[llvm-bugs] [Bug 51984] New: [X86] Can we not skip ZEXT's, not only SEXT's, for GATHER's?

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=51984

            Bug ID: 51984
           Summary: [X86] Can we not skip ZEXT's, not only SEXT's, for
                    GATHER's?
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Backend: X86
          Assignee: unassignedbugs at nondot.org
          Reporter: lebedev.ri at gmail.com
                CC: craig.topper at gmail.com, llvm-bugs at lists.llvm.org,
                    llvm-dev at redking.me.uk, pengfei.wang at intel.com,
                    spatel+llvm at rotateright.com

I was trying to evaluate if znver3 should be marked
as having fast gathers (i believe it should me.),
and stumbled into this:

https://godbolt.org/z/r5qPnMsWj

It's pretty expected that we split the GATHER
because the index is too wide, iff we can't tell that we can narrow it,
but can we not narrow the ZEXT just like we do SEXT?

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