[llvm-bugs] [Bug 36212] New: AVX-512: VPBROADCASTD from general purpose register is suboptimal?

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=36212

            Bug ID: 36212
           Summary: AVX-512: VPBROADCASTD from general purpose register is
                    suboptimal?
           Product: libraries
           Version: 6.0
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Backend: X86
          Assignee: unassignedbugs at nondot.org
          Reporter: nekotekina at gmail.com
                CC: llvm-bugs at lists.llvm.org

Hello, I notice that LLVM likes to emit instructions like:
mov r9d, ...
vpbroadcastd xmm0{k1}, r9d

On the other hand, broadcast from the xmm register should have better latency:
vpbroadcastd xmm0{k1}, xmm1

I'm not an expert, but from what I know it's better to avoid any gpr<>xmm
transition because it's penalized.

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