Simple native code Forth compiler.

• Inlining
• Register allocation
• Constant folding

Sample output:

Compile: t: rot   >r swap r> swap ;
LD r0 0(SP)
LD r1 4(SP)
LD r2 8(SP)
ST r2 0(SP)
ST r0 4(SP)
ST r1 8(SP)
RET

Compile: t: -rot   rot rot ;
LD r0 0(SP)
LD r1 4(SP)
LD r2 8(SP)
ST r1 0(SP)
ST r2 4(SP)
ST r0 8(SP)
RET

Compile: t: +!   tuck @ + swap ! ;
LD r0 0(SP)
LD r1 4(SP)
LD r2 (r0)
ADD r1 r2 
ST r1 (r0)
ADD SP #8 
RET

Compile: t: test4   2 + 3 ;
LD r0 0(SP)
ADD r0 #2 
ADD SP #-4 
ST #3 0(SP)
ST r0 4(SP)
RET

Compile: t: test5   2 test4 * ;
ADD SP #-4 
ST #12 0(SP)
RET