src/gallium/auxiliary/gallivm/lp_bld_debug.cpp

   1 /**************************************************************************
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   3  * Copyright 2009-2011 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
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  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
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  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include <stddef.h>
  29
  30 #include <llvm-c/Core.h>
  31 #include <llvm/Target/TargetMachine.h>
  32 #include <llvm/Target/TargetInstrInfo.h>
  33 #include <llvm/Support/raw_ostream.h>
  34 #include <llvm/Support/Format.h>
  35 #include <llvm/Support/MemoryObject.h>
  36
  37 #include <llvm/Support/TargetRegistry.h>
  38 #include <llvm/MC/MCSubtargetInfo.h>
  39
  40 #include <llvm/Support/Host.h>
  41
  42 #if HAVE_LLVM >= 0x0303
  43 #include <llvm/IR/Module.h>
  44 #else
  45 #include <llvm/Module.h>
  46 #endif
  47
  48 #include <llvm/MC/MCDisassembler.h>
  49 #include <llvm/MC/MCAsmInfo.h>
  50 #include <llvm/MC/MCInst.h>
  51 #include <llvm/MC/MCInstPrinter.h>
  52 #include <llvm/MC/MCRegisterInfo.h>
  53
  54 #if HAVE_LLVM >= 0x0305
  55 #define OwningPtr std::unique_ptr
  56 #elif HAVE_LLVM >= 0x0303
  57 #include <llvm/ADT/OwningPtr.h>
  58 #endif
  59
  60 #if HAVE_LLVM >= 0x0305
  61 #include <llvm/MC/MCContext.h>
  62 #endif
  63
  64 #include "util/u_math.h"
  65 #include "util/u_debug.h"
  66
  67 #include "lp_bld_debug.h"
  68
  69 #ifdef __linux__
  70 #include <sys/stat.h>
  71 #include <fcntl.h>
  72 #endif
  73
  74
  75
  76 /**
  77  * Check alignment.
  78  *
  79  * It is important that this check is not implemented as a macro or inlined
  80  * function, as the compiler assumptions in respect to alignment of global
  81  * and stack variables would often make the check a no op, defeating the
  82  * whole purpose of the exercise.
  83  */
  84 extern "C" boolean
  85 lp_check_alignment(const void *ptr, unsigned alignment)
  86 {
  87    assert(util_is_power_of_two(alignment));
  88    return ((uintptr_t)ptr & (alignment - 1)) == 0;
  89 }
  90
  91
  92 class raw_debug_ostream :
  93    public llvm::raw_ostream
  94 {
  95 private:
  96    uint64_t pos;
  97
  98 public:
  99    raw_debug_ostream() : pos(0) { }
 100
 101    void write_impl(const char *Ptr, size_t Size);
 102
 103    uint64_t current_pos() const { return pos; }
 104    size_t preferred_buffer_size() const { return 512; }
 105 };
 106
 107
 108 void
 109 raw_debug_ostream::write_impl(const char *Ptr, size_t Size)
 110 {
 111    if (Size > 0) {
 112       char *lastPtr = (char *)&Ptr[Size];
 113       char last = *lastPtr;
 114       *lastPtr = 0;
 115       _debug_printf("%*s", Size, Ptr);
 116       *lastPtr = last;
 117       pos += Size;
 118    }
 119 }
 120
 121
 122 extern "C" const char *
 123 lp_get_module_id(LLVMModuleRef module)
 124 {
 125    return llvm::unwrap(module)->getModuleIdentifier().c_str();
 126 }
 127
 128
 129 /**
 130  * Same as LLVMDumpValue, but through our debugging channels.
 131  */
 132 extern "C" void
 133 lp_debug_dump_value(LLVMValueRef value)
 134 {
 135 #if (defined(PIPE_OS_WINDOWS) && !defined(PIPE_CC_MSVC)) || defined(PIPE_OS_EMBDDED)
 136    raw_debug_ostream os;
 137    llvm::unwrap(value)->print(os);
 138    os.flush();
 139 #else
 140    LLVMDumpValue(value);
 141 #endif
 142 }
 143
 144
 145 /*
 146  * MemoryObject wrapper around a buffer of memory, to be used by MC
 147  * disassembler.
 148  */
 149 class BufferMemoryObject:
 150    public llvm::MemoryObject
 151 {
 152 private:
 153    const uint8_t *Bytes;
 154    uint64_t Length;
 155 public:
 156    BufferMemoryObject(const uint8_t *bytes, uint64_t length) :
 157       Bytes(bytes), Length(length)
 158    {
 159    }
 160
 161    uint64_t getBase() const
 162    {
 163       return 0;
 164    }
 165
 166    uint64_t getExtent() const
 167    {
 168       return Length;
 169    }
 170
 171    int readByte(uint64_t addr, uint8_t *byte) const
 172    {
 173       if (addr > getExtent())
 174          return -1;
 175       *byte = Bytes[addr];
 176       return 0;
 177    }
 178 };
 179
 180
 181 /*
 182  * Disassemble a function, using the LLVM MC disassembler.
 183  *
 184  * See also:
 185  * - http://blog.llvm.org/2010/01/x86-disassembler.html
 186  * - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html
 187  */
 188 static size_t
 189 disassemble(const void* func, llvm::raw_ostream & Out)
 190 {
 191    using namespace llvm;
 192
 193    const uint8_t *bytes = (const uint8_t *)func;
 194
 195    /*
 196     * Limit disassembly to this extent
 197     */
 198    const uint64_t extent = 96 * 1024;
 199
 200    uint64_t max_pc = 0;
 201
 202    /*
 203     * Initialize all used objects.
 204     */
 205
 206    std::string Triple = sys::getDefaultTargetTriple();
 207
 208    std::string Error;
 209    const Target *T = TargetRegistry::lookupTarget(Triple, Error);
 210
 211 #if HAVE_LLVM >= 0x0304
 212    OwningPtr<const MCAsmInfo> AsmInfo(T->createMCAsmInfo(*T->createMCRegInfo(Triple), Triple));
 213 #else
 214    OwningPtr<const MCAsmInfo> AsmInfo(T->createMCAsmInfo(Triple));
 215 #endif
 216
 217    if (!AsmInfo) {
 218       Out << "error: no assembly info for target " << Triple << "\n";
 219       Out.flush();
 220       return 0;
 221    }
 222
 223    unsigned int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
 224
 225    OwningPtr<const MCRegisterInfo> MRI(T->createMCRegInfo(Triple));
 226    if (!MRI) {
 227       Out << "error: no register info for target " << Triple.c_str() << "\n";
 228       Out.flush();
 229       return 0;
 230    }
 231
 232    OwningPtr<const MCInstrInfo> MII(T->createMCInstrInfo());
 233    if (!MII) {
 234       Out << "error: no instruction info for target " << Triple.c_str() << "\n";
 235       Out.flush();
 236       return 0;
 237    }
 238
 239 #if HAVE_LLVM >= 0x0305
 240    OwningPtr<const MCSubtargetInfo> STI(T->createMCSubtargetInfo(Triple, sys::getHostCPUName(), ""));
 241    OwningPtr<MCContext> MCCtx(new MCContext(AsmInfo.get(), MRI.get(), 0));
 242    OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler(*STI, *MCCtx));
 243 #else
 244    OwningPtr<const MCSubtargetInfo> STI(T->createMCSubtargetInfo(Triple, sys::getHostCPUName(), ""));
 245    OwningPtr<const MCDisassembler> DisAsm(T->createMCDisassembler(*STI));
 246 #endif
 247    if (!DisAsm) {
 248       Out << "error: no disassembler for target " << Triple << "\n";
 249       Out.flush();
 250       return 0;
 251    }
 252
 253
 254    OwningPtr<MCInstPrinter> Printer(
 255          T->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, *MII, *MRI, *STI));
 256    if (!Printer) {
 257       Out << "error: no instruction printer for target " << Triple.c_str() << "\n";
 258       Out.flush();
 259       return 0;
 260    }
 261
 262    TargetOptions options;
 263 #if defined(DEBUG)
 264    options.JITEmitDebugInfo = true;
 265 #endif
 266 #if defined(PIPE_ARCH_X86)
 267    options.StackAlignmentOverride = 4;
 268 #endif
 269 #if defined(DEBUG) || defined(PROFILE)
 270    options.NoFramePointerElim = true;
 271 #endif
 272    OwningPtr<TargetMachine> TM(T->createTargetMachine(Triple, sys::getHostCPUName(), "", options));
 273
 274    const TargetInstrInfo *TII = TM->getInstrInfo();
 275
 276    /*
 277     * Wrap the data in a MemoryObject
 278     */
 279    BufferMemoryObject memoryObject((const uint8_t *)bytes, extent);
 280
 281    uint64_t pc;
 282    pc = 0;
 283    while (true) {
 284       MCInst Inst;
 285       uint64_t Size;
 286
 287       /*
 288        * Print address.  We use addresses relative to the start of the function,
 289        * so that between runs.
 290        */
 291
 292       Out << llvm::format("%6lu:\t", (unsigned long)pc);
 293
 294       if (!DisAsm->getInstruction(Inst, Size, memoryObject,
 295                                  pc,
 296                                   nulls(), nulls())) {
 297          Out << "invalid";
 298          pc += 1;
 299       }
 300
 301       /*
 302        * Output the bytes in hexidecimal format.
 303        */
 304
 305       if (0) {
 306          unsigned i;
 307          for (i = 0; i < Size; ++i) {
 308             Out << llvm::format("%02x ", ((const uint8_t*)bytes)[pc + i]);
 309          }
 310          for (; i < 16; ++i) {
 311             Out << "   ";
 312          }
 313       }
 314
 315       /*
 316        * Print the instruction.
 317        */
 318       Printer->printInst(&Inst, Out, "");
 319
 320       /*
 321        * Advance.
 322        */
 323
 324       pc += Size;
 325
 326       const MCInstrDesc &TID = TII->get(Inst.getOpcode());
 327
 328       /*
 329        * Keep track of forward jumps to a nearby address.
 330        */
 331
 332       if (TID.isBranch()) {
 333          for (unsigned i = 0; i < Inst.getNumOperands(); ++i) {
 334             const MCOperand &operand = Inst.getOperand(i);
 335             if (operand.isImm()) {
 336                uint64_t jump;
 337
 338                /*
 339                 * FIXME: Handle both relative and absolute addresses correctly.
 340                 * EDInstInfo actually has this info, but operandTypes and
 341                 * operandFlags enums are not exposed in the public interface.
 342                 */
 343
 344                if (1) {
 345                   /*
 346                    * PC relative addr.
 347                    */
 348
 349                   jump = pc + operand.getImm();
 350                } else {
 351                   /*
 352                    * Absolute addr.
 353                    */
 354
 355                   jump = (uint64_t)operand.getImm();
 356                }
 357
 358                /*
 359                 * Output the address relative to the function start, given
 360                 * that MC will print the addresses relative the current pc.
 361                 */
 362                Out << "\t\t; " << jump;
 363
 364                /*
 365                 * Ignore far jumps given it could be actually a tail return to
 366                 * a random address.
 367                 */
 368
 369                if (jump > max_pc &&
 370                    jump < extent) {
 371                   max_pc = jump;
 372                }
 373             }
 374          }
 375       }
 376
 377       Out << "\n";
 378
 379       /*
 380        * Stop disassembling on return statements, if there is no record of a
 381        * jump to a successive address.
 382        */
 383
 384       if (TID.isReturn()) {
 385          if (pc > max_pc) {
 386             break;
 387          }
 388       }
 389    }
 390
 391    /*
 392     * Print GDB command, useful to verify output.
 393     */
 394
 395    if (0) {
 396       _debug_printf("disassemble %p %p\n", bytes, bytes + pc);
 397    }
 398
 399    Out << "\n";
 400    Out.flush();
 401
 402    return pc;
 403 }
 404
 405
 406 extern "C" void
 407 lp_disassemble(LLVMValueRef func, const void *code) {
 408    raw_debug_ostream Out;
 409    disassemble(code, Out);
 410 }
 411
 412
 413 /*
 414  * Linux perf profiler integration.
 415  *
 416  * See also:
 417  * - http://penberg.blogspot.co.uk/2009/06/jato-has-profiler.html
 418  * - https://github.com/penberg/jato/commit/73ad86847329d99d51b386f5aba692580d1f8fdc
 419  * - http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=80d496be89ed7dede5abee5c057634e80a31c82d
 420  */
 421 extern "C" void
 422 lp_profile(LLVMValueRef func, const void *code)
 423 {
 424 #if defined(__linux__) && (defined(DEBUG) || defined(PROFILE))
 425    static boolean first_time = TRUE;
 426    static FILE *perf_map_file = NULL;
 427    static int perf_asm_fd = -1;
 428    if (first_time) {
 429       /*
 430        * We rely on the disassembler for determining a function's size, but
 431        * the disassembly is a leaky and slow operation, so avoid running
 432        * this except when running inside linux perf, which can be inferred
 433        * by the PERF_BUILDID_DIR environment variable.
 434        */
 435       if (getenv("PERF_BUILDID_DIR")) {
 436          pid_t pid = getpid();
 437          char filename[256];
 438          util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map", (unsigned long long)pid);
 439          perf_map_file = fopen(filename, "wt");
 440          util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map.asm", (unsigned long long)pid);
 441          mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
 442          perf_asm_fd = open(filename, O_WRONLY | O_CREAT, mode);
 443       }
 444       first_time = FALSE;
 445    }
 446    if (perf_map_file) {
 447       const char *symbol = LLVMGetValueName(func);
 448       unsigned long addr = (uintptr_t)code;
 449       llvm::raw_fd_ostream Out(perf_asm_fd, false);
 450       Out << symbol << ":\n";
 451       unsigned long size = disassemble(code, Out);
 452       fprintf(perf_map_file, "%lx %lx %s\n", addr, size, symbol);
 453       fflush(perf_map_file);
 454    }
 455 #else
 456    (void)func;
 457    (void)code;
 458 #endif
 459 }
 460
 461