;	TITLE	"SMTH03 - Syslib 4.0"
	NAME	('ROTLH')
;=================================================================
;   The Libraries, Version 4, (C) 1989 by Alpha Systems Corp.
;-----------------------------------------------------------------
; Author  : Harold F. Bower
;		Derived from SMTH03.Z80 Ver 1.1 by Richard Conn
; Date    : 17 Sep 89
; Version : 1.2
; Module  : SMTH03
; Abstract: This module contains the routine ROTLH which rotates
;	the HL register pair Left 1 bit.  Bit 15 is rotated in a
;	circular fashion into Bit 0.
; Revision:
;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
; Module Entry Points

	PUBLIC		ROTLH

	.Z80
	CSEG
;===============================================================
; NAME - ROTLH
; Entry: HL - Contains a 16-bit value to rotate
; Exit : HL - Contains the shifted value
; Uses : HL
; Special Requirements: None
;===============================================================

ROTLH:	PUSH	AF		; Save A and flags
	ADD	HL,HL		; Shift all 16 bits by addition
	JR	NC,EXIT		; Quit if no need to compensate for LSB
	SET	0,L		; ..else set LSB from Carry
EXIT:	POP	AF		; Restore A and flags
	RET

	END