<html>
    <head>
      <base href="http://llvm.org/bugs/" />
    </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 --- - Excessive compile time when using -fsanitize=undefined"
   href="http://llvm.org/bugs/show_bug.cgi?id=19163">19163</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Excessive compile time when using -fsanitize=undefined
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>new-bugs
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>unspecified
          </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>new bugs
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>octoploid@yandex.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvmbugs@cs.uiuc.edu
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>The attached file takes almost 9 minutes to compile on my machine:

markus@x4 blink % time clang++ -fsanitize=undefined -fno-sanitize=vptr -c 
-Qunused-arguments -Qunused-arguments -Wall -Wpointer-arith
-Woverloaded-virtual -Werror=return-type -Werror=int-to-pointer-cast
-Wtype-limits -Wempty-body -Wsign-compare -Wno-invalid-offsetof
-Wno-inline-new-delete -Wno-c++0x-extensions -Wno-extended-offsetof
-Wno-unknown-warning-option -Wno-return-type-c-linkage -Wno-mismatched-tags
-march=native -fno-exceptions -fno-strict-aliasing -fno-rtti -fno-exceptions
-fno-math-errno -std=gnu++0x -pthread -pipe -DDEBUG -D_DEBUG -DTRACING -g -O3
-fno-omit-frame-pointer Unified_cpp_content_media_webaudio_blink0.ii

clang++ -fsanitize=undefined -fno-sanitize=vptr -c -Qunused-arguments  -Wall  
531.00s user 0.09s system 100% cpu 8:51.00 total

Without -fsanitize=undefined it takes 3.3 seconds.

Perf shows:
 61.78%  libLLVMCodeGen.so  [.] (anonymous
namespace)::InlineSpiller::propagateSiblingValue(llvm::DenseMapIterator<llvm::VNInfo*,
(anonymous namespace)::InlineSpille
 12.88%  libLLVMCodeGen.so  [.] (anonymous
namespace)::InlineSpiller::traceSiblingValue(unsigned int, llvm::VNInfo*,
llvm::VNInfo*)
...</pre>
        </div>
      </p>
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