From: Richard Henderson <r...@redhat.com> Date: Wed, 12 Oct 2011 15:32:46 -0700
> I suppose technically the middle-end could be improved to implement > ashl<mode> as vashl<mode> by broadcasting the scalar, but Altivec > is the only extant SIMD ISA that would make use of this. All of > the others can arrange for constant shifts to be encoded into the > insn, and so implement the ashl<mode> named pattern. I'm pretty sure Sparc's VIS3 can do this too, see the '<vis3_shift_insn><vbits>_vis' patterns in sparc.md
