commit 1db65aae618a6b7941410052d33808a12af80f34
parent 830e23b805e3e2aa989d3b3f37251de72facd554
Author: Henry Wilson <m3henry@googlemail.com>
Date: Fri, 16 Jun 2017 13:47:19 +0100
rudimentary dot
Diffstat:
| M | README.md | | | 4 | +++- |
| M | main.s | | | 50 | +++++++++++++++++++++++++++++++++----------------- |
2 files changed, 36 insertions(+), 18 deletions(-)
diff --git a/README.md b/README.md
@@ -1,5 +1,7 @@
# aforth
-A FORTH written in assembly language
+A FORTH written in assembly language for Linux x64
+
+Compiles with GNU Assembler
Written by Henry Wilson
diff --git a/main.s b/main.s
@@ -18,20 +18,20 @@
2:
.endm
-.macro while label
- .quad dowhile
- .quad . - \label
+.macro if label
+ .quad dobranch
+ .quad \label
.endm
.data
-cold: forthword
+cold: forthword
_cold: .quad abort
-abort: forthword
+abort: forthword
.quad quit
-quit: forthword
+quit: forthword
const 10
const 4
.quad flag
@@ -39,41 +39,57 @@ quit: forthword
string "Hello, World!"
.quad print
.quad cr
+ const -8
+ .quad dot
+ .quad cr
const -10
.quad negate
const 10
.quad equal
.quad halt
-flag: forthword
+flag: forthword
flaglp: .quad over
.quad line
.quad dec
.quad dup
- while flaglp
+ if flaglp
.quad drop
.quad drop
endword
-line: forthword
+line: forthword
starlp: .quad star
.quad dec
.quad dup
- while starlp
+ if starlp
.quad drop
.quad cr
endword
-star: forthword
- const 42
+star: forthword
+ const '*'
.quad emit
endword
-cr: forthword
+cr: forthword
string "\n\r"
.quad print
endword
+dot: forthword
+ .quad dup
+ const 0
+ .quad gequal
+ if dotif
+ const '-'
+ .quad emit
+ .quad negate
+dotif: const '0'
+ .quad plus
+ .quad emit
+ endword
+
buff: .quad
stack: .skip 1024 #1048576
@@ -174,14 +190,14 @@ dostr: codeword
advanceIP
jmp next
-doagain: codeword
- sub (IP), IP
+dojump: codeword
+ mov (IP), IP
jmp next
-dowhile: codeword
+dobranch: codeword
cmp $0, TOS
je __brk
- sub (IP), IP
+ mov (IP), IP
jmp _drop
__brk: advanceIP
jmp _drop
