<html>
    <head>
      <base href="https://bugs.llvm.org/">
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - compile-time explosion with assumes at -O3 in clang-8.0 upwards versions"
   href="https://bugs.llvm.org/show_bug.cgi?id=49206">49206</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>compile-time explosion with assumes at -O3 in clang-8.0 upwards versions
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>libraries
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>trunk
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>Scalar Optimizations
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>haoxintu@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Hi, all.

This code makes Clang-8.0 to clang-trunk versions hung on with -O3 at compile
time.

$cat s.c
#include <stdint.h>
int a;
int64_t b;
void c(int d) {
  int e;
  uint64_t f;
  int16_t g;
  int8_t i = a;
  for (;;) {
    int16_t k = i;
    uint64_t *j = d;
    for (; k; k++)
      for (; e;) {
        uint64_t *m = &f;
        if ((e += g) <= 0) {
          *m &= 4;
          if (b || *j) {
          l:
            *j *= b;
            goto l;
          }
        }
      }
  }
}

$clang -c -w -O3 s.c
//endless compiling

$clang -v
clang version 13.0.0 (<a href="https://github.com/llvm/llvm-project">https://github.com/llvm/llvm-project</a>
22f00f61dd5483a9fdaed3b7592d392c23b3646a)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir:
/home/haoxin/haoxin-data/dut-research/compilers/llvm-project/build-20210216/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Candidate multilib: .;@m64
Selected multilib: .;@m64


Thanks,
Haoxin</pre>
        </div>
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