xref: /openbmc/qemu/target/i386/tcg/decode-new.h (revision db96605a)
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 } X86OpSize;
96 
97 typedef enum X86CPUIDFeature {
98     X86_FEAT_None,
99     X86_FEAT_3DNOW,
100     X86_FEAT_ADX,
101     X86_FEAT_AES,
102     X86_FEAT_AVX,
103     X86_FEAT_AVX2,
104     X86_FEAT_BMI1,
105     X86_FEAT_BMI2,
106     X86_FEAT_MOVBE,
107     X86_FEAT_PCLMULQDQ,
108     X86_FEAT_SSE,
109     X86_FEAT_SSE2,
110     X86_FEAT_SSE3,
111     X86_FEAT_SSSE3,
112     X86_FEAT_SSE41,
113     X86_FEAT_SSE42,
114     X86_FEAT_SSE4A,
115 } X86CPUIDFeature;
116 
117 /* Execution flags */
118 
119 typedef enum X86OpUnit {
120     X86_OP_SKIP,    /* not valid or managed by emission function */
121     X86_OP_SEG,     /* segment selector */
122     X86_OP_CR,      /* control register */
123     X86_OP_DR,      /* debug register */
124     X86_OP_INT,     /* loaded into/stored from s->T0/T1 */
125     X86_OP_IMM,     /* immediate */
126     X86_OP_SSE,     /* address in either s->ptrX or s->A0 depending on has_ea */
127     X86_OP_MMX,     /* address in either s->ptrX or s->A0 depending on has_ea */
128 } X86OpUnit;
129 
130 typedef enum X86InsnSpecial {
131     X86_SPECIAL_None,
132 
133     /* Always locked if it has a memory operand (XCHG) */
134     X86_SPECIAL_Locked,
135 
136     /* Fault outside protected mode */
137     X86_SPECIAL_ProtMode,
138 
139     /*
140      * Register operand 0/2 is zero extended to 32 bits.  Rd/Mb or Rd/Mw
141      * in the manual.
142      */
143     X86_SPECIAL_ZExtOp0,
144     X86_SPECIAL_ZExtOp2,
145 
146     /*
147      * Register operand 2 is extended to full width, while a memory operand
148      * is doubled in size if VEX.L=1.
149      */
150     X86_SPECIAL_AVXExtMov,
151 
152     /*
153      * MMX instruction exists with no prefix; if there is no prefix, V/H/W/U operands
154      * become P/P/Q/N, and size "x" becomes "q".
155      */
156     X86_SPECIAL_MMX,
157 
158     /* Illegal or exclusive to 64-bit mode */
159     X86_SPECIAL_i64,
160     X86_SPECIAL_o64,
161 } X86InsnSpecial;
162 
163 /*
164  * Special cases for instructions that operate on XMM/YMM registers.  Intel
165  * retconned all of them to have VEX exception classes other than 0 and 13, so
166  * all these only matter for instructions that have a VEX exception class.
167  * Based on tables in the "AVX and SSE Instruction Exception Specification"
168  * section of the manual.
169  */
170 typedef enum X86VEXSpecial {
171     /* Legacy SSE instructions that allow unaligned operands */
172     X86_VEX_SSEUnaligned,
173 
174     /*
175      * Used for instructions that distinguish the XMM operand type with an
176      * instruction prefix; legacy SSE encodings will allow unaligned operands
177      * for scalar operands only (identified by a REP prefix).  In this case,
178      * the decoding table uses "x" for the vector operands instead of specifying
179      * pd/ps/sd/ss individually.
180      */
181     X86_VEX_REPScalar,
182 
183     /*
184      * VEX instructions that only support 256-bit operands with AVX2 (Table 2-17
185      * column 3).  Columns 2 and 4 (instructions limited to 256- and 127-bit
186      * operands respectively) are implicit in the presence of dq and qq
187      * operands, and thus handled by decode_op_size.
188      */
189     X86_VEX_AVX2_256,
190 } X86VEXSpecial;
191 
192 
193 typedef struct X86OpEntry  X86OpEntry;
194 typedef struct X86DecodedInsn X86DecodedInsn;
195 
196 /* Decode function for multibyte opcodes.  */
197 typedef void (*X86DecodeFunc)(DisasContext *s, CPUX86State *env, X86OpEntry *entry, uint8_t *b);
198 
199 /* Code generation function.  */
200 typedef void (*X86GenFunc)(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode);
201 
202 struct X86OpEntry {
203     /* Based on the is_decode flags.  */
204     union {
205         X86GenFunc gen;
206         X86DecodeFunc decode;
207     };
208     /* op0 is always written, op1 and op2 are always read.  */
209     X86OpType    op0:8;
210     X86OpSize    s0:8;
211     X86OpType    op1:8;
212     X86OpSize    s1:8;
213     X86OpType    op2:8;
214     X86OpSize    s2:8;
215     /* Must be I and b respectively if present.  */
216     X86OpType    op3:8;
217     X86OpSize    s3:8;
218 
219     X86InsnSpecial special:8;
220     X86CPUIDFeature cpuid:8;
221     unsigned     vex_class:8;
222     X86VEXSpecial vex_special:8;
223     uint16_t     valid_prefix:16;
224     bool         is_decode:1;
225 };
226 
227 typedef struct X86DecodedOp {
228     int8_t n;
229     MemOp ot;     /* For b/c/d/p/s/q/v/w/y/z */
230     X86OpUnit unit;
231     bool has_ea;
232     int offset;   /* For MMX and SSE */
233 
234     /*
235      * This field is used internally by macros OP0_PTR/OP1_PTR/OP2_PTR,
236      * do not access directly!
237      */
238     TCGv_ptr v_ptr;
239 } X86DecodedOp;
240 
241 struct X86DecodedInsn {
242     X86OpEntry e;
243     X86DecodedOp op[3];
244     target_ulong immediate;
245     AddressParts mem;
246 
247     uint8_t b;
248 };
249 
250