static sljit_s32 emit_op()

in pcre/sljit/sljitNativeMIPS_common.c [897:1030]

• 116 lines of code
• 49 McCabe index (conditional complexity)

static sljit_s32 emit_op(struct sljit_compiler *compiler, sljit_s32 op, sljit_s32 flags,
	sljit_s32 dst, sljit_sw dstw,
	sljit_s32 src1, sljit_sw src1w,
	sljit_s32 src2, sljit_sw src2w)
{
	/* arg1 goes to TMP_REG1 or src reg
	   arg2 goes to TMP_REG2, imm or src reg
	   TMP_REG3 can be used for caching
	   result goes to TMP_REG2, so put result can use TMP_REG1 and TMP_REG3. */
	sljit_s32 dst_r = TMP_REG2;
	sljit_s32 src1_r;
	sljit_sw src2_r = 0;
	sljit_s32 sugg_src2_r = TMP_REG2;

	if (!(flags & ALT_KEEP_CACHE)) {
		compiler->cache_arg = 0;
		compiler->cache_argw = 0;
	}

	if (SLJIT_UNLIKELY(dst == SLJIT_UNUSED)) {
		if (op >= SLJIT_MOV && op <= SLJIT_MOVU_S32 && !(src2 & SLJIT_MEM))
			return SLJIT_SUCCESS;
		if (GET_FLAGS(op))
			flags |= UNUSED_DEST;
	}
	else if (FAST_IS_REG(dst)) {
		dst_r = dst;
		flags |= REG_DEST;
		if (op >= SLJIT_MOV && op <= SLJIT_MOVU_S32)
			sugg_src2_r = dst_r;
	}
	else if ((dst & SLJIT_MEM) && !getput_arg_fast(compiler, flags | ARG_TEST, DR(TMP_REG1), dst, dstw))
		flags |= SLOW_DEST;

	if (flags & IMM_OP) {
		if ((src2 & SLJIT_IMM) && src2w) {
			if ((!(flags & LOGICAL_OP) && (src2w <= SIMM_MAX && src2w >= SIMM_MIN))
				|| ((flags & LOGICAL_OP) && !(src2w & ~UIMM_MAX))) {
				flags |= SRC2_IMM;
				src2_r = src2w;
			}
		}
		if (!(flags & SRC2_IMM) && (flags & CUMULATIVE_OP) && (src1 & SLJIT_IMM) && src1w) {
			if ((!(flags & LOGICAL_OP) && (src1w <= SIMM_MAX && src1w >= SIMM_MIN))
				|| ((flags & LOGICAL_OP) && !(src1w & ~UIMM_MAX))) {
				flags |= SRC2_IMM;
				src2_r = src1w;

				/* And swap arguments. */
				src1 = src2;
				src1w = src2w;
				src2 = SLJIT_IMM;
				/* src2w = src2_r unneeded. */
			}
		}
	}

	/* Source 1. */
	if (FAST_IS_REG(src1)) {
		src1_r = src1;
		flags |= REG1_SOURCE;
	}
	else if (src1 & SLJIT_IMM) {
		if (src1w) {
			FAIL_IF(load_immediate(compiler, DR(TMP_REG1), src1w));
			src1_r = TMP_REG1;
		}
		else
			src1_r = 0;
	}
	else {
		if (getput_arg_fast(compiler, flags | LOAD_DATA, DR(TMP_REG1), src1, src1w))
			FAIL_IF(compiler->error);
		else
			flags |= SLOW_SRC1;
		src1_r = TMP_REG1;
	}

	/* Source 2. */
	if (FAST_IS_REG(src2)) {
		src2_r = src2;
		flags |= REG2_SOURCE;
		if (!(flags & REG_DEST) && op >= SLJIT_MOV && op <= SLJIT_MOVU_S32)
			dst_r = src2_r;
	}
	else if (src2 & SLJIT_IMM) {
		if (!(flags & SRC2_IMM)) {
			if (src2w) {
				FAIL_IF(load_immediate(compiler, DR(sugg_src2_r), src2w));
				src2_r = sugg_src2_r;
			}
			else {
				src2_r = 0;
				if ((op >= SLJIT_MOV && op <= SLJIT_MOVU_S32) && (dst & SLJIT_MEM))
					dst_r = 0;
			}
		}
	}
	else {
		if (getput_arg_fast(compiler, flags | LOAD_DATA, DR(sugg_src2_r), src2, src2w))
			FAIL_IF(compiler->error);
		else
			flags |= SLOW_SRC2;
		src2_r = sugg_src2_r;
	}

	if ((flags & (SLOW_SRC1 | SLOW_SRC2)) == (SLOW_SRC1 | SLOW_SRC2)) {
		SLJIT_ASSERT(src2_r == TMP_REG2);
		if (!can_cache(src1, src1w, src2, src2w) && can_cache(src1, src1w, dst, dstw)) {
			FAIL_IF(getput_arg(compiler, flags | LOAD_DATA, DR(TMP_REG2), src2, src2w, src1, src1w));
			FAIL_IF(getput_arg(compiler, flags | LOAD_DATA, DR(TMP_REG1), src1, src1w, dst, dstw));
		}
		else {
			FAIL_IF(getput_arg(compiler, flags | LOAD_DATA, DR(TMP_REG1), src1, src1w, src2, src2w));
			FAIL_IF(getput_arg(compiler, flags | LOAD_DATA, DR(TMP_REG2), src2, src2w, dst, dstw));
		}
	}
	else if (flags & SLOW_SRC1)
		FAIL_IF(getput_arg(compiler, flags | LOAD_DATA, DR(TMP_REG1), src1, src1w, dst, dstw));
	else if (flags & SLOW_SRC2)
		FAIL_IF(getput_arg(compiler, flags | LOAD_DATA, DR(sugg_src2_r), src2, src2w, dst, dstw));

	FAIL_IF(emit_single_op(compiler, op, flags, dst_r, src1_r, src2_r));

	if (dst & SLJIT_MEM) {
		if (!(flags & SLOW_DEST)) {
			getput_arg_fast(compiler, flags, DR(dst_r), dst, dstw);
			return compiler->error;
		}
		return getput_arg(compiler, flags, DR(dst_r), dst, dstw, 0, 0);
	}

	return SLJIT_SUCCESS;
}