[llvm-bugs] [Bug 43719] New: [AARCH64] vector zext hangs/crashes with NEON disabled

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=43719

            Bug ID: 43719
           Summary: [AARCH64] vector zext hangs/crashes with NEON disabled
           Product: libraries
           Version: trunk
          Hardware: Other
                OS: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: Backend: AArch64
          Assignee: unassignedbugs at nondot.org
          Reporter: husseydevin at gmail.com
                CC: arnaud.degrandmaison at arm.com,
                    llvm-bugs at lists.llvm.org, peter.smith at linaro.org,
                    Ties.Stuij at arm.com

define @zext_v2xi32(<2 x i32> %vec)
{
    %extended = zext <2 x i32> %vec to <2 x i64>
    ret <2 x i64> %extended
}

llc -march=aarch64 -mattr=-neon

I would expect something like this (if I am correct in that <2 x i32> is passed
as i32 *):

zext_v2xi32:
    ldp   w0, w1, [x0]
    ret

But instead, I either get a segfault (on Termux's 8.0.1 build), or an infinite
loop (9.0.0 on archlinuxarm or trunk w/debug). With every other known
architecture, SIMD types still scalarize properly with SIMD disabled, given
that llvm intrinsics aren't used.

Enabling debug output in llc spams this:

Combining: t7: i64 = Constant<0>

Combining: t6: v2i64 = zero_extend t5
Creating new node: tNNNNN: v1i64 = extract_subvector t6, Constant:i64<0>
Creating new node: tNNNNN+1: v1i64 = extract_subvector t6, Constant:i64<1>

-- 
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/20191019/5fe2a74c/attachment.html>