1/*
2 *    Stack-less Just-In-Time compiler
3 *
4 *    Copyright Zoltan Herczeg (hzmester@freemail.hu). All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without modification, are
7 * permitted provided that the following conditions are met:
8 *
9 *   1. Redistributions of source code must retain the above copyright notice, this list of
10 *      conditions and the following disclaimer.
11 *
12 *   2. Redistributions in binary form must reproduce the above copyright notice, this list
13 *      of conditions and the following disclaimer in the documentation and/or other materials
14 *      provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) AND CONTRIBUTORS ``AS IS'' AND ANY
17 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
19 * SHALL THE COPYRIGHT HOLDER(S) OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
21 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
22 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
24 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27/* mips 32-bit arch dependent functions. */
28
29static sljit_s32 load_immediate(struct sljit_compiler *compiler, sljit_s32 dst_ar, sljit_sw imm)
30{
31	if (!(imm & ~0xffff))
32		return push_inst(compiler, ORI | SA(0) | TA(dst_ar) | IMM(imm), dst_ar);
33
34	if (imm < 0 && imm >= SIMM_MIN)
35		return push_inst(compiler, ADDIU | SA(0) | TA(dst_ar) | IMM(imm), dst_ar);
36
37	FAIL_IF(push_inst(compiler, LUI | TA(dst_ar) | IMM(imm >> 16), dst_ar));
38	return (imm & 0xffff) ? push_inst(compiler, ORI | SA(dst_ar) | TA(dst_ar) | IMM(imm), dst_ar) : SLJIT_SUCCESS;
39}
40
41static SLJIT_INLINE sljit_s32 emit_const(struct sljit_compiler *compiler, sljit_s32 dst, sljit_sw init_value)
42{
43	FAIL_IF(push_inst(compiler, LUI | T(dst) | IMM(init_value >> 16), DR(dst)));
44	return push_inst(compiler, ORI | S(dst) | T(dst) | IMM(init_value), DR(dst));
45}
46
47SLJIT_API_FUNC_ATTRIBUTE void sljit_set_jump_addr(sljit_uw addr, sljit_uw new_target, sljit_sw executable_offset)
48{
49	sljit_ins *inst = (sljit_ins *)addr;
50	SLJIT_UNUSED_ARG(executable_offset);
51
52	SLJIT_UPDATE_WX_FLAGS(inst, inst + 2, 0);
53	SLJIT_ASSERT((inst[0] & 0xffe00000) == LUI && (inst[1] & 0xfc000000) == ORI);
54	inst[0] = (inst[0] & 0xffff0000) | ((new_target >> 16) & 0xffff);
55	inst[1] = (inst[1] & 0xffff0000) | (new_target & 0xffff);
56	SLJIT_UPDATE_WX_FLAGS(inst, inst + 2, 1);
57	inst = (sljit_ins *)SLJIT_ADD_EXEC_OFFSET(inst, executable_offset);
58	SLJIT_CACHE_FLUSH(inst, inst + 2);
59}
60
61SLJIT_API_FUNC_ATTRIBUTE void sljit_set_const(sljit_uw addr, sljit_sw new_constant, sljit_sw executable_offset)
62{
63	sljit_set_jump_addr(addr, (sljit_uw)new_constant, executable_offset);
64}
65
66static sljit_s32 call_with_args(struct sljit_compiler *compiler, sljit_s32 arg_types, sljit_ins *ins_ptr, sljit_u32 *extra_space)
67{
68	sljit_u32 is_tail_call = *extra_space & SLJIT_CALL_RETURN;
69	sljit_u32 offset = 0;
70	sljit_s32 float_arg_count = 0;
71	sljit_s32 word_arg_count = 0;
72	sljit_s32 types = 0;
73	sljit_ins prev_ins = NOP;
74	sljit_ins ins = NOP;
75	sljit_u8 offsets[4];
76	sljit_u8 *offsets_ptr = offsets;
77
78	SLJIT_ASSERT(reg_map[TMP_REG1] == 4 && freg_map[TMP_FREG1] == 12);
79
80	arg_types >>= SLJIT_ARG_SHIFT;
81
82	/* See ABI description in sljit_emit_enter. */
83
84	while (arg_types) {
85		types = (types << SLJIT_ARG_SHIFT) | (arg_types & SLJIT_ARG_MASK);
86		*offsets_ptr = (sljit_u8)offset;
87
88		switch (arg_types & SLJIT_ARG_MASK) {
89		case SLJIT_ARG_TYPE_F64:
90			if (offset & 0x7) {
91				offset += sizeof(sljit_sw);
92				*offsets_ptr = (sljit_u8)offset;
93			}
94
95			if (word_arg_count == 0 && float_arg_count <= 1)
96				*offsets_ptr = (sljit_u8)(254 + float_arg_count);
97
98			offset += sizeof(sljit_f64);
99			float_arg_count++;
100			break;
101		case SLJIT_ARG_TYPE_F32:
102			if (word_arg_count == 0 && float_arg_count <= 1)
103				*offsets_ptr = (sljit_u8)(254 + float_arg_count);
104
105			offset += sizeof(sljit_f32);
106			float_arg_count++;
107			break;
108		default:
109			offset += sizeof(sljit_sw);
110			word_arg_count++;
111			break;
112		}
113
114		arg_types >>= SLJIT_ARG_SHIFT;
115		offsets_ptr++;
116	}
117
118	/* Stack is aligned to 16 bytes. */
119	SLJIT_ASSERT(offset <= 8 * sizeof(sljit_sw));
120
121	if (offset > 4 * sizeof(sljit_sw) && (!is_tail_call || offset > compiler->args_size)) {
122		if (is_tail_call) {
123			offset = (offset + sizeof(sljit_sw) + 15) & ~(sljit_uw)0xf;
124			FAIL_IF(emit_stack_frame_release(compiler, (sljit_s32)offset, &prev_ins));
125			*extra_space = offset;
126		} else {
127			FAIL_IF(push_inst(compiler, ADDIU | S(SLJIT_SP) | T(SLJIT_SP) | IMM(-16), DR(SLJIT_SP)));
128			*extra_space = 16;
129		}
130	} else {
131		if (is_tail_call)
132			FAIL_IF(emit_stack_frame_release(compiler, 0, &prev_ins));
133		*extra_space = 0;
134	}
135
136	while (types) {
137		--offsets_ptr;
138
139		switch (types & SLJIT_ARG_MASK) {
140		case SLJIT_ARG_TYPE_F64:
141			if (*offsets_ptr < 4 * sizeof (sljit_sw)) {
142				if (prev_ins != NOP)
143					FAIL_IF(push_inst(compiler, prev_ins, MOVABLE_INS));
144
145				/* Must be preceded by at least one other argument,
146				 * and its starting offset must be 8 because of alignment. */
147				SLJIT_ASSERT((*offsets_ptr >> 2) == 2);
148
149				prev_ins = MFC1 | TA(6) | FS(float_arg_count) | (1 << 11);
150				ins = MFC1 | TA(7) | FS(float_arg_count);
151			} else if (*offsets_ptr < 254)
152				ins = SDC1 | S(SLJIT_SP) | FT(float_arg_count) | IMM(*offsets_ptr);
153			else if (*offsets_ptr == 254)
154				ins = MOV_S | FMT_D | FS(SLJIT_FR0) | FD(TMP_FREG1);
155
156			float_arg_count--;
157			break;
158		case SLJIT_ARG_TYPE_F32:
159			if (*offsets_ptr < 4 * sizeof (sljit_sw))
160				ins = MFC1 | TA(4 + (*offsets_ptr >> 2)) | FS(float_arg_count);
161			else if (*offsets_ptr < 254)
162				ins = SWC1 | S(SLJIT_SP) | FT(float_arg_count) | IMM(*offsets_ptr);
163			else if (*offsets_ptr == 254)
164				ins = MOV_S | FMT_S | FS(SLJIT_FR0) | FD(TMP_FREG1);
165
166			float_arg_count--;
167			break;
168		default:
169			if (*offsets_ptr >= 4 * sizeof (sljit_sw))
170				ins = SW | S(SLJIT_SP) | T(word_arg_count) | IMM(*offsets_ptr);
171			else if ((*offsets_ptr >> 2) != word_arg_count - 1)
172				ins = ADDU | S(word_arg_count) | TA(0) | DA(4 + (*offsets_ptr >> 2));
173			else if (*offsets_ptr == 0)
174				ins = ADDU | S(SLJIT_R0) | TA(0) | DA(4);
175
176			word_arg_count--;
177			break;
178		}
179
180		if (ins != NOP) {
181			if (prev_ins != NOP)
182				FAIL_IF(push_inst(compiler, prev_ins, MOVABLE_INS));
183			prev_ins = ins;
184			ins = NOP;
185		}
186
187		types >>= SLJIT_ARG_SHIFT;
188	}
189
190	*ins_ptr = prev_ins;
191
192	return SLJIT_SUCCESS;
193}
194
195SLJIT_API_FUNC_ATTRIBUTE struct sljit_jump* sljit_emit_call(struct sljit_compiler *compiler, sljit_s32 type,
196	sljit_s32 arg_types)
197{
198	struct sljit_jump *jump;
199	sljit_u32 extra_space = 0;
200	sljit_ins ins = NOP;
201
202	CHECK_ERROR_PTR();
203	CHECK_PTR(check_sljit_emit_call(compiler, type, arg_types));
204
205	jump = (struct sljit_jump*)ensure_abuf(compiler, sizeof(struct sljit_jump));
206	PTR_FAIL_IF(!jump);
207	set_jump(jump, compiler, type & SLJIT_REWRITABLE_JUMP);
208
209	if ((type & 0xff) != SLJIT_CALL_REG_ARG) {
210		extra_space = (sljit_u32)type;
211		PTR_FAIL_IF(call_with_args(compiler, arg_types, &ins, &extra_space));
212	} else if (type & SLJIT_CALL_RETURN)
213		PTR_FAIL_IF(emit_stack_frame_release(compiler, 0, &ins));
214
215	SLJIT_ASSERT(DR(PIC_ADDR_REG) == 25 && PIC_ADDR_REG == TMP_REG2);
216
217	if (ins == NOP && compiler->delay_slot != UNMOVABLE_INS)
218		jump->flags |= IS_MOVABLE;
219
220	if (!(type & SLJIT_CALL_RETURN) || extra_space > 0) {
221		jump->flags |= IS_JAL;
222
223		if ((type & 0xff) != SLJIT_CALL_REG_ARG)
224			jump->flags |= IS_CALL;
225
226		PTR_FAIL_IF(push_inst(compiler, JALR | S(PIC_ADDR_REG) | DA(RETURN_ADDR_REG), UNMOVABLE_INS));
227	} else
228		PTR_FAIL_IF(push_inst(compiler, JR | S(PIC_ADDR_REG), UNMOVABLE_INS));
229
230	jump->addr = compiler->size;
231	PTR_FAIL_IF(push_inst(compiler, ins, UNMOVABLE_INS));
232
233	/* Maximum number of instructions required for generating a constant. */
234	compiler->size += 2;
235
236	if (extra_space == 0)
237		return jump;
238
239	if (type & SLJIT_CALL_RETURN)
240		PTR_FAIL_IF(emit_op_mem(compiler, WORD_DATA | LOAD_DATA, RETURN_ADDR_REG,
241			SLJIT_MEM1(SLJIT_SP), (sljit_sw)(extra_space - sizeof(sljit_sw))));
242
243	if (type & SLJIT_CALL_RETURN)
244		PTR_FAIL_IF(push_inst(compiler, JR | SA(RETURN_ADDR_REG), UNMOVABLE_INS));
245
246	PTR_FAIL_IF(push_inst(compiler, ADDIU | S(SLJIT_SP) | T(SLJIT_SP) | IMM(extra_space),
247		(type & SLJIT_CALL_RETURN) ? UNMOVABLE_INS : DR(SLJIT_SP)));
248	return jump;
249}
250
251SLJIT_API_FUNC_ATTRIBUTE sljit_s32 sljit_emit_icall(struct sljit_compiler *compiler, sljit_s32 type,
252	sljit_s32 arg_types,
253	sljit_s32 src, sljit_sw srcw)
254{
255	sljit_u32 extra_space = (sljit_u32)type;
256	sljit_ins ins;
257
258	CHECK_ERROR();
259	CHECK(check_sljit_emit_icall(compiler, type, arg_types, src, srcw));
260
261	if (src & SLJIT_MEM) {
262		ADJUST_LOCAL_OFFSET(src, srcw);
263		FAIL_IF(emit_op_mem(compiler, WORD_DATA | LOAD_DATA, DR(PIC_ADDR_REG), src, srcw));
264		src = PIC_ADDR_REG;
265		srcw = 0;
266	}
267
268	if ((type & 0xff) == SLJIT_CALL_REG_ARG) {
269		if (type & SLJIT_CALL_RETURN) {
270			if (src >= SLJIT_FIRST_SAVED_REG && src <= (SLJIT_S0 - SLJIT_KEPT_SAVEDS_COUNT(compiler->options))) {
271				FAIL_IF(push_inst(compiler, ADDU | S(src) | TA(0) | D(PIC_ADDR_REG), DR(PIC_ADDR_REG)));
272				src = PIC_ADDR_REG;
273				srcw = 0;
274			}
275
276			FAIL_IF(emit_stack_frame_release(compiler, 0, &ins));
277
278			if (ins != NOP)
279				FAIL_IF(push_inst(compiler, ins, MOVABLE_INS));
280		}
281
282		SLJIT_SKIP_CHECKS(compiler);
283		return sljit_emit_ijump(compiler, type, src, srcw);
284	}
285
286	SLJIT_ASSERT(DR(PIC_ADDR_REG) == 25 && PIC_ADDR_REG == TMP_REG2);
287
288	if (src & SLJIT_IMM)
289		FAIL_IF(load_immediate(compiler, DR(PIC_ADDR_REG), srcw));
290	else if (src != PIC_ADDR_REG)
291		FAIL_IF(push_inst(compiler, ADDU | S(src) | TA(0) | D(PIC_ADDR_REG), DR(PIC_ADDR_REG)));
292
293	FAIL_IF(call_with_args(compiler, arg_types, &ins, &extra_space));
294
295	/* Register input. */
296	if (!(type & SLJIT_CALL_RETURN) || extra_space > 0)
297		FAIL_IF(push_inst(compiler, JALR | S(PIC_ADDR_REG) | DA(RETURN_ADDR_REG), UNMOVABLE_INS));
298	else
299		FAIL_IF(push_inst(compiler, JR | S(PIC_ADDR_REG), UNMOVABLE_INS));
300	FAIL_IF(push_inst(compiler, ins, UNMOVABLE_INS));
301
302	if (extra_space == 0)
303		return SLJIT_SUCCESS;
304
305	if (type & SLJIT_CALL_RETURN)
306		FAIL_IF(emit_op_mem(compiler, WORD_DATA | LOAD_DATA, RETURN_ADDR_REG,
307			SLJIT_MEM1(SLJIT_SP), (sljit_sw)(extra_space - sizeof(sljit_sw))));
308
309	if (type & SLJIT_CALL_RETURN)
310		FAIL_IF(push_inst(compiler, JR | SA(RETURN_ADDR_REG), UNMOVABLE_INS));
311
312	return push_inst(compiler, ADDIU | S(SLJIT_SP) | T(SLJIT_SP) | IMM(extra_space),
313		(type & SLJIT_CALL_RETURN) ? UNMOVABLE_INS : DR(SLJIT_SP));
314}
315