[llvm-bugs] [Bug 47942] New: [PPC] Suspicious repeated condition in PPCTargetLowering.LowerBUILD_VECTOR

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=47942

            Bug ID: 47942
           Summary: [PPC] Suspicious repeated condition in
                    PPCTargetLowering.LowerBUILD_VECTOR
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Windows NT
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Backend: PowerPC
          Assignee: unassignedbugs at nondot.org
          Reporter: llvm-dev at redking.me.uk
                CC: llvm-bugs at lists.llvm.org, nemanja.i.ibm at gmail.com

Noticed by cppcheck:

// vsplti + srl self.
if (SextVal == (int)((unsigned)i >> TypeShiftAmt)) {
...
}

// vsplti + sra self.
if (SextVal == (int)((unsigned)i >> TypeShiftAmt)) {
...
}

The second condition is always dead code - its also suspicious that a "SextVal"
is being used for a logical shift right splat extraction.

Looking in a recent code coverage report, some of the other splat patterns are
not tested either:

http://lab.llvm.org:8080/coverage/coverage-reports/coverage/Users/buildslave/jenkins/workspace/coverage/llvm-project/llvm/lib/Target/PowerPC/PPCISelLowering.cpp.html

// t = vsplti c, result = vsldoi t, t, 2
// t = vsplti c, result = vsldoi t, t, 3

-- 
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/20201022/9dff1520/attachment.html>