duskos

commit 0cea10a86ec571464d114fb420feb3cea0f4634e
parent 141628ce0db0f671283ccc4ec446a3dc7fda84f3
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Mon, 24 Oct 2022 14:24:12 -0400

asm/arm: add LDR and STR

Diffstat:
M
fs/asm/arm.fs
 | 
42
+++++++++++++++++++++++++++++++++++++-----
M
fs/tests/asm/arm.fs
 | 
3
++-

2 files changed, 39 insertions(+), 6 deletions(-)
diff --git a/fs/asm/arm.fs b/fs/asm/arm.fs
@@ -10,6 +10,10 @@
 14 ( AL ) value curcond \ current condition flag
 0 value shift \ contains the whole "shift" field (8 bits)
 -1 value imm \ must be < $ff
+0 value setcond \ set condition flag
+\ those 2 below are only for LDR and STR
+0 value sdtflags \ I P U B W
+0 value sdtoff
 
 : cond doer , does> @ to curcond ;
 0 cond EQ          1 cond NE           2 cond CS           3 cond CC
@@ -29,26 +33,54 @@
 : rror) 4 lshift 7 or to shift ;
 
 : i) to imm ;
+: s) 1 to setcond ;
 : imm? imm 0>= ;
-: asm$ 14 ( AL ) to curcond 0 to shift -1 to imm ;
+: asm$
+  14 ( AL ) to curcond 0 to shift -1 to imm 0 to setcond 0 to sdtflags
+  0 to sdtoff ;
 : op, ( op -- ) curcond 28 lshift or , asm$ ;
+: oprdrn, ( rd rn op -- )
+  swap 16 lshift or swap 12 lshift or ( opcode ) op, ;
 
 \ Data processing ops
 : _ ( rd rop1 rop2? opcode -- )
-  21 lshift
+  21 lshift setcond 20 lshift or
   imm? if ( rd rop1 opcode )
     shift $f and 8 lshift imm or or $02000000 or
   else ( rd rop1 rop2 opcode )
-    shift $ff and 4 lshift or or then ( rd rop1 opcode )
-  swap 12 lshift or swap 16 lshift or ( opcode ) op, ;
+    shift $ff and 4 lshift or or then ( rd rop1 opcode ) oprdrn, ;
 
 : op ( opcode -- ) doer , does> @ _ ;
 0 op and,          1 op eor,           2 op sub,           3 op rsb,
 4 op add,          5 op adc,           6 op sbc,           7 op rsc,
-8 op tst,          9 op teq,           10 op cmp,          11 op cmn,
 12 op orr,         14 op bic,
 
+\ TST TEQ CMP CMN have no destination register and s) is implicit
+: op ( opcode -- ) doer , does> @ s) imm? if 0 rot> else >r 0 rot> r> then _ ;
+8 op tst,          9 op teq,           10 op cmp,          11 op cmn,
+
 \ MOV and MVN only have one operand
 : op ( opcode -- ) doer , does> @ 0 imm? if swap else rot> then _ ;
 13 op mov,         15 op mvn,
 
+
+\ Single Data Transfer (LDR, STR)
+
+: pre) sdtflags $8 or to sdtflags ;
+: post) sdtflags $17 and to sdtflags ;
+: +) to sdtoff sdtflags $4 or to sdtflags ;
+: -) to sdtoff sdtflags $1b and to sdtflags ;
+: +i) sdtflags $f and to sdtflags +) ;
+: -i) sdtflags $f and to sdtflags -) ;
+: +r) sdtflags $10 or to sdtflags +) ;
+: -r) sdtflags $10 or to sdtflags -) ;
+: 8b) sdtflags $2 or to sdtflags ;
+: !) sdtflags $1 or to sdtflags ;
+
+: op ( lflag -- ) doer , does> @ ( rd rn lflag )
+  20 lshift sdtflags 21 lshift or $04000000 or sdtoff or ( rd rn opcode )
+  sdtflags $10 and if \ is a register offset
+    shift $ff and 4 lshift or then ( rd rn opcode )
+  oprdrn, ;
+
+0 op str,          1 op ldr,
diff --git a/fs/tests/asm/arm.fs b/fs/tests/asm/arm.fs
@@ -6,7 +6,8 @@
 testbegin
 \ Tests for asm/arm.fs
 code foo1
-  r0 42 i) mov,
+  r0 42 i) mov, \ mov r0, #42
+  r1 r2 r3 +r) pre) 1 lsr) ldr,    \ ldr r1, [r2, r3 lsr #1]
 
 current here over - spit
 testend