Hi Jeff On 07/12/2019 17:44, Jeff Law wrote: > On Fri, 2019-12-06 at 14:05 +0000, Sudakshina Das wrote: >> Hi >> >> While looking at the vectorization for following example, we >> realized >> that even though vectorizable_shift function was distinguishing >> vector >> shifted by vector from vector shifted by scalar, while modeling the >> cost >> it would always add the cost of building a vector constant despite >> not >> needing it for vector shifted by scalar. >> >> This patch fixes this by using scalar_shift_arg to determine whether >> we >> need to build a vector for the second operand or not. This reduces >> prologue cost as shown in the test. >> >> Build and regression tests pass on aarch64-none-elf and >> x86_64-pc-linux-gnu-gcc. This gives a 3.42% boost to 525.x264_r in >> Spec2017 for AArch64. >> >> gcc/ChangeLog: >> >> 2019-xx-xx Sudakshina Das <sudi....@arm.com> >> Richard Sandiford <richard.sandif...@arm.com> >> >> * tree-vect-stmt.c (vectorizable_shift): Condition ndts for >> vect_model_simple_cost call on scalar_shift_arg. >> >> gcc/testsuite/ChangeLog: >> >> 2019-xx-xx Sudakshina Das <sudi....@arm.com> >> >> * gcc.dg/vect/vect-shift-5.c: New test. > It's a bit borderline, but it's really just twiddling a cost, so OK.
Thanks :) Committed as r279114. Sudi > > jeff >
