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* [Bug tree-optimization/60362] New: Failure to optimize away bounds check on switch when range outside bounds is unreachable
@ 2014-02-28  1:26 kvanberendonck at gmail dot com
  2014-02-28  1:37 ` [Bug tree-optimization/60362] " pinskia at gcc dot gnu.org
  0 siblings, 1 reply; 2+ messages in thread
From: kvanberendonck at gmail dot com @ 2014-02-28  1:26 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60362

            Bug ID: 60362
           Summary: Failure to optimize away bounds check on switch when
                    range outside bounds is unreachable
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kvanberendonck at gmail dot com

Created attachment 32229
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32229&action=edit
The test program

Test program attacked. Compiled with -O3. I had to disassemble the test program
with IDA since gdb gets really confused.

In this program I've spammed __builtin_unreachable(); everywhere to try and get
gcc to optimize away this check it emits after every switch:

cmp     byte ptr [rdx+1], 5 ; switch 6 cases
ja      sub_1004012B0

gcc isn't getting the hint, and I think it's a bug.


^ permalink raw reply	[flat|nested] 2+ messages in thread

* [Bug tree-optimization/60362] Failure to optimize away bounds check on switch when range outside bounds is unreachable
  2014-02-28  1:26 [Bug tree-optimization/60362] New: Failure to optimize away bounds check on switch when range outside bounds is unreachable kvanberendonck at gmail dot com
@ 2014-02-28  1:37 ` pinskia at gcc dot gnu.org
  0 siblings, 0 replies; 2+ messages in thread
From: pinskia at gcc dot gnu.org @ 2014-02-28  1:37 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60362

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Dup of bug 51513.

*** This bug has been marked as a duplicate of bug 51513 ***


^ permalink raw reply	[flat|nested] 2+ messages in thread

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2014-02-28  1:26 [Bug tree-optimization/60362] New: Failure to optimize away bounds check on switch when range outside bounds is unreachable kvanberendonck at gmail dot com
2014-02-28  1:37 ` [Bug tree-optimization/60362] " pinskia at gcc dot gnu.org

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