Update on macOS, prepare ngspice-36

INSTALL

@@ -1,7 +1,7 @@
 Ngspice installation instructions
 =================================
 
-Important notice: with ngspice-35 there has been an update
+Important notice: since ngspice-35 there has been an update
 to the XSPICE code models (analog.cm etc.). Therefore it 
 is not sufficient to only re-make the main executable,
 you will have to compile and install the code models as well,
@@ -11,7 +11,7 @@ Table of contents
 
   1 Ngspice installation (LINUX)
    1.1 Prerequisites
-   1.2 Install from tarball (e.g. ngspice-35.tar.gz)
+   1.2 Install from tarball (e.g. ngspice-36.tar.gz)
    1.3 Install from git repository
    1.4 ngspice as a shared library
    1.5 Advanced Install
@@ -31,7 +31,11 @@ Table of contents
    9.3 make ngspice with pure CYGWIN
    9.4 ngspice console app with MINGW or CYGWIN
    9.5 cross compiling ngspice for Windows from LINUX
-  10 NGSPICE COMPILATION UNDER macOS
+ 10 NGSPICE COMPILATION UNDER macOS
+  10.1 Use precompiled binary package
+  10.2 Compile NGSPICE manually from a tarball
+  10.3 Compile NGSPICE manually from git
+  10.4 About compilers
 
 This file describes the procedures to install ngspice from sources.
 
@@ -60,7 +64,7 @@ This file describes the procedures to install ngspice from sources.
  will need bison and flex only.
 
  If libfftw is detected on your system, it will be used instead of the
- internal fft procedure.
+ internal fft algorithms.
 
  If you want to compile the source from the git repository you need
  additional software: autoconf, automake, libtool.
@@ -75,14 +79,14 @@ This file describes the procedures to install ngspice from sources.
  For compiling ngspice as a shared library, see section 1.4.
 
 
-1.2 Install from tarball (e.g. ngspice-35.tar.gz)
+1.2 Install from tarball (e.g. ngspice-36.tar.gz)
 
  This covers installation from a release distribution (for example
- ngspice-35.tar.gz, the so called tar ball).
+ ngspice-36.tar.gz, the so called tar ball).
 
  After downloading the tar ball to a local directory unpack it using:
 
- $ tar -zxvf ngspice-35.tar.gz
+ $ tar -zxvf ngspice-36.tar.gz
 
  Now change directories in to the top-level source directory (where this
  INSTALL file can be found).
@@ -456,7 +460,7 @@ This file describes the procedures to install ngspice from sources.
  automake, libtool, FLEX and BISON, all available with pacman in MSYSS2).
  Some links are given below which describe the procedures.
 
-     Installing from the tarball, e.g. ngspice-35.tar.gz, is simple: After
+     Installing from the tarball, e.g. ngspice-36.tar.gz, is simple: After
  expanding, you may just run ./compile_min.sh from the ngspice directory.
 
      The default installation location of ngspice is the Windows path
@@ -680,7 +684,9 @@ cross-compile-shared.sh.
 
 10.1 Use precompiled binary package
  1. Install an X11 interface (like Xquartz)
- 2. Install the downloaded NGSPICE package
+ 2. Packages are available from Homebrew or MacPorts
+    Install the downloaded NGSPICE package
+    It may happen though that a package has been compiled without graphics support
  3. Open a terminal window and start using NGSPICE
 
 10.2 Compile NGSPICE manually from a tarball
@@ -701,7 +707,7 @@ cross-compile-shared.sh.
  2. Install MacPorts from http://www.macports.org
  3. Execute this command:
       sudo port install automake autoconf libtool bison flex ncurses xorg-libXaw
-          readline fontconfig freetype libomp
+          readline fontconfig freetype libomp SM ICE
  4. Execute this command:
       ./autogen.sh or ./autogen.sh --adms (if you want to enable ADMS)
  5. Configure NGSPICE invoking "./configure". A complete set of feature is:
@@ -710,6 +716,30 @@ cross-compile-shared.sh.
       ./configure --enable-adms --enable-cider --enable-xspice --enable-openmp --enable-pss --with-readline=yes --enable-debug=no
  6. Compile NGSPICE invoking "make -j4"
  7. Install NGSPICE invoking "make install" or "sudo make install"
+ 
+Resulting dependencies of ngspice
+    /usr/local/opt/ncurses/lib/libncursesw.6.dylib
+    /usr/local/opt/gcc/lib/gcc/11/libstdc++.6.dylib
+    /usr/local/opt/fftw/lib/fftw3.3.dylib
+    /usr/local/opt/readline/lib/libreadline.8.dylib
+    /opt/local/lib/libXaw.7.dylib
+    /opt/local/lib/libXmu.6.dylib
+    /opt/local/lib/libXt.6.dylib
+    /opt/local/lib/libXext.6.dylib
+    /opt/local/lib/libX11.6.dylib
+    /opt/local/lib/libfontconfig.1.dylib
+    /opt/local/lib/libXrender.1.dylib
+    /opt/local/lib/libfreetype.6.dylib
+    /opt/local/lib/libSM.6.dylib
+    /opt/local/lib/libICE.6.dylib
+    /usr/local/opt/gcc/lib/gcc/11/libgomp.1.dylib
+    /usr/lib/libSystem.B.dylib
+    /usr/local/lib/gcc/11/libgcc_s.1.dylib
 
- A compile script compile_macos.sh contains all necessary steps.
+ 10.5 About compilers
+    A compile script compile_macos_clang.sh contains all necessary steps for compiling
+    with the Xcode clang/llvm compiler. This compiler however does not support -fopenmp.
+    Therefore you may download and install gcc, e.g. from Homebrew and run the new
+    compile script compile_macos_gcc.sh. OpenMp enables parallel processing of
+    BSIM3/4 model evaluation, thus speeding up simulation.