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-rw-r--r--boot/stage2.elna350
1 files changed, 214 insertions, 136 deletions
diff --git a/boot/stage2.elna b/boot/stage2.elna
index 3ee1f32..0eb713c 100644
--- a/boot/stage2.elna
+++ b/boot/stage2.elna
@@ -14,6 +14,9 @@ type checking.
hexadecimal format).
- Comments are accepted only at the end of a line.
+
+- Return can be used only as the last statement of a procedure. It
+doesn't actually return, but sets a0 to the appropriate value.
*)
program
@@ -36,7 +39,7 @@ begin
end
proc _build_binary_expression()
-var loca0, loca4, loca8: Word
+var loca0, loca4, loca8, loca20: Word
begin
_build_expression(0)
@@ -44,8 +47,7 @@ begin
loca8 := 0x0a316120 (* _a1\n *)
_skip_spaces()
- call _read_token
- sw a0, 20(sp)
+ loca20 := _read_token()
li t0, 0x26 # &
sw t0, 16(sp)
@@ -87,6 +89,14 @@ begin
call _token_compare
beqz a0, .L_build_binary_expression_minus
+ li t0, 0x2a # *
+ sw t0, 16(sp)
+ mv a0, s1
+ lw a1, 20(sp)
+ addi a2, sp, 16
+ call _token_compare
+ beqz a0, .L_build_binary_expression_product
+
goto .Lbuild_binary_expression_end
.L_build_binary_expression_equal
@@ -146,6 +156,19 @@ begin
_write_out(@loca4, 4)
_write_out(@loca8, 4)
+ goto .Lbuild_binary_expression_end
+
+ .L_build_binary_expression_product
+ _advance(1) (* Skip *. *)
+ _build_expression(1)
+ loca0 := 0x6c756d (* mul *)
+ _write_out(@loca0, 3)
+ _write_out(@loca4, 4)
+ _write_out(@loca4, 4)
+ _write_out(@loca8, 4)
+
+ goto .Lbuild_binary_expression_end
+
.Lbuild_binary_expression_end
end
@@ -156,28 +179,30 @@ a0 - X in aX, the register number to save the result.
*)
proc _build_expression()
var
- loca20, loca28, loca8: Word
- loca24: ^Byte
+ loca0, loca20, loca28, loca8: Word
+ loca24, loca4: ^Byte
begin
- addi a0, a0, '0' # Make the register number to a character.
- sw a0, 28(sp) # And save it.
+ (* Make the register number to a character and save it. *)
+ loca28 := loca84 + 0x30 (* 0 *)
_skip_spaces()
loca20 := _read_token()
loca24 := _current()
- addi a0, s1, 0
- lbu a0, (a0)
+ lbu a0, (s1)
+ li t0, '-'
+ beq a0, t0, .Lbuild_expression_negate
+
+ lbu a0, (s1)
li t0, '@'
beq a0, t0, .Lbuild_expression_address
- addi a0, s1, 0
- lbu a0, (a0)
- call _is_digit
- bnez a0, .Lbuild_expression_literal
+ loca0 := _front()
+ if _is_digit(loca0) then
+ goto .Lbuild_expression_literal
+ end
- addi a0, s1, 0
- lbu a0, (a0)
+ lbu a0, (s1)
li t0, '_'
beq a0, t0, .Lbuild_expression_call
@@ -200,6 +225,19 @@ begin
goto .Lbuild_expression_advance
+ .Lbuild_expression_negate
+ _advance(1) (* Skip the -. *)
+ _build_expression(0)
+
+ loca8 := 0x2067656e (* neg_ *)
+ _write_out(@loca8, 4)
+ loca8 := 0x202c3061 (* a0,_ *)
+ _write_out(@loca8, 4)
+ loca8 := 0x0a3061 (* a0,_ *)
+ _write_out(@loca8, 3)
+
+ goto .Lbuild_expression_advance
+
.Lbuild_expression_address
loca8 := 0x69646461 (* addi *)
_write_out(@loca8, 4)
@@ -216,40 +254,28 @@ begin
loca24 := _current()
loca20 := _read_token()
- lw a0, 24(sp)
- lw a1, 20(sp)
- addi a0, a0, 4 # Skip the "loca" variable prefix.
- addi a1, a1, -4 # Skip the "loca" variable prefix.
- call _write_out
+ (* Skip the "loca" variable prefix. *)
+ loca4 := loca24 + 4
+ loca0 := loca20 - 4
+ _write_out(loca4, loca0)
_put_char(0xa)
goto .Lbuild_expression_advance
.Lbuild_expression_identifier
- lw t1, 28(sp)
- li t0, 0x00202c00 # \0,_
- or t0, t0, t1
- sw t0, 8(sp)
- li t0, 0x6120776c # lw a
- sw t0, 4(sp)
- addi a0, sp, 4
- li a1, 7
- call _write_out
+ loca8 := 0x6120776c (* lw a *)
+ _write_out(@loca8, 4)
+ loca8 := 0x00202c00 or loca28 # \0,_
+ _write_out(@loca8, 3)
- lw a0, 24(sp)
- lw a1, 20(sp)
- addi a0, a0, 4 # Skip the "loca" variable prefix.
- addi a1, a1, -4 # Skip the "loca" variable prefix.
- call _write_out
+ loca4 := loca24 + 4
+ loca0 := loca20 - 4
+ _write_out(loca4, loca0) (* Skip the "loca" variable prefix. *)
- li t0, 0x0a # \n
- sw t0, 8(sp)
- li t0, 0x29707328 # (sp)
- sw t0, 4(sp)
- addi a0, sp, 4
- li a1, 5
- call _write_out
+ loca8 := 0x29707328 (* (sp) *)
+ _write_out(@loca8, 4)
+ _put_char(0x0a) (* \n *)
goto .Lbuild_expression_advance
@@ -261,18 +287,13 @@ begin
goto .Lbuild_expression_end
.Lbuild_expression_literal
- lw t1, 28(sp)
- li t0, 0x00202c00 # \0,_
- or t0, t0, t1
- sw t0, 8(sp)
- li t0, 0x6120696c # li a
- sw t0, 4(sp)
- addi a0, sp, 4
- li a1, 7
- call _write_out
+ loca8 := 0x6120696c (* li a *)
+ _write_out(@loca8, 4)
+ loca8 := 0x00202c00 or loca28 (* \0,_ *)
+ _write_out(@loca8, 3)
_write_out(loca24, loca20)
- _put_char(0x0a) # \n
+ _put_char(0x0a) (* \n *)
goto .Lbuild_expression_advance
@@ -335,11 +356,9 @@ begin
loca0 := 0x202c30 (* 0,_ *)
_write_out(@loca0, 3)
- lw a0, 20(sp)
- lw a1, 16(sp)
- addi a0, a0, 4 # Skip the "loca" variable prefix.
- addi a1, a1, -4 # Skip the "loca" variable prefix.
- call _write_out
+ loca20 := loca20 + 4
+ loca16 := loca16 - 4
+ _write_out(loca20, loca16)
loca0 := 0x29707328 (* (sp) *)
_write_out(@loca0, 4)
@@ -359,7 +378,7 @@ Returns the procedure result in a0.
*)
proc _compile_call(loca84: ^Byte, loca80: Word)
var
- loca0, loca12: Word
+ loca0, loca4, loca12: Word
begin
loca12 := 0 (* Argument count for a procedure call. *)
@@ -377,49 +396,24 @@ begin
loca0 := 0x202c30 (* 0,_ *)
_write_out(@loca0, 3)
- lw t0, 12(sp) # Argument count for a procedure call.
-
(*
Only 6 arguments are supported with a0-a5.
Save all arguments on the stack so they aren't overriden afterwards.
- The offset on the stack always has two digits in this case.
*)
- li t1, -4
- mul t1, t0, t1
- addi t1, t1, 60
- li t2, 10
- div t3, t1, t2
- rem t4, t1, t2
- addi t3, t3, '0'
- addi t4, t4, '0'
-
- sw t3, 8(sp)
- sw t4, 4(sp)
-
- addi a0, sp, 8
- li a1, 1
- call _write_out
-
- addi a0, sp, 4
- li a1, 1
- call _write_out
+ loca0 := -4 * loca12
+ loca0 := loca0 + 60
+ _printi(loca0)
- li t0, 0x0a # \n
- sw t0, 8(sp)
- li t0, 0x29707328 # (sp)
- sw t0, 4(sp)
- addi a0, sp, 4
- li a1, 5
- call _write_out
+ loca0 := 0x29707328 (* (sp) *)
+ _write_out(@loca0, 4)
+ _put_char(0x0a) (* \n *)
_skip_spaces()
lbu t0, (s1)
li t1, ','
bne t0, t1, .Lcompile_call_paren
- lw t0, 12(sp) # Argument count for a procedure call.
- addi t0, t0, 1
- sw t0, 12(sp)
+ loca12 := loca12 + 1 (* Argument count for a procedure call. *)
_advance(1) (* Skip the comma between the arguments. *)
goto .Lcompile_call_argument
@@ -432,47 +426,62 @@ begin
Just go through all a0-a5 registers and read them from stack.
If this stack value contains garbage, the procedure just shouldn't use it.
*)
- lw t0, 12(sp)
- li t1, 5
- bgt t0, t1, .Lcompile_call_perform
+ loca0 := 0x6120776c (* lw a *)
+ (* lw a0, 60(sp) *)
+ _write_out(@loca0, 4)
+ loca4 := 0x36202c30 (* 0, 6 *)
+ _write_out(@loca4, 4)
+ loca4 := 0x70732830 (* 0(sp *)
+ _write_out(@loca4, 4)
+ loca4 := 0x0a29 (* )\n *)
+ _write_out(@loca4, 2)
- li t0, 0x6120776c # lw a
- sw t0, 4(sp)
- addi a0, sp, 4
- li a1, 4
- call _write_out
-
- lw t0, 12(sp) # Argument count for a procedure call.
-
- li t1, -4
- mul t1, t0, t1
- addi t1, t1, 60
- li t2, 10
- div t3, t1, t2
- rem t4, t1, t2
- addi t3, t3, '0'
- addi t4, t4, '0'
- addi t0, t0, '0'
-
- li t5, 0x0a # \n
- sb t5, 11(sp)
- li t5, 0x29707328 # (sp)
- sw t5, 7(sp)
- sb t4, 6(sp)
- sb t3, 5(sp)
- li t5, 0x202c # ,_
- sh t5, 3(sp)
- sb t0, 2(sp)
-
- addi a0, sp, 2
- li a1, 10
- call _write_out
-
- loca12 := loca12 + 1
- goto .Lcompile_call_restore
-
- .Lcompile_call_perform
- loca0 := 0x6c6c6163
+ (* lw a1, 56(sp) *)
+ _write_out(@loca0, 4)
+ loca4 := 0x35202c31 (* 1, 5 *)
+ _write_out(@loca4, 4)
+ loca4 := 0x70732836 (* 6(sp *)
+ _write_out(@loca4, 4)
+ loca4 := 0x0a29 (* )\n *)
+ _write_out(@loca4, 2)
+
+ (* lw a2, 52(sp) *)
+ _write_out(@loca0, 4)
+ loca4 := 0x35202c32 (* 2, 5 *)
+ _write_out(@loca4, 4)
+ loca4 := 0x70732832 (* 2(sp *)
+ _write_out(@loca4, 4)
+ loca4 := 0x0a29 (* )\n *)
+ _write_out(@loca4, 2)
+
+ (* lw a3, 48(sp) *)
+ _write_out(@loca0, 4)
+ loca4 := 0x34202c33 (* 3, 4 *)
+ _write_out(@loca4, 4)
+ loca4 := 0x70732838 (* 8(sp *)
+ _write_out(@loca4, 4)
+ loca4 := 0x0a29 (* )\n *)
+ _write_out(@loca4, 2)
+
+ (* lw a4, 44(sp) *)
+ _write_out(@loca0, 4)
+ loca4 := 0x34202c34 (* 4, 4 *)
+ _write_out(@loca4, 4)
+ loca4 := 0x70732834 (* 4(sp *)
+ _write_out(@loca4, 4)
+ loca4 := 0x0a29 (* )\n *)
+ _write_out(@loca4, 2)
+
+ (* lw a5, 40(sp) *)
+ _write_out(@loca0, 4)
+ loca4 := 0x34202c35 (* 5, 4 *)
+ _write_out(@loca4, 4)
+ loca4 := 0x70732830 (* 0(sp *)
+ _write_out(@loca4, 4)
+ loca4 := 0x0a29 (* )\n *)
+ _write_out(@loca4, 2)
+
+ loca0 := 0x6c6c6163 (* call *)
_write_out(@loca0, 4)
_put_char(0x20) (* _ *)
@@ -532,6 +541,9 @@ begin
li t1, '-'
beq t0, t1, .Ltoken_character_single
+ li t1, '*'
+ beq t0, t1, .Ltoken_character_single
+
li t1, '@'
beq t0, t1, .Ltoken_character_single
(* Expect an identifier or a number. *)
@@ -1125,6 +1137,61 @@ begin
_build_binary_expression()
end
+proc _compile_if()
+var
+ loca8, loca12, loca16, loca20: Word
+ loca4: ^Byte
+begin
+ _advance(2) (* Skip the if. *)
+ _skip_spaces()
+
+ _build_binary_expression()
+
+ _skip_spaces()
+ _advance(4) (* Skip the then. *)
+
+ loca20 := 0x00646e65 (* if end marker and newline. *)
+ loca16 := 0x66694c2e (* Label prefix ".Lif". *)
+
+ loca12 := 0x7a716562 (* beqz *)
+ _write_out(@loca12, 4)
+ loca12 := 0x2c306120 (* _a0, *)
+ _write_out(@loca12, 4)
+ _put_char(0x20) (* _ *)
+
+ (* Write the label *)
+ _write_out(@loca16, 4)
+ mv a0, s2
+ call _printi
+
+ _put_char(0x0a) (* \n *)
+
+ .Lcompile_if_loop
+ _skip_spaces()
+ loca12 := _read_token()
+
+ loca4 := _current()
+ loca8 := _token_compare(loca4, loca12, @loca20)
+
+ if loca8 then
+ loca12 := _read_line()
+ _compile_line(loca12, 1)
+
+ goto .Lcompile_if_loop
+ end
+
+ (* Write the label *)
+ _write_out(@loca16, 4)
+ mv a0, s2
+ call _printi
+
+ loca12 := 0x0a3a0a3a (* :\n:\n *)
+ _write_out(@loca12, 2)
+
+ addi s2, s2, 1 # Increment the label counter.
+ _advance(4) (* Skip the end with newline. *)
+end
+
(*
Parameters:
a0 - Line length.
@@ -1234,6 +1301,14 @@ begin
call _memcmp
beqz a0, .Lcompile_line_return
+ li t0, 0x6669 # if
+ sw t0, 12(sp)
+ mv a0, s1
+ addi a1, sp, 12
+ li a2, 2
+ call _memcmp
+ beqz a0, .Lcompile_line_if
+
lbu t0, (s1)
li t1, '.'
beq t0, t1, .Lcompile_line_label
@@ -1242,6 +1317,10 @@ begin
goto .Lcompile_line_unchanged (* Else. *)
+ .Lcompile_line_if:
+ _compile_if()
+ goto .Lcompile_line_section
+
.Lcompile_line_label
_compile_label(loca84)
goto .Lcompile_line_section
@@ -1409,7 +1488,9 @@ begin
end
proc _compile()
-var loca0, loca4: Word
+var
+ loca0, loca4: Word
+ loca8: Bool
begin
loca4 := 0 (* Whether the text section header was already emitted. *)
@@ -1419,15 +1500,11 @@ begin
_skip_indentation()
loca0 := _read_line()
- lw a0, 0(sp)
- lw a1, 4(sp)
- call _compile_line
+ loca8 := _compile_line(loca0, loca4)
beqz a0, .Lcompile_do
(* Update whether the text section header was already emitted. *)
- lw t0, 4(sp)
- or t0, t0, a0
- sw t0, 4(sp)
+ loca4 := loca4 or loca8
goto .Lcompile_do
.Lcompile_end
@@ -1460,5 +1537,6 @@ begin
call _read_file
la s1, source_code # s1 = Source code position.
+ li s2, 1
_compile()
end.
generated by cgit v1.2.3 (git 2.26.2) at 2026-06-28 12:23:14 +0000