[Bug 1856682] Comment bridged from LTC Bugzilla

[bugproxy]

------- Comment From Andreas.Krebbel at de.ibm.com 2019-12-17 06:42 EDT-------
(In reply to comment #7)
> which releases need a fix?

All releases on GCC 5 branch starting with 5.2
and all releases on 6, 7, 8, and 9 branches unfortunately.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to gcc-8 in Ubuntu.
https://bugs.launchpad.net/bugs/1856682

Title:
  GCC Miscompilation in vectorized code

Status in Ubuntu on IBM z Systems:
  Triaged
Status in gcc-7 package in Ubuntu:
  New
Status in gcc-8 package in Ubuntu:
  New
Status in gcc-9 package in Ubuntu:
  New

Bug description:
  Miscompilation in autovectorized code.
   
  ---Steps to Reproduce---
   See GCC BZ: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92950

  The following testcase abort when being compiled with -O3 -march=z13
  on IBM Z:

  struct a {
    int b;
    char c;
  };
  struct a d = {1, 16};
  struct a *e = &d;

  int f = 0;

  int main() {
    struct a g = {0, 0 };
    f = 0;

    for (; f <= 1; f++) {
      g = d;
      *e = g;
    }

    if (d.c != 16)
      __builtin_abort();
  }

  The movv1qi pattern emits halfword load instructions instead of character
  loads.

  All GCC versions since GCC 5 are affected.
  Patches for GCC 8, 9, and 10 have been committed to the gcc.gnu.org branches.
   
  Userspace tool common name: gcc  
  The userspace tool has the following bit modes: 64 
  Userspace rpm: various Ubuntu gcc packages

  
  Package need to updated within LP

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu-z-systems/+bug/1856682/+subscriptions