## Mu's instructions and their table-driven translation See http://akkartik.name/akkartik-convivial-20200607.pdf for the complete story. In brief: Mu is a statement-oriented language. Blocks consist of flat lists of instructions. Instructions can have inputs after the operation, and outputs to the left of a '<-'. Inputs and outputs must be variables. They can't include nested expressions. Variables can be literals ('n'), or live in a register ('var/reg') or in memory ('var') at some 'stack-offset' from the 'ebp' register. Outputs must be registers. To modify a variable in memory, pass it in by reference as an input. (Inputs are more precisely called 'inouts'.) Conversely, registers that are just read from must not be passed as outputs. The following chart shows all the instruction forms supported by Mu, along with the SubX instruction they're translated to. ## Integer instructions These instructions use the general-purpose registers. var/eax <- increment => "40/increment-eax" var/ecx <- increment => "41/increment-ecx" var/edx <- increment => "42/increment-edx" var/ebx <- increment => "43/increment-ebx" var/esi <- increment => "46/increment-esi" var/edi <- increment => "47/increment-edi" increment var => "ff 0/subop/increment *(ebp+" var.stack-offset ")" increment *var/reg => "ff 0/subop/increment *" reg var/eax <- decrement => "48/decrement-eax" var/ecx <- decrement => "49/decrement-ecx" var/edx <- decrement => "4a/decrement-edx" var/ebx <- decrement => "4b/decrement-ebx" var/esi <- decrement => "4e/decrement-esi" var/edi <- decrement => "4f/decrement-edi" decrement var => "ff 1/subop/decrement *(ebp+" var.stack-offset ")" decrement *var/reg => "ff 1/subop/decrement *" reg var/reg <- add var2/reg2 => "01/add-to %" reg " " reg2 "/r32" var/reg <- add var2 => "03/add *(ebp+" var2.stack-offset ") " reg "/r32" var/reg <- add *var2/reg2 => "03/add *" reg2 " " reg "/r32" add-to var1, var2/reg => "01/add-to *(ebp+" var1.stack-offset ") " reg "/r32" add-to *var1/reg1, var2/reg2 => "01/add-to *" reg1 " " reg2 "/r32" var/eax <- add n => "05/add-to-eax " n "/imm32" var/reg <- add n => "81 0/subop/add %" reg " " n "/imm32" add-to var, n => "81 0/subop/add *(ebp+" var.stack-offset ") " n "/imm32" add-to *var/reg, n => "81 0/subop/add *" reg " " n "/imm32" var/reg <- subtract var2/reg2 => "29/subtract-from %" reg " " reg2 "/r32" var/reg <- subtract var2 => "2b/subtract *(ebp+" var2.stack-offset ") " reg "/r32" var/reg <- subtract *var2/reg2 => "2b/subtract *" reg2 " " reg1 "/r32" subtract-from var1, var2/reg2 => "29/subtract-from *(ebp+" var1.stack-offset ") " reg2 "/r32" subtract-from *var1/reg1, var2/reg2 => "29/subtract-from *" reg1 " " reg2 "/r32" var/eax <- subtract n => "2d/subtract-from-eax " n "/imm32" var/reg <- subtract n => "81 5/subop/subtract %" reg " " n "/imm32" subtract-from var, n => "81 5/subop/subtract *(ebp+" var.stack-offset ") " n "/imm32" subtract-from *var/reg, n => "81 5/subop/subtract *" reg " " n "/imm32" var/reg <- and var2/reg2 => "21/and-with %" reg " " reg2 "/r32" var/reg <- and var2 => "23/and *(ebp+" var2.stack-offset " " reg "/r32" var/reg <- and *var2/reg2 => "23/and *" reg2 " " reg "/r32" and-with var1, var2/reg => "21/and-with *(ebp+" var1.stack-offset ") " reg "/r32" and-with *var1/reg1, var2/reg2 => "21/and-with *" reg1 " " reg2 "/r32" var/eax <- and n => "25/and-with-eax " n "/imm32" var/reg <- and n => "81 4/subop/and %" reg " " n "/imm32" and-with var, n => "81 4/subop/and *(ebp+" var.stack-offset ") " n "/imm32" and-with *var/reg, n => "81 4/subop/and *" reg " " n "/imm32" var/reg <- or var2/reg2 => "09/or-with %" reg " " reg2 "/r32" var/reg <- or var2 => "0b/or *(ebp+" var2.stack-offset ") " reg "/r32" var/reg <- or *var2/reg2 => "0b/or *" reg2 " " reg "/r32" or-with var1, var2/reg2 => "09/or-with *(ebp+" var1.stack-offset " " reg2 "/r32" or-with *var1/reg1, var2/reg2 => "09/or-with *" reg1 " " reg2 "/r32" var/eax <- or n => "0d/or-with-eax " n "/imm32" var/reg <- or n => "81 1/subop/or %" reg " " n "/imm32" or-with var, n => "81 1/subop/or *(ebp+" var.stack-offset ") " n "/imm32" or-with *var/reg, n => "81 1/subop/or *" reg " " n "/imm32" var/reg <- not => "f7 2/subop/not %" reg not var => "f7 2/subop/not *(ebp+" var.stack-offset ")" not *var/reg => "f7 2/subop/not *" reg var/reg <- xor var2/reg2 => "31/xor-with %" reg " " reg2 "/r32" var/reg <- xor var2 => "33/xor *(ebp+" var2.stack-offset ") " reg "/r32" var/reg <- xor *var2/reg2 => "33/xor *" reg2 " " reg "/r32" xor-with var1, var2/reg => "31/xor-with *(ebp+" var1.stack-offset ") " reg "/r32" xor-with *var1/reg1, var2/reg2 => "31/xor-with *" reg1 " " reg2 "/r32" var/eax <- xor n => "35/xor-with-eax " n "/imm32" var/reg <- xor n => "81 6/subop/xor %" reg " " n "/imm32" xor-with var, n => "81 6/subop/xor *(ebp+" var.stack-offset ") " n "/imm32" xor-with *var/reg, n => "81 6/subop/xor *" reg " " n "/imm32" var/reg <- negate => "f7 3/subop/negate %" reg negate var => "f7 3/subop/negate *(ebp+" var.stack-offset ")" negate *var/reg => "f7 3/subop/negate *" reg var/reg <- shift-left n => "c1/shift 4/subop/left %" reg " " n "/imm32" var/reg <- shift-right n => "c1/shift 5/subop/right %" reg " " n "/imm32" var/reg <- shift-right-signed n => "c1/shift 7/subop/right-signed %" reg " " n "/imm32" shift-left var, n => "c1/shift 4/subop/left *(ebp+" var.stack-offset ") " n "/imm32" shift-left *var/reg, n => "c1/shift 4/subop/left *" reg " " n "/imm32" shift-right var, n => "c1/shift 5/subop/right *(ebp+" var.stack-offset ") " n "/imm32" shift-right *var/reg, n => "c1/shift 5/subop/right *" reg " " n "/imm32" shift-right-signed var, n => "c1/shift 7/subop/right-signed *(ebp+" var.stack-offset ") " n "/imm32" shift-right-signed *var/reg, n => "c1/shift 7/subop/right-signed *" reg " " n "/imm32" var/eax <- copy n => "b8/copy-to-eax " n "/imm32" var/ecx <- copy n => "b9/copy-to-ecx " n "/imm32" var/edx <- copy n => "ba/copy-to-edx " n "/imm32" var/ebx <- copy n => "bb/copy-to-ebx " n "/imm32" var/esi <- copy n => "be/copy-to-esi " n "/imm32" var/edi <- copy n => "bf/copy-to-edi " n "/imm32" var/reg <- copy var2/reg2 => "89/<- %" reg " " reg2 "/r32" copy-to var1, var2/reg => "89/<- *(ebp+" var1.stack-offset ") " reg "/r32" copy-to *var1/reg1, var2/reg2 => "89/<- *" reg1 " " reg2 "/r32" var/reg <- copy var2 => "8b/-> *(ebp+" var2.stack-offset ") " reg "/r32" var/reg <- copy *var2/reg2 => "8b/-> *" reg2 " " reg "/r32" var/reg <- copy n => "c7 0/subop/copy %" reg " " n "/imm32" copy-to var, n => "c7 0/subop/copy *(ebp+" var.stack-offset ") " n "/imm32" copy-to *var/reg, n => "c7 0/subop/copy *" reg " " n "/imm32" var/reg <- copy-byte var2/reg2 => "8a/byte-> %" reg2 " " reg "/r32" "81 4/subop/and %" reg " 0xff/imm32" var/reg <- copy-byte *var2/reg2 => "8a/byte-> *" reg2 " " reg "/r32" "81 4/subop/and %" reg " 0xff/imm32" copy-byte-to *var1/reg1, var2/reg2 => "88/byte<- *" reg1 " " reg2 "/r32" compare var1, var2/reg2 => "39/compare *(ebp+" var1.stack-offset ") " reg2 "/r32" compare *var1/reg1, var2/reg2 => "39/compare *" reg1 " " reg2 "/r32" compare var1/reg1, var2 => "3b/compare<- *(ebp+" var2.stack-offset ") " reg1 "/r32" compare var/reg, *var2/reg2 => "3b/compare<- *" reg " " n "/imm32" compare var/eax, n => "3d/compare-eax-with " n "/imm32" compare var/reg, n => "81 7/subop/compare %" reg " " n "/imm32" compare var, n => "81 7/subop/compare *(ebp+" var.stack-offset ") " n "/imm32" compare *var/reg, n => "81 7/subop/compare *" reg " " n "/imm32" var/reg <- multiply var2 => "0f af/multiply *(ebp+" var2.stack-offset ") " reg "/r32" var/reg <- multiply var2/reg2 => "0f af/multiply %" reg2 " " reg "/r32" var/reg <- multiply *var2/reg2 => "0f af/multiply *" reg2 " " reg "/r32" ## Floating-point operations These instructions operate on either floating-point registers (xreg) or general-purpose registers (reg) in indirect mode. var/xreg <- add var2/xreg2 => "f3 0f 58/add %" xreg2 " " xreg1 "/x32" var/xreg <- add var2 => "f3 0f 58/add *(ebp+" var2.stack-offset ") " xreg "/x32" var/xreg <- add *var2/reg2 => "f3 0f 58/add *" reg2 " " xreg "/x32" var/xreg <- subtract var2/xreg2 => "f3 0f 5c/subtract %" xreg2 " " xreg1 "/x32" var/xreg <- subtract var2 => "f3 0f 5c/subtract *(ebp+" var2.stack-offset ") " xreg "/x32" var/xreg <- subtract *var2/reg2 => "f3 0f 5c/subtract *" reg2 " " xreg "/x32" var/xreg <- multiply var2/xreg2 => "f3 0f 59/multiply %" xreg2 " " xreg1 "/x32" var/xreg <- multiply var2 => "f3 0f 59/multiply *(ebp+" var2.stack-offset ") " xreg "/x32" var/xreg <- multiply *var2/reg2 => "f3 0f 59/multiply *" reg2 " " xreg "/x32" var/xreg <- divide var2/xreg2 => "f3 0f 5e/divide %" xreg2 " " xreg1 "/x32" var/xreg <- divide var2 => "f3 0f 5e/divide *(ebp+" var2.stack-offset ") " xreg "/x32" var/xreg <- divide *var2/reg2 => "f3 0f 5e/divide *" reg2 " " xreg "/x32" There are also some exclusively floating-point instructions: var/xreg <- reciprocal var2/xreg2 => "f3 0f 53/reciprocal %" xreg2 " " xreg1 "/x32" var/xreg <- reciprocal var2 => "f3 0f 53/reciprocal *(ebp+" var2.stack-offset ") " xreg "/x32" var/xreg <- reciprocal *var2/reg2 => "f3 0f 53/reciprocal *" reg2 " " xreg "/x32" var/xreg <- square-root var2/xreg2 => "f3 0f 51/square-root %" xreg2
/*
 * (C)opyright MMIV-MMVI Anselm R. Garbe <garbeam at gmail dot com>
 * See LICENSE file for license details.
 */
#include "dwm.h"
#include <stdio.h>
#include <string.h>
#include <X11/Xlocale.h>

/* static */

static void
drawborder(void)
{
	XPoint points[5];

	XSetLineAttributes(dpy, dc.gc, 1, LineSolid, CapButt, JoinMiter);
	XSetForeground(dpy, dc.gc, dc.border);
	points[0].x = dc.x;
	points[0].y = dc.y;
	points[1].x = dc.w - 1;
	points[1].y = 0;
	points[2].x = 0;
	points[2].y = dc.h - 1;
	points[3].x = -(dc.w - 1);
	points[3].y = 0;
	points[4].x = 0;
	points[4].y = -(dc.h - 1);
	XDrawLines(dpy, dc.drawable, dc.gc, points, 5, CoordModePrevious);
}

static unsigned int
textnw(const char *text, unsigned int len)
{
	XRectangle r;

	if(dc.font.set) {
		XmbTextExtents(dc.font.set, text, len, NULL, &r);
		return r.width;
	}
	return XTextWidth(dc.font.xfont, text, len