<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/63778>63778</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            when running opt, llvm-symbolizer's cpu is 100%, then opt crash
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          zzyongx
      </td>
    </tr>
</table>

<pre>
    I modified LoopDataPrefetch.cpp as follows:

> for (auto &P : Prefetches) {
    // Check if the stride of the accesses is large enough to warrant a
    // prefetch.
    if (!isStrideLargeEnough(P.LSCEVAddRec, TargetMinStride))
      continue;
 const llvm::DebugLoc &debugInfo = P.InsertPt->getDebugLoc();
 LLVM_DEBUG(dbgs() << "  LDP InsertPt: "
               << debugInfo->getFilename()
               << " " << debugInfo->getLine() << "\n");

then compile the follow code:

clang test.c -g -Wall -S -emit-llvm -O3
opt -debug -stats -passes='loop-data-prefetch' --prefetch-distance=64 --cache-line-size=64 --max-prefetch-iters-ahead=64 test.ll -o test.bc

```#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define BN (2 * 64)
#define N (200 * 1024 * 1024 / sizeof(int))
int a[N];

int main(int argc, char *argv[])
{
  memset(a, argc, sizeof(a));

  long sum = 0;
 int i;
  long k;
  for (k = 0; k < 1000; k++) {
    for(i=0; i<N; i += BN) {
      int j;
      int m;
      for(j=i; j <= i+4 && j < N; j++) {
        for (m = 0; m < 5; m++) sum += a[j] * i;
      }
 }
  }
  printf("%ld\n", sum);
}
```

the opt output
 LDP InsertPt: PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.

the llvm-symbolizer cpu usage was 100%.
the backtrace is(use gstack):
`
#0  0x00000000005e7d23 in llvm::DWARFFormValue::DWARFFormValue (this=0x7fff2280f4e0, F=llvm::dwarf::DW_FORM_ref4) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/include/llvm/DebugInfo/DWARF/DWARFFormValue.h:69
#1 0x000000000065ecc6 in llvm::DWARFAbbreviationDeclaration::getAttributeValueFromOffset (this=0x303bcde0, AttrIndex=3, Offset=236593725, U=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp:179
#2 0x000000000065ee0f in llvm::DWARFAbbreviationDeclaration::getAttributeValue (this=0x303bcde0, DIEOffset=236593717, Attr=llvm::dwarf::DW_AT_type, U=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp:198
#3 0x000000000060165d in llvm::DWARFDie::find (this=0x7fff2280f880, Attr=llvm::dwarf::DW_AT_type) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp:257
#4 0x0000000000601a81 in llvm::DWARFDie::getAttributeValueAsReferencedDie (this=0x7fff2280f880, Attr=llvm::dwarf::DW_AT_type) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp:310
#5 0x000000000060314e in llvm::DWARFDie::getTypeSize (this=0x7fff2280f880, PointerSize=8) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp:548
#6 0x00000000006217e2 in llvm::DWARFUnit::updateVariableDieMap (this=0x2113280, Die=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp:822
#7 0x0000000000621323 in llvm::DWARFUnit::updateVariableDieMap (this=0x2113280, Die=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp:759
#8 0x0000000000621323 in llvm::DWARFUnit::updateVariableDieMap (this=0x2113280, Die=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp:759
#9 0x0000000000621323 in llvm::DWARFUnit::updateVariableDieMap (this=0x2113280, Die=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp:759
#10 0x0000000000621941 in llvm::DWARFUnit::getVariableForAddress (this=0x2113280, Address=28291989) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp:836
#11 0x00000000005949eb in llvm::DWARFContext::getCompileUnitForAddress (this=0x20e65e0, Address=28291989) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp:1070
#12 0x0000000000595ebb in llvm::DWARFContext::getInliningInfoForAddress (this=0x20e65e0, Address=..., Spec=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp:1337
#13 0x0000000000574a54 in llvm::symbolize::SymbolizableObjectFile::symbolizeInlinedCode (this=0x20e67f0, ModuleOffset=..., LineInfoSpecifier=..., UseSymbolTable=true) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp:300
#14 0x000000000055e985 in llvm::symbolize::LLVMSymbolizer::symbolizeInlinedCodeCommon<std::string> (this=0x7fff22811600, ModuleSpecifier="./bin/opt", ModuleOffset=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/Symbolize/Symbolize.cpp:118
#15 0x0000000000556686 in llvm::symbolize::LLVMSymbolizer::symbolizeInlinedCode (this=0x7fff22811600, ModuleName="./bin/opt", ModuleOffset=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/lib/DebugInfo/Symbolize/Symbolize.cpp:139
#16 0x0000000000415fa1 in executeCommand<std::string> (ModuleName=..., ModuleSpec="./bin/opt", Cmd=Code, Offset=28291989, AdjustVMA=0, ShouldInline=true, Style=LLVM, Symbolizer=..., Printer=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp:224
#17 0x000000000040d9dd in symbolizeInput (Args=..., IncomingBuildID=..., AdjustVMA=0, IsAddr2Line=false, Style=LLVM, InputString=..., Symbolizer=..., Printer=...) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp:273
#18 0x000000000040ef68 in main (argc=4, argv=0x7fff22811e48) at /home/sre/data/llvm-project-llvmorg-15.0.2/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp:490
`

clang version: 15.0.2
opt version: 15.0.2

but, when replace `for (m = 0; m < 5; m++) sum += a[j] * i;` with `sum += a[j] * i;`, there is no crash.




</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzcWd1u2zoSfhrmhrAhkfq9yIVjxYsAThs0bc9lQUkjmalEGiTVJH36BSnJshUn53S3p9s9gWPzZ0jO93FmSI2Y1rwWAJcovEJhdsE6s5Pq8vv3Zynqp4tcls-XN7iVJa84lHgr5T5jht0pqMAUu2Wx32OmcSWbRj5qRFfIy5A3ftNrXEmFEUlYZyRGJLrDiK7wOBw0IilG8VUvjzHGiGwQ2eD1DoqvmFfY7ABro3gJWPY1VhSgNWjMNW6YqgGDkF29w0biR6YUEwazFxPuR42nHl5ZzRDxub53K2ztbNduMkSSu-X2fn39eVWWH6BAZI0_2m5zy0UvjUhqP4fpMC6kMFx0gOgIqJBCG9w031pLDV1lkHf1VhaWitKWb0QlMaIZvlveCA3K3JkFotc1mFHUqZhOU263n2-_ZNdXn_6FSFLmte4FMKJrRNcYEYLxNrvD43SWb0TIsZ6Hv2HMQZNh6Q1vQLAWhqXfGGlXc__nJ9pyAS_UQ-Fa2J8jUP232YHAhWz3vAG3071V4UKWMLOsomGixga0WRZ4UePFH6xp8OIeL6DlZmEJx4v3tBeWe4MXTjW80IYZjRd7Zi0I0QyRuJFyvyiZYYvRRhCJ8eJQW5RcGyYKQDSLArxYFKzYwaLhAhaafz80t-xpGsMNKL1gO2Bl3-90tTrKvpgXJ54SecOHUC6KpivBMqZNyeVyh-j1IDbvbXj-Rrfioj7uHoVKqLgAfPXO2r_dwBWOgsNOTwJ9v-c5Cd8jwXFhgy14WSGScGGOnYE7Bwyv3qEwm22x7WoZF_0gzFTtPKvYMRslVkzV3_pANGkzBYcWWg3GBhM7Zhx70IINOpyuiHEjRY111zo38yZHsgrwqdrLfT1qGELX18NAbItr7HteX0Pkyn1mIaySyuJDNHNiHNH1O1fAVppm-OrdizHYqfNwtPrY1s7a-tkfEM2s8vih96wMc0Su7L5EiER9K3arPryi5TCXRThRg1s3MHTFaaBjr9fdbuwDCjNnCnymG4qzoTqVjot7xYWpXEQgiIRNeYgFa7vGye6NoybXOA0V2Lq17My-M2NknEW9u-316v4a6y5vucEM2wCgYC-VsUfFzpi9O7Dc-VBzs-vyZSFbRDYuXvc_i72SD1AYRDZc684eWBvMRIlHR7OaFIrpHc5Z8dUoVsByrqmbSD-3uWz4d1C42He406wG_Mi0NSdEwuUkfpgIcxvcOw241oYVXx0_RxFjdFcPY-_JO_yFEJeEYi6OD54_Vh82G6naz6zp4FybNQSz4zYoek9xVVWEJF4VgGc3Z4NoNk1WPjJVjXN82bz_cPtFQWUjCGbGhoadtIfHRiv7bUPrjE0XoKWqF3649JZkonxgdWrIxhPFlq2-4-9BbxvgVtEUu_wTLqIQiiI6w8UqzxV848xwKTIoGqZcsZeowayMUTzvDLhFNkq276tKgzmhiXo0L8qeIjvgRpTwhGhGbUMvj2hGaBSmNCahbf2EaLZcLn8CVw3P3yLoFYD2xoboyo8nxsicMfCq_5qxV3nKbq7nzPjxSOAbZrb6-MU87-F34jBNDhzSUw49PwrLMxxmfPC9iovyvMclifcjbPzdFGQcBrgkjA9wgzlclvhvwX1hHiv9ASpQIAooM_5K8PltqaD-FHzDGRXUD-BPqPj4vId7_v1t1HeSCwPqvr9hJr8SXhhMhh2dwiN-DOQMvE-Cm77a7UtmN1lxljeQcbhl-xOgxPcp6TE6Un6NK1sFB3jJ-DSECI3n8OjZk_P_CV4cTqE9-WfDS__Z8Hxvji8NzoXZCV8NZgS3kWpVlgq0fg3g0G3P4YSkfpqkv9YNaTQhPb21hWmQQn4G6VoKA08T2HWfLbCzvobXgyiE_xneQeHxxuDF08HhkxnmEPK_gvlGNFxw4Zb7EdDOktf4fg_Fr7LrGXpKpxuEf3pjCuOAhcEp-sMTU1-9H6rWuN_nVq0Nb2Am6siBci1LeMFIXDlGbmXZNXC4gw60bLkAC8HSwysOaur6pKFf-6NdGtHMqO7vuW7cHxBP5VO44wXEO7Kj08tYGEKahG8yud1-vj0spV5ncC3b1l7w19qUg5TLKSF6fe7q4vuRd8TwMZOIkCUim5wLRDZyb4Zn_nNb8YtoHZn0_emu44czJqMoiX4Kk3-Brneshd-bKXp0Mp1eCwM_rJg7meAJis44y2GifNV0TiAPbjZZzes0rNsS0cwyevqEfYjnNuA9dNp8vl25_JsNeDvZNWW_GQfnXeN78-yc2W6hqx9t46jSnXJ38J9GuJGy0aPwlBB62TI-cpFgovz0qhp4ZVq6R8wje9t3Lj-xUvVRwL8RhWy5qK863pQ32dTxgqkbbU8Lsu2JqlijzzLl1rkftvNwrPyO9MV0oi-Z0QdVlFj6WsaFe0Olamt4wZBb_nbqqhD8jCewHwUQpN4823f0-uMbKN0nYPCw0OF1xytd_XfeGQvycQcCK9g3rACMIu-nJIMjDz9ys7Pz_YmcVcHsQAHmGgvZJ1FPUqfH3xflJS1TmrILuPSjJElT6kfBxe7SyyFlcQ5RHviVH-V-zooqDZPYz4M0zckFvyQeoV7sez4JIi9YQhqSJKFx6lVRyiBHgQct483S7sFSqvrCZXovIxrHyUXDcmi0ez1KiIBH7Drda6zsQl26fcu7WqPAa7g2eprFcNPAZc9yJ-yNDbtAtp7ngxGJtcsJ8zEZPHAjXI7bEXPRqebyP09ZOyz_DgAA__-l7c93">