xref: /qemu/target/i386/tcg/decode-new.h (revision e7bbb7cb71b3001c54f23c66848d84e694c47243)
1 /*
2  * Decode table flags, mostly based on Intel SDM.
3  *
4  *  Copyright (c) 2022 Red Hat, Inc.
5  *
6  * Author: Paolo Bonzini <pbonzini@redhat.com>
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 typedef enum X86OpType {
23     X86_TYPE_None,
24 
25     X86_TYPE_A, /* Implicit */
26     X86_TYPE_B, /* VEX.vvvv selects a GPR */
27     X86_TYPE_C, /* REG in the modrm byte selects a control register */
28     X86_TYPE_D, /* REG in the modrm byte selects a debug register */
29     X86_TYPE_E, /* ALU modrm operand */
30     X86_TYPE_F, /* EFLAGS/RFLAGS */
31     X86_TYPE_G, /* REG in the modrm byte selects a GPR */
32     X86_TYPE_H, /* For AVX, VEX.vvvv selects an XMM/YMM register */
33     X86_TYPE_I, /* Immediate */
34     X86_TYPE_J, /* Relative offset for a jump */
35     X86_TYPE_L, /* The upper 4 bits of the immediate select a 128-bit register */
36     X86_TYPE_M, /* modrm byte selects a memory operand */
37     X86_TYPE_N, /* R/M in the modrm byte selects an MMX register */
38     X86_TYPE_O, /* Absolute address encoded in the instruction */
39     X86_TYPE_P, /* reg in the modrm byte selects an MMX register */
40     X86_TYPE_Q, /* MMX modrm operand */
41     X86_TYPE_R, /* R/M in the modrm byte selects a register */
42     X86_TYPE_S, /* reg selects a segment register */
43     X86_TYPE_U, /* R/M in the modrm byte selects an XMM/YMM register */
44     X86_TYPE_V, /* reg in the modrm byte selects an XMM/YMM register */
45     X86_TYPE_W, /* XMM/YMM modrm operand */
46     X86_TYPE_X, /* string source */
47     X86_TYPE_Y, /* string destination */
48 
49     /* Custom */
50     X86_TYPE_WM, /* modrm byte selects an XMM/YMM memory operand */
51     X86_TYPE_2op, /* 2-operand RMW instruction */
52     X86_TYPE_LoBits, /* encoded in bits 0-2 of the operand + REX.B */
53     X86_TYPE_0, /* Hard-coded GPRs (RAX..RDI) */
54     X86_TYPE_1,
55     X86_TYPE_2,
56     X86_TYPE_3,
57     X86_TYPE_4,
58     X86_TYPE_5,
59     X86_TYPE_6,
60     X86_TYPE_7,
61     X86_TYPE_ES, /* Hard-coded segment registers */
62     X86_TYPE_CS,
63     X86_TYPE_SS,
64     X86_TYPE_DS,
65     X86_TYPE_FS,
66     X86_TYPE_GS,
67 } X86OpType;
68 
69 typedef enum X86OpSize {
70     X86_SIZE_None,
71 
72     X86_SIZE_a,  /* BOUND operand */
73     X86_SIZE_b,  /* byte */
74     X86_SIZE_d,  /* 32-bit */
75     X86_SIZE_dq, /* SSE/AVX 128-bit */
76     X86_SIZE_p,  /* Far pointer */
77     X86_SIZE_pd, /* SSE/AVX packed double precision */
78     X86_SIZE_pi, /* MMX */
79     X86_SIZE_ps, /* SSE/AVX packed single precision */
80     X86_SIZE_q,  /* 64-bit */
81     X86_SIZE_qq, /* AVX 256-bit */
82     X86_SIZE_s,  /* Descriptor */
83     X86_SIZE_sd, /* SSE/AVX scalar double precision */
84     X86_SIZE_ss, /* SSE/AVX scalar single precision */
85     X86_SIZE_si, /* 32-bit GPR */
86     X86_SIZE_v,  /* 16/32/64-bit, based on operand size */
87     X86_SIZE_w,  /* 16-bit */
88     X86_SIZE_x,  /* 128/256-bit, based on operand size */
89     X86_SIZE_y,  /* 32/64-bit, based on operand size */
90     X86_SIZE_z,  /* 16-bit for 16-bit operand size, else 32-bit */
91 
92     /* Custom */
93     X86_SIZE_d64,
94     X86_SIZE_f64,
95     X86_SIZE_xh, /* SSE/AVX packed half register */
96 } X86OpSize;
97 
98 typedef enum X86CPUIDFeature {
99     X86_FEAT_None,
100     X86_FEAT_3DNOW,
101     X86_FEAT_ADX,
102     X86_FEAT_AES,
103     X86_FEAT_AVX,
104     X86_FEAT_AVX2,
105     X86_FEAT_BMI1,
106     X86_FEAT_BMI2,
107     X86_FEAT_F16C,
108     X86_FEAT_FMA,
109     X86_FEAT_MOVBE,
110     X86_FEAT_PCLMULQDQ,
111     X86_FEAT_SHA_NI,
112     X86_FEAT_SSE,
113     X86_FEAT_SSE2,
114     X86_FEAT_SSE3,
115     X86_FEAT_SSSE3,
116     X86_FEAT_SSE41,
117     X86_FEAT_SSE42,
118     X86_FEAT_SSE4A,
119 } X86CPUIDFeature;
120 
121 /* Execution flags */
122 
123 typedef enum X86OpUnit {
124     X86_OP_SKIP,    /* not valid or managed by emission function */
125     X86_OP_SEG,     /* segment selector */
126     X86_OP_CR,      /* control register */
127     X86_OP_DR,      /* debug register */
128     X86_OP_INT,     /* loaded into/stored from s->T0/T1 */
129     X86_OP_IMM,     /* immediate */
130     X86_OP_SSE,     /* address in either s->ptrX or s->A0 depending on has_ea */
131     X86_OP_MMX,     /* address in either s->ptrX or s->A0 depending on has_ea */
132 } X86OpUnit;
133 
134 typedef enum X86InsnCheck {
135     /* Illegal or exclusive to 64-bit mode */
136     X86_CHECK_i64 = 1,
137     X86_CHECK_o64 = 2,
138 
139     /* Fault outside protected mode */
140     X86_CHECK_prot = 4,
141 
142     /* Privileged instruction checks */
143     X86_CHECK_cpl0 = 8,
144     X86_CHECK_vm86_iopl = 16,
145     X86_CHECK_cpl_iopl = 32,
146     X86_CHECK_iopl = X86_CHECK_cpl_iopl | X86_CHECK_vm86_iopl,
147 
148     /* Fault if VEX.L=1 */
149     X86_CHECK_VEX128 = 64,
150 
151     /* Fault if VEX.W=1 */
152     X86_CHECK_W0 = 128,
153 
154     /* Fault if VEX.W=0 */
155     X86_CHECK_W1 = 256,
156 } X86InsnCheck;
157 
158 typedef enum X86InsnSpecial {
159     X86_SPECIAL_None,
160 
161     /* Accepts LOCK prefix; LOCKed operations do not load or writeback operand 0 */
162     X86_SPECIAL_HasLock,
163 
164     /* Always locked if it has a memory operand (XCHG) */
165     X86_SPECIAL_Locked,
166 
167     /*
168      * Rd/Mb or Rd/Mw in the manual: register operand 0 is treated as 32 bits
169      * (and writeback zero-extends it to 64 bits if applicable).  PREFIX_DATA
170      * does not trigger 16-bit writeback and, as a side effect, high-byte
171      * registers are never used.
172      */
173     X86_SPECIAL_Op0_Rd,
174 
175     /*
176      * Ry/Mb in the manual (PINSRB).  However, the high bits are never used by
177      * the instruction in either the register or memory cases; the *real* effect
178      * of this modifier is that high-byte registers are never used, even without
179      * a REX prefix.  Therefore, PINSRW does not need it despite having Ry/Mw.
180      */
181     X86_SPECIAL_Op2_Ry,
182 
183     /*
184      * Register operand 2 is extended to full width, while a memory operand
185      * is doubled in size if VEX.L=1.
186      */
187     X86_SPECIAL_AVXExtMov,
188 
189     /*
190      * MMX instruction exists with no prefix; if there is no prefix, V/H/W/U operands
191      * become P/P/Q/N, and size "x" becomes "q".
192      */
193     X86_SPECIAL_MMX,
194 
195     /* When loaded into s->T0, register operand 1 is zero/sign extended.  */
196     X86_SPECIAL_SExtT0,
197     X86_SPECIAL_ZExtT0,
198 } X86InsnSpecial;
199 
200 /*
201  * Special cases for instructions that operate on XMM/YMM registers.  Intel
202  * retconned all of them to have VEX exception classes other than 0 and 13, so
203  * all these only matter for instructions that have a VEX exception class.
204  * Based on tables in the "AVX and SSE Instruction Exception Specification"
205  * section of the manual.
206  */
207 typedef enum X86VEXSpecial {
208     /* Legacy SSE instructions that allow unaligned operands */
209     X86_VEX_SSEUnaligned,
210 
211     /*
212      * Used for instructions that distinguish the XMM operand type with an
213      * instruction prefix; legacy SSE encodings will allow unaligned operands
214      * for scalar operands only (identified by a REP prefix).  In this case,
215      * the decoding table uses "x" for the vector operands instead of specifying
216      * pd/ps/sd/ss individually.
217      */
218     X86_VEX_REPScalar,
219 
220     /*
221      * VEX instructions that only support 256-bit operands with AVX2 (Table 2-17
222      * column 3).  Columns 2 and 4 (instructions limited to 256- and 127-bit
223      * operands respectively) are implicit in the presence of dq and qq
224      * operands, and thus handled by decode_op_size.
225      */
226     X86_VEX_AVX2_256,
227 } X86VEXSpecial;
228 
229 
230 typedef struct X86OpEntry  X86OpEntry;
231 typedef struct X86DecodedInsn X86DecodedInsn;
232 
233 /* Decode function for multibyte opcodes.  */
234 typedef void (*X86DecodeFunc)(DisasContext *s, CPUX86State *env, X86OpEntry *entry, uint8_t *b);
235 
236 /* Code generation function.  */
237 typedef void (*X86GenFunc)(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode);
238 
239 struct X86OpEntry {
240     /* Based on the is_decode flags.  */
241     union {
242         X86GenFunc gen;
243         X86DecodeFunc decode;
244     };
245     /* op0 is always written, op1 and op2 are always read.  */
246     X86OpType    op0:8;
247     X86OpSize    s0:8;
248     X86OpType    op1:8;
249     X86OpSize    s1:8;
250     X86OpType    op2:8;
251     X86OpSize    s2:8;
252     /* Must be I and b respectively if present.  */
253     X86OpType    op3:8;
254     X86OpSize    s3:8;
255 
256     X86InsnSpecial special:8;
257     X86CPUIDFeature cpuid:8;
258     unsigned     vex_class:8;
259     X86VEXSpecial vex_special:8;
260     unsigned     valid_prefix:16;
261     unsigned     check:16;
262     unsigned     intercept:8;
263     bool         is_decode:1;
264 };
265 
266 typedef struct X86DecodedOp {
267     int8_t n;
268     MemOp ot;     /* For b/c/d/p/s/q/v/w/y/z */
269     X86OpUnit unit;
270     bool has_ea;
271     int offset;   /* For MMX and SSE */
272 
273     /*
274      * This field is used internally by macros OP0_PTR/OP1_PTR/OP2_PTR,
275      * do not access directly!
276      */
277     TCGv_ptr v_ptr;
278 } X86DecodedOp;
279 
280 struct X86DecodedInsn {
281     X86OpEntry e;
282     X86DecodedOp op[3];
283     target_ulong immediate;
284     AddressParts mem;
285 
286     TCGv cc_dst, cc_src, cc_src2;
287     TCGv_i32 cc_op_dynamic;
288     int8_t cc_op;
289 
290     uint8_t b;
291 };
292 
293