Do not require setting MONO_CHECKOUT if run from <checkout>/eglib/test; ignore functi...

[mono.git] / docs / mini-porting.txt

diff --git a/docs/mini-porting.txt b/docs/mini-porting.txt
index 25be0a775665700e4144717a60be84635f938c60..acca411cdbb9e68b72e1ec2dde5e5382c8f22d4e 100644 (file)
--- a/docs/mini-porting.txt
+++ b/docs/mini-porting.txt
@@ -241,6 +241,9 @@
        collecting liveness information and in a backward pass on the
        same list performs the actual register allocation, inserting
        the instructions needed to spill values, if necessary.
+
+       The cross-platform local register allocator is now implemented
+       and it is documented in the jit-regalloc file.
        
        When this part of code is implemented, some testing can be
        done with the generated code for the new architecture. Most
@@ -254,7 +257,14 @@
        tests.  Also, using multiple -v switches on the command line
        makes the JIT dump an increasing amount of information during
        compilation.
-       
+
+       Values loaded into registers need to be extened as needed by
+       the ECMA specs:
+
+       *) integers smaller than 4 bytes are extended to int32 values
+       *) 32 bit floats are extended to double precision (in particular
+       this means that currently all the floating point operations operate
+       on doubles)
        
 * Method trampolines
 
@@ -422,3 +432,30 @@
        we replace one or more instructions with others that perform
        better for the given architecture or CPU.
        
+* 64 bit support tips, by Zoltan Varga (vargaz@gmail.com)
+
+       For a 64-bit port of the Mono runtime, you will typically do
+       the following:
+
+               * need to use inssel-long.brg instead of
+                 inssel-long32.brg.
+
+               * need to implement lots of new opcodes:
+                      OP_I<OP> is 32 bit op
+                      OP_L<OP> and CEE_<OP> are 64 bit ops
+
+
+       The 64 bit version of an existing port might share the code
+       with the 32 bit port (for example SPARC/SPARV9), or it might
+       be separate (x86/AMD64).  
+
+       That will depend on the similarities of the two instructions
+       sets/ABIs etc.
+
+       The runtime and most parts of the JIT are 64 bit clean
+       at this point, so the only parts which require changing are
+       the arch dependent files.
+
+
+
+