On Thu, 2015-09-03 at 11:36 -0400, David Edelsohn wrote: > On Thu, Sep 3, 2015 at 11:20 AM, Bill Schmidt > <wschm...@linux.vnet.ibm.com> wrote: > > Hi, > > > > It was pointed out to me recently that multiplying two vector chars is > > performed using scalarization, even though we have hardware support for > > byte multiplies in vectors. This patch adds an expansion for mulv16qi3 > > to correct this. > > > > The expansion is pretty simple. We do a multiply-even and multiply-odd > > to create halfword results, and then use a permute to extract the > > low-order bytes of each result. This particular form of a permute uses > > a different set of input/output vector modes than have been used before, > > so I added the altivec_vperm_v8hiv16qi insn to represent this. (The two > > source operands are vector halfword types, while the target operand is a > > vector char type.) > > > > I've added two test variants, one to test the code generation, and one > > executable test to check correctness. One other test failed with this > > change. This turned out to be because PowerPC was excluded from the > > check_effective_target_vect_char_mult target support test. I resolved > > this by adding check_effective_target_powerpc_altivec to that test. > > > > Bootstrapped and tested on powerpc64le-unknown-linux-gnu with no > > regressions. Is this ok for trunk? > > > > Thanks, > > Bill > > > > > > [gcc] > > > > 2015-09-03 Bill Schmidt <wschm...@vnet.linux.ibm.com> > > > > * config/rs6000/altivec.md (altivec_vperm_v8hiv16qi): New > > define_insn. > > (mulv16qi3): New define_expand. > > > > [gcc/testsuite] > > > > 2015-09-03 Bill Schmidt <wschm...@vnet.linux.ibm.com> > > > > * gcc.target/powerpc/vec-mult-char-1.c: New test. > > * gcc.target/powerpc/vec-mult-char-2.c: New test. > > This is okay. > > The "bool be = BYTES_BIG_ENDIAN" and use of "be" is not a common style in GCC.
OK. I thought that helped with readability, but I will revise this to use BYTES_BIG_ENDIAN directly in the expressions. Thanks, Bill > > Thanks, David >
