[llvm-bugs] [Bug 37100] New: clang crashes with "-mllvm -enable-newgvn": error in backend: Cannot lower EFLAGS copy that lives out of a basic block!

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=37100

            Bug ID: 37100
           Summary: clang crashes with "-mllvm -enable-newgvn": error in
                    backend: Cannot lower EFLAGS copy that lives out of a
                    basic block!
           Product: clang
           Version: trunk
          Hardware: PC
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: LLVM Codegen
          Assignee: unassignedclangbugs at nondot.org
          Reporter: helloqirun at gmail.com
                CC: llvm-bugs at lists.llvm.org

It appears to be a backend problem.


$ clang-trunk -v
clang version 7.0.0 (trunk 329784)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin

$ clang-trunk -mllvm -enable-newgvn -m32 -O3 abc.c
abc.c:8:9: warning: incompatible pointer types initializing 'long *' with an
expression of type 'long long **' [-Wincompatible-pointer-types]
  long *g = &e;
        ^   ~~
abc.c:9:6: warning: incompatible pointer to integer conversion assigning to
'long' from 'long long *' [-Wint-conversion]
  *g = &c;
     ^ ~~
fatal error: error in backend: Cannot lower EFLAGS copy that lives out of a
basic block!
clang-7: error: clang frontend command failed with exit code 70 (use -v to see
invocation)
clang version 7.0.0 (trunk 329784)
Target: i386-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
clang-7: note: diagnostic msg: PLEASE submit a bug report to
https://bugs.llvm.org/ and include the crash backtrace, preprocessed source,
and associated run script.
clang-7: note: diagnostic msg:
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-7: note: diagnostic msg: /tmp/abc-3be3fd.c
clang-7: note: diagnostic msg: /tmp/abc-3be3fd.sh
clang-7: note: diagnostic msg:

********************

$ cat abc.c
short a;
int b;
long long c;
long d;
long long *e;
char f;
void fn1() {
  long *g = &e;
  *g = &c;
  for (;;) {
    long h = 0;
    for (; b; b++) {
      for (; a <= 6; a++)
        ;
      a %= (h -= f > c) ?: (f = d);
      *e = 0;
    }
  }
}

-- 
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/20180412/01707097/attachment.html>