/*
 * txt.c — print a Prog list as Plan 9-flavoured amd64 asm text.
 *
 * Format we emit (and that w6a expects):
 *   TEXT name<framesize>
 *       MOVQ $1, AX
 *       MOVQ AX, name(SB)        ; extern symbol
 *       MOVQ off(BP), AX         ; local
 *       CMPQ AX, $0
 *       JE   label
 *       RET
 *   label:
 *
 * Operand order is Plan 9-ish: source first, dest second. (Same as
 * AT&T; the convention diverges from Plan 9 only on a few items we
 * don't yet emit.)
 */
#include "gc.h"
#include <string.h>

const char *
anames(int op)
{
	switch (op) {
	case A_NOP:	return "NOP";
	case A_TEXT:	return "TEXT";
	case A_DATA:	return "DATA";
	case A_DATAW:	return "DATAW";
	case A_DATAR:	return "DATAR";
	case A_GLOBL:	return "GLOBL";
	case A_END:	return "END";
	case A_MOVQ:	return "MOVQ";
	case A_MOVL:	return "MOVL";
	case A_MOVW:	return "MOVW";
	case A_MOVB:	return "MOVB";
	case A_MOVZBQ:	return "MOVZBQ";
	case A_MOVZWQ:	return "MOVZWQ";
	case A_MOVSXD:	return "MOVSXD";
	case A_MOVSWQ:	return "MOVSWQ";
	case A_MOVSBQ:	return "MOVSBQ";
	case A_MOVSD:	return "MOVSD";
	case A_ADDSD:	return "ADDSD";
	case A_SUBSD:	return "SUBSD";
	case A_MULSD:	return "MULSD";
	case A_DIVSD:	return "DIVSD";
	case A_UCOMISD:	return "UCOMISD";
	case A_CVTTSD2SI: return "CVTTSD2SI";
	case A_CVTSI2SD:return "CVTSI2SD";
	case A_MOVSS:	return "MOVSS";
	case A_ADDSS:	return "ADDSS";
	case A_SUBSS:	return "SUBSS";
	case A_MULSS:	return "MULSS";
	case A_DIVSS:	return "DIVSS";
	case A_UCOMISS:	return "UCOMISS";
	case A_CVTTSS2SI: return "CVTTSS2SI";
	case A_CVTSI2SS:return "CVTSI2SS";
	case A_CVTSD2SS:return "CVTSD2SS";
	case A_CVTSS2SD:return "CVTSS2SD";
	case A_ADDQ:	return "ADDQ";
	case A_SUBQ:	return "SUBQ";
	case A_IMULQ:	return "IMULQ";
	case A_IDIVQ:	return "IDIVQ";
	case A_DIVQ:	return "DIVQ";
	case A_CQO:	return "CQO";
	case A_NEGQ:	return "NEGQ";
	case A_NOTQ:	return "NOTQ";
	case A_ANDQ:	return "ANDQ";
	case A_ORQ:	return "ORQ";
	case A_XORQ:	return "XORQ";
	case A_SHLQ:	return "SHLQ";
	case A_SHRQ:	return "SHRQ";
	case A_CMPQ:	return "CMPQ";
	case A_PUSHQ:	return "PUSHQ";
	case A_POPQ:	return "POPQ";
	case A_LEAQ:	return "LEAQ";
	case A_CALL:	return "CALL";
	case A_RET:	return "RET";
	case A_JMP:	return "JMP";
	case A_JE:	return "JE";
	case A_JNE:	return "JNE";
	case A_JL:	return "JL";
	case A_JLE:	return "JLE";
	case A_JG:	return "JG";
	case A_JGE:	return "JGE";
	case A_JB:	return "JB";
	case A_JBE:	return "JBE";
	case A_JA:	return "JA";
	case A_JAE:	return "JAE";
	case A_JZ:	return "JZ";
	case A_JNZ:	return "JNZ";
	case A_JP:	return "JP";
	case A_SYSCALL:	return "SYSCALL";
	}
	return "??";
}

const char *
rnames(int r)
{
	switch (r) {
	case D_AX: return "AX"; case D_CX: return "CX";
	case D_DX: return "DX"; case D_BX: return "BX";
	case D_SP: return "SP"; case D_BP: return "BP";
	case D_SI: return "SI"; case D_DI: return "DI";
	case D_R8: return "R8"; case D_R9: return "R9";
	case D_R10: return "R10"; case D_R11: return "R11";
	case D_R12: return "R12"; case D_R13: return "R13";
	case D_R14: return "R14"; case D_R15: return "R15";
	case D_X0: return "X0"; case D_X1: return "X1";
	case D_X2: return "X2"; case D_X3: return "X3";
	case D_X4: return "X4"; case D_X5: return "X5";
	case D_X6: return "X6"; case D_X7: return "X7";
	case D_X8: return "X8"; case D_X9: return "X9";
	case D_X10: return "X10"; case D_X11: return "X11";
	case D_X12: return "X12"; case D_X13: return "X13";
	case D_X14: return "X14"; case D_X15: return "X15";
	case D_PSP: return "SP"; case D_PFP: return "FP"; case D_PSB: return "SB";
	}
	return "?";
}

static void
prAdr(FILE *f, Adr a)
{
	switch (a.type) {
	case D_NONE: fputs("?", f); break;
	case D_CONST:
		fprintf(f, "$%lld", a.offset);
		break;
	case D_INDIR:
		if (a.offset)
			fprintf(f, "%lld(%s)", a.offset, rnames(a.reg));
		else
			fprintf(f, "(%s)", rnames(a.reg));
		break;
	case D_BRANCH:
		fputs(a.sym ? a.sym : "?", f);
		break;
	case D_EXTERN:
		fprintf(f, "%s(SB)", a.sym ? a.sym : "?");
		break;
	default:
		fputs(rnames(a.type), f);
	}
}

void
txt_emit(FILE *f, Prog *head)
{
	for (Prog *p = head; p; p = p->link) {
		if (p->label) {
			fprintf(f, "%s:\n", p->label);
			if (p->as == A_NOP) continue;
		}
		switch (p->as) {
		case A_NOP:
			break;
		case A_TEXT:
			fprintf(f, "TEXT %s,$%lld\n",
			    p->to.sym ? p->to.sym : "?",
			    p->from.offset);
			break;
		case A_RET:
			fputs("\tRET\n", f);
			break;
		case A_SYSCALL:
			fputs("\tSYSCALL\n", f);
			break;
		case A_CQO:
			fputs("\tCQO\n", f);
			break;
		case A_NEGQ:
		case A_NOTQ:
		case A_PUSHQ:
		case A_POPQ:
		case A_IDIVQ:
		case A_DIVQ:
			fprintf(f, "\t%s\t", anames(p->as));
			prAdr(f, p->to);
			fputc('\n', f);
			break;
		case A_CALL:
		case A_JMP:
		case A_JE: case A_JNE:
		case A_JL: case A_JLE: case A_JG: case A_JGE:
		case A_JB: case A_JBE: case A_JA: case A_JAE:
		case A_JZ: case A_JNZ:
		case A_JP:
			fprintf(f, "\t%s\t", anames(p->as));
			prAdr(f, p->to);
			fputc('\n', f);
			break;
		default:
			fprintf(f, "\t%s\t", anames(p->as));
			prAdr(f, p->from);
			fputs(", ", f);
			prAdr(f, p->to);
			fputc('\n', f);
		}
	}
}