// Basic macros to emit ARM instructions and some utils

// (c) Copyright 2008, Grazvydas "notaz" Ignotas
// Free for non-commercial use.

#define EMIT(x) *tcache_ptr++ = x

#define A_R4M  (1 << 4)
#define A_R5M  (1 << 5)
#define A_R6M  (1 << 6)
#define A_R7M  (1 << 7)
#define A_R8M  (1 << 8)
#define A_R9M  (1 << 9)
#define A_R10M (1 << 10)
#define A_R11M (1 << 11)
#define A_R14M (1 << 14)

#define A_COND_AL 0xe
#define A_COND_EQ 0x0
#define A_COND_NE 0x1
#define A_COND_MI 0x4
#define A_COND_PL 0x5
#define A_COND_LE 0xd

/* addressing mode 1 */
#define A_AM1_LSL 0
#define A_AM1_LSR 1
#define A_AM1_ASR 2
#define A_AM1_ROR 3

#define A_AM1_IMM(ror2,imm8)                  (((ror2)<<8) | (imm8) | 0x02000000)
#define A_AM1_REG_XIMM(shift_imm,shift_op,rm) (((shift_imm)<<7) | ((shift_op)<<5) | (rm))
#define A_AM1_REG_XREG(rs,shift_op,rm)        (((rs)<<8) | ((shift_op)<<5) | 0x10 | (rm))

/* data processing op */
#define A_OP_AND 0x0
#define A_OP_EOR 0x1
#define A_OP_SUB 0x2
#define A_OP_RSB 0x3
#define A_OP_ADD 0x4
#define A_OP_TST 0x8
#define A_OP_CMP 0xa
#define A_OP_ORR 0xc
#define A_OP_MOV 0xd
#define A_OP_BIC 0xe

#define EOP_C_DOP_X(cond,op,s,rn,rd,shifter_op) \
	EMIT(((cond)<<28) | ((op)<< 21) | ((s)<<20) | ((rn)<<16) | ((rd)<<12) | (shifter_op))

#define EOP_C_DOP_IMM(     cond,op,s,rn,rd,ror2,imm8)             EOP_C_DOP_X(cond,op,s,rn,rd,A_AM1_IMM(ror2,imm8))
#define EOP_C_DOP_REG_XIMM(cond,op,s,rn,rd,shift_imm,shift_op,rm) EOP_C_DOP_X(cond,op,s,rn,rd,A_AM1_REG_XIMM(shift_imm,shift_op,rm))
#define EOP_C_DOP_REG_XREG(cond,op,s,rn,rd,rs,       shift_op,rm) EOP_C_DOP_X(cond,op,s,rn,rd,A_AM1_REG_XREG(rs,       shift_op,rm))

#define EOP_MOV_IMM(rd,   ror2,imm8) EOP_C_DOP_IMM(A_COND_AL,A_OP_MOV,0, 0,rd,ror2,imm8)
#define EOP_ORR_IMM(rd,rn,ror2,imm8) EOP_C_DOP_IMM(A_COND_AL,A_OP_ORR,0,rn,rd,ror2,imm8)
#define EOP_ADD_IMM(rd,rn,ror2,imm8) EOP_C_DOP_IMM(A_COND_AL,A_OP_ADD,0,rn,rd,ror2,imm8)
#define EOP_BIC_IMM(rd,rn,ror2,imm8) EOP_C_DOP_IMM(A_COND_AL,A_OP_BIC,0,rn,rd,ror2,imm8)
#define EOP_AND_IMM(rd,rn,ror2,imm8) EOP_C_DOP_IMM(A_COND_AL,A_OP_AND,0,rn,rd,ror2,imm8)
#define EOP_SUB_IMM(rd,rn,ror2,imm8) EOP_C_DOP_IMM(A_COND_AL,A_OP_SUB,0,rn,rd,ror2,imm8)
#define EOP_TST_IMM(   rn,ror2,imm8) EOP_C_DOP_IMM(A_COND_AL,A_OP_TST,1,rn, 0,ror2,imm8)
#define EOP_CMP_IMM(   rn,ror2,imm8) EOP_C_DOP_IMM(A_COND_AL,A_OP_CMP,1,rn, 0,ror2,imm8)
#define EOP_RSB_IMM(rd,rn,ror2,imm8) EOP_C_DOP_IMM(A_COND_AL,A_OP_RSB,0,rn,rd,ror2,imm8)

#define EOP_MOV_REG(s,   rd,shift_imm,shift_op,rm) EOP_C_DOP_REG_XIMM(A_COND_AL,A_OP_MOV,s, 0,rd,shift_imm,shift_op,rm)
#define EOP_ORR_REG(s,rn,rd,shift_imm,shift_op,rm) EOP_C_DOP_REG_XIMM(A_COND_AL,A_OP_ORR,s,rn,rd,shift_imm,shift_op,rm)
#define EOP_ADD_REG(s,rn,rd,shift_imm,shift_op,rm) EOP_C_DOP_REG_XIMM(A_COND_AL,A_OP_ADD,s,rn,rd,shift_imm,shift_op,rm)
#define EOP_TST_REG(  rn,   shift_imm,shift_op,rm) EOP_C_DOP_REG_XIMM(A_COND_AL,A_OP_TST,1,rn, 0,shift_imm,shift_op,rm)

#define EOP_MOV_REG2(s,   rd,rs,shift_op,rm) EOP_C_DOP_REG_XREG(A_COND_AL,A_OP_MOV,s, 0,rd,rs,shift_op,rm)
#define EOP_ADD_REG2(s,rn,rd,rs,shift_op,rm) EOP_C_DOP_REG_XREG(A_COND_AL,A_OP_ADD,s,rn,rd,rs,shift_op,rm)
#define EOP_SUB_REG2(s,rn,rd,rs,shift_op,rm) EOP_C_DOP_REG_XREG(A_COND_AL,A_OP_SUB,s,rn,rd,rs,shift_op,rm)

#define EOP_MOV_REG_SIMPLE(rd,rm)           EOP_MOV_REG(0,rd,0,A_AM1_LSL,rm)
#define EOP_MOV_REG_LSL(rd,   rm,shift_imm) EOP_MOV_REG(0,rd,shift_imm,A_AM1_LSL,rm)
#define EOP_MOV_REG_LSR(rd,   rm,shift_imm) EOP_MOV_REG(0,rd,shift_imm,A_AM1_LSR,rm)
#define EOP_MOV_REG_ASR(rd,   rm,shift_imm) EOP_MOV_REG(0,rd,shift_imm,A_AM1_ASR,rm)
#define EOP_MOV_REG_ROR(rd,   rm,shift_imm) EOP_MOV_REG(0,rd,shift_imm,A_AM1_ROR,rm)

#define EOP_ORR_REG_SIMPLE(rd,rm)           EOP_ORR_REG(0,rd,rd,0,A_AM1_LSL,rm)
#define EOP_ORR_REG_LSL(rd,rn,rm,shift_imm) EOP_ORR_REG(0,rn,rd,shift_imm,A_AM1_LSL,rm)
#define EOP_ORR_REG_LSR(rd,rn,rm,shift_imm) EOP_ORR_REG(0,rn,rd,shift_imm,A_AM1_LSR,rm)
#define EOP_ORR_REG_ASR(rd,rn,rm,shift_imm) EOP_ORR_REG(0,rn,rd,shift_imm,A_AM1_ASR,rm)
#define EOP_ORR_REG_ROR(rd,rn,rm,shift_imm) EOP_ORR_REG(0,rn,rd,shift_imm,A_AM1_ROR,rm)

#define EOP_ADD_REG_SIMPLE(rd,rm)           EOP_ADD_REG(0,rd,rd,0,A_AM1_LSL,rm)
#define EOP_ADD_REG_LSL(rd,rn,rm,shift_imm) EOP_ADD_REG(0,rn,rd,shift_imm,A_AM1_LSL,rm)
#define EOP_ADD_REG_LSR(rd,rn,rm,shift_imm) EOP_ADD_REG(0,rn,rd,shift_imm,A_AM1_LSR,rm)

#define EOP_TST_REG_SIMPLE(rn,rm)           EOP_TST_REG(  rn,   0,A_AM1_LSL,rm)

#define EOP_MOV_REG2_LSL(rd,   rm,rs)       EOP_MOV_REG2(0,   rd,rs,A_AM1_LSL,rm)
#define EOP_MOV_REG2_ROR(rd,   rm,rs)       EOP_MOV_REG2(0,   rd,rs,A_AM1_ROR,rm)
#define EOP_ADD_REG2_LSL(rd,rn,rm,rs)       EOP_ADD_REG2(0,rn,rd,rs,A_AM1_LSL,rm)
#define EOP_SUB_REG2_LSL(rd,rn,rm,rs)       EOP_SUB_REG2(0,rn,rd,rs,A_AM1_LSL,rm)

/* addressing mode 2 */
#define EOP_C_AM2_IMM(cond,u,b,l,rn,rd,offset_12) \
	EMIT(((cond)<<28) | 0x05000000 | ((u)<<23) | ((b)<<22) | ((l)<<20) | ((rn)<<16) | ((rd)<<12) | (offset_12))

/* addressing mode 3 */
#define EOP_C_AM3(cond,u,r,l,rn,rd,s,h,immed_reg) \
	EMIT(((cond)<<28) | 0x01000090 | ((u)<<23) | ((r)<<22) | ((l)<<20) | ((rn)<<16) | ((rd)<<12) | \
			((s)<<6) | ((h)<<5) | (immed_reg))

#define EOP_C_AM3_IMM(cond,u,l,rn,rd,s,h,offset_8) EOP_C_AM3(cond,u,1,l,rn,rd,s,h,(((offset_8)&0xf0)<<4)|((offset_8)&0xf))

#define EOP_C_AM3_REG(cond,u,l,rn,rd,s,h,rm)       EOP_C_AM3(cond,u,0,l,rn,rd,s,h,rm)

/* ldr and str */
#define EOP_LDR_IMM(   rd,rn,offset_12) EOP_C_AM2_IMM(A_COND_AL,1,0,1,rn,rd,offset_12)
#define EOP_LDR_NEGIMM(rd,rn,offset_12) EOP_C_AM2_IMM(A_COND_AL,0,0,1,rn,rd,offset_12)
#define EOP_LDR_SIMPLE(rd,rn)           EOP_C_AM2_IMM(A_COND_AL,1,0,1,rn,rd,0)
#define EOP_STR_IMM(   rd,rn,offset_12) EOP_C_AM2_IMM(A_COND_AL,1,0,0,rn,rd,offset_12)
#define EOP_STR_SIMPLE(rd,rn)           EOP_C_AM2_IMM(A_COND_AL,1,0,0,rn,rd,0)

#define EOP_LDRH_IMM(   rd,rn,offset_8)  EOP_C_AM3_IMM(A_COND_AL,1,1,rn,rd,0,1,offset_8)
#define EOP_LDRH_SIMPLE(rd,rn)           EOP_C_AM3_IMM(A_COND_AL,1,1,rn,rd,0,1,0)
#define EOP_LDRH_REG(   rd,rn,rm)        EOP_C_AM3_REG(A_COND_AL,1,1,rn,rd,0,1,rm)
#define EOP_STRH_IMM(   rd,rn,offset_8)  EOP_C_AM3_IMM(A_COND_AL,1,0,rn,rd,0,1,offset_8)
#define EOP_STRH_SIMPLE(rd,rn)           EOP_C_AM3_IMM(A_COND_AL,1,0,rn,rd,0,1,0)
#define EOP_STRH_REG(   rd,rn,rm)        EOP_C_AM3_REG(A_COND_AL,1,0,rn,rd,0,1,rm)

/* ldm and stm */
#define EOP_XXM(cond,p,u,s,w,l,rn,list) \
	EMIT(((cond)<<28) | (1<<27) | ((p)<<24) | ((u)<<23) | ((s)<<22) | ((w)<<21) | ((l)<<20) | ((rn)<<16) | (list))

#define EOP_STMFD_ST(list) EOP_XXM(A_COND_AL,1,0,0,1,0,13,list)
#define EOP_LDMFD_ST(list) EOP_XXM(A_COND_AL,0,1,0,1,1,13,list)

/* branches */
#define EOP_C_BX(cond,rm) \
	EMIT(((cond)<<28) | 0x012fff10 | (rm))

#define EOP_BX(rm) EOP_C_BX(A_COND_AL,rm)

#define EOP_C_B(cond,l,signed_immed_24) \
	EMIT(((cond)<<28) | 0x0a000000 | ((l)<<24) | (signed_immed_24))

#define EOP_B( signed_immed_24) EOP_C_B(A_COND_AL,0,signed_immed_24)
#define EOP_BL(signed_immed_24) EOP_C_B(A_COND_AL,1,signed_immed_24)

/* misc */
#define EOP_C_MUL(cond,s,rd,rs,rm) \
	EMIT(((cond)<<28) | ((s)<<20) | ((rd)<<16) | ((rs)<<8) | 0x90 | (rm))

#define EOP_MUL(rd,rm,rs) EOP_C_MUL(A_COND_AL,0,rd,rs,rm) // note: rd != rm

#define EOP_C_MRS(cond,rd) \
	EMIT(((cond)<<28) | 0x010f0000 | ((rd)<<12))

#define EOP_C_MSR_IMM(cond,ror2,imm) \
	EMIT(((cond)<<28) | 0x0328f000 | ((ror2)<<8) | (imm)) // cpsr_f

#define EOP_C_MSR_REG(cond,rm) \
	EMIT(((cond)<<28) | 0x0128f000 | (rm)) // cpsr_f

#define EOP_MRS(rd)           EOP_C_MRS(A_COND_AL,rd)
#define EOP_MSR_IMM(ror2,imm) EOP_C_MSR_IMM(A_COND_AL,ror2,imm)
#define EOP_MSR_REG(rm)       EOP_C_MSR_REG(A_COND_AL,rm)


static void emit_mov_const(int cond, int d, unsigned int val)
{
	int need_or = 0;
	if (val & 0xff000000) {
		EOP_C_DOP_IMM(cond, A_OP_MOV, 0, 0, d, 8/2, (val>>24)&0xff);
		need_or = 1;
	}
	if (val & 0x00ff0000) {
		EOP_C_DOP_IMM(cond, need_or ? A_OP_ORR : A_OP_MOV, 0, need_or ? d : 0, d, 16/2, (val>>16)&0xff);
		need_or = 1;
	}
	if (val & 0x0000ff00) {
		EOP_C_DOP_IMM(cond, need_or ? A_OP_ORR : A_OP_MOV, 0, need_or ? d : 0, d, 24/2, (val>>8)&0xff);
		need_or = 1;
	}
	if ((val &0x000000ff) || !need_or)
		EOP_C_DOP_IMM(cond, need_or ? A_OP_ORR : A_OP_MOV, 0, need_or ? d : 0, d, 0, val&0xff);
}

static int is_offset_24(int val)
{
	if (val >= (int)0xff000000 && val <= 0x00ffffff) return 1;
	return 0;
}

static int emit_xbranch(int cond, void *target, int is_call)
{
	int val = (unsigned int *)target - tcache_ptr - 2;
	int direct = is_offset_24(val);
	u32 *start_ptr = tcache_ptr;

	if (direct)
	{
		EOP_C_B(cond,is_call,val & 0xffffff);		// b, bl target
	}
	else
	{
#ifdef __EPOC32__
//		elprintf(EL_SVP, "emitting indirect jmp %08x->%08x", tcache_ptr, target);
		if (is_call)
			EOP_ADD_IMM(14,15,0,8);			// add lr,pc,#8
		EOP_C_AM2_IMM(cond,1,0,1,15,15,0);		// ldrcc pc,[pc]
		EOP_MOV_REG_SIMPLE(15,15);			// mov pc, pc
		EMIT((u32)target);
#else
		// should never happen
		elprintf(EL_STATUS|EL_SVP|EL_ANOMALY, "indirect jmp %08x->%08x", target, tcache_ptr);
		exit(1);
#endif
	}

	return tcache_ptr - start_ptr;
}

static int emit_call(int cond, void *target)
{
	return emit_xbranch(cond, target, 1);
}

static int emit_jump(int cond, void *target)
{
	return emit_xbranch(cond, target, 0);
}

static void handle_caches(void)
{
#ifdef ARM
	extern void cache_flush_d_inval_i(const void *start_addr, const void *end_addr);
	cache_flush_d_inval_i(tcache, tcache_ptr);
#endif
}


