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[rs6000] Enable scalar shifts of vectors

From: Richard Henderson <rth at redhat dot com>
To: dje dot gcc at gmail dot com
Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>
Date: Wed, 12 Oct 2011 15:32:46 -0700
Subject: [rs6000] Enable scalar shifts of vectors

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.

Tested on ppc64-linux, --with-cpu=G5.

Ok?


r~


	* config/rs6000/rs6000.c (rs6000_expand_vector_broadcast): New.
	* config/rs6000/rs6000-protos.h: Update.
	* config/rs6000/vector.md (ashl<VEC_I>3): New.
	(lshr<VEC_I>3, ashr<VEC_I>3): New.

Attachment: d-ppc-shiftv
Description: Text document

Follow-Ups:
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