=@PACKAGE_VERSION@
-MINOR=2
-RELEASE=0
 
 # Tools needed to build libquantum
 
-CC=@CC@ -O2 -g -pg
+CC=@CC@
 INSTALL=@INSTALL@
 LIBTOOL=@LIBTOOL@
 
 # Flags passed to C compiler
 
 CFLAGS=@CFLAGS@
-LDFLAGS=-rpath $(LIBDIR) -version-info 2:0:2
+LDFLAGS=-rpath $(LIBDIR) -version-info 3:0:0
 
 # Dependencies
 
 all:	libquantum.la
 
 libquantum.la: complex.lo measure.lo matrix.lo gates.lo qft.lo classic.lo\
-	qureg.lo decoherence.lo oaddn.lo omuln.lo expn.lo qec.lo Makefile
+	qureg.lo decoherence.lo oaddn.lo omuln.lo expn.lo qec.lo version.lo\
+	Makefile
 	$(LIBTOOL) $(CC) $(LDFLAGS) -o libquantum.la complex.lo measure.lo\
 	matrix.lo gates.lo oaddn.lo omuln.lo expn.lo qft.lo classic.lo\
-	qureg.lo decoherence.lo qec.lo -lm
+	qureg.lo decoherence.lo qec.lo version.lo -lm
 
 complex.lo: complex.c complex.h Makefile
 	$(LIBTOOL) $(CC) $(CFLAGS) -c complex.c	
 
-measure.lo: measure.c measure.h matrix.h qureg.h config.h Makefile
+measure.lo: measure.c measure.h matrix.h qureg.h complex.h config.h Makefile
 	$(LIBTOOL) $(CC) $(CFLAGS) -c measure.c
 
 matrix.lo: matrix.c matrix.h complex.h Makefile
@@ -94,14 +94,11 @@ decoherence.lo: decoherence.c decoherence.h measure.h gates.h qureg.h\
 	complex.h config.h Makefile
 	$(LIBTOOL) $(CC) $(CFLAGS) -c decoherence.c
 
-qec.lo: qec.c qec.h gates.h qureg.h config.h Makefile
+qec.lo: qec.c qec.h gates.h qureg.h decoherence.h measure.h config.h Makefile
 	$(LIBTOOL) $(CC) $(CFLAGS) -c qec.c
 
-# Bring this savage back home
+version.lo: version.c version.h config.h Makefile
-
+	$(LIBTOOL) $(CC) $(CFLAGS) -c version.c
-install: libquantum.la
-	$(LIBTOOL) $(INSTALL) -m 0644 libquantum.la $(LIBDIR)
-	$(INSTALL) -m 0644 quantum.h $(INCLUDEDIR)
 
 # Build demos of Shor's and Grover's algorithms
 
@@ -114,6 +111,12 @@ grover: libquantum.la grover.c Makefile
 	$(LIBTOOL) $(CC) $(CFLAGS) -o grover grover.c -I./ -lquantum -static\
 	-lm
 
+# Bring this savage back home
+
+install: libquantum.la
+	$(LIBTOOL) $(INSTALL) -m 0644 libquantum.la $(LIBDIR)
+	$(INSTALL) -m 0644 quantum.h $(INCLUDEDIR)
+
 # Make everything neat and tidy
 
 clean:
@@ -127,10 +130,9 @@ distclean:
 
 dist:
 	-rm quantum.h config.h
-	mkdir libquantum-$(MAJOR).$(MINOR).$(RELEASE)
+	mkdir libquantum-$(VERSION)
 	cp *.c *.h quantum.h.in Makefile.in config.h.in configure configure.in\
 	COPYING	install-sh ltmain.sh config.sub config.guess README INSTALL\
-	CHANGES	libquantum-$(MAJOR).$(MINOR).$(RELEASE)
+	CHANGES	libquantum-$(VERSION)
-	tar czf libquantum-$(MAJOR).$(MINOR).$(RELEASE).tar.gz\
+	tar czf libquantum-$(VERSION).tar.gz libquantum-$(VERSION)/
-	libquantum-$(MAJOR).$(MINOR).$(RELEASE)/
+	rm -rf libquantum-$(VERSION)
-	rm -rf libquantum-$(MAJOR).$(MINOR).$(RELEASE)

README

@@ -1,4 +1,4 @@
-libquantum 0.2.0 README file
+libquantum 0.2.1 README file
 ----------------------------
 
 libquantum is a C library for quantum computing. It provides quantum

complex.c

@@ -26,24 +26,6 @@
 #include "complex.h"
 #include "config.h"
 
-/* Return the real part of a complex number */
-
-float
-quantum_real(COMPLEX_FLOAT a)
-{
-  float *p = (float *) &a;
-  return p[0];
-}
-
-/* Return the imaginary part of a complex number */
-
-float
-quantum_imag(COMPLEX_FLOAT a)
-{
-  float *p = (float *) &a;
-  return p[1];
-}
-
 /* Return the complex conjugate of a complex number */
 
 COMPLEX_FLOAT
@@ -62,7 +44,7 @@ quantum_conj(COMPLEX_FLOAT a)
 float 
 quantum_prob(COMPLEX_FLOAT a)
 {
-  return (float) (a * quantum_conj(a));
+  return quantum_prob_inline(a);
 }
 
 /* Calculate e^(i * phi) */

complex.h

@@ -27,11 +27,40 @@
 
 #include "config.h"
 
-extern float quantum_real(COMPLEX_FLOAT a);
-extern float quantum_imag(COMPLEX_FLOAT a);
 extern COMPLEX_FLOAT quantum_conj(COMPLEX_FLOAT a);
 
 extern float quantum_prob (COMPLEX_FLOAT a);
 extern COMPLEX_FLOAT quantum_cexp(float phi);
 
+/* Return the real part of a complex number */
+
+static inline float
+quantum_real(COMPLEX_FLOAT a)
+{
+  float *p = (float *) &a;
+  return p[0];
+}
+
+/* Return the imaginary part of a complex number */
+
+static inline float
+quantum_imag(COMPLEX_FLOAT a)
+{
+  float *p = (float *) &a;
+  return p[1];
+}
+
+/* Calculate the square of a complex number (i.e. the probability) */
+
+static inline float 
+quantum_prob_inline(COMPLEX_FLOAT a)
+{
+  float r, i;
+
+  r = quantum_real(a);
+  i = quantum_imag(a);
+
+  return r * r + i * i;
+}
+
 #endif

configure

@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.57 for libquantum 0.2.0.
+# Generated by GNU Autoconf 2.57 for libquantum 0.2.1.
 #
 # Report bugs to <libquantum@enyo.de>.
 #
@@ -427,8 +427,8 @@ SHELL=${CONFIG_SHELL-/bin/sh}
 # Identity of this package.
 PACKAGE_NAME='libquantum'
 PACKAGE_TARNAME='libquantum'
-PACKAGE_VERSION='0.2.0'
+PACKAGE_VERSION='0.2.1'
-PACKAGE_STRING='libquantum 0.2.0'
+PACKAGE_STRING='libquantum 0.2.1'
 PACKAGE_BUGREPORT='libquantum@enyo.de'
 
 ac_unique_file="classic.c"
@@ -938,7 +938,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures libquantum 0.2.0 to adapt to many kinds of systems.
+\`configure' configures libquantum 0.2.1 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -999,7 +999,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of libquantum 0.2.0:";;
+     short | recursive ) echo "Configuration of libquantum 0.2.1:";;
    esac
   cat <<\_ACEOF
 
@@ -1010,6 +1010,7 @@ Optional Features:
   --enable-static=PKGS  build static libraries default=yes
   --enable-fast-install=PKGS  optimize for fast installation default=yes
   --disable-libtool-lock  avoid locking (might break parallel builds)
+  --enable-profiling      compile with profiling support
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -1092,7 +1093,7 @@ fi
 test -n "$ac_init_help" && exit 0
 if $ac_init_version; then
   cat <<\_ACEOF
-libquantum configure 0.2.0
+libquantum configure 0.2.1
 generated by GNU Autoconf 2.57
 
 Copyright 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002
@@ -1107,7 +1108,7 @@ cat >&5 <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by libquantum $as_me 0.2.0, which was
+It was created by libquantum $as_me 0.2.1, which was
 generated by GNU Autoconf 2.57.  Invocation command line was
 
   $ $0 $@
@@ -2225,12 +2226,12 @@ if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   (exit $ac_status); }; }; then
   for ac_declaration in \
    ''\
-   '#include <stdlib.h>' \
    'extern "C" void std::exit (int) throw (); using std::exit;' \
    'extern "C" void std::exit (int); using std::exit;' \
    'extern "C" void exit (int) throw ();' \
    'extern "C" void exit (int);' \
-   'void exit (int);'
+   'void exit (int);' \
+   '#include <stdlib.h>'
 do
   cat >conftest.$ac_ext <<_ACEOF
 #line $LINENO "configure"
@@ -4130,7 +4131,7 @@ test "x$enable_libtool_lock" != xno && enable_libtool_lock=yes
 case $host in
 *-*-irix6*)
   # Find out which ABI we are using.
-  echo '#line 4133 "configure"' > conftest.$ac_ext
+  echo '#line 4134 "configure"' > conftest.$ac_ext
   if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   (eval $ac_compile) 2>&5
   ac_status=$?
@@ -4673,7 +4674,7 @@ chmod -w .
 save_CFLAGS="$CFLAGS"
 CFLAGS="$CFLAGS -o out/conftest2.$ac_objext"
 compiler_c_o=no
-if { (eval echo configure:4676: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>out/conftest.err; } && test -s out/conftest2.$ac_objext; then
+if { (eval echo configure:4677: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>out/conftest.err; } && test -s out/conftest2.$ac_objext; then
   # The compiler can only warn and ignore the option if not recognized
   # So say no if there are warnings
   if test -s out/conftest.err; then
@@ -6556,7 +6557,7 @@ else
     lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<EOF
-#line 6559 "configure"
+#line 6560 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -6654,7 +6655,7 @@ else
     lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<EOF
-#line 6657 "configure"
+#line 6658 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -7391,7 +7392,6 @@ LIBTOOL='$(SHELL) $(top_builddir)/libtool'
 
 
 # Checks for libraries.
-# FIXME: Replace `main' with a function in `-lm':
 
 echo "$as_me:$LINENO: checking for sqrt in -lm" >&5
 echo $ECHO_N "checking for sqrt in -lm... $ECHO_C" >&6
@@ -8255,9 +8255,24 @@ fi
 echo "$as_me:$LINENO: result: $I" >&5
 echo "${ECHO_T}$I" >&6
 
+# Substitute fields in quantum.h.in
 
 
 
+# Profiling check
+# Check whether --enable-profiling or --disable-profiling was given.
+if test "${enable_profiling+set}" = set; then
+  enableval="$enable_profiling"
+  CFLAGS="$CFLAGS -pg"
+fi;
+
+# Enable -Wall for gcc
+if test $CC = "gcc"
+then
+	CFLAGS="$CFLAGS -Wall"
+fi
+
+# Write the output files
                     ac_config_files="$ac_config_files Makefile quantum.h"
 
 cat >confcache <<\_ACEOF
@@ -8620,7 +8635,7 @@ _ASBOX
 } >&5
 cat >&5 <<_CSEOF
 
-This file was extended by libquantum $as_me 0.2.0, which was
+This file was extended by libquantum $as_me 0.2.1, which was
 generated by GNU Autoconf 2.57.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -8680,7 +8695,7 @@ _ACEOF
 
 cat >>$CONFIG_STATUS <<_ACEOF
 ac_cs_version="\\
-libquantum config.status 0.2.0
+libquantum config.status 0.2.1
 configured by $0, generated by GNU Autoconf 2.57,
   with options \\"`echo "$ac_configure_args" | sed 's/[\\""\`\$]/\\\\&/g'`\\"
 
@@ -9358,3 +9373,4 @@ if test "$no_create" != yes; then
   # would make configure fail if this is the last instruction.
   $ac_cs_success || { (exit 1); exit 1; }
 fi
+

configure.in

@@ -1,5 +1,5 @@
 # Process this file with autoconf to produce a configure script.
-AC_INIT([libquantum], [0.2.0], [libquantum@enyo.de])
+AC_INIT([libquantum], [0.2.1], [libquantum@enyo.de])
 AC_CONFIG_SRCDIR([classic.c])
 AC_CONFIG_HEADER([config.h])
 
@@ -12,7 +12,6 @@ AC_PROG_INSTALL
 AC_PROG_LIBTOOL
 
 # Checks for libraries.
-# FIXME: Replace `main' with a function in `-lm':
 AC_CHECK_LIB([m], [sqrt])
 
 # Checks for header files.
@@ -72,8 +71,22 @@ then
 fi
 AC_MSG_RESULT($I)
 
+# Substitute fields in quantum.h.in
 AC_SUBST(MU_TYPE)
 AC_SUBST(CF_TYPE)
 
+# Profiling check
+AC_ARG_ENABLE(profiling, 
+	[  --enable-profiling      compile with profiling support],
+	[CFLAGS="$CFLAGS -pg"], 
+	[])
+
+# Enable -Wall for gcc
+if test $CC = "gcc"
+then
+	CFLAGS="$CFLAGS -Wall"
+fi
+
+# Write the output files
 AC_CONFIG_FILES([Makefile quantum.h])
 AC_OUTPUT

gates.c

@@ -1,4 +1,4 @@
- /* gates.c: Basic gates for quantum register manipulation
+/* gates.c: Basic gates for quantum register manipulation
 
    Copyright 2003 Bjoern Butscher, Hendrik Weimer
 
@@ -24,6 +24,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <math.h>
+#include <stdarg.h>
 
 #include "matrix.h"
 #include "defs.h"
@@ -48,7 +49,7 @@ quantum_cnot(int control, int target, quantum_reg *reg)
     {
       for(i=0; i<reg->size; i++)
 	{
-	  /* Flip the target bit of a base state if the control bit is set */
+	  /* Flip the target bit of a basis state if the control bit is set */
       
 	  if((reg->node[i].state & ((MAX_UNSIGNED) 1 << control)))
 	    reg->node[i].state ^= ((MAX_UNSIGNED) 1 << target);
@@ -73,7 +74,7 @@ quantum_toffoli(int control1, int control2, int target, quantum_reg *reg)
     {
       for(i=0; i<reg->size; i++)
 	{
-	  /* Flip the target bit of a base state if both control bits are
+	  /* Flip the target bit of a basis state if both control bits are
 	     set */
 
 	  if(reg->node[i].state & ((MAX_UNSIGNED) 1 << control1))
@@ -88,6 +89,53 @@ quantum_toffoli(int control1, int control2, int target, quantum_reg *reg)
     }
 }
 
+/* Apply an unbounded toffoli gate. This gate is not considered
+elementary and is not available on all physical realizations of a
+quantum computer. Be sure to pass the function the correct number of
+controlling qubits. The target is given in the last argument. */
+
+void
+quantum_unbounded_toffoli(int controlling, quantum_reg *reg, ...)
+{
+  va_list bits;
+  int target;
+  int *controls;
+  int i, j;
+
+  controls = malloc(controlling * sizeof(int));
+  if(!controls)
+    {
+      printf("Error allocating %i-element int array!\n", controlling);
+      exit(1);
+    }
+  quantum_memman(controlling * sizeof(int));
+
+  va_start(bits, reg);
+  
+  for(i=0; i<controlling; i++)
+    controls[i] = va_arg(bits, int);
+
+  target = va_arg(bits, int);
+
+  va_end(bits);
+
+  for(i=0; i<reg->size; i++)
+    {
+      for(j=0; (j < controlling) && 
+	    (reg->node[i].state & (MAX_UNSIGNED) 1 << controls[j]); j++);
+      
+      if(j == controlling) /* all control bits are set */
+	reg->node[i].state ^= ((MAX_UNSIGNED) 1 << target);
+    }
+
+  free(controls);
+  quantum_memman(-controlling * sizeof(int));
+
+  quantum_decohere(reg);
+
+}
+  
+
 /* Apply a sigma_x (or not) gate */
 
 void
@@ -104,7 +152,7 @@ quantum_sigma_x(int target, quantum_reg *reg)
     {
       for(i=0; i<reg->size; i++)
 	{
-	  /* Flip the target bit of each base state */
+	  /* Flip the target bit of each basis state */
 
 	  reg->node[i].state ^= ((MAX_UNSIGNED) 1 << target);
 	} 
@@ -121,7 +169,7 @@ quantum_sigma_y(int target, quantum_reg *reg)
   
   for(i=0; i<reg->size;i++)
     {
-      /* Flip the target bit of each base state and multiply with 
+      /* Flip the target bit of each basis state and multiply with 
 	 +/- i */
 
       reg->node[i].state ^= ((MAX_UNSIGNED) 1 << target);
@@ -221,12 +269,12 @@ quantum_swaptheleads_omuln_controlled(int control, int width, quantum_reg *reg)
 void 
 quantum_gate1(int target, quantum_matrix m, quantum_reg *reg)
 {
-  int i, j, k;
+  int i, j, k, iset;
   int addsize=0, decsize=0;
   COMPLEX_FLOAT t, tnot=0;
+  float limit;
   char *done;
-  quantum_reg out;
+  //  quantum_reg_hash *p;
-  quantum_reg_hash *p;
 
   if((m.cols != 2) || (m.rows != 2))
     {
@@ -238,19 +286,20 @@ quantum_gate1(int target, quantum_matrix m, quantum_reg *reg)
 
   for(i=0; i<(1 << reg->hashw); i++)
     {
-      while(reg->hash[i])
+      /*      while(reg->hash[i])
 	{
 	  p = reg->hash[i]->next;
 	  free(reg->hash[i]);
 	  quantum_memman(-sizeof(quantum_reg_hash));
 	  reg->hash[i] = p;
-	}
+	  }*/
+      reg->hash[i] = 0;
     }
       
   for(i=0; i<reg->size; i++)
     quantum_add_hash(reg->node[i].state, i, reg);
 
-  /* calculate the number of base states to be added */
+  /* calculate the number of basis states to be added */
 
   for(i=0; i<reg->size; i++)
     {
@@ -267,7 +316,7 @@ quantum_gate1(int target, quantum_matrix m, quantum_reg *reg)
 	}
     }
 
-  /* allocate memory for the new base states */
+  /* allocate memory for the new basis states */
   
   reg->node = realloc(reg->node, 
 		      (reg->size + addsize) * sizeof(quantum_reg_node));
@@ -295,12 +344,18 @@ quantum_gate1(int target, quantum_matrix m, quantum_reg *reg)
 
   k = reg->size;
 
+  limit = (1.0 / ((MAX_UNSIGNED) 1 << reg->width)) / 1000000;
+
   /* perform the actual matrix multiplication */
 
   for(i=0; i<reg->size; i++)
     {
       if(!done[i])
 	{
+	  /* determine if the target of the basis state is set */
+	  
+	  iset = reg->node[i].state & ((MAX_UNSIGNED) 1 << target);
+
 	  tnot = 0;
 	  j = quantum_get_state(reg->node[i].state 
 				^ ((MAX_UNSIGNED) 1<<target), *reg);
@@ -309,7 +364,7 @@ quantum_gate1(int target, quantum_matrix m, quantum_reg *reg)
 	  if(j >= 0)
 	    tnot = reg->node[j].amplitude;
 
-	  if(reg->node[i].state & ((MAX_UNSIGNED) 1 << target))
+	  if(iset)
 	    reg->node[i].amplitude = m.t[2] * tnot + m.t[3] * t;
 
 	  else
@@ -317,7 +372,7 @@ quantum_gate1(int target, quantum_matrix m, quantum_reg *reg)
 
 	  if(j >= 0)
 	    {
-	      if(reg->node[i].state & ((MAX_UNSIGNED) 1 << target))
+	      if(iset)
 		reg->node[j].amplitude = m.t[0] * tnot + m.t[1] * t;
 
 	      else
@@ -325,20 +380,18 @@ quantum_gate1(int target, quantum_matrix m, quantum_reg *reg)
 	    }
 
 	  
-	  else /* new base state will be created */
+	  else /* new basis state will be created */
 	    {
 	      
-	      if((m.t[1] == 0) 
+	      if((m.t[1] == 0) && (iset))
-		 && (reg->node[i].state & ((MAX_UNSIGNED) 1 << target)))
 		break;
-	      if((m.t[2] == 0)
+	      if((m.t[2] == 0) && !(iset))
-		 && !(reg->node[i].state & ((MAX_UNSIGNED) 1 << target)))
 		 break; 
 
 	      reg->node[k].state = reg->node[i].state 
 		^ ((MAX_UNSIGNED) 1 << target);
 
-	      if(reg->node[i].state & ((MAX_UNSIGNED) 1 << target))
+	      if(iset)
 		reg->node[k].amplitude = m.t[1] * t;
 
 	      else
@@ -350,14 +403,6 @@ quantum_gate1(int target, quantum_matrix m, quantum_reg *reg)
 	  if(j >= 0)
 	    done[j] = 1;
 
-	  if(!reg->node[i].amplitude)
-	    decsize++;
-
-	  if(j >= 0)
-	    {
-	      if(!reg->node[j].amplitude)
-		decsize++;
-	    }
 	}
     }
 
@@ -366,34 +411,33 @@ quantum_gate1(int target, quantum_matrix m, quantum_reg *reg)
   free(done);
   quantum_memman(-reg->size * sizeof(char));
 
-  /* remove base states with zero amplitude */
+  /* remove basis states with extremely small amplitude */
+
+  for(i=0, j=0; i<reg->size; i++)
+    {
+      if(quantum_prob_inline(reg->node[i].amplitude) < limit)
+	{
+	  j++;
+	  decsize++;
+	}
+      
+      else if(j)
+	{
+	  reg->node[i-j].state = reg->node[i].state;
+	  reg->node[i-j].amplitude = reg->node[i].amplitude;
+	}
+    }
 
   if(decsize)
     {
-      out.width = reg->width;
+      reg->size -= decsize;
-      out.size = reg->size - decsize;
+      reg->node = realloc(reg->node, reg->size * sizeof(quantum_reg_node));
-      out.node = calloc(out.size, sizeof(quantum_reg_node));
+      if(!reg->node) 
-      if(!out.node)
 	{
-	  printf("Not enough memory for %i-sized qubit!\n", out.size);
+	  printf("Not enough memory for %i-sized qubit!\n",
+		 reg->size + addsize);
 	  exit(1);
 	}
-      quantum_memman(out.size * sizeof(quantum_reg_node));
-      out.hashw = reg->hashw;
-      out.hash = reg->hash;
-
-      for(i=0, j=0; i<reg->size; i++)
-	{
-	  if(reg->node[i].amplitude)
-	    {
-	      out.node[j].state = reg->node[i].state;
-	      out.node[j].amplitude = reg->node[i].amplitude;
-	      j++;
-	    }
-	}
-
-      quantum_delete_qureg_hashpreserve(reg);
-      *reg = out;
     }
 
   quantum_decohere(reg);
@@ -417,21 +461,15 @@ quantum_hadamard(int target, quantum_reg *reg)
 
 }
 
-/* Apply a walsh-hadamard gate */
+/* Apply a walsh-hadamard transform */
 
 void
-quantum_walsh(int target, quantum_reg *reg)
+quantum_walsh(int width, quantum_reg *reg)
 {
-  quantum_matrix m;
+  int i;
 
-  m = quantum_new_matrix(2, 2);
+  for(i=0; i<width; i++)
-
+    quantum_hadamard(i, reg);
-  m.t[0] = IMAGINARY*sqrt(1.0/2);  m.t[1] = IMAGINARY*sqrt(1.0/2);
-  m.t[2] = IMAGINARY*sqrt(1.0/2);  m.t[3] = -IMAGINARY*sqrt(1.0/2);
-
-  quantum_gate1(target, m, reg);
-  
-  quantum_delete_matrix(&m);
   
 }
 
@@ -477,13 +515,16 @@ void
 quantum_r_z(int target, float gamma, quantum_reg *reg)
 {
   int i;
+  COMPLEX_FLOAT z;
+
+  z = quantum_cexp(gamma/2);
   
   for(i=0; i<reg->size; i++)
     {
       if(reg->node[i].state & ((MAX_UNSIGNED) 1 << target))
-	reg->node[i].amplitude *= quantum_cexp(gamma/2);
+	reg->node[i].amplitude *= z;
       else
-	reg->node[i].amplitude *= quantum_cexp(-gamma/2);
+	reg->node[i].amplitude /= z;
     }
 
   quantum_decohere(reg);
@@ -495,10 +536,13 @@ void
 quantum_phase_scale(int target, float gamma, quantum_reg *reg)
 {
   int i;
+  COMPLEX_FLOAT z;
+
+  z = quantum_cexp(gamma);
   
   for(i=0; i<reg->size; i++)
     {
-      reg->node[i].amplitude *= quantum_cexp(gamma);
+      reg->node[i].amplitude *= z;
     }
 
   quantum_decohere(reg);
@@ -511,11 +555,14 @@ void
 quantum_phase_kick(int target, float gamma, quantum_reg *reg)
 {
   int i;
+  COMPLEX_FLOAT z;
+
+  z = quantum_cexp(gamma);
   
   for(i=0; i<reg->size; i++)
     {
       if(reg->node[i].state & ((MAX_UNSIGNED) 1 << target))
-	reg->node[i].amplitude *= quantum_cexp(gamma);
+	reg->node[i].amplitude *= z;
     }
 
   quantum_decohere(reg);
@@ -527,14 +574,16 @@ void
 quantum_cond_phase(int control, int target, quantum_reg *reg)
 {
   int i;
+  COMPLEX_FLOAT z;
+
+  z = quantum_cexp(pi / ((MAX_UNSIGNED) 1 << (control - target)));
 
   for(i=0; i<reg->size; i++)
     {
       if(reg->node[i].state & ((MAX_UNSIGNED) 1 << control))
 	{
 	  if(reg->node[i].state & ((MAX_UNSIGNED) 1 << target))
-	    reg->node[i].amplitude 
+	    reg->node[i].amplitude *= z;
-	      *= quantum_cexp(pi / ((MAX_UNSIGNED) 1 << (control - target)));
 	}
     }
 
@@ -546,14 +595,16 @@ void
 quantum_cond_phase_inv(int control, int target, quantum_reg *reg)
 {
   int i;
+  COMPLEX_FLOAT z;
+
+  z = quantum_cexp(-pi / ((MAX_UNSIGNED) 1 << (control - target)));
 
   for(i=0; i<reg->size; i++)
     {
       if(reg->node[i].state & ((MAX_UNSIGNED) 1 << control))
 	{
 	  if(reg->node[i].state & ((MAX_UNSIGNED) 1 << target))
-	    reg->node[i].amplitude 
+	    reg->node[i].amplitude *= z;
-	      *= quantum_cexp(-pi / ((MAX_UNSIGNED) 1 << (control - target)));
 	}
     }
 
@@ -566,13 +617,16 @@ void
 quantum_cond_phase_kick(int control, int target, float gamma, quantum_reg *reg)
 {
   int i;
+  COMPLEX_FLOAT z;
+
+  z = quantum_cexp(gamma);
 
   for(i=0; i<reg->size; i++)
     {
       if(reg->node[i].state & ((MAX_UNSIGNED) 1 << control))
 	{
 	  if(reg->node[i].state & ((MAX_UNSIGNED) 1 << target))
-	    reg->node[i].amplitude *= quantum_cexp(gamma);
+	    reg->node[i].amplitude *= z;
 	}
      }
   quantum_decohere(reg);

gates.h

@@ -31,6 +31,8 @@
 extern void quantum_cnot(int control, int target, quantum_reg *reg);
 extern void quantum_toffoli(int control1, int control2, int target, 
 			    quantum_reg *reg);
+extern void quantum_unbounded_toffoli(int controlling, quantum_reg *reg, ...);
+
 extern void quantum_sigma_x(int target, quantum_reg *reg);
 extern void quantum_sigma_y(int target, quantum_reg *reg);
 extern void quantum_sigma_z(int target, quantum_reg *reg);
@@ -46,7 +48,7 @@ extern void quantum_r_y(int target, float gamma, quantum_reg *reg);
 extern void quantum_r_z(int target, float gamma, quantum_reg *reg);
 
 extern void quantum_hadamard(int target, quantum_reg *reg);
-extern void quantum_walsh(int target, quantum_reg *reg);
+extern void quantum_walsh(int width, quantum_reg *reg);
 
 extern void quantum_phase_scale(int target, float gamma, quantum_reg *reg);
 extern void quantum_phase_kick(int target, float gamma, quantum_reg *reg);

grover.c

@@ -120,14 +120,6 @@ void grover(int target, quantum_reg *reg)
 
 }
 
-void print_grover(quantum_reg *reg)
-{
-  int i;
-
-  for(i=0;i<reg->size;i++)
-    printf("%llu %f\n", reg->node[i].state, __real__ reg->node[i].amplitude);
-}
-
 int main(int argc, char **argv)
 {
   quantum_reg reg;

measure.c

@@ -59,8 +59,8 @@ quantum_measure(quantum_reg reg)
 	 given base state - r, return the base state as the
 	 result. Otherwise, continue with the next base state. */
 
-      r -= quantum_prob(reg.node[i].amplitude);
+      r -= quantum_prob_inline(reg.node[i].amplitude);
-      if(quantum_prob(reg.node[i].amplitude) >= r)
+      if(quantum_prob_inline(reg.node[i].amplitude) >= r)
 	return reg.node[i].state;
     }
 
@@ -86,14 +86,14 @@ quantum_bmeasure(int pos, quantum_reg *reg)
   MAX_UNSIGNED lpat=0, rpat=0, pos2;
   quantum_reg out;
 
-  pos2 = 1 << pos;
+  pos2 = (MAX_UNSIGNED) 1 << pos;
 
   /* Sum up the probability for 0 being the result */
 
   for(i=0; i<reg->size; i++)
     {
       if(!(reg->node[i].state & pos2))
-	pa += quantum_prob(reg->node[i].amplitude);
+	pa += quantum_prob_inline(reg->node[i].amplitude);
     }
 
   /* Compare the probability for 0 with a random number and determine
@@ -115,7 +115,7 @@ quantum_bmeasure(int pos, quantum_reg *reg)
 	    reg->node[i].amplitude = 0;
 	  else
 	    {
-	      d += quantum_prob(reg->node[i].amplitude);
+	      d += quantum_prob_inline(reg->node[i].amplitude);
 	      size++;
 	    }
 	}
@@ -125,7 +125,7 @@ quantum_bmeasure(int pos, quantum_reg *reg)
 	    reg->node[i].amplitude = 0;
 	  else
 	    {
-	      d += quantum_prob(reg->node[i].amplitude);
+	      d += quantum_prob_inline(reg->node[i].amplitude);
 	      size++;
 	    }
 	}
@@ -173,3 +173,93 @@ quantum_bmeasure(int pos, quantum_reg *reg)
   *reg = out;
   return result;
 }
+
+/* Measure a single bit, but do not remove it from the quantum
+   register */
+
+int
+quantum_bmeasure_bitpreserve(int pos, quantum_reg *reg)
+{
+  int i, j;
+  int size=0, result=0;
+  double d=0, pa=0, r;
+  MAX_UNSIGNED pos2;
+  quantum_reg out;
+
+  pos2 = (MAX_UNSIGNED) 1 << pos;
+
+  /* Sum up the probability for 0 being the result */
+
+  for(i=0; i<reg->size; i++)
+    {
+      if(!(reg->node[i].state & pos2))
+	pa += quantum_prob_inline(reg->node[i].amplitude);
+    }
+
+  /* Compare the probability for 0 with a random number and determine
+     the result of the measurement */
+
+  r = quantum_frand();
+  
+  if (r > pa)
+    result = 1;
+
+  /* Eradicate all amplitudes of base states which have been ruled out
+     by the measurement and get the absolute of the new register */
+
+  for(i=0;i<reg->size;i++)
+    {
+      if(reg->node[i].state & pos2)
+	{
+	  if(!result)
+	    reg->node[i].amplitude = 0;
+	  else
+	    {
+	      d += quantum_prob_inline(reg->node[i].amplitude);
+	      size++;
+	    }
+	}
+      else
+	{
+	  if(result)
+	    reg->node[i].amplitude = 0;
+	  else
+	    {
+	      d += quantum_prob_inline(reg->node[i].amplitude);
+	      size++;
+	    }
+	}
+    }
+
+  /* Build the new quantum register */
+
+  out.size = size;
+  out.node = calloc(size, sizeof(quantum_reg_node));
+  if(!out.node)
+    {
+      printf("Not enough memory for %i-sized qubit!\n", size);
+      exit(1);
+    }
+  quantum_memman(size * sizeof(quantum_reg_node));
+  out.hashw = reg->hashw;
+  out.hash = reg->hash;
+  out.width = reg->width;
+
+  /* Determine the numbers of the new base states and norm the quantum
+     register */
+  
+  for(i=0, j=0; i<reg->size; i++)
+    {
+      if(reg->node[i].amplitude)
+	{
+	  out.node[j].state = reg->node[i].state;
+	  out.node[j].amplitude = reg->node[i].amplitude * 1 / (float) sqrt(d);
+	
+	  j++;
+	}
+    }
+
+  quantum_delete_qureg_hashpreserve(reg);
+  *reg = out;
+  return result;
+}

measure.h

@@ -33,5 +33,6 @@ extern double quantum_frand();
 
 extern MAX_UNSIGNED quantum_measure(quantum_reg reg);
 extern int quantum_bmeasure(int pos, quantum_reg *reg);
+extern int quantum_bmeasure_bitpreserve(int pos, quantum_reg *reg);
 
 #endif

qec.c

@@ -27,6 +27,7 @@
 #include "gates.h"
 #include "config.h"
 #include "decoherence.h"
+#include "measure.h"
 
 /* Type of the QEC. Currently implemented versions are:
 

qft.c

@@ -40,10 +40,20 @@ void quantum_qft(int width, quantum_reg *reg)
       quantum_hadamard(i, reg);
     }
 
-  for(i=0; i<width/2; i++)
+}
-    {
+
-      quantum_cnot(i, width-i-1, reg);
+
-      quantum_cnot(width-i-1, i, reg);
+void quantum_qft_inv(int width, quantum_reg *reg)
-      quantum_cnot(i, width-i-1, reg);
+{
-    }
+  int i, j;
+
+  for(i=0; i<width; i++)
+    {
+      quantum_hadamard(i, reg);
+
+      for(j=i+1; j<width; j++)
+	quantum_cond_phase_inv(j, i, reg);
+
+    }
+
 }

qft.h

@@ -1,4 +1,4 @@
-/* qft.c: Declarations for qft.c
+/* qft.h: Declarations for qft.c
    
    Copyright 2003 Bjoern Butscher, Hendrik Weimer
 
@@ -27,4 +27,6 @@
 
 extern void quantum_qft(int width, quantum_reg *reg);
 
+extern void quantum_qft_inv(int width, quantum_reg *reg);
+
 #endif

quantum.h.in

@@ -46,16 +46,6 @@ struct quantum_reg_node_struct
 
 typedef struct quantum_reg_node_struct quantum_reg_node;
 
-/* One element of the hash table */
-
-struct quantum_reg_hash_struct
-{
-  int i;
-  struct quantum_reg_hash_struct *next;
-};
-
-typedef struct quantum_reg_hash_struct quantum_reg_hash;
-
 /* The quantum register */
 
 struct quantum_reg_struct
@@ -64,7 +54,7 @@ struct quantum_reg_struct
   int size;     /* number of non-zero vectors */
   int hashw;    /* width of the hash array */
   quantum_reg_node *node;
-  quantum_reg_hash **hash;
+  int *hash;
 };
 
 typedef struct quantum_reg_struct quantum_reg;
@@ -77,6 +67,7 @@ extern void quantum_addscratch(int bits, quantum_reg *reg);
 extern void quantum_cnot(int control, int target, quantum_reg *reg);
 extern void quantum_toffoli(int control1, int control2, int target, 
 			    quantum_reg *reg);
+extern void quantum_unbounded_toffoli(int controlling, quantum_reg *reg, ...);
 extern void quantum_sigma_x(int target, quantum_reg *reg);
 extern void quantum_sigma_y(int target, quantum_reg *reg);
 extern void quantum_sigma_z(int target, quantum_reg *reg);
@@ -87,7 +78,7 @@ extern void quantum_r_z(int target, float gamma, quantum_reg *reg);
 extern void quantum_phase_scale(int target, float gamma, quantum_reg *reg);
 extern void quantum_phase_kick(int target, float gamma, quantum_reg *reg);
 extern void quantum_hadamard(int target, quantum_reg *reg);
-extern void quantum_walsh(int target, quantum_reg *reg);
+extern void quantum_walsh(int width, quantum_reg *reg);
 extern void quantum_cond_phase(int control, int target, quantum_reg *reg);
 extern void quantum_cond_phase_inv(int control, int target, quantum_reg *reg);
 extern void quantum_cond_phase_kick(int control, int target, float gamma, 
@@ -95,12 +86,14 @@ extern void quantum_cond_phase_kick(int control, int target, float gamma,
 extern int quantum_gate_counter(int inc);
 
 extern void quantum_qft(int width, quantum_reg *reg);
+extern void quantum_qft_inv(int width, quantum_reg *reg);
 
 extern void quantum_exp_mod_n(int N, int x, int width_input, int width, 
 			      quantum_reg *reg);
 
 extern MAX_UNSIGNED quantum_measure(quantum_reg reg);
 extern int quantum_bmeasure(int pos, quantum_reg *reg);
+extern int quantum_bmeasure_bitpreserve(int pos, quantum_reg *reg);
 
 extern quantum_matrix quantum_new_matrix(int cols, int rows);
 extern void quantum_delete_matrix(quantum_matrix *m);
@@ -123,4 +116,6 @@ extern quantum_matrix quantum_qureg2matrix(quantum_reg reg);
 extern void quantum_qec_encode(int type, int width, quantum_reg *reg);
 extern void quantum_qec_decode(int type, int width, quantum_reg *reg);
 
+extern const char * quantum_get_version();
+
 #endif

qureg.c

@@ -69,13 +69,13 @@ quantum_matrix2qureg(quantum_matrix *m, int width)
 
   /* Allocate the hash table */
 
-  reg.hash = calloc(1 << reg.hashw, sizeof(quantum_reg_hash *));
+  reg.hash = calloc(1 << reg.hashw, sizeof(int));
   if(!reg.hash)
     {
       printf("Not enough memory for %i-sized hash!\n", 1 << reg.hashw);
       exit(1);
     }
-  quantum_memman((1 << reg.hashw) * sizeof(quantum_reg_hash *));
+  quantum_memman((1 << reg.hashw) * sizeof(int));
 
   /* Copy the nonzero amplitudes of the vector into the quantum
      register */
@@ -120,13 +120,13 @@ quantum_new_qureg(MAX_UNSIGNED initval, int width)
 
   /* Allocate the hash table */
 
-  reg.hash = calloc(1 << reg.hashw, sizeof(quantum_reg_hash *));
+  reg.hash = calloc(1 << reg.hashw, sizeof(int));
   if(!reg.hash)
     {
       printf("Not enough memory for %i-sized hash!\n", 1 << reg.hashw);
       exit(1);
     }
-  quantum_memman((1 << reg.hashw) * sizeof(quantum_reg_hash *));
+  quantum_memman((1 << reg.hashw) * sizeof(int));
 
   /* Initialize the quantum register */
   
@@ -161,22 +161,8 @@ quantum_qureg2matrix(quantum_reg reg)
 void
 quantum_destroy_hash(quantum_reg *reg)
 {
-  int i;
-  quantum_reg_hash *p;
-
-  for(i=0; i<(1 << reg->hashw); i++)
-    {
-      while(reg->hash[i])
-	{
-	  p = reg->hash[i]->next;
-	  free(reg->hash[i]);
-	  quantum_memman(-sizeof(quantum_reg_hash));
-	  reg->hash[i] = p;
-	}
-    }
-
   free(reg->hash);
-  quantum_memman(-(1 << reg->hashw) * sizeof(quantum_reg_hash *));
+  quantum_memman(-(1 << reg->hashw) * sizeof(int));
 }
 
 /* Delete a quantum register */
@@ -205,12 +191,16 @@ quantum_delete_qureg_hashpreserve(quantum_reg *reg)
 void
 quantum_print_qureg(quantum_reg reg)
 {
-  int i;
+  int i,j;
   
   for(i=0; i<reg.size; i++)
     {
-      printf("%f %+fi|%lli>\n", quantum_real(reg.node[i].amplitude),
+      printf("%f %+fi|%lli> (%e) (|", quantum_real(reg.node[i].amplitude),
-	     quantum_imag(reg.node[i].amplitude), reg.node[i].state);
+	     quantum_imag(reg.node[i].amplitude), reg.node[i].state, 
+	     quantum_prob_inline(reg.node[i].amplitude));
+      for(j=reg.width-1;j>=0;j--)
+	printf("%i", ((((MAX_UNSIGNED) 1 << j) & reg.node[i].state) > 0));
+      printf(">)\n");
     }
 
   printf("\n");
@@ -249,122 +239,19 @@ quantum_addscratch(int bits, quantum_reg *reg)
     }
 }
 
-/* Add an element to the hash table */
-
-void
-quantum_add_hash(MAX_UNSIGNED a, int pos, quantum_reg *reg)
-{
-  int i;
-  quantum_reg_hash *p;
-
-  i = quantum_hash64(a, reg->hashw);
-
-  p = calloc(1, sizeof(quantum_reg_hash));
-  if(!p)
-    {
-      printf("Not enough memory for hash element!\n");
-      exit(1);
-    }
-
-  quantum_memman(sizeof(quantum_reg_hash));
-
-  p->i = pos;
-  p->next = reg->hash[i];
-
-  reg->hash[i] = p;
-  
-}
-
-/* Remove an element from the hash table */
-
-void
-delete_hash(MAX_UNSIGNED a, int pos, quantum_reg *reg)
-{
-  int i;
-  quantum_reg_hash *p, *q=0;
-
-  i = quantum_hash64(a, reg->hashw);
-
-  p = reg->hash[i];
-
-  while(p->i != pos)
-    {
-      q = p;
-      p = p->next;
-    }
-
-  if(q)
-    {
-      q->next = p->next;
-      free(p);
-    }
-  else
-    {
-      if(p)
-	{
-	  reg->hash[i] = p->next;
-	  free(p);
-	}
-      else
-	{
-	  reg->hash[i] = 0;
-	  free(reg->hash[i]);
-	}
-    }
-}
-
 /* Print the hash table to stdout and test if the hash table is
    corrupted */
 
 void
-print_hash(quantum_reg reg)
+quantum_print_hash(quantum_reg reg)
 {
   int i;
-  quantum_reg_hash *p;
-  char *done;
-
-  done = calloc(reg.size, sizeof(char));
-  if(!done)
-    {
-      printf("Not enough memory for %i bytes array!\n", 
-	     (reg.size)*sizeof(char));
-      exit(1);
-    }
 
   for(i=0; i < (1 << reg.hashw); i++)
     {
-      printf("%i: ", i);
+      if(i)
-
+	printf("%i: %i %llu\n", i, reg.hash[i]-1, 
-      if(reg.hash[i])
+	       reg.node[reg.hash[i]-1].state);
-	{
-	  p = reg.hash[i];
-
-	  while(p->next)
-	    {
-	      printf("%llu ", reg.node[p->i].state);
-	      if(quantum_hash64(reg.node[p->i].state, reg.hashw) != i)
-		printf(" Corrupted hash table!\n... ");
-	      done[p->i] = 1;
-	      p = p->next;
-	    }
-
-	  printf("%llu", reg.node[p->i].state);
-	  if(quantum_hash64(reg.node[p->i].state, reg.hashw) != i)
-	    printf(" Corrupted hash table!");
-	  done[p->i] = 1;
-	}
-
-      printf("\n");
     }
 
-  /* Test if there are elements in the quantum register which are not
-     in the hash table */
-
-  for(i=0; i<reg.size; i++)
-    {
-      if(!done[i])
-	printf("Corrupted hash table: %llu is detached!\n", reg.node[i].state);
-    }
-
-  free(done);
 }

qureg.h

@@ -40,16 +40,6 @@ struct quantum_reg_node_struct
 
 typedef struct quantum_reg_node_struct quantum_reg_node;
 
-/* One element of the hash table */
-
-struct quantum_reg_hash_struct
-{
-  int i;
-  struct quantum_reg_hash_struct *next;
-};
-
-typedef struct quantum_reg_hash_struct quantum_reg_hash;
-
 /* The quantum register */
 
 struct quantum_reg_struct
@@ -58,7 +48,7 @@ struct quantum_reg_struct
   int size;     /* number of non-zero vectors */
   int hashw;    /* width of the hash array */
   quantum_reg_node *node;
-  quantum_reg_hash **hash;
+  int *hash;
 };
 
 typedef struct quantum_reg_struct quantum_reg;
@@ -75,8 +65,6 @@ extern void quantum_print_expn(quantum_reg reg);
 
 extern void quantum_addscratch(int bits, quantum_reg *reg);
 
-extern void quantum_add_hash(MAX_UNSIGNED a, int pos, quantum_reg *reg);
-extern void quantum_delete_hash(MAX_UNSIGNED a, int pos, quantum_reg *reg);
 extern void quantum_print_hash(quantum_reg reg);
 
 /* Our 64-bit multiplicative hash function */
@@ -100,56 +88,40 @@ static inline int
 quantum_get_state(MAX_UNSIGNED a, quantum_reg reg)
 {
   int i;
-  quantum_reg_hash *p;
 
   i = quantum_hash64(a, reg.hashw);
 
-  if(reg.hash[i])
+  while(reg.hash[i])
     {
-      p = reg.hash[i];
+      if(reg.node[reg.hash[i]-1].state == a)
-
+	return reg.hash[i]-1;
-      do 
+      i++;
-	{
+      if(i == (1 << reg.hashw))
-	  if(reg.node[p->i].state == a)
+	i = 0;
-	    return p->i;
-	  if(p->next)
-	    p = p->next;
-	} while(p->next);
-      
-      if(reg.node[p->i].state == a)
-	return p->i;
     }
   
   return -1;
+    
 }
 
-/* Update an element of the hash table */
+/* Add an element to the hash table */
 
 static inline void
-quantum_change_hash(MAX_UNSIGNED a, int oldpos, MAX_UNSIGNED b, int pos, 
+quantum_add_hash(MAX_UNSIGNED a, int pos, quantum_reg *reg)
-	    quantum_reg *reg)
 {
-  int i, j;
+  int i;
-  quantum_reg_hash *p, *q=0;
 
   i = quantum_hash64(a, reg->hashw);
 
-  p = reg->hash[i];
+  while(reg->hash[i])
-  q = reg->hash[i];
+    {
-  j = p->i;
+      i++;
+      if(i == (1 << reg->hashw))
+	i = 0;
+    }
 
-  while(p->i != oldpos)
+  reg->hash[i] = pos+1;
-    p = p->next;
 
-  p->i = j;
-  reg->hash[i] = q->next;
-
-  i = quantum_hash64(b, reg->hashw);
-  
-  q->next = reg->hash[i];
-  reg->hash[i] = q;
-  q->i = pos;
 }
 
 #endif
-

shor.c

@@ -81,6 +81,13 @@ int main(int argc, char **argv) {
 
   quantum_qft(width, &qr); 
   
+  for(i=0; i<width/2; i++)
+    {
+      quantum_cnot(i, width-i-1, &qr);
+      quantum_cnot(width-i-1, i, &qr);
+      quantum_cnot(i, width-i-1, &qr);
+    }
+  
   //  quantum_print_qureg(qr);
 
   c=quantum_measure(qr);

version.c

@@ -0,0 +1,30 @@
+/* version.c: libquantum version information
+
+   Copyright 2003 Bjoern Butscher, Hendrik Weimer
+
+   This file is part of libquantum
+
+   libquantum is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published
+   by the Free Software Foundation; either version 2 of the License,
+   or (at your option) any later version.
+
+   libquantum is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with libquantum; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+   USA
+
+*/
+
+#include "config.h"
+
+const char *
+quantum_get_version()
+{
+  return PACKAGE_VERSION;
+}

version.h

@@ -0,0 +1,30 @@
+/* version.h: Declarations for version.c
+   
+   Copyright 2003 Bjoern Butscher, Hendrik Weimer
+
+   This file is part of libquantum
+
+   libquantum is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published
+   by the Free Software Foundation; either version 2 of the License,
+   or (at your option) any later version.
+
+   libquantum is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with libquantum; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+   USA
+
+*/
+
+#ifndef __VERSION_H
+
+#define __VERSION_H
+
+extern const char * quantum_get_version();
+
+#endif