contrib/plugins/howvec.c

   1 /*
   2  * Copyright (C) 2019, Alex Bennée <alex.bennee@linaro.org>
   3  *
   4  * How vectorised is this code?
   5  *
   6  * Attempt to measure the amount of vectorisation that has been done
   7  * on some code by counting classes of instruction.
   8  *
   9  * License: GNU GPL, version 2 or later.
  10  *   See the COPYING file in the top-level directory.
  11  */
  12 #include <inttypes.h>
  13 #include <assert.h>
  14 #include <stdlib.h>
  15 #include <inttypes.h>
  16 #include <string.h>
  17 #include <unistd.h>
  18 #include <stdio.h>
  19 #include <glib.h>
  20
  21 #include <qemu-plugin.h>
  22
  23 QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
  24
  25 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  26
  27 typedef enum {
  28     COUNT_CLASS,
  29     COUNT_INDIVIDUAL,
  30     COUNT_NONE
  31 } CountType;
  32
  33 static int limit = 50;
  34 static bool do_inline;
  35 static bool verbose;
  36
  37 static GMutex lock;
  38 static GHashTable *insns;
  39
  40 typedef struct {
  41     const char *class;
  42     const char *opt;
  43     uint32_t mask;
  44     uint32_t pattern;
  45     CountType what;
  46     uint64_t count;
  47 } InsnClassExecCount;
  48
  49 typedef struct {
  50     char *insn;
  51     uint32_t opcode;
  52     uint64_t count;
  53     InsnClassExecCount *class;
  54 } InsnExecCount;
  55
  56 /*
  57  * Matchers for classes of instructions, order is important.
  58  *
  59  * Your most precise match must be before looser matches. If no match
  60  * is found in the table we can create an individual entry.
  61  *
  62  * 31..28 27..24 23..20 19..16 15..12 11..8 7..4 3..0
  63  */
  64 static InsnClassExecCount aarch64_insn_classes[] = {
  65     /* "Reserved"" */
  66     { "  UDEF",              "udef",   0xffff0000, 0x00000000, COUNT_NONE},
  67     { "  SVE",               "sve",    0x1e000000, 0x04000000, COUNT_CLASS},
  68     { "Reserved",            "res",    0x1e000000, 0x00000000, COUNT_CLASS},
  69     /* Data Processing Immediate */
  70     { "  PCrel addr",        "pcrel",  0x1f000000, 0x10000000, COUNT_CLASS},
  71     { "  Add/Sub (imm,tags)", "asit",   0x1f800000, 0x11800000, COUNT_CLASS},
  72     { "  Add/Sub (imm)",     "asi",    0x1f000000, 0x11000000, COUNT_CLASS},
  73     { "  Logical (imm)",     "logi",   0x1f800000, 0x12000000, COUNT_CLASS},
  74     { "  Move Wide (imm)",   "movwi",  0x1f800000, 0x12800000, COUNT_CLASS},
  75     { "  Bitfield",          "bitf",   0x1f800000, 0x13000000, COUNT_CLASS},
  76     { "  Extract",           "extr",   0x1f800000, 0x13800000, COUNT_CLASS},
  77     { "Data Proc Imm",       "dpri",   0x1c000000, 0x10000000, COUNT_CLASS},
  78     /* Branches */
  79     { "  Cond Branch (imm)", "cndb",   0xfe000000, 0x54000000, COUNT_CLASS},
  80     { "  Exception Gen",     "excp",   0xff000000, 0xd4000000, COUNT_CLASS},
  81     { "    NOP",             "nop",    0xffffffff, 0xd503201f, COUNT_NONE},
  82     { "  Hints",             "hint",   0xfffff000, 0xd5032000, COUNT_CLASS},
  83     { "  Barriers",          "barr",   0xfffff000, 0xd5033000, COUNT_CLASS},
  84     { "  PSTATE",            "psta",   0xfff8f000, 0xd5004000, COUNT_CLASS},
  85     { "  System Insn",       "sins",   0xffd80000, 0xd5080000, COUNT_CLASS},
  86     { "  System Reg",        "sreg",   0xffd00000, 0xd5100000, COUNT_CLASS},
  87     { "  Branch (reg)",      "breg",   0xfe000000, 0xd6000000, COUNT_CLASS},
  88     { "  Branch (imm)",      "bimm",   0x7c000000, 0x14000000, COUNT_CLASS},
  89     { "  Cmp & Branch",      "cmpb",   0x7e000000, 0x34000000, COUNT_CLASS},
  90     { "  Tst & Branch",      "tstb",   0x7e000000, 0x36000000, COUNT_CLASS},
  91     { "Branches",            "branch", 0x1c000000, 0x14000000, COUNT_CLASS},
  92     /* Loads and Stores */
  93     { "  AdvSimd ldstmult",  "advlsm", 0xbfbf0000, 0x0c000000, COUNT_CLASS},
  94     { "  AdvSimd ldstmult++", "advlsmp", 0xbfb00000, 0x0c800000, COUNT_CLASS},
  95     { "  AdvSimd ldst",      "advlss", 0xbf9f0000, 0x0d000000, COUNT_CLASS},
  96     { "  AdvSimd ldst++",    "advlssp", 0xbf800000, 0x0d800000, COUNT_CLASS},
  97     { "  ldst excl",         "ldstx",  0x3f000000, 0x08000000, COUNT_CLASS},
  98     { "    Prefetch",        "prfm",   0xff000000, 0xd8000000, COUNT_CLASS},
  99     { "  Load Reg (lit)",    "ldlit",  0x1b000000, 0x18000000, COUNT_CLASS},
 100     { "  ldst noalloc pair", "ldstnap", 0x3b800000, 0x28000000, COUNT_CLASS},
 101     { "  ldst pair",         "ldstp",  0x38000000, 0x28000000, COUNT_CLASS},
 102     { "  ldst reg",          "ldstr",  0x3b200000, 0x38000000, COUNT_CLASS},
 103     { "  Atomic ldst",       "atomic", 0x3b200c00, 0x38200000, COUNT_CLASS},
 104     { "  ldst reg (reg off)", "ldstro", 0x3b200b00, 0x38200800, COUNT_CLASS},
 105     { "  ldst reg (pac)",    "ldstpa", 0x3b200200, 0x38200800, COUNT_CLASS},
 106     { "  ldst reg (imm)",    "ldsti",  0x3b000000, 0x39000000, COUNT_CLASS},
 107     { "Loads & Stores",      "ldst",   0x0a000000, 0x08000000, COUNT_CLASS},
 108     /* Data Processing Register */
 109     { "Data Proc Reg",       "dprr",   0x0e000000, 0x0a000000, COUNT_CLASS},
 110     /* Scalar FP */
 111     { "Scalar FP ",          "fpsimd", 0x0e000000, 0x0e000000, COUNT_CLASS},
 112     /* Unclassified */
 113     { "Unclassified",        "unclas", 0x00000000, 0x00000000, COUNT_CLASS},
 114 };
 115
 116 static InsnClassExecCount sparc32_insn_classes[] = {
 117     { "Call",                "call",   0xc0000000, 0x40000000, COUNT_CLASS},
 118     { "Branch ICond",        "bcc",    0xc1c00000, 0x00800000, COUNT_CLASS},
 119     { "Branch Fcond",        "fbcc",   0xc1c00000, 0x01800000, COUNT_CLASS},
 120     { "SetHi",               "sethi",  0xc1c00000, 0x01000000, COUNT_CLASS},
 121     { "FPU ALU",             "fpu",    0xc1f00000, 0x81a00000, COUNT_CLASS},
 122     { "ALU",                 "alu",    0xc0000000, 0x80000000, COUNT_CLASS},
 123     { "Load/Store",          "ldst",   0xc0000000, 0xc0000000, COUNT_CLASS},
 124     /* Unclassified */
 125     { "Unclassified",        "unclas", 0x00000000, 0x00000000, COUNT_INDIVIDUAL},
 126 };
 127
 128 static InsnClassExecCount sparc64_insn_classes[] = {
 129     { "SetHi & Branches",     "op0",   0xc0000000, 0x00000000, COUNT_CLASS},
 130     { "Call",                 "op1",   0xc0000000, 0x40000000, COUNT_CLASS},
 131     { "Arith/Logical/Move",   "op2",   0xc0000000, 0x80000000, COUNT_CLASS},
 132     { "Arith/Logical/Move",   "op3",   0xc0000000, 0xc0000000, COUNT_CLASS},
 133     /* Unclassified */
 134     { "Unclassified",        "unclas", 0x00000000, 0x00000000, COUNT_INDIVIDUAL},
 135 };
 136
 137 /* Default matcher for currently unclassified architectures */
 138 static InsnClassExecCount default_insn_classes[] = {
 139     { "Unclassified",        "unclas", 0x00000000, 0x00000000, COUNT_INDIVIDUAL},
 140 };
 141
 142 typedef struct {
 143     const char *qemu_target;
 144     InsnClassExecCount *table;
 145     int table_sz;
 146 } ClassSelector;
 147
 148 static ClassSelector class_tables[] = {
 149     { "aarch64", aarch64_insn_classes, ARRAY_SIZE(aarch64_insn_classes) },
 150     { "sparc",   sparc32_insn_classes, ARRAY_SIZE(sparc32_insn_classes) },
 151     { "sparc64", sparc64_insn_classes, ARRAY_SIZE(sparc64_insn_classes) },
 152     { NULL, default_insn_classes, ARRAY_SIZE(default_insn_classes) },
 153 };
 154
 155 static InsnClassExecCount *class_table;
 156 static int class_table_sz;
 157
 158 static gint cmp_exec_count(gconstpointer a, gconstpointer b)
 159 {
 160     InsnExecCount *ea = (InsnExecCount *) a;
 161     InsnExecCount *eb = (InsnExecCount *) b;
 162     return ea->count > eb->count ? -1 : 1;
 163 }
 164
 165 static void free_record(gpointer data)
 166 {
 167     InsnExecCount *rec = (InsnExecCount *) data;
 168     g_free(rec->insn);
 169     g_free(rec);
 170 }
 171
 172 static void plugin_exit(qemu_plugin_id_t id, void *p)
 173 {
 174     g_autoptr(GString) report = g_string_new("Instruction Classes:\n");
 175     int i;
 176     GList *counts;
 177     InsnClassExecCount *class = NULL;
 178
 179     for (i = 0; i < class_table_sz; i++) {
 180         class = &class_table[i];
 181         switch (class->what) {
 182         case COUNT_CLASS:
 183             if (class->count || verbose) {
 184                 g_string_append_printf(report, "Class: %-24s\t(%ld hits)\n",
 185                                        class->class,
 186                                        class->count);
 187             }
 188             break;
 189         case COUNT_INDIVIDUAL:
 190             g_string_append_printf(report, "Class: %-24s\tcounted individually\n",
 191                                    class->class);
 192             break;
 193         case COUNT_NONE:
 194             g_string_append_printf(report, "Class: %-24s\tnot counted\n",
 195                                    class->class);
 196             break;
 197         default:
 198             break;
 199         }
 200     }
 201
 202     counts = g_hash_table_get_values(insns);
 203     if (counts && g_list_next(counts)) {
 204         g_string_append_printf(report, "Individual Instructions:\n");
 205         counts = g_list_sort(counts, cmp_exec_count);
 206
 207         for (i = 0; i < limit && g_list_next(counts);
 208              i++, counts = g_list_next(counts)) {
 209             InsnExecCount *rec = (InsnExecCount *) counts->data;
 210             g_string_append_printf(report,
 211                                    "Instr: %-24s\t(%ld hits)\t(op=0x%08x/%s)\n",
 212                                    rec->insn,
 213                                    rec->count,
 214                                    rec->opcode,
 215                                    rec->class ?
 216                                    rec->class->class : "un-categorised");
 217         }
 218         g_list_free(counts);
 219     }
 220
 221     g_hash_table_destroy(insns);
 222
 223     qemu_plugin_outs(report->str);
 224 }
 225
 226 static void plugin_init(void)
 227 {
 228     insns = g_hash_table_new_full(NULL, g_direct_equal, NULL, &free_record);
 229 }
 230
 231 static void vcpu_insn_exec_before(unsigned int cpu_index, void *udata)
 232 {
 233     uint64_t *count = (uint64_t *) udata;
 234     (*count)++;
 235 }
 236
 237 static uint64_t *find_counter(struct qemu_plugin_insn *insn)
 238 {
 239     int i;
 240     uint64_t *cnt = NULL;
 241     uint32_t opcode;
 242     InsnClassExecCount *class = NULL;
 243
 244     /*
 245      * We only match the first 32 bits of the instruction which is
 246      * fine for most RISCs but a bit limiting for CISC architectures.
 247      * They would probably benefit from a more tailored plugin.
 248      * However we can fall back to individual instruction counting.
 249      */
 250     opcode = *((uint32_t *)qemu_plugin_insn_data(insn));
 251
 252     for (i = 0; !cnt && i < class_table_sz; i++) {
 253         class = &class_table[i];
 254         uint32_t masked_bits = opcode & class->mask;
 255         if (masked_bits == class->pattern) {
 256             break;
 257         }
 258     }
 259
 260     g_assert(class);
 261
 262     switch (class->what) {
 263     case COUNT_NONE:
 264         return NULL;
 265     case COUNT_CLASS:
 266         return &class->count;
 267     case COUNT_INDIVIDUAL:
 268     {
 269         InsnExecCount *icount;
 270
 271         g_mutex_lock(&lock);
 272         icount = (InsnExecCount *) g_hash_table_lookup(insns,
 273                                                        GUINT_TO_POINTER(opcode));
 274
 275         if (!icount) {
 276             icount = g_new0(InsnExecCount, 1);
 277             icount->opcode = opcode;
 278             icount->insn = qemu_plugin_insn_disas(insn);
 279             icount->class = class;
 280
 281             g_hash_table_insert(insns, GUINT_TO_POINTER(opcode),
 282                                 (gpointer) icount);
 283         }
 284         g_mutex_unlock(&lock);
 285
 286         return &icount->count;
 287     }
 288     default:
 289         g_assert_not_reached();
 290     }
 291
 292     return NULL;
 293 }
 294
 295 static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
 296 {
 297     size_t n = qemu_plugin_tb_n_insns(tb);
 298     size_t i;
 299
 300     for (i = 0; i < n; i++) {
 301         uint64_t *cnt;
 302         struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
 303         cnt = find_counter(insn);
 304
 305         if (cnt) {
 306             if (do_inline) {
 307                 qemu_plugin_register_vcpu_insn_exec_inline(
 308                     insn, QEMU_PLUGIN_INLINE_ADD_U64, cnt, 1);
 309             } else {
 310                 qemu_plugin_register_vcpu_insn_exec_cb(
 311                     insn, vcpu_insn_exec_before, QEMU_PLUGIN_CB_NO_REGS, cnt);
 312             }
 313         }
 314     }
 315 }
 316
 317 QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
 318                                            const qemu_info_t *info,
 319                                            int argc, char **argv)
 320 {
 321     int i;
 322
 323     /* Select a class table appropriate to the guest architecture */
 324     for (i = 0; i < ARRAY_SIZE(class_tables); i++) {
 325         ClassSelector *entry = &class_tables[i];
 326         if (!entry->qemu_target ||
 327             strcmp(entry->qemu_target, info->target_name) == 0) {
 328             class_table = entry->table;
 329             class_table_sz = entry->table_sz;
 330             break;
 331         }
 332     }
 333
 334     for (i = 0; i < argc; i++) {
 335         char *p = argv[i];
 336         if (strcmp(p, "inline") == 0) {
 337             do_inline = true;
 338         } else if (strcmp(p, "verbose") == 0) {
 339             verbose = true;
 340         } else {
 341             int j;
 342             CountType type = COUNT_INDIVIDUAL;
 343             if (*p == '!') {
 344                 type = COUNT_NONE;
 345                 p++;
 346             }
 347             for (j = 0; j < class_table_sz; j++) {
 348                 if (strcmp(p, class_table[j].opt) == 0) {
 349                     class_table[j].what = type;
 350                     break;
 351                 }
 352             }
 353         }
 354     }
 355
 356     plugin_init();
 357
 358     qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
 359     qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
 360     return 0;
 361 }