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 /* ppc 32-bit arch dependent functions. */
28 
load_immediate(struct sljit_compiler * compiler,sljit_s32 reg,sljit_sw imm)29 static sljit_s32 load_immediate(struct sljit_compiler *compiler, sljit_s32 reg, sljit_sw imm)
30 {
31 	if (imm <= SIMM_MAX && imm >= SIMM_MIN)
32 		return push_inst(compiler, ADDI | D(reg) | A(0) | IMM(imm));
33 
34 	if (!(imm & ~0xffff))
35 		return push_inst(compiler, ORI | S(TMP_ZERO) | A(reg) | IMM(imm));
36 
37 	FAIL_IF(push_inst(compiler, ADDIS | D(reg) | A(0) | IMM(imm >> 16)));
38 	return (imm & 0xffff) ? push_inst(compiler, ORI | S(reg) | A(reg) | IMM(imm)) : SLJIT_SUCCESS;
39 }
40 
41 /* Simplified mnemonics: clrlwi. */
42 #define INS_CLEAR_LEFT(dst, src, from) \
43 	(RLWINM | S(src) | A(dst) | RLWI_MBE(from, 31))
44 
emit_single_op(struct sljit_compiler * compiler,sljit_s32 op,sljit_s32 flags,sljit_s32 dst,sljit_s32 src1,sljit_s32 src2)45 static SLJIT_INLINE sljit_s32 emit_single_op(struct sljit_compiler *compiler, sljit_s32 op, sljit_s32 flags,
46 	sljit_s32 dst, sljit_s32 src1, sljit_s32 src2)
47 {
48 	sljit_u32 imm;
49 
50 	switch (op) {
51 	case SLJIT_MOV:
52 	case SLJIT_MOV_U32:
53 	case SLJIT_MOV_S32:
54 	case SLJIT_MOV_P:
55 		SLJIT_ASSERT(src1 == TMP_REG1);
56 		if (dst != src2)
57 			return push_inst(compiler, OR | S(src2) | A(dst) | B(src2));
58 		return SLJIT_SUCCESS;
59 
60 	case SLJIT_MOV_U8:
61 	case SLJIT_MOV_S8:
62 		SLJIT_ASSERT(src1 == TMP_REG1);
63 		if ((flags & (REG_DEST | REG2_SOURCE)) == (REG_DEST | REG2_SOURCE)) {
64 			if (op == SLJIT_MOV_S8)
65 				return push_inst(compiler, EXTSB | S(src2) | A(dst));
66 			return push_inst(compiler, INS_CLEAR_LEFT(dst, src2, 24));
67 		}
68 		else if ((flags & REG_DEST) && op == SLJIT_MOV_S8)
69 			return push_inst(compiler, EXTSB | S(src2) | A(dst));
70 		else {
71 			SLJIT_ASSERT(dst == src2);
72 		}
73 		return SLJIT_SUCCESS;
74 
75 	case SLJIT_MOV_U16:
76 	case SLJIT_MOV_S16:
77 		SLJIT_ASSERT(src1 == TMP_REG1);
78 		if ((flags & (REG_DEST | REG2_SOURCE)) == (REG_DEST | REG2_SOURCE)) {
79 			if (op == SLJIT_MOV_S16)
80 				return push_inst(compiler, EXTSH | S(src2) | A(dst));
81 			return push_inst(compiler, INS_CLEAR_LEFT(dst, src2, 16));
82 		}
83 		else {
84 			SLJIT_ASSERT(dst == src2);
85 		}
86 		return SLJIT_SUCCESS;
87 
88 	case SLJIT_NOT:
89 		SLJIT_ASSERT(src1 == TMP_REG1);
90 		return push_inst(compiler, NOR | RC(flags) | S(src2) | A(dst) | B(src2));
91 
92 	case SLJIT_CLZ:
93 		SLJIT_ASSERT(src1 == TMP_REG1);
94 		return push_inst(compiler, CNTLZW | S(src2) | A(dst));
95 
96 	case SLJIT_CTZ:
97 		SLJIT_ASSERT(src1 == TMP_REG1);
98 		FAIL_IF(push_inst(compiler, NEG | D(TMP_REG1) | A(src2)));
99 		FAIL_IF(push_inst(compiler, AND | S(src2) | A(dst) | B(TMP_REG1)));
100 		FAIL_IF(push_inst(compiler, CNTLZW | S(dst) | A(dst)));
101 		FAIL_IF(push_inst(compiler, ADDI | D(TMP_REG1) | A(dst) | IMM(-32)));
102 		/* The highest bits are set, if dst < 32, zero otherwise. */
103 		FAIL_IF(push_inst(compiler, SRWI(27) | S(TMP_REG1) | A(TMP_REG1)));
104 		return push_inst(compiler, XOR | S(dst) | A(dst) | B(TMP_REG1));
105 
106 	case SLJIT_ADD:
107 		if (flags & ALT_FORM1) {
108 			/* Setting XER SO is not enough, CR SO is also needed. */
109 			return push_inst(compiler, ADD | OE(ALT_SET_FLAGS) | RC(ALT_SET_FLAGS) | D(dst) | A(src1) | B(src2));
110 		}
111 
112 		if (flags & ALT_FORM2) {
113 			/* Flags does not set: BIN_IMM_EXTS unnecessary. */
114 			SLJIT_ASSERT(src2 == TMP_REG2);
115 
116 			if (flags & ALT_FORM3)
117 				return push_inst(compiler, ADDIS | D(dst) | A(src1) | compiler->imm);
118 
119 			imm = compiler->imm;
120 
121 			if (flags & ALT_FORM4) {
122 				FAIL_IF(push_inst(compiler, ADDIS | D(dst) | A(src1) | (((imm >> 16) & 0xffff) + ((imm >> 15) & 0x1))));
123 				src1 = dst;
124 			}
125 
126 			return push_inst(compiler, ADDI | D(dst) | A(src1) | (imm & 0xffff));
127 		}
128 		if (flags & ALT_FORM3) {
129 			SLJIT_ASSERT(src2 == TMP_REG2);
130 			return push_inst(compiler, ADDIC | D(dst) | A(src1) | compiler->imm);
131 		}
132 		SLJIT_ASSERT(!(flags & ALT_FORM4));
133 		if (!(flags & ALT_SET_FLAGS))
134 			return push_inst(compiler, ADD | D(dst) | A(src1) | B(src2));
135 		if (flags & ALT_FORM5)
136 			return push_inst(compiler, ADDC | RC(ALT_SET_FLAGS) | D(dst) | A(src1) | B(src2));
137 		return push_inst(compiler, ADD | RC(flags) | D(dst) | A(src1) | B(src2));
138 
139 	case SLJIT_ADDC:
140 		return push_inst(compiler, ADDE | D(dst) | A(src1) | B(src2));
141 
142 	case SLJIT_SUB:
143 		if (flags & ALT_FORM1) {
144 			if (flags & ALT_FORM2) {
145 				FAIL_IF(push_inst(compiler, CMPLI | CRD(0) | A(src1) | compiler->imm));
146 				if (!(flags & ALT_FORM3))
147 					return SLJIT_SUCCESS;
148 				return push_inst(compiler, ADDI | D(dst) | A(src1) | (-compiler->imm & 0xffff));
149 			}
150 			FAIL_IF(push_inst(compiler, CMPL | CRD(0) | A(src1) | B(src2)));
151 			if (!(flags & ALT_FORM3))
152 				return SLJIT_SUCCESS;
153 			return push_inst(compiler, SUBF | D(dst) | A(src2) | B(src1));
154 		}
155 
156 		if (flags & ALT_FORM2) {
157 			if (flags & ALT_FORM3) {
158 				FAIL_IF(push_inst(compiler, CMPI | CRD(0) | A(src1) | compiler->imm));
159 				if (!(flags & ALT_FORM4))
160 					return SLJIT_SUCCESS;
161 				return push_inst(compiler, ADDI | D(dst) | A(src1) | (-compiler->imm & 0xffff));
162 			}
163 			FAIL_IF(push_inst(compiler, CMP | CRD(0) | A(src1) | B(src2)));
164 			if (!(flags & ALT_FORM4))
165 				return SLJIT_SUCCESS;
166 			return push_inst(compiler, SUBF | D(dst) | A(src2) | B(src1));
167 		}
168 
169 		if (flags & ALT_FORM3) {
170 			/* Setting XER SO is not enough, CR SO is also needed. */
171 			if (src1 != TMP_ZERO)
172 				return push_inst(compiler, SUBF | OE(ALT_SET_FLAGS) | RC(ALT_SET_FLAGS) | D(dst) | A(src2) | B(src1));
173 			return push_inst(compiler, NEG | OE(ALT_SET_FLAGS) | RC(ALT_SET_FLAGS) | D(dst) | A(src2));
174 		}
175 
176 		if (flags & ALT_FORM4) {
177 			/* Flags does not set: BIN_IMM_EXTS unnecessary. */
178 			SLJIT_ASSERT(src2 == TMP_REG2);
179 			return push_inst(compiler, SUBFIC | D(dst) | A(src1) | compiler->imm);
180 		}
181 
182 		if (!(flags & ALT_SET_FLAGS)) {
183 			SLJIT_ASSERT(src1 != TMP_ZERO);
184 			return push_inst(compiler, SUBF | D(dst) | A(src2) | B(src1));
185 		}
186 
187 		if (flags & ALT_FORM5)
188 			return push_inst(compiler, SUBFC | RC(ALT_SET_FLAGS) | D(dst) | A(src2) | B(src1));
189 
190 		if (src1 != TMP_ZERO)
191 			return push_inst(compiler, SUBF | RC(ALT_SET_FLAGS) | D(dst) | A(src2) | B(src1));
192 		return push_inst(compiler, NEG | RC(ALT_SET_FLAGS) | D(dst) | A(src2));
193 
194 	case SLJIT_SUBC:
195 		return push_inst(compiler, SUBFE | D(dst) | A(src2) | B(src1));
196 
197 	case SLJIT_MUL:
198 		if (flags & ALT_FORM1) {
199 			SLJIT_ASSERT(src2 == TMP_REG2);
200 			return push_inst(compiler, MULLI | D(dst) | A(src1) | compiler->imm);
201 		}
202 		return push_inst(compiler, MULLW | OE(flags) | RC(flags) | D(dst) | A(src2) | B(src1));
203 
204 	case SLJIT_AND:
205 		if (flags & ALT_FORM1) {
206 			SLJIT_ASSERT(src2 == TMP_REG2);
207 			return push_inst(compiler, ANDI | S(src1) | A(dst) | compiler->imm);
208 		}
209 		if (flags & ALT_FORM2) {
210 			SLJIT_ASSERT(src2 == TMP_REG2);
211 			return push_inst(compiler, ANDIS | S(src1) | A(dst) | compiler->imm);
212 		}
213 		return push_inst(compiler, AND | RC(flags) | S(src1) | A(dst) | B(src2));
214 
215 	case SLJIT_OR:
216 		if (flags & ALT_FORM1) {
217 			SLJIT_ASSERT(src2 == TMP_REG2);
218 			return push_inst(compiler, ORI | S(src1) | A(dst) | compiler->imm);
219 		}
220 		if (flags & ALT_FORM2) {
221 			SLJIT_ASSERT(src2 == TMP_REG2);
222 			return push_inst(compiler, ORIS | S(src1) | A(dst) | compiler->imm);
223 		}
224 		if (flags & ALT_FORM3) {
225 			SLJIT_ASSERT(src2 == TMP_REG2);
226 			imm = compiler->imm;
227 
228 			FAIL_IF(push_inst(compiler, ORI | S(src1) | A(dst) | IMM(imm)));
229 			return push_inst(compiler, ORIS | S(dst) | A(dst) | IMM(imm >> 16));
230 		}
231 		return push_inst(compiler, OR | RC(flags) | S(src1) | A(dst) | B(src2));
232 
233 	case SLJIT_XOR:
234 		if (flags & ALT_FORM1) {
235 			SLJIT_ASSERT(src2 == TMP_REG2);
236 			return push_inst(compiler, XORI | S(src1) | A(dst) | compiler->imm);
237 		}
238 		if (flags & ALT_FORM2) {
239 			SLJIT_ASSERT(src2 == TMP_REG2);
240 			return push_inst(compiler, XORIS | S(src1) | A(dst) | compiler->imm);
241 		}
242 		if (flags & ALT_FORM3) {
243 			SLJIT_ASSERT(src2 == TMP_REG2);
244 			imm = compiler->imm;
245 
246 			FAIL_IF(push_inst(compiler, XORI | S(src1) | A(dst) | IMM(imm)));
247 			return push_inst(compiler, XORIS | S(dst) | A(dst) | IMM(imm >> 16));
248 		}
249 		return push_inst(compiler, XOR | RC(flags) | S(src1) | A(dst) | B(src2));
250 
251 	case SLJIT_SHL:
252 	case SLJIT_MSHL:
253 		if (flags & ALT_FORM1) {
254 			SLJIT_ASSERT(src2 == TMP_REG2);
255 			imm = compiler->imm & 0x1f;
256 			return push_inst(compiler, SLWI(imm) | RC(flags) | S(src1) | A(dst));
257 		}
258 
259 		if (op == SLJIT_MSHL) {
260 			FAIL_IF(push_inst(compiler, ANDI | S(src2) | A(TMP_REG2) | 0x1f));
261 			src2 = TMP_REG2;
262 		}
263 
264 		return push_inst(compiler, SLW | RC(flags) | S(src1) | A(dst) | B(src2));
265 
266 	case SLJIT_LSHR:
267 	case SLJIT_MLSHR:
268 		if (flags & ALT_FORM1) {
269 			SLJIT_ASSERT(src2 == TMP_REG2);
270 			imm = compiler->imm & 0x1f;
271 			/* Since imm can be 0, SRWI() cannot be used. */
272 			return push_inst(compiler, RLWINM | RC(flags) | S(src1) | A(dst) | RLWI_SH((32 - imm) & 0x1f) | RLWI_MBE(imm, 31));
273 		}
274 
275 		if (op == SLJIT_MLSHR) {
276 			FAIL_IF(push_inst(compiler, ANDI | S(src2) | A(TMP_REG2) | 0x1f));
277 			src2 = TMP_REG2;
278 		}
279 
280 		return push_inst(compiler, SRW | RC(flags) | S(src1) | A(dst) | B(src2));
281 
282 	case SLJIT_ASHR:
283 	case SLJIT_MASHR:
284 		if (flags & ALT_FORM1) {
285 			SLJIT_ASSERT(src2 == TMP_REG2);
286 			imm = compiler->imm & 0x1f;
287 			return push_inst(compiler, SRAWI | RC(flags) | S(src1) | A(dst) | (imm << 11));
288 		}
289 
290 		if (op == SLJIT_MASHR) {
291 			FAIL_IF(push_inst(compiler, ANDI | S(src2) | A(TMP_REG2) | 0x1f));
292 			src2 = TMP_REG2;
293 		}
294 
295 		return push_inst(compiler, SRAW | RC(flags) | S(src1) | A(dst) | B(src2));
296 
297 	case SLJIT_ROTL:
298 	case SLJIT_ROTR:
299 		if (flags & ALT_FORM1) {
300 			SLJIT_ASSERT(src2 == TMP_REG2);
301 			imm = compiler->imm;
302 
303 			if (op == SLJIT_ROTR)
304 				imm = (sljit_u32)(-(sljit_s32)imm);
305 
306 			imm &= 0x1f;
307 			return push_inst(compiler, RLWINM | S(src1) | A(dst) | RLWI_SH(imm) | RLWI_MBE(0, 31));
308 		}
309 
310 		if (op == SLJIT_ROTR) {
311 			FAIL_IF(push_inst(compiler, SUBFIC | D(TMP_REG2) | A(src2) | 0));
312 			src2 = TMP_REG2;
313 		}
314 
315 		return push_inst(compiler, RLWNM | S(src1) | A(dst) | B(src2) | RLWI_MBE(0, 31));
316 	}
317 
318 	SLJIT_UNREACHABLE();
319 	return SLJIT_SUCCESS;
320 }
321 
emit_const(struct sljit_compiler * compiler,sljit_s32 reg,sljit_sw init_value)322 static SLJIT_INLINE sljit_s32 emit_const(struct sljit_compiler *compiler, sljit_s32 reg, sljit_sw init_value)
323 {
324 	FAIL_IF(push_inst(compiler, ADDIS | D(reg) | A(0) | IMM(init_value >> 16)));
325 	return push_inst(compiler, ORI | S(reg) | A(reg) | IMM(init_value));
326 }
327 
sljit_set_jump_addr(sljit_uw addr,sljit_uw new_target,sljit_sw executable_offset)328 SLJIT_API_FUNC_ATTRIBUTE void sljit_set_jump_addr(sljit_uw addr, sljit_uw new_target, sljit_sw executable_offset)
329 {
330 	sljit_ins *inst = (sljit_ins *)addr;
331 	SLJIT_UNUSED_ARG(executable_offset);
332 
333 	SLJIT_UPDATE_WX_FLAGS(inst, inst + 2, 0);
334 	SLJIT_ASSERT((inst[0] & 0xfc1f0000) == ADDIS && (inst[1] & 0xfc000000) == ORI);
335 	inst[0] = (inst[0] & 0xffff0000) | ((new_target >> 16) & 0xffff);
336 	inst[1] = (inst[1] & 0xffff0000) | (new_target & 0xffff);
337 	SLJIT_UPDATE_WX_FLAGS(inst, inst + 2, 1);
338 	inst = (sljit_ins *)SLJIT_ADD_EXEC_OFFSET(inst, executable_offset);
339 	SLJIT_CACHE_FLUSH(inst, inst + 2);
340 }
341