[LLVMdev] Spilling & UNPCKLPS Question

[David Greene]

I'm working on adding some more annotations to asm and I
cam across this odd construct generated for X86/split-vector-rem.ll:

        movss   %xmm0, 32(%rsp)                         # Scalar Spill
[...]
        unpcklps        48(%rsp), %xmm0                 # Vector Folded Reload
[...]
        movaps  %xmm0, 16(%rsp)                         # Vector Spill
[...]
        unpcklps        32(%rsp), %xmm0                 # Vector Folded Reload

How is this possibly legal?  First we spill %xmm0 (a 32-bit value)
to a stack slot that's onlt 16 bits wide (the next $rsp offsets are 48
and 16).  Then we load 64 bits from 32(%rsp) via unpcklps and consider it a 
reload of the spill.

This seems really wrong.  Can someone explain?

                             -Dave