src/gallium/auxiliary/gallivm/lp_bld_debug.cpp

   1 /**************************************************************************
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   3  * Copyright 2009-2011 VMware, Inc.
   4  * All Rights Reserved.
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   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
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   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.
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  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include <stddef.h>
  29 #include <fstream>
  30 #include <sstream>
  31 #include <iomanip>
  32
  33 #include <llvm-c/Core.h>
  34 #include <llvm-c/Disassembler.h>
  35 #include <llvm/Support/raw_ostream.h>
  36 #include <llvm/Support/Format.h>
  37 #include <llvm/Support/Host.h>
  38 #include <llvm/IR/Module.h>
  39
  40 #include "util/u_math.h"
  41 #include "util/u_debug.h"
  42
  43 #include "lp_bld_debug.h"
  44
  45 #ifdef __linux__
  46 #include <sys/stat.h>
  47 #include <fcntl.h>
  48 #endif
  49
  50
  51
  52 /**
  53  * Check alignment.
  54  *
  55  * It is important that this check is not implemented as a macro or inlined
  56  * function, as the compiler assumptions in respect to alignment of global
  57  * and stack variables would often make the check a no op, defeating the
  58  * whole purpose of the exercise.
  59  */
  60 extern "C" boolean
  61 lp_check_alignment(const void *ptr, unsigned alignment)
  62 {
  63    assert(util_is_power_of_two_or_zero(alignment));
  64    return ((uintptr_t)ptr & (alignment - 1)) == 0;
  65 }
  66
  67
  68 /**
  69  * Same as LLVMDumpValue, but through our debugging channels.
  70  */
  71 extern "C" void
  72 lp_debug_dump_value(LLVMValueRef value)
  73 {
  74 #if HAVE_LLVM >= 0x0304
  75    char *str = LLVMPrintValueToString(value);
  76    if (str) {
  77       os_log_message(str);
  78       LLVMDisposeMessage(str);
  79    }
  80 #elif defined(PIPE_OS_WINDOWS) || defined(PIPE_OS_EMBEDDED)
  81    std::string str;
  82    llvm::raw_string_ostream os(str);
  83    llvm::unwrap(value)->print(os);
  84    os_log_message(str.c_str());
  85 #else
  86    LLVMDumpValue(value);
  87 #endif
  88 }
  89
  90
  91 /*
  92  * Disassemble a function, using the LLVM MC disassembler.
  93  *
  94  * See also:
  95  * - http://blog.llvm.org/2010/01/x86-disassembler.html
  96  * - http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html
  97  */
  98 static size_t
  99 disassemble(const void* func, std::ostream &buffer)
 100 {
 101    const uint8_t *bytes = (const uint8_t *)func;
 102
 103    /*
 104     * Limit disassembly to this extent
 105     */
 106    const uint64_t extent = 96 * 1024;
 107
 108    /*
 109     * Initialize all used objects.
 110     */
 111
 112    const char *triple = LLVM_HOST_TRIPLE;
 113    LLVMDisasmContextRef D = LLVMCreateDisasm(triple, NULL, 0, NULL, NULL);
 114    char outline[1024];
 115
 116    if (!D) {
 117       buffer << "error: could not create disassembler for triple "
 118              << triple << '\n';
 119       return 0;
 120    }
 121
 122    uint64_t pc;
 123    pc = 0;
 124    while (pc < extent) {
 125       size_t Size;
 126
 127       /*
 128        * Print address.  We use addresses relative to the start of the function,
 129        * so that between runs.
 130        */
 131
 132       buffer << std::setw(6) << (unsigned long)pc << ":\t";
 133
 134       Size = LLVMDisasmInstruction(D, (uint8_t *)bytes + pc, extent - pc, 0, outline,
 135                                    sizeof outline);
 136
 137       if (!Size) {
 138          buffer << "invalid\n";
 139          pc += 1;
 140          break;
 141       }
 142
 143       /*
 144        * Output the bytes in hexidecimal format.
 145        */
 146
 147       if (0) {
 148          unsigned i;
 149          for (i = 0; i < Size; ++i) {
 150             buffer << std::hex << std::setfill('0') << std::setw(2)
 151                    << static_cast<int> (bytes[pc + i]);
 152          }
 153          for (; i < 16; ++i) {
 154             buffer << std::dec << "   ";
 155          }
 156       }
 157
 158       /*
 159        * Print the instruction.
 160        */
 161
 162       buffer << std::setw(Size) << outline << '\n';
 163
 164       /*
 165        * Stop disassembling on return statements, if there is no record of a
 166        * jump to a successive address.
 167        *
 168        * XXX: This currently assumes x86
 169        */
 170
 171 #if defined(PIPE_ARCH_X86) || defined(PIPE_ARCH_X86_64)
 172       if (Size == 1 && bytes[pc] == 0xc3) {
 173          break;
 174       }
 175 #endif
 176
 177       /*
 178        * Advance.
 179        */
 180
 181       pc += Size;
 182
 183       if (pc >= extent) {
 184          buffer << "disassembly larger than " << extent << " bytes, aborting\n";
 185          break;
 186       }
 187    }
 188
 189    buffer << '\n';
 190
 191    LLVMDisasmDispose(D);
 192
 193    /*
 194     * Print GDB command, useful to verify output.
 195     */
 196    if (0) {
 197       buffer << "disassemble " << static_cast<const void*>(bytes) << ' '
 198              << static_cast<const void*>(bytes + pc) << '\n';
 199    }
 200
 201    return pc;
 202 }
 203
 204
 205 extern "C" void
 206 lp_disassemble(LLVMValueRef func, const void *code)
 207 {
 208    std::ostringstream buffer;
 209    std::string s;
 210
 211    buffer << LLVMGetValueName(func) << ":\n";
 212    disassemble(code, buffer);
 213    s = buffer.str();
 214    os_log_message(s.c_str());
 215    os_log_message("\n");
 216 }
 217
 218
 219 /*
 220  * Linux perf profiler integration.
 221  *
 222  * See also:
 223  * - http://penberg.blogspot.co.uk/2009/06/jato-has-profiler.html
 224  * - https://github.com/penberg/jato/commit/73ad86847329d99d51b386f5aba692580d1f8fdc
 225  * - http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=80d496be89ed7dede5abee5c057634e80a31c82d
 226  */
 227 extern "C" void
 228 lp_profile(LLVMValueRef func, const void *code)
 229 {
 230 #if defined(__linux__) && defined(PROFILE)
 231    static std::ofstream perf_asm_file;
 232    static boolean first_time = TRUE;
 233    static FILE *perf_map_file = NULL;
 234    if (first_time) {
 235       /*
 236        * We rely on the disassembler for determining a function's size, but
 237        * the disassembly is a leaky and slow operation, so avoid running
 238        * this except when running inside linux perf, which can be inferred
 239        * by the PERF_BUILDID_DIR environment variable.
 240        */
 241       if (getenv("PERF_BUILDID_DIR")) {
 242          pid_t pid = getpid();
 243          char filename[256];
 244          util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map", (unsigned long long)pid);
 245          perf_map_file = fopen(filename, "wt");
 246          util_snprintf(filename, sizeof filename, "/tmp/perf-%llu.map.asm", (unsigned long long)pid);
 247          perf_asm_file.open(filename);
 248       }
 249       first_time = FALSE;
 250    }
 251    if (perf_map_file) {
 252       const char *symbol = LLVMGetValueName(func);
 253       unsigned long addr = (uintptr_t)code;
 254       perf_asm_file << symbol << ":\n";
 255       unsigned long size = disassemble(code, perf_asm_file);
 256       perf_asm_file.flush();
 257       fprintf(perf_map_file, "%lx %lx %s\n", addr, size, symbol);
 258       fflush(perf_map_file);
 259    }
 260 #else
 261    (void)func;
 262    (void)code;
 263 #endif
 264 }
 265
 266