[llvm-bugs] [Bug 46114] New: wrong debug info at -O3

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=46114

            Bug ID: 46114
           Summary: wrong debug info at -O3
           Product: clang
           Version: unspecified
          Hardware: PC
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: LLVM Codegen
          Assignee: unassignedclangbugs at nondot.org
          Reporter: qrzhang at gatech.edu
                CC: llvm-bugs at lists.llvm.org, neeilans at live.com,
                    richard-llvm at metafoo.co.uk

Bisection points to e5f07080b8ac73dd573e81a186925a122ab8a39d.

l_52 = 1 is a wrong value. 


$ clang-trunk -g -O3 abc.c
$ lldb-trunk -s cmds -b a.out
(lldb) b 6
Breakpoint 1: where = a.out`main + 6 at abc.c:6:20, address =
0x0000000000400486
(lldb) r
Process 2616 stopped
* thread #1, name = 'a.out', stop reason = breakpoint 1.1
    frame #0: 0x0000000000400486 a.out`main at abc.c:6:20
   3    char c;
   4    int main() {
   5      int d = a, l_52 = 0;
-> 6      b = (l_52 = a) - c; //   stop here
   7      if (d) {
   8        int e=1;
   9      }

(lldb) p l_52
(int) $0 = 1


$ cat abc.c
int a = 1;
short b;
char c;
int main() {
  int d = a, l_52 = 0;
  b = (l_52 = a) - c; //   qirun0
  if (d) {
    int e=1;
  }
}

$ cat cmds
b 6
r
p l_52
kill
q

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