A2OS/source/ARM.ARMRuntime.Mod

MODULE ARMRuntime;
IMPORT SYSTEM, FPE64;

CONST
	B = 127; 
	C = 800000H; 
	E = 100H; 
	S = LONGINT(80000000H); (* used by VFP unit emulation *)
	MAXREAL = LONGINT(7F7FFFFFH);

TYPE
	ULONGINT = LONGINT; (* alias to make distinction between signed and unsigned more clear *)
	UHUGEINT = HUGEINT;
	FLOAT32 = LONGINT; (* alias to make clear that the integer actually contains a IEEE 32 bit float *)
	FLOAT64= HUGEINT;

	PROCEDURE DivS8*(left, right: SHORTINT): SHORTINT;
	VAR result, dummy: LONGINT;
	BEGIN	 DivModS32(left, right, result, dummy); RETURN SHORTINT(result)
	END DivS8;

	PROCEDURE DivS16*(left, right: INTEGER): INTEGER;
	VAR result, dummy: LONGINT;
	BEGIN	 DivModS32(left, right, result, dummy); RETURN INTEGER(result)
	END DivS16;

	PROCEDURE DivS32*(left, right: LONGINT): LONGINT;
	VAR result, dummy: LONGINT;
	BEGIN	 DivModS32(left, right, result, dummy); RETURN result
	END DivS32;

	PROCEDURE DivU32*(left, right: ULONGINT): ULONGINT;
	VAR result, dummy: LONGINT;
	BEGIN DivModU32(left, right, result, dummy); RETURN result
	END DivU32;

	PROCEDURE DivS64*(left, right: HUGEINT): HUGEINT;
	VAR result, dummy: HUGEINT;
	BEGIN
		DivModS64(left, right, result, dummy); RETURN result
	END DivS64;

	PROCEDURE ModS8*(left, right: SHORTINT): SHORTINT;
	VAR result, dummy: LONGINT;
	BEGIN DivModS32(left, right, dummy, result); RETURN SHORTINT(result)
	END ModS8;

	PROCEDURE ModS16*(left, right: INTEGER): INTEGER;
	VAR result, dummy: LONGINT;
	BEGIN DivModS32(left, right, dummy, result); RETURN INTEGER(result)
	END ModS16;

	PROCEDURE ModS32*(left, right: LONGINT): LONGINT;
	VAR result, dummy: LONGINT;
	BEGIN DivModS32(left, right, dummy, result); RETURN result
	END ModS32;

	PROCEDURE ModU32*(left, right: ULONGINT): ULONGINT;
	VAR result, dummy: LONGINT;
	BEGIN DivModU32(left, right, dummy, result); RETURN result
	END ModU32;

	PROCEDURE ModS64*(left, right: HUGEINT): HUGEINT;
	VAR result, dummy: HUGEINT;
	BEGIN
			DivModS64(left, right, dummy, result); RETURN result
	END ModS64;

	PROCEDURE RolS64*(source: HUGEINT; amount: ULONGINT): HUGEINT;
	CODE
		LDR R2, [FP, #+8] ; R2 := amount
		LDR R3, [FP, #+12] ; R3 := source[Low]
		LDR R4, [FP, #+16] ; R4 := source[High]

		; source = R4:R3

		AND R2, R2, #3FH ; R2 := R2 MOD 64

		CMP R2, #32

		; IF R2 < 32:
		MOVLT R0, R3, LSL R2
		MOVLT R1, R4, LSL R2
		RSBLT R2, R2, #32 ; R2 := 32 - R2
		ORRLT R0, R0, R4, LSR R2
		ORRLT R1, R1, R3, LSR R2

		; IF R2 >= 32:
		SUBGE R2, R2, #32 ; R2 := R2 - 32
		MOVGE R0, R4, LSL R2
		MOVGE R1, R3, LSL R2
		RSBGE R2, R2, #32 ; R2 := 32 - R2
		ORRGE R0, R0, R3, LSR R2
		ORRGE R1, R1, R4, LSR R2

		; result = R1:R0
	END RolS64;

	PROCEDURE RolU64*(source: HUGEINT; amount: ULONGINT): HUGEINT;
	BEGIN RETURN RolS64(source, amount)
	END RolU64;

	PROCEDURE RorS64*(source: HUGEINT; amount: ULONGINT): HUGEINT;
	BEGIN RETURN RolS64(source, 64 - (amount MOD 64))
	END RorS64;
	
	PROCEDURE RorU64*(source: HUGEINT; amount: ULONGINT): HUGEINT;
	BEGIN RETURN RolS64(source, 64 - (amount MOD 64))
	END RorU64;

	(* signed division and modulus
	- note: this implements the mathematical definition of DIV and MOD in contrast to the symmetric one
	*)
	PROCEDURE DivModS32(dividend, divisor: LONGINT; VAR quotient, remainder: LONGINT);
	BEGIN
		ASSERT(divisor > 0);
		IF dividend >= 0 THEN
			DivModU32(dividend, divisor, quotient, remainder)
		ELSE
			dividend := -dividend;
			DivModU32(dividend, divisor, quotient, remainder);
			quotient := -quotient;
			IF remainder # 0 THEN
				DEC(quotient);
				remainder := divisor - remainder
			END
		END
	END DivModS32;

	(*
		Fast 32-bit unsigned integer division/modulo (author Alexey Morozov)
	*)
	PROCEDURE DivModU32(dividend, divisor: ULONGINT; VAR quotient, remainder: ULONGINT);
	CODE
		MOV R2, #0 ; quotient will be stored in R2

		LDR R0, [FP,#dividend] ; R0 := dividend
		LDR R1, [FP,#divisor] ; R1 := divisor

		; check for the case dividend < divisor
		CMP R0, R1
		BLT Exit ; nothing to do than setting quotient to 0 and remainder to dividend (R0)

		CLZ R3, R0 ; R3 := clz(dividend)
		CLZ R4, R1 ; R4 := clz(divisor)

		SUB R3, R4, R3 ; R2 := clz(divisor) - clz(dividend) , R2 >= 0
		LSL R1, R1, R3 ; scale divisor: divisor := LSH(divisor,clz(divisor)-clz(dividend))

	Loop:
		CMP R0, R1
		ADC R2, R2, R2
		SUBCS R0, R0, R1
		LSR R1, R1, #1
		SUBS R3, R3, #1
		BPL Loop

		; R0 holds the remainder

	Exit:
		LDR R1, [FP,#quotient] ; R1 := address of quotient
		LDR R3, [FP,#remainder] ; R3 := address of remainder

		STR R2, [R1,#0] ; quotient := R1
		STR R0, [R3,#0] ; remainder := R0
	END DivModU32;

	(**
		Signed 64-bit multiplication. Adapted version based on the original code
		from "Runtime ABI for the ARM Cortex-M0" (https://github.com/bobbl/libaeabi-cortexm0/blob/master/lmul.S)

		/* Runtime ABI for the ARM Cortex-M0
		 * lmul.S: 64 bit multiplication
		 *
		 * Copyright (c) 2013 Jörg Mische <bobbl@gmx.de>
		 *
		 * Permission to use, copy, modify, and/or distribute this software for any
		 * purpose with or without fee is hereby granted, provided that the above
		 * copyright notice and this permission notice appear in all copies.
		 *
		 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
		 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
		 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
		 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
		 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
		 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
		 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
		 */

		Multiply r1:r0 and r3:r2 and return the product in r1:r0
		Can also be used for unsigned long product
	*)
	PROCEDURE MulS64*(x, y: HUGEINT): HUGEINT;
	CODE
		ldr r0, [FP,#x]
		ldr r1, [FP,#x+4]

		ldr r2, [FP,#y]
		ldr r3, [FP,#y+4]

		muls	r1, r1, r2
		muls	r3, r3, r0
		adds	r1, r1, r3

		lsrs	r3, r0, #16
		lsrs	r4, r2, #16
		muls	r3, r3, r4
		adds	r1, r1, r3

		lsrs	r3, r0, #16
		uxth	r0, r0
		uxth	r2, r2
		muls	r3, r3, r2
		muls	r4, r4, r0
		muls	r0, r0, r2

		movs	r2, #0
		adds	r3, r3, r4
		adcs	r2, r2, r2
		lsls	r2, r2, #16
		adds	r1, r1, r2

		lsls	r2, r3, #16
		lsrs	r3, r3, #16
		adds	r0, r0, r2
		adcs	r1, r1, r3

	END MulS64;

	(* signed division and modulus
	- note: this implements the mathematical definition of DIV and MOD in contrast to the symmetric one
	*)
	PROCEDURE DivModS64*(dividend, divisor: HUGEINT; VAR quotient, remainder: HUGEINT);
	BEGIN
		ASSERT(divisor > 0);
		IF dividend >= 0 THEN
			DivModU64(dividend, divisor, quotient, remainder)
		ELSE
			dividend := -dividend;
			DivModU64(dividend, divisor, quotient, remainder);
			quotient := -quotient;
			IF remainder # 0 THEN
				DEC(quotient);
				remainder := divisor - remainder
			END
		END
	END DivModS64;

	(* Count leading zeros in a binary representation of a given 64-bit integer number *)
	PROCEDURE Clz64*(x: UHUGEINT): LONGINT;
	CODE
		; high-half
		LDR R1, [FP,#x+4]
		CMP R1, #0 ; if high-half is zero count leading zeros of the low-half
		BEQ LowHalf

		CLZ R0, R1
		B Exit

		; low-half
	LowHalf:
		LDR R1, [FP,#x]
		CLZ R0, R1
		ADD R0, R0, #32 ; add 32 zeros from the high-half

	Exit:
	END Clz64;

	(*
		Fast 64-bit unsigned integer division/modulo (Alexey Morozov)
	*)
	PROCEDURE DivModU64*(dividend, divisor: UHUGEINT; VAR quotient, remainder: UHUGEINT);
	VAR m: LONGINT;
	BEGIN
		quotient := 0;

		IF dividend = 0 THEN remainder := 0; RETURN; END;
		IF dividend < divisor THEN remainder := dividend; RETURN; END;

		m := Clz64(divisor) - Clz64(dividend);
		ASSERT(m >= 0);

		divisor := LSH(divisor,m);
		WHILE m >= 0 DO
			quotient := LSH(quotient,1);
			IF dividend >= divisor THEN
				INC(quotient);
				DEC(dividend,divisor);
			END;
			divisor := LSH(divisor,-1);
			DEC(m);
		END;

		remainder := dividend;
	(*
	CODE

		ldr r0, [FP,#dividend]
		ldr r1, [FP,#dividend+4]

		ldr r2, [FP,#divisor]
		ldr r3, [FP,#divisor+4]




		ldr r5, [FP,#quotient]
		ldr r6, [FP,#remainder]

		str r0, [r5,#0]
		str r1, [r5,#4]

		str r2, [r6,#0]
		str r3, [r6,#4]
	*)
	END DivModU64;

	(* ---- FLOATING POINT EMULATION ----
	The following procedures are used in case the target platform does not feature a math coprocessor (aka VFP unit).
	Most of the code was taken from the Minos FPU emulation module "FPU.Mos".

	Note that parameters and return types are declared as integers, even though they do contain floating point values
	according to the IEEE standard.
	*)

	(** Tests for 0.0 (+0 or -0)
	- corresponds to SYSTEM.NULL **)
	PROCEDURE IsZeroF32(float: FLOAT32): BOOLEAN;
	CODE
		LDR R0, [FP, #+float] ; R0 := float
		BIC R0, R0, #S ; clear the sign bit
		CMP R0, #0 ; IF R0 = 0
		MOVEQ R0, #1 ; THEN RETURN TRUE
		MOVNE R0, #0 ; ELSE RETURN FALSE
	END IsZeroF32;

	(** Serves to obtain the sign for products and quotients.
	- corresponds to SYSTEM.XOR **)
	PROCEDURE SignXorF32(left, right: FLOAT32): FLOAT32;
	CODE
		LDR R0, [FP, #+left] ; R0 := left
		LDR R1, [FP, #+right] ; R1: = right
		EOR R0, R0, R1 ; R0 := R0 xor R1
		AND R0, R0, #S ; clear all bits except the sign bit
	END SignXorF32;

	(** multiplies two 32-bit unsigned integer to produce a 64-bit result: [resultLow | resultHigh] = left * right
	- corresponds to SYSTEM.MULD (but the low and high part of the result are passed explicitly) **)
	PROCEDURE MulD(VAR resultLow, resultHigh: FLOAT32; left, right: FLOAT32);
	CODE
		LDR R2, [FP, #+resultLow] ; R2 := address of resultLow
		LDR R3, [FP, #+resultHigh] ; R3: = address of resultHigh
		LDR R4, [FP, #+left] ; R4 := left
		LDR R5, [FP, #+right] ; R5: = right

		UMULL R0, R1, R4, R5

		STR R0, [R4, #+0]
		STR R1, [R5, #+0]
	END MulD;

	PROCEDURE NegF32*(float: FLOAT32): FLOAT32;
	CODE
		LDR R0, [FP, #+float] ; R0 := float
		EOR R0, R0, #S ; invert only the sign bit
	END NegF32;

	PROCEDURE AbsF32*(float: FLOAT32): FLOAT32;
	CODE
		LDR R0, [FP, #+float] ; R0 := float
		BIC R0, R0, #S ; clear the sign bit
	END AbsF32;

	PROCEDURE AddF32*(x, y: FLOAT32): FLOAT32;		
	VAR xe, ye, s: LONGINT;
	BEGIN
		IF SYSTEM.NULL(x) = TRUE THEN x := y
		ELSIF SYSTEM.NULL(y) = FALSE THEN
			xe := x DIV C MOD E; (* exponent with bias *)
			IF x >= 0 THEN x := (x MOD C + C)*2 ELSE x := -(x MOD C + C)*2 END ;
			ye := y DIV C MOD E; (* exponent with bias *)
			IF y >= 0 THEN y := (y MOD C + C)*2 ELSE y := -(y MOD C + C)*2 END ;
			IF xe < ye THEN
				ye := ye - xe; xe := xe + ye; (*denorm x*)
				IF ye <= 25 THEN x := ASH(x, -ye) ELSE x := 0 END
			ELSIF ye < xe THEN
				ye := xe - ye;  (*denorm y*)
				IF ye <= 25 THEN y := ASH(y, -ye) ELSE y := 0 END
			END ;
			s := x + y; x := ABS(s);
			s := SYSTEM.VAL(LONGINT, SYSTEM.VAL(SET, s)*{31});
			IF x # 0 THEN
				IF x >= 4*C THEN x := (x+2) DIV 4; INC(xe)
				ELSIF x >= 2*C THEN x := (x+1) DIV 2
				ELSE DEC(xe);
					WHILE x < C DO x := 2*x; DEC(xe) END
				END ;
				IF xe < 0 THEN x := 0  (*underflow*)
				ELSIF xe > 0FEH THEN x := MAXREAL + s; (* overflow *)
				ELSE x := xe*C + (x - C) + s;
				END;
			END
		END ;
		RETURN x
	END AddF32;
	
	PROCEDURE AddF64*(x,y: FLOAT64): FLOAT64;
	VAR z: FLOAT64;
	BEGIN FPE64.Add(SYSTEM.VAL(FPE64.Float64,x),SYSTEM.VAL(FPE64.Float64,y),SYSTEM.VAL(FPE64.Float64,z)); RETURN z
	END AddF64;

	PROCEDURE MulF64*(x,y: FLOAT64): FLOAT64;
	VAR z: FLOAT64;
	BEGIN FPE64.Mul(SYSTEM.VAL(FPE64.Float64,x),SYSTEM.VAL(FPE64.Float64,y),SYSTEM.VAL(FPE64.Float64,z)); RETURN z
	END MulF64;

	PROCEDURE DivF64*(x,y: FLOAT64): FLOAT64;
	VAR z: FLOAT64;
	BEGIN FPE64.Div(SYSTEM.VAL(FPE64.Float64,x),SYSTEM.VAL(FPE64.Float64,y),SYSTEM.VAL(FPE64.Float64,z)); RETURN z
	END DivF64;

	PROCEDURE SubF64*(x,y: FLOAT64): FLOAT64;
	VAR z: FLOAT64;
	BEGIN FPE64.Sub(SYSTEM.VAL(FPE64.Float64,x),SYSTEM.VAL(FPE64.Float64,y),SYSTEM.VAL(FPE64.Float64,z)); RETURN z
	END SubF64;

	PROCEDURE AbsF64*(x: FLOAT64): FLOAT64;
	VAR z: FLOAT64;
	BEGIN FPE64.Abs(SYSTEM.VAL(FPE64.Float64,x),SYSTEM.VAL(FPE64.Float64,z)); RETURN z
	END AbsF64;

	PROCEDURE NegF64*(x: FLOAT64): FLOAT64;
	VAR z: FLOAT64;
	BEGIN FPE64.Neg(SYSTEM.VAL(FPE64.Float64,x),SYSTEM.VAL(FPE64.Float64,z)); RETURN z
	END NegF64;

	PROCEDURE ConvS32F64*(x: FLOAT64): LONGINT;
	BEGIN RETURN FPE64.Fix(SYSTEM.VAL(FPE64.Float64,x))
	END ConvS32F64;

	PROCEDURE ConvF32F64*(x: FLOAT64): REAL;
	BEGIN RETURN FPE64.Single(SYSTEM.VAL(FPE64.Float64,x))
	END ConvF32F64;

	PROCEDURE ConvF64F32*(x: REAL): FLOAT64;
	VAR z: FLOAT64;
	BEGIN FPE64.Double(x,SYSTEM.VAL(FPE64.Float64,z)); RETURN z
	END ConvF64F32;

	PROCEDURE ConvF64S32*(x: LONGINT): FLOAT64;
	VAR flt: FLOAT64;
	BEGIN FPE64.Float(x, SYSTEM.VAL(FPE64.Float64,flt)); RETURN flt
	END ConvF64S32;

	PROCEDURE ConvF64S16*(x: INTEGER): FLOAT64;
	VAR flt: FLOAT64;
	BEGIN FPE64.Float(x, SYSTEM.VAL(FPE64.Float64,flt)); RETURN flt
	END ConvF64S16;

	PROCEDURE ConvF32S16*(x: INTEGER): REAL;
	BEGIN
		RETURN ConvF32S32(LONGINT(x))
	END ConvF32S16;
	
	PROCEDURE ConvF32S8*(x: SHORTINT): REAL;
	BEGIN
		RETURN ConvF32S16(INTEGER(x))
	END ConvF32S8;
	
	PROCEDURE ConvF64S8*(x: SHORTINT): FLOAT64;
	BEGIN
		RETURN ConvF64S16(INTEGER(x))
	END ConvF64S8;

	PROCEDURE SubF32*(left, right: FLOAT32): FLOAT32;
	BEGIN RETURN AddF32(left, NegF32(right))
	END SubF32;

	PROCEDURE MulF32*(x, y: FLOAT32): FLOAT32;
	VAR xe, zh, ye, s: LONGINT;  (*zh, ye in this order; ye used as zh in MULD*)
	BEGIN
		IF SYSTEM.NULL(y) = TRUE THEN x := 0
		ELSIF SYSTEM.NULL(y) = FALSE THEN
			s := SYSTEM.VAL(LONGINT, SYSTEM.VAL(SET, SYSTEM.XOR(x, y))*{31});
			xe := x DIV C MOD E; (* exponent with bias *)
			ye := y DIV C MOD E; (* exponent with bias *)
			x := (x MOD C + C) * 20H;
			y := (y MOD C + C) * 20H;
			xe := xe + ye - B; (* exponent with bias *)
			
			SYSTEM.MULD(ye, x, y); (* note that this implicitly changes zh *)
			
			IF zh >= 4*C THEN
				x := (zh+2) DIV 4;
				INC(xe);
			ELSE
				x := (zh+1) DIV 2;
			END;
			IF xe < 0 THEN (* underflow *)
				x := 0;
			ELSIF xe > 0FEH THEN (* overflow *)
				x := MAXREAL + s;
			ELSE
				x := xe*C + (x-C) + s;
			END;
		END ;
		RETURN x
	END MulF32;
	
	PROCEDURE DivF32*(x, y: FLOAT32): FLOAT32;
	VAR xe, ye, q, s: LONGINT;
	BEGIN
		s := SYSTEM.VAL(LONGINT, SYSTEM.VAL(SET, SYSTEM.XOR(x, y))*{31});
		IF SYSTEM.NULL(y) = TRUE THEN
			x := MAXREAL + s;
		ELSIF SYSTEM.NULL(x) = FALSE THEN
			xe := x DIV C MOD E; (* exponent with bias *)
			ye := y DIV C MOD E; (* exponent with bias *)
			x := x MOD C + C;
			y := y MOD C + C;
			xe := xe - ye + B; (* exponent with bias *)
			IF x < y THEN
				x := x*2; DEC(xe);
			END ;
			IF xe < 0 THEN (* underflow *)
				x := 0;
			ELSIF xe > 0FEH THEN (* overflow *)
				x := MAXREAL + s;
			ELSE (* divide *)
				q := 0;
				WHILE q < LONGINT(1000000H) DO (* 2*C *)
					q := 2*q;
					IF x >= y THEN
						x := x - y;
						INC(q);
					END;
					x := 2*x;
				END;
				q := (q+1) DIV 2;  (*round*)
				x := xe*C + (q-C) + s;
			END;
		END;
		RETURN x
	END DivF32;

	(** converts a float into an integer, ignores the fractional part
	- corresponds to ENTIER(x) **)
	PROCEDURE ConvS32F32*(x: FLOAT32): LONGINT;
	VAR xe, s: LONGINT;
	BEGIN
		IF SYSTEM.NULL(x) = TRUE THEN
			x := 0
		ELSE
			s := x; xe := x DIV C MOD E - B; x := x MOD C + C;
			IF s < 0 THEN x := -x END ;
			IF xe < 24 THEN x := ASH(x, xe - 23)
			ELSIF xe < 31 THEN x := LSH(x, xe - 23)
			ELSIF s < 0 THEN x := LONGINT(80000000H);
			ELSE x := LONGINT(7FFFFFFFH);
			END;
		END ;
		RETURN x
	END ConvS32F32;
	
	(** converts an integer into a float, ignores the non-integer part
	- corresponds to REAL(int)
	- note that no rounding occurs
	**)
	PROCEDURE ConvF32S32*(x: LONGINT): FLOAT32;
	VAR xe, s: LONGINT;
	BEGIN
		IF x = LONGINT(80000000H) THEN (* ABS cannot handle the most negative LONGINT number! *)
			x := LONGINT(0CF000000H);
		ELSIF x # 0 THEN
			s := x;
			x := ABS(x); xe := 23;
			WHILE x >= 2*C DO
				x := x DIV 2; INC(xe);
			END;
			WHILE x < C DO
				x := 2*x; DEC(xe);
			END;
			x := (xe + B)*C - C + x;
			IF s < 0 THEN x := x+S END
		END ;
		RETURN x
	END ConvF32S32;
	
	(** whether x < y
	- note that this operation should rather be done by direct code emission of the backend
	**)
	PROCEDURE LessThanF32(x, y: FLOAT32): BOOLEAN;
	BEGIN
		HALT(200)
	END LessThanF32;

	(* ---- STRING OPERATIONS ---- *)

	(** compare two strings
	- returns 0 if both strings are lexicographically equal
	- returns +1 if 'left' is lexicographically greater than 'right'
	- returns -1 if 'left' is lexicographically less than 'right'
	**)
	PROCEDURE CompareString*(CONST left, right: ARRAY OF CHAR): SHORTINT;
	VAR
		result: SHORTINT;
		i: LONGINT;
		leftChar, rightChar: CHAR;
	BEGIN
		result := 0;
		i := 0;
		REPEAT
			leftChar := left[i]; rightChar := right[i];
			IF leftChar < rightChar THEN result := -1
			ELSIF leftChar > rightChar THEN result := +1
			END;
			INC(i)
		UNTIL (result # 0) OR (leftChar = 0X) OR (rightChar = 0X);
		RETURN result
	END CompareString;

	(** copy a string from 'source' to 'destination'
	- note that PACO semantics are used **)
	PROCEDURE CopyString*(VAR destination: ARRAY OF CHAR; CONST source: ARRAY OF CHAR);
	VAR
		sourceLength, destinationLength: LONGINT;
	BEGIN
		destinationLength := LEN(destination);
		sourceLength := LEN(source);
		IF destinationLength < sourceLength THEN sourceLength := destinationLength END;
		SYSTEM.MOVE(ADDRESSOF(source[0]), ADDRESSOF(destination[0]), sourceLength)
	END CopyString;

END ARMRuntime.