Commit b4d92b65 authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

vt: deduplicate setGx code 



The code for setting G0 and G1 is duplicated -- for each of them. Move
the code to a separate function (vc_setGx) and distinguish the two cases
by a parameter.

Change if-else-if to switch which allows for slightly better
optimization (decision tree).

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-4-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 77bc14f2

drivers/tty/vt/vt.c

+26 −20
Original line number Diff line number Diff line
@@ -2103,6 +2103,30 @@ static void reset_terminal(struct vc_data *vc, int do_clear) 
	    csi_J(vc, 2);

}



static void vc_setGx(struct vc_data *vc, unsigned int which, int c)

{

	unsigned char *charset = which == 0 ? &vc->state.G0_charset :

		&vc->state.G1_charset;



	switch (c) {

	case '0':

		*charset = GRAF_MAP;

		break;

	case 'B':

		*charset = LAT1_MAP;

		break;

	case 'U':

		*charset = IBMPC_MAP;

		break;

	case 'K':

		*charset = USER_MAP;

		break;

	}



	if (vc->state.charset == which)

		vc->vc_translate = set_translate(*charset, vc);

}



/* console_lock is held */

static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)

{
@@ -2485,29 +2509,11 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c) 
		}

		return;

	case ESsetG0:

		if (c == '0')

			vc->state.G0_charset = GRAF_MAP;

		else if (c == 'B')

			vc->state.G0_charset = LAT1_MAP;

		else if (c == 'U')

			vc->state.G0_charset = IBMPC_MAP;

		else if (c == 'K')

			vc->state.G0_charset = USER_MAP;

		if (vc->state.charset == 0)

			vc->vc_translate = set_translate(vc->state.G0_charset, vc);

		vc_setGx(vc, 0, c);

		vc->vc_state = ESnormal;

		return;

	case ESsetG1:

		if (c == '0')

			vc->state.G1_charset = GRAF_MAP;

		else if (c == 'B')

			vc->state.G1_charset = LAT1_MAP;

		else if (c == 'U')

			vc->state.G1_charset = IBMPC_MAP;

		else if (c == 'K')

			vc->state.G1_charset = USER_MAP;

		if (vc->state.charset == 1)

			vc->vc_translate = set_translate(vc->state.G1_charset, vc);

		vc_setGx(vc, 1, c);

		vc->vc_state = ESnormal;

		return;

	case ESosc:

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