commit 7c564c2bdfec3ad170e5fab00f810266b7324eb1
parent deeb1b70ee97718303cf23f56947f8c5a7acda12
Author: Christian Ermann <christianermann@gmail.com>
Date: Tue, 3 Dec 2024 22:43:17 -0800
Refactor 'skip-while', 'skip-until', and 'parse'
Diffstat:
| M | src/forth.s | | | 125 | ++++++++++++++++++++++++++++++++++--------------------------------------------- |
1 file changed, 54 insertions(+), 71 deletions(-)
diff --git a/src/forth.s b/src/forth.s
@@ -392,87 +392,70 @@ defcode "fib", fib, 0xBCE49236
load_cell w, 0(w)
next
-defword "skip-while", skip_while, 0xBBFD4B86
+defcode "skip-while", skip_while, 0xBBFD4B86
# ( addr1 len1 -- addr2 len2 )
+ lw x, 0*cell(psp)
+ blez w, _skip_while_done
+ la y, _delimiter
+ lb y, 0(y)
_skip_while_loop:
- jal dup
- jal q_branch
- .int _skip_while_done
- jal over
- jal char_fetch
- jal delimiter
- jal fetch
- jal equal
- jal q_branch
- .int _skip_while_done
- jal lit
- .int 1
- jal apply_offset
- jal branch
- .int _skip_while_loop
+ lb t0, 0(x)
+ bne t0, y, _skip_while_done
+ addi x, x, 1
+ addi w, w, -1
+ bgtz w, _skip_while_loop
_skip_while_done:
- exit
+ sw x, 0*cell(psp)
+ next
-defword "skip-until", skip_until, 0x661A5D67
- # ( addr1 len1 -- addr2 len2 )
+defcode "skip-until", skip_until, 0x661D5D67
+ # (addr1 len1 -- addr2 len2 )
+ lw x, 0*cell(psp)
+ blez w, _skip_until_done
+ la y, _delimiter
+ lb y, 0(y)
_skip_until_loop:
- jal dup
- jal q_branch
- .int _skip_until_done
- jal over
- jal char_fetch
- jal delimiter
- jal fetch
- jal not_equal
- jal q_branch
- .int _skip_until_done
- jal lit
- .int 1
- jal apply_offset
- jal branch
- .int _skip_until_loop
+ lb t0, 0(x)
+ beq t0, y, _skip_until_done
+ addi x, x, 1
+ addi w, w, -1
+ bgtz w, _skip_until_loop
_skip_until_done:
- exit
-
-defword "apply-offset", apply_offset, 0x605143A5
- # ( addr1 len1 offset -- addr2 len2 )
- jal tuck
- jal minus
- jal to_ret
- jal plus
- jal from_ret
- exit
-
-defword "parse-offset", parse_offset, 0x9E5C3F80
- # ( addr1 len1 -- offset )
- jal lit
- .int 1
- jal min
- jal plus
- jal source
- jal drop
- jal minus
- exit
+ sw x, 0*cell(psp)
+ next
defword "parse", parse, 0x423B42EC
- jal delimiter
- jal store
- jal source
- jal source_offset
- jal fetch
- jal apply_offset
+ # ( delimiter -- addr len )
+ # set delimiter
+ la x, _delimiter
+ sw w, 0(x)
+ # load source
+ la x, _tick_source
+ lw w, 0*cell(x)
+ lw x, 1*cell(x)
+ # apply offset
+ la y, _source_offset
+ lw y, 0*cell(y)
+ add x, x, y
+ sub w, w, y
+ # find start of token
+ push x
jal skip_while
- jal over
- jal to_ret
+ lw x, 0*cell(psp)
+ push_ret x
+ # find end of token
jal skip_until
- jal two_dup
- jal parse_offset
- jal source_offset
- jal store
- jal drop
- jal from_ret
- jal tuck
- jal minus
+ # compute offset
+ lw w, 0*cell(psp)
+ la x, _tick_source
+ lw x, 1*cell(x)
+ sub y, w, x
+ la x, _source_offset
+ sw y, 0(x)
+ # set outputs
+ pop_ret x
+ sw x, 0*cell(psp)
+ sub w, w, x
exit
defword "parse-word", parse_word, 0xB218226F
