[llvm-bugs] [Bug 28102] New: clang generates invalid assembly on ppc64le

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=28102

            Bug ID: 28102
           Summary: clang generates invalid assembly on ppc64le
           Product: clang
           Version: 3.5
          Hardware: Other
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P
         Component: C++11
          Assignee: unassignedclangbugs at nondot.org
          Reporter: kb9vqf at pearsoncomputing.net
                CC: dgregor at apple.com, llvm-bugs at lists.llvm.org
    Classification: Unclassified

Created attachment 16523
  --> https://llvm.org/bugs/attachment.cgi?id=16523&action=edit
Test case

When building a large, proprietary codebase against ppc64le for the first time,
clang generated an invalid intermediate assembly file.

Reducing the failing code as much as possible yielded the attached test case. 
It generates a significant amount of assembler output, but the most critical
section is:

.L0_0_set_4294967295 = ".LBB0_-1"-.LJTI0_0
.L0_0_set_3 = .LBB0_3-.LJTI0_0
.L0_0_set_4 = .LBB0_4-.LJTI0_0
.L0_0_set_5 = .LBB0_5-.LJTI0_0

There appears to be integer wrap-around causing an invalid .LBB label to be
generated.  Reducing the number of the case statements in the switch block
resolved the failure, and the failure remained when adding additional
statements, implying clang is not handling anything over 5 statements correctly
in this case.

clang arguments were:
-fPIC -Wno-switch -Wno-unused-value -fvisibility=hidden -DNDEBUG -g -O2 -v
-save-temps -std=c++11

The relevant sections of the generated assembler file are attached.  I (likely)
cannot post code outside of the provided sections due to license restrictions
on the codebase.

Please let me know if you  need any further information!

-- 
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/20160613/e2c51704/attachment-0001.html>