Commit Graph

4 Commits

Author SHA1 Message Date
Simon Pilgrim cacf4db571 [CostModel][X86] Add scalar sext/zext cost tests
llvm-svn: 370684
2019-09-02 21:02:51 +00:00
Craig Topper 30d3e9c395 [X86][CostModel] Adjust the costs of ZERO_EXTEND/SIGN_EXTEND with less than 128-bit inputs
Now that we legalize by widening, the element types here won't change. Previously these were modeled as the elements being widened and then the instruction might become an AND or SHL/ASHR pair. But now they'll become something like a ZERO_EXTEND_VECTOR_INREG/SIGN_EXTEND_VECTOR_INREG.

For AVX2, when the destination type is legal its clear the cost should be 1 since we have extend instructions that can produce 256 bit vectors from less than 128 bit vectors. I'm a little less sure about AVX1 costs, but I think the ones I changed were definitely too high, but they might still be too high.

Differential Revision: https://reviews.llvm.org/D66169

llvm-svn: 368858
2019-08-14 14:52:39 +00:00
Craig Topper d3bb036bc9 [X86] Add some cost model entries for sext/zext for avx512bw
This fixes some of scalarization costs reported for sext/zext using avx512bw. This does not fix all scalarization costs being reported. Just the worst.

I've restricted this only to combinations of types that are legal with avx512bw like v32i1/v64i1/v32i16/v64i8 and conversions between vXi1 and vXi8/vXi16 with legal vXi8/vXi16 result types.

Differential Revision: https://reviews.llvm.org/D54979

llvm-svn: 347785
2018-11-28 18:11:39 +00:00
Craig Topper 5e7dcc65bd [X86] Add exhaustive cost model testing for sext/zext for all vector types we reasonably support. Add cost model tests for truncating to vXi1.
Our sext/zext cost modeling was somewhat incomplete. And had no coverage for the fact that avx512bw v32i16/v64i8 types return a scalarization cost.

Truncates are a whole different mess because isTruncateFree is returning true for vectors when it shouldn't and that's the fall back for anything not in the tables.

llvm-svn: 347719
2018-11-27 22:46:05 +00:00