[llvm-bugs] [Bug 32935] New: wrong code in NewGVN on x86_64-linux-gnu (with "opt -mem2reg -instcombine -inline -loop-rotate -loop-unroll -adce -simplifycfg -instcombine -globals-aa -lcssa -loop-rotate -loop-vectorize -newgvn")

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=32935

            Bug ID: 32935
           Summary: wrong code in NewGVN on x86_64-linux-gnu (with "opt
                    -mem2reg -instcombine -inline -loop-rotate
                    -loop-unroll -adce -simplifycfg -instcombine
                    -globals-aa -lcssa -loop-rotate -loop-vectorize
                    -newgvn")
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Scalar Optimizations
          Assignee: unassignedbugs at nondot.org
          Reporter: su at cs.ucdavis.edu
                CC: llvm-bugs at lists.llvm.org

$ clang -v
clang version 5.0.0 (trunk 302200)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/clang-trunk/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/4.9.4
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5.3.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.3.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.2.0
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
$ 
$ clang -O3 -mllvm -disable-llvm-optzns -S -emit-llvm -o small.bc small.c
$ opt -mem2reg -instcombine -inline -loop-rotate -loop-unroll -adce
-simplifycfg -instcombine -globals-aa -lcssa -loop-rotate -loop-vectorize
-newgvn -o small-opt.bc small.bc
$ clang small-opt.bc
$ ./a.out
0
$ 
$ clang -O0 small.c; ./a.out
1
$ 


---------------------------------------


int a[64], b, c;

int main ()
{
  int d = 0;
  for (; d < 64; d++)
    a[d] = d;
  int e = 1;
L:
  for (c = 0; c < 1; c++)
    __builtin_printf ("%d\n", e);
  e = 0;
  while (b)
    goto L;
  return 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/20170505/e3192413/attachment.html>