static SLJIT_INLINE sljit_s32 emit_single_op()

in pcre/sljit/sljitNativeMIPS_32.c [69:342]

• 237 lines of code
• 87 McCabe index (conditional complexity)

static SLJIT_INLINE sljit_s32 emit_single_op(struct sljit_compiler *compiler, sljit_s32 op, sljit_s32 flags,
	sljit_s32 dst, sljit_s32 src1, sljit_sw src2)
{
	switch (GET_OPCODE(op)) {
	case SLJIT_MOV:
	case SLJIT_MOV_U32:
	case SLJIT_MOV_S32:
	case SLJIT_MOV_P:
		SLJIT_ASSERT(src1 == TMP_REG1 && !(flags & SRC2_IMM));
		if (dst != src2)
			return push_inst(compiler, ADDU | S(src2) | TA(0) | D(dst), DR(dst));
		return SLJIT_SUCCESS;

	case SLJIT_MOV_U8:
	case SLJIT_MOV_S8:
		SLJIT_ASSERT(src1 == TMP_REG1 && !(flags & SRC2_IMM));
		if ((flags & (REG_DEST | REG2_SOURCE)) == (REG_DEST | REG2_SOURCE)) {
			if (op == SLJIT_MOV_S8) {
#if (defined SLJIT_MIPS_R1 && SLJIT_MIPS_R1)
				return push_inst(compiler, SEB | T(src2) | D(dst), DR(dst));
#else
				FAIL_IF(push_inst(compiler, SLL | T(src2) | D(dst) | SH_IMM(24), DR(dst)));
				return push_inst(compiler, SRA | T(dst) | D(dst) | SH_IMM(24), DR(dst));
#endif
			}
			return push_inst(compiler, ANDI | S(src2) | T(dst) | IMM(0xff), DR(dst));
		}
		else if (dst != src2)
			SLJIT_ASSERT_STOP();
		return SLJIT_SUCCESS;

	case SLJIT_MOV_U16:
	case SLJIT_MOV_S16:
		SLJIT_ASSERT(src1 == TMP_REG1 && !(flags & SRC2_IMM));
		if ((flags & (REG_DEST | REG2_SOURCE)) == (REG_DEST | REG2_SOURCE)) {
			if (op == SLJIT_MOV_S16) {
#if (defined SLJIT_MIPS_R1 && SLJIT_MIPS_R1)
				return push_inst(compiler, SEH | T(src2) | D(dst), DR(dst));
#else
				FAIL_IF(push_inst(compiler, SLL | T(src2) | D(dst) | SH_IMM(16), DR(dst)));
				return push_inst(compiler, SRA | T(dst) | D(dst) | SH_IMM(16), DR(dst));
#endif
			}
			return push_inst(compiler, ANDI | S(src2) | T(dst) | IMM(0xffff), DR(dst));
		}
		else if (dst != src2)
			SLJIT_ASSERT_STOP();
		return SLJIT_SUCCESS;

	case SLJIT_NOT:
		SLJIT_ASSERT(src1 == TMP_REG1 && !(flags & SRC2_IMM));
		if (op & SLJIT_SET_E)
			FAIL_IF(push_inst(compiler, NOR | S(src2) | T(src2) | DA(EQUAL_FLAG), EQUAL_FLAG));
		if (CHECK_FLAGS(SLJIT_SET_E))
			FAIL_IF(push_inst(compiler, NOR | S(src2) | T(src2) | D(dst), DR(dst)));
		return SLJIT_SUCCESS;

	case SLJIT_CLZ:
		SLJIT_ASSERT(src1 == TMP_REG1 && !(flags & SRC2_IMM));
#if (defined SLJIT_MIPS_R1 && SLJIT_MIPS_R1)
		if (op & SLJIT_SET_E)
			FAIL_IF(push_inst(compiler, CLZ | S(src2) | TA(EQUAL_FLAG) | DA(EQUAL_FLAG), EQUAL_FLAG));
		if (CHECK_FLAGS(SLJIT_SET_E))
			FAIL_IF(push_inst(compiler, CLZ | S(src2) | T(dst) | D(dst), DR(dst)));
#else
		if (SLJIT_UNLIKELY(flags & UNUSED_DEST)) {
			FAIL_IF(push_inst(compiler, SRL | T(src2) | DA(EQUAL_FLAG) | SH_IMM(31), EQUAL_FLAG));
			return push_inst(compiler, XORI | SA(EQUAL_FLAG) | TA(EQUAL_FLAG) | IMM(1), EQUAL_FLAG);
		}
		/* Nearly all instructions are unmovable in the following sequence. */
		FAIL_IF(push_inst(compiler, ADDU | S(src2) | TA(0) | D(TMP_REG1), DR(TMP_REG1)));
		/* Check zero. */
		FAIL_IF(push_inst(compiler, BEQ | S(TMP_REG1) | TA(0) | IMM(5), UNMOVABLE_INS));
		FAIL_IF(push_inst(compiler, ORI | SA(0) | T(dst) | IMM(32), UNMOVABLE_INS));
		FAIL_IF(push_inst(compiler, ADDIU | SA(0) | T(dst) | IMM(-1), DR(dst)));
		/* Loop for searching the highest bit. */
		FAIL_IF(push_inst(compiler, ADDIU | S(dst) | T(dst) | IMM(1), DR(dst)));
		FAIL_IF(push_inst(compiler, BGEZ | S(TMP_REG1) | IMM(-2), UNMOVABLE_INS));
		FAIL_IF(push_inst(compiler, SLL | T(TMP_REG1) | D(TMP_REG1) | SH_IMM(1), UNMOVABLE_INS));
		if (op & SLJIT_SET_E)
			return push_inst(compiler, ADDU | S(dst) | TA(0) | DA(EQUAL_FLAG), EQUAL_FLAG);
#endif
		return SLJIT_SUCCESS;

	case SLJIT_ADD:
		if (flags & SRC2_IMM) {
			if (op & SLJIT_SET_O) {
				if (src2 >= 0)
					FAIL_IF(push_inst(compiler, OR | S(src1) | T(src1) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
				else
					FAIL_IF(push_inst(compiler, NOR | S(src1) | T(src1) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
			}
			if (op & SLJIT_SET_E)
				FAIL_IF(push_inst(compiler, ADDIU | S(src1) | TA(EQUAL_FLAG) | IMM(src2), EQUAL_FLAG));
			if (op & (SLJIT_SET_C | SLJIT_SET_O)) {
				if (src2 >= 0)
					FAIL_IF(push_inst(compiler, ORI | S(src1) | TA(ULESS_FLAG) | IMM(src2), ULESS_FLAG));
				else {
					FAIL_IF(push_inst(compiler, ADDIU | SA(0) | TA(ULESS_FLAG) | IMM(src2), ULESS_FLAG));
					FAIL_IF(push_inst(compiler, OR | S(src1) | TA(ULESS_FLAG) | DA(ULESS_FLAG), ULESS_FLAG));
				}
			}
			/* dst may be the same as src1 or src2. */
			if (CHECK_FLAGS(SLJIT_SET_E))
				FAIL_IF(push_inst(compiler, ADDIU | S(src1) | T(dst) | IMM(src2), DR(dst)));
		}
		else {
			if (op & SLJIT_SET_O)
				FAIL_IF(push_inst(compiler, XOR | S(src1) | T(src2) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
			if (op & SLJIT_SET_E)
				FAIL_IF(push_inst(compiler, ADDU | S(src1) | T(src2) | DA(EQUAL_FLAG), EQUAL_FLAG));
			if (op & (SLJIT_SET_C | SLJIT_SET_O))
				FAIL_IF(push_inst(compiler, OR | S(src1) | T(src2) | DA(ULESS_FLAG), ULESS_FLAG));
			/* dst may be the same as src1 or src2. */
			if (CHECK_FLAGS(SLJIT_SET_E))
				FAIL_IF(push_inst(compiler, ADDU | S(src1) | T(src2) | D(dst), DR(dst)));
		}

		/* a + b >= a | b (otherwise, the carry should be set to 1). */
		if (op & (SLJIT_SET_C | SLJIT_SET_O))
			FAIL_IF(push_inst(compiler, SLTU | S(dst) | TA(ULESS_FLAG) | DA(ULESS_FLAG), ULESS_FLAG));
		if (!(op & SLJIT_SET_O))
			return SLJIT_SUCCESS;
		FAIL_IF(push_inst(compiler, SLL | TA(ULESS_FLAG) | D(TMP_REG1) | SH_IMM(31), DR(TMP_REG1)));
		FAIL_IF(push_inst(compiler, XOR | S(TMP_REG1) | TA(OVERFLOW_FLAG) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
		FAIL_IF(push_inst(compiler, XOR | S(dst) | TA(OVERFLOW_FLAG) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
		return push_inst(compiler, SLL | TA(OVERFLOW_FLAG) | DA(OVERFLOW_FLAG) | SH_IMM(31), OVERFLOW_FLAG);

	case SLJIT_ADDC:
		if (flags & SRC2_IMM) {
			if (op & SLJIT_SET_C) {
				if (src2 >= 0)
					FAIL_IF(push_inst(compiler, ORI | S(src1) | TA(OVERFLOW_FLAG) | IMM(src2), OVERFLOW_FLAG));
				else {
					FAIL_IF(push_inst(compiler, ADDIU | SA(0) | TA(OVERFLOW_FLAG) | IMM(src2), OVERFLOW_FLAG));
					FAIL_IF(push_inst(compiler, OR | S(src1) | TA(OVERFLOW_FLAG) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
				}
			}
			FAIL_IF(push_inst(compiler, ADDIU | S(src1) | T(dst) | IMM(src2), DR(dst)));
		} else {
			if (op & SLJIT_SET_C)
				FAIL_IF(push_inst(compiler, OR | S(src1) | T(src2) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
			/* dst may be the same as src1 or src2. */
			FAIL_IF(push_inst(compiler, ADDU | S(src1) | T(src2) | D(dst), DR(dst)));
		}
		if (op & SLJIT_SET_C)
			FAIL_IF(push_inst(compiler, SLTU | S(dst) | TA(OVERFLOW_FLAG) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));

		FAIL_IF(push_inst(compiler, ADDU | S(dst) | TA(ULESS_FLAG) | D(dst), DR(dst)));
		if (!(op & SLJIT_SET_C))
			return SLJIT_SUCCESS;

		/* Set ULESS_FLAG (dst == 0) && (ULESS_FLAG == 1). */
		FAIL_IF(push_inst(compiler, SLTU | S(dst) | TA(ULESS_FLAG) | DA(ULESS_FLAG), ULESS_FLAG));
		/* Set carry flag. */
		return push_inst(compiler, OR | SA(ULESS_FLAG) | TA(OVERFLOW_FLAG) | DA(ULESS_FLAG), ULESS_FLAG);

	case SLJIT_SUB:
		if ((flags & SRC2_IMM) && ((op & (SLJIT_SET_U | SLJIT_SET_S)) || src2 == SIMM_MIN)) {
			FAIL_IF(push_inst(compiler, ADDIU | SA(0) | T(TMP_REG2) | IMM(src2), DR(TMP_REG2)));
			src2 = TMP_REG2;
			flags &= ~SRC2_IMM;
		}

		if (flags & SRC2_IMM) {
			if (op & SLJIT_SET_O) {
				if (src2 >= 0)
					FAIL_IF(push_inst(compiler, OR | S(src1) | T(src1) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
				else
					FAIL_IF(push_inst(compiler, NOR | S(src1) | T(src1) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
			}
			if (op & SLJIT_SET_E)
				FAIL_IF(push_inst(compiler, ADDIU | S(src1) | TA(EQUAL_FLAG) | IMM(-src2), EQUAL_FLAG));
			if (op & (SLJIT_SET_C | SLJIT_SET_O))
				FAIL_IF(push_inst(compiler, SLTIU | S(src1) | TA(ULESS_FLAG) | IMM(src2), ULESS_FLAG));
			/* dst may be the same as src1 or src2. */
			if (CHECK_FLAGS(SLJIT_SET_E))
				FAIL_IF(push_inst(compiler, ADDIU | S(src1) | T(dst) | IMM(-src2), DR(dst)));
		}
		else {
			if (op & SLJIT_SET_O)
				FAIL_IF(push_inst(compiler, XOR | S(src1) | T(src2) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
			if (op & SLJIT_SET_E)
				FAIL_IF(push_inst(compiler, SUBU | S(src1) | T(src2) | DA(EQUAL_FLAG), EQUAL_FLAG));
			if (op & (SLJIT_SET_U | SLJIT_SET_C | SLJIT_SET_O))
				FAIL_IF(push_inst(compiler, SLTU | S(src1) | T(src2) | DA(ULESS_FLAG), ULESS_FLAG));
			if (op & SLJIT_SET_U)
				FAIL_IF(push_inst(compiler, SLTU | S(src2) | T(src1) | DA(UGREATER_FLAG), UGREATER_FLAG));
			if (op & SLJIT_SET_S) {
				FAIL_IF(push_inst(compiler, SLT | S(src1) | T(src2) | DA(LESS_FLAG), LESS_FLAG));
				FAIL_IF(push_inst(compiler, SLT | S(src2) | T(src1) | DA(GREATER_FLAG), GREATER_FLAG));
			}
			/* dst may be the same as src1 or src2. */
			if (CHECK_FLAGS(SLJIT_SET_E | SLJIT_SET_U | SLJIT_SET_S | SLJIT_SET_C))
				FAIL_IF(push_inst(compiler, SUBU | S(src1) | T(src2) | D(dst), DR(dst)));
		}

		if (!(op & SLJIT_SET_O))
			return SLJIT_SUCCESS;
		FAIL_IF(push_inst(compiler, SLL | TA(ULESS_FLAG) | D(TMP_REG1) | SH_IMM(31), DR(TMP_REG1)));
		FAIL_IF(push_inst(compiler, XOR | S(TMP_REG1) | TA(OVERFLOW_FLAG) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
		FAIL_IF(push_inst(compiler, XOR | S(dst) | TA(OVERFLOW_FLAG) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
		return push_inst(compiler, SRL | TA(OVERFLOW_FLAG) | DA(OVERFLOW_FLAG) | SH_IMM(31), OVERFLOW_FLAG);

	case SLJIT_SUBC:
		if ((flags & SRC2_IMM) && src2 == SIMM_MIN) {
			FAIL_IF(push_inst(compiler, ADDIU | SA(0) | T(TMP_REG2) | IMM(src2), DR(TMP_REG2)));
			src2 = TMP_REG2;
			flags &= ~SRC2_IMM;
		}

		if (flags & SRC2_IMM) {
			if (op & SLJIT_SET_C)
				FAIL_IF(push_inst(compiler, SLTIU | S(src1) | TA(OVERFLOW_FLAG) | IMM(src2), OVERFLOW_FLAG));
			/* dst may be the same as src1 or src2. */
			FAIL_IF(push_inst(compiler, ADDIU | S(src1) | T(dst) | IMM(-src2), DR(dst)));
		}
		else {
			if (op & SLJIT_SET_C)
				FAIL_IF(push_inst(compiler, SLTU | S(src1) | T(src2) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG));
			/* dst may be the same as src1 or src2. */
			FAIL_IF(push_inst(compiler, SUBU | S(src1) | T(src2) | D(dst), DR(dst)));
		}

		if (op & SLJIT_SET_C)
			FAIL_IF(push_inst(compiler, SLTU | S(dst) | TA(ULESS_FLAG) | DA(LESS_FLAG), LESS_FLAG));

		FAIL_IF(push_inst(compiler, SUBU | S(dst) | TA(ULESS_FLAG) | D(dst), DR(dst)));
		return (op & SLJIT_SET_C) ? push_inst(compiler, OR | SA(OVERFLOW_FLAG) | TA(LESS_FLAG) | DA(ULESS_FLAG), ULESS_FLAG) : SLJIT_SUCCESS;

	case SLJIT_MUL:
		SLJIT_ASSERT(!(flags & SRC2_IMM));
		if (!(op & SLJIT_SET_O)) {
#if (defined SLJIT_MIPS_R1 && SLJIT_MIPS_R1)
			return push_inst(compiler, MUL | S(src1) | T(src2) | D(dst), DR(dst));
#else
			FAIL_IF(push_inst(compiler, MULT | S(src1) | T(src2), MOVABLE_INS));
			return push_inst(compiler, MFLO | D(dst), DR(dst));
#endif
		}
		FAIL_IF(push_inst(compiler, MULT | S(src1) | T(src2), MOVABLE_INS));
		FAIL_IF(push_inst(compiler, MFHI | DA(ULESS_FLAG), ULESS_FLAG));
		FAIL_IF(push_inst(compiler, MFLO | D(dst), DR(dst)));
		FAIL_IF(push_inst(compiler, SRA | T(dst) | DA(UGREATER_FLAG) | SH_IMM(31), UGREATER_FLAG));
		return push_inst(compiler, SUBU | SA(ULESS_FLAG) | TA(UGREATER_FLAG) | DA(OVERFLOW_FLAG), OVERFLOW_FLAG);

	case SLJIT_AND:
		EMIT_LOGICAL(ANDI, AND);
		return SLJIT_SUCCESS;

	case SLJIT_OR:
		EMIT_LOGICAL(ORI, OR);
		return SLJIT_SUCCESS;

	case SLJIT_XOR:
		EMIT_LOGICAL(XORI, XOR);
		return SLJIT_SUCCESS;

	case SLJIT_SHL:
		EMIT_SHIFT(SLL, SLLV);
		return SLJIT_SUCCESS;

	case SLJIT_LSHR:
		EMIT_SHIFT(SRL, SRLV);
		return SLJIT_SUCCESS;

	case SLJIT_ASHR:
		EMIT_SHIFT(SRA, SRAV);
		return SLJIT_SUCCESS;
	}

	SLJIT_ASSERT_STOP();
	return SLJIT_SUCCESS;
}