Cypherpunks repositories - gostls13.git/commit

author	Michael Munday <munday@ca.ibm.com>
	Mon, 11 Apr 2016 00:01:49 +0000 (20:01 -0400)
committer	Brad Fitzpatrick <bradfitz@golang.org>
	Mon, 11 Apr 2016 18:53:36 +0000 (18:53 +0000)
commit	cd6b2b7451c6feb277d38820f41f81ce4a036af2
tree	4c27f58cd9e0c84b95e4dc4edb02d86f85cec3f9	tree
parent	cabb1402568ae7d05d9d5adf56953a4792085a81	commit \| diff

cmd/internal/obj/s390x: add MULHD instruction

Emulate 64-bit signed high multiplication ((a*b)>>64). To do this
we use the 64-bit unsigned high multiplication method and then
fix the result as shown in Hacker's Delight 2nd ed., chapter 8-3.

Required to enable some division optimizations.

Change-Id: I9194f428e09d3d029cb1afb4715cd5424b5d922e
Reviewed-on: https://go-review.googlesource.com/21774
Reviewed-by: Bill O'Farrell <billotosyr@gmail.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/asm/internal/asm/testdata/s390x.s		diff \| blob \| history
src/cmd/internal/obj/s390x/a.out.go		diff \| blob \| history
src/cmd/internal/obj/s390x/anames.go		diff \| blob \| history
src/cmd/internal/obj/s390x/asmz.go		diff \| blob \| history