more consterxprs

04/in03

@@ -1005,7 +1005,7 @@ align
 	I=:line
 	call :set_rax_to_rvalue
 	call :set_rbx_to_rdi
-	call :emit_zero_rdx_idiv_rbx
+	call :emit_cqo_idiv_rbx
 	I=:line
 	call :set_lvalue_to_rax
 	!:read_line
@@ -1014,7 +1014,7 @@ align
 	I=:line
 	call :set_rax_to_rvalue
 	call :set_rbx_to_rdi
-	call :emit_zero_rdx_idiv_rbx
+	call :emit_cqo_idiv_rbx
 	call :set_rax_to_rdx
 	I=:line
 	call :set_lvalue_to_rax
@@ -1475,11 +1475,11 @@ align
 	
 :rvalue_div
 	call :set_rbx_to_rsi
-	!:emit_zero_rdx_idiv_rbx
+	!:emit_cqo_idiv_rbx
 
 :rvalue_rem
 	call :set_rbx_to_rsi
-	call :emit_zero_rdx_idiv_rbx
+	call :emit_cqo_idiv_rbx
 	call :set_rax_to_rdx
 	return
 
@@ -1745,16 +1745,6 @@ align
 	x31
 	xc0
 
-:zero_rdx
-	J=d4
-	I=:xor_edx_edx
-	D=d2
-	syscall x1
-	return
-:xor_edx_edx
-	x31
-	xd2
-
 :set_rbx_to_rax
 	J=d4
 	I=:mov_rbx_rax
@@ -2014,14 +2004,15 @@ align
 	xf7
 	xeb
 
-:emit_zero_rdx_idiv_rbx
+:emit_cqo_idiv_rbx
-	call :zero_rdx
 	J=d4
-	I=:idiv_rbx
+	I=:cqo_idiv_rbx
-	D=d3
+	D=d5
 	syscall x1
 	return
-:idiv_rbx
+:cqo_idiv_rbx
+	x48
+	x99
 	x48
 	xf7
 	xfb

05/constants.b

@@ -126,7 +126,7 @@
 ;    uchar kind  (one of the constants below)
 ;    uchar info
 ;    ushort (padding)
-;    uint type (0 if expression hasn't been typed yet)
+;    uint type
 ; immediately following the header in memory are the arguments of the expression
 ;    - for constant ints, the 64-bit integral value
 ;    - for constant floats, the 64-bit double value (even if expression has type float)

05/main.c

@@ -3,4 +3,4 @@
 	long double d;
 } (*x)(void);
 */
-typedef long int unsigned Foo[3 * 3];
+typedef long int unsigned Foo[19 + (-3) % 187 - 28 + 5 * 6];

05/parse.b

@@ -943,6 +943,7 @@ function evaluate_constant_expression
 	argument p_value
 	local a
 	local b
+	local p
 	
 	if *1expr == EXPRESSION_CONSTANT_INT goto eval_constant_int
 	if *1expr == EXPRESSION_IDENTIFIER goto eval_constant_identifier
@@ -951,8 +952,11 @@ function evaluate_constant_expression
 	if *1expr == EXPRESSION_BITWISE_NOT goto eval_bitwise_not
 	if *1expr == EXPRESSION_LOGICAL_NOT goto eval_logical_not
 	if *1expr == EXPRESSION_CAST goto eval_todo ; @TODO
-	if *1expr == EXPRESSION_LOGICAL_NOT goto eval_logical_not
+	if *1expr == EXPRESSION_ADD goto eval_add
+	if *1expr == EXPRESSION_SUB goto eval_sub
 	if *1expr == EXPRESSION_MUL goto eval_mul
+	if *1expr == EXPRESSION_DIV goto eval_div
+	if *1expr == EXPRESSION_REMAINDER goto eval_remainder
 	byte 0xcc
 	
 	:eval_todo
@@ -998,13 +1002,49 @@ function evaluate_constant_expression
 		:eval_logical_not0
 		*8p_value = 1
 		return expr
+	:eval_add
+		expr += 8
+		expr = evaluate_constant_expression(expr, &a)
+		expr = evaluate_constant_expression(expr, &b)
+		*8p_value = a + b
+		return expr
+	:eval_sub
+		expr += 8
+		expr = evaluate_constant_expression(expr, &a)
+		expr = evaluate_constant_expression(expr, &b)
+		*8p_value = a - b
+		return expr
 	:eval_mul
 		expr += 8
 		expr = evaluate_constant_expression(expr, &a)
 		expr = evaluate_constant_expression(expr, &b)
 		*8p_value = a * b
 		return expr
-		
+	:eval_div
+		p = expr + 4 ; pointer to type
+		expr += 8
+		expr = evaluate_constant_expression(expr, &a)
+		expr = evaluate_constant_expression(expr, &b)
+		if *1p == TYPE_UNSIGNED_LONG goto eval_div_unsigned
+			; division is signed or uses a small type, so we can use 64-bit signed division
+			*8p_value = a / b
+			return expr
+		:eval_div_unsigned
+			; must use unsigned division
+			divmod_unsigned(a, b, p_value, &a)
+			return expr
+	:eval_remainder
+		p = expr + 4 ; pointer to type
+		expr += 8
+		expr = evaluate_constant_expression(expr, &a)
+		expr = evaluate_constant_expression(expr, &b)
+		if *1p == TYPE_UNSIGNED_LONG goto eval_rem_unsigned
+			*8p_value = a % b
+			return expr
+		:eval_rem_unsigned
+			divmod_unsigned(a, b, &a, p_value)
+			return expr
+	
 ; the "usual conversions" for binary operators, as the C standard calls it
 function expr_binary_type_usual_conversions
 	argument token ; for errors

05/util.b

@@ -25,6 +25,75 @@ function full_multiply_signed
 	*8p_upper = upper
 	return
 
+
+function divmod_unsigned
+	argument a
+	argument b
+	argument p_quotient
+	argument p_remainder
+	local q
+	local r
+	
+	; mov rax, [rbp-16]
+	byte 0x48
+	byte 0x8b
+	byte 0x85
+	byte 0xf0
+	byte 0xff
+	byte 0xff
+	byte 0xff
+	
+	; mov rbx, rax
+	byte 0x48
+	byte 0x89
+	byte 0xc3
+	
+	; mov rax, [rbp-8]
+	byte 0x48
+	byte 0x8b
+	byte 0x85
+	byte 0xf8
+	byte 0xff
+	byte 0xff
+	byte 0xff
+	
+	; xor edx, edx
+	byte 0x31
+	byte 0xd2
+	
+	; div rbx
+	byte 0x48
+	byte 0xf7
+	byte 0xf3
+	
+	; mov [rbp-40], rax
+	byte 0x48
+	byte 0x89
+	byte 0x85
+	byte 0xd8
+	byte 0xff
+	byte 0xff
+	byte 0xff
+	
+	; mov rax, rdx
+	byte 0x48
+	byte 0x89
+	byte 0xd0
+	
+	; mov [rbp-48], rax
+	byte 0x48
+	byte 0x89
+	byte 0x85
+	byte 0xd0
+	byte 0xff
+	byte 0xff
+	byte 0xff
+	
+	*8p_quotient = q
+	*8p_remainder = r
+	
+	return
+
 ; allows for negative shifts
 function right_shift
 	argument x
@@ -93,7 +162,8 @@ function free
 	syscall(11, psize, size)
 	return
 
-; returns a pointer to a null-terminated string containing the number given
+; returns a pointer to a null-terminated string containing the
+; (unsigned) number given
 function itos
 	global 32 itos_string
 	argument x
@@ -102,10 +172,9 @@ function itos
 	p = &itos_string
 	p += 30
 	:itos_loop
-		c = x % 10
+		divmod_unsigned(x, 10, &x, &c)
 		c += '0
 		*1p = c
-		x /= 10
 		if x == 0 goto itos_loop_end
 		p -= 1
 		goto itos_loop

README.md

@@ -137,6 +137,7 @@ In the table below, `IMM64` means a 64-bit *immediate* (a constant number).
 │ add rax, rbx         │ 48 01 d8          │ add rbx to rax                         │
 │ sub rax, rbx         │ 48 29 d8          │ subtract rbx from rax                  │
 │ imul rbx             │ 48 f7 eb          │ set rdx:rax to rax * rbx (signed)      │
+│ cqo                  │ 48 99             │ sign-extend rax to rdx:rax             |
 │ idiv rbx             │ 48 f7 fb          │ divide rdx:rax by rbx (signed); put    │
 │                      │                   │    quotient in rax, remainder in rbx   │
 │ mul rbx              │ 48 f7 e3          │ like imul, but unsigned                │