[llvm-bugs] [Bug 31536] New: Assertion failed: (NodeToMatch->getOpcode() != ISD::DELETED_NODE && "NodeToMatch was removed partway through selection"), function SelectCodeCommon

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=31536

            Bug ID: 31536
           Summary: Assertion failed: (NodeToMatch->getOpcode() !=
                    ISD::DELETED_NODE && "NodeToMatch was removed partway
                    through selection"), function SelectCodeCommon
           Product: new-bugs
           Version: 3.9
          Hardware: PC
                OS: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: new bugs
          Assignee: unassignedbugs at nondot.org
          Reporter: dimitry at andric.com
                CC: llvm-bugs at lists.llvm.org
    Classification: Unclassified

As noted in bug 28705, the following test case, reduced from
https://bugs.freebsd.org/215649:

//////////////////////////////////////////////////////////////////////
// clang -cc1 -triple x86_64 -S -O2 -vectorize-loops testcase.cpp
double x0;
int x1, x2, x3, x4;
double *x5;
void x6() {
  x4 = (x1 & 512 - 1) + 1;
  for (; x3; x3++, x5 += x4)
    for (; x2 < 0; x2++)
      x5[x2] = x0;
}
//////////////////////////////////////////////////////////////////////

results in:

Assertion failed: (NodeToMatch->getOpcode() != ISD::DELETED_NODE &&
"NodeToMatch was removed partway through selection"), function
SelectCodeCommon, file lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp, line
3387.

It turned out that this assertion already fired in the very first
release_39 branch point, r275826, and has not been fixed during the
3.9.0 and 3.9.1 release cycles.

When I followed trunk from r275826 onwards, I ended up at Wei Mi's r276136,
which seemed to fix this assertion.  However, in bug 28705 he agrees that
r276136, and its follow-ups r278160 and r278161 just seem to paper over it.

Thus I am filing this bug as a separate case.  It may or may not be related to
bug 30775, which is about the same assertion (but with a different test case,
and it still occurs with the latest trunk, as of 2017-01-01).

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20170104/3a0ae440/attachment.html>