commit 90a0255ae349403331447d79b0081a7ffb5f348c
parent 556b58f8f77a2633e20aed7dcb7972a0d6cbe5a4
Author: Henry Wilson <m3henry@googlemail.com>
Date: Wed, 21 Jun 2017 04:20:49 +0100
Proper catch stack underflow
Diffstat:
| M | macros.i | | | 10 | ++++++++++ |
| M | main.s | | | 62 | +++++++++++++++++++++++++++++++++++++++++++++++++------------- |
2 files changed, 59 insertions(+), 13 deletions(-)
diff --git a/macros.i b/macros.i
@@ -133,6 +133,7 @@
.macro compare op name altname
verb code \name "\altname\()"
+ minstk 2
cmp TOS, (SP)
\op truecmp
movq $0, (SP)
@@ -141,6 +142,7 @@ verb code \name "\altname\()"
.macro cmpaddr op name altname
verb code \name "\altname\()"
+ minstk 2
mov (SP), ACC
mov (ACC), ACC
cmp (TOS), ACC
@@ -148,3 +150,11 @@ verb code \name "\altname\()"
movq $0, (SP)
jmp _drop
.endm
+
+.macro minstk depth:req
+ cmp $stack + ( \depth * 8 ), SP
+ jge 1f
+ mov $_uflow, IP
+ jmp next
+1:
+.endm
diff --git a/main.s b/main.s
@@ -210,7 +210,7 @@ verb forth dot "."
_dot: forthword
test less 10 1f
const 10
- do divide
+ do divmod
do SWAP
do _dot
1:
@@ -275,7 +275,7 @@ verb forth STRCMP
do OVER
do fetch
const 8
- do divide
+ do divmod
do SWAP
do pushret # Quotient
do DUP #
@@ -317,17 +317,22 @@ verb forth QUADCMP
do FALSE
endword
-verb forth divdied "/"
- do divide
+verb forth divide "/"
+ do divmod
do DROP
endword
verb forth mod "%"
- do divide
+ do divmod
do SWAP
do DROP
endword
+verb forth muldiv "*/"
+ do muldivmod
+ do DROP
+ endword
+
rspbk: .quad 0
buff: .quad 0
@@ -356,6 +361,7 @@ stack: .skip 1024 #1048576
.set ARGE, %r8
.set ARGF, %r9
+
# Stack manipulation
verb code RESETDATA
@@ -367,35 +373,37 @@ verb code RESETRETURN
jmp next
verb code DUP
+ minstk 1
_dup
jmp next
verb code drop2 "2DROP"
+ minstk 2
_drop2: retreat SP
mov (SP), TOS
retreat SP
jmp next
verb code DROP
+ minstk 1
_drop: mov (SP), TOS
retreat SP
- cmp $stack, SP
- jge next # normal operation
- mov $1f, IP
jmp next
-1: do RESETDATA
+_uflow: do RESETDATA
do CR
saycr "Stack underflow!"
do QUIT
verb code SWAP
+ minstk 2
push TOS
mov (SP), TOS
pop (SP)
jmp next
verb code OVER
+ minstk 2
push (SP)
_dup
pop TOS
@@ -404,6 +412,7 @@ verb code OVER
# Output
verb code EMIT
+ minstk 1
movq TOS, buff
mov $1, CMD # system call 1 is write
mov $1, ARGA # file handle 1 is stdout
@@ -413,6 +422,7 @@ verb code EMIT
jmp _drop
verb code PRINT
+ minstk 1
mov $1, CMD
mov $1, ARGA
mov (TOS), ARGC
@@ -422,6 +432,7 @@ verb code PRINT
jmp _drop
verb code TYPE
+ minstk 2
mov $1, CMD
mov $1, ARGA
mov (SP), ARGB
@@ -440,6 +451,7 @@ _halt: xor ARGA, ARGA # default return code 0
# Input
verb code ACCEPT
+ minstk 2
mov $0, CMD
mov $0, ARGA
mov (SP), ARGB
@@ -474,6 +486,7 @@ dogoto: codeword
jmp next
dobranch: codeword
+ minstk 1
cmp $0, TOS
je __brk
mov (IP), IP
@@ -482,6 +495,7 @@ __brk: advance IP
jmp _drop
dountil: codeword
+ minstk 1
cmp $0, TOS
jne __brk
sub (IP), IP
@@ -490,20 +504,24 @@ dountil: codeword
# Memory management
verb code fetch "@>"
+ minstk 1
mov (TOS), TOS
jmp next
fetchb: codeword
+ minstk 1
movb (TOS), TOSB
and $0xFF, TOS
jmp next
verb code store ">@"
+ minstk 2
mov (SP), ACC
mov ACC, (TOS)
jmp _drop2
storeb: codeword
+ minstk 2
mov (SP), ACC
movb ACCB, (TOS)
jmp _drop2
@@ -515,6 +533,7 @@ top: codeword
jmp next
verb code pushret ">R"
+ minstk 1
push TOS
jmp _drop
@@ -536,70 +555,86 @@ verb code FALSE "0"
jmp next
verb code lshift "<<"
+ minstk 1
shl TOS
jmp next
verb code rshift ">>"
+ minstk 1
shr TOS
jmp next
verb code halve "2/"
+ minstk 1
sar TOS
jmp next
verb code NOT
+ minstk 1
not TOS
jmp next
verb code AND
+ minstk 2
and TOS, (SP)
jmp _drop
verb code OR
+ minstk 2
or TOS, (SP)
jmp _drop
verb code XOR
+ minstk 2
xor TOS, (SP)
jmp _drop
# Maths
verb code plus "+"
+ minstk 2
add TOS, (SP)
jmp _drop
verb code minus "-"
+ minstk 2
sub TOS, (SP)
jmp _drop
verb code inc "1+"
+ minstk 1
inc TOS
jmp next
verb code dec "1-"
+ minstk 1
dec TOS
jmp next
verb code incaddr "@1+"
+ minstk 1
incq (TOS)
jmp _drop
verb code decaddr "@1-"
+ minstk 1
decq (TOS)
jmp _drop
verb code NEGATE
+ minstk 1
neg TOS
jmp next
verb code mult "*"
+ minstk 2
mov (SP), %rax
mul TOS
mov %rax, (SP)
jmp _drop
-verb code divide "/%"
+verb code divmod "/%"
+ minstk 2
xor %rdx, %rdx
mov (SP), %rax
div TOS
@@ -607,7 +642,8 @@ verb code divide "/%"
mov %rdx, TOS
jmp next
-verb code muldiv "*/%"
+verb code muldivmod "*/%"
+ minstk 3
mov (SP), %rax
mul TOS
divq -8(SP)
@@ -643,6 +679,7 @@ verb code EXIT
dictionaryhead:
verb code EXECUTE
+ minstk 1
mov TOS, WP
mov (SP), TOS
retreat SP
@@ -650,8 +687,7 @@ verb code EXECUTE
.text
-_start: #mov $stack, SP
- movq %rsp, rspbk
+_start: movq %rsp, rspbk
mov $_cold, IP
next:
mov (IP), WP
