Commit Graph

4 Commits

Author SHA1 Message Date
Ayman Musa 86c00b799f [X86][AVX512] Detect repeated constant patterns in BUILD_VECTOR suitable for broadcasting.
Check if a build_vector node includes a repeated constant pattern and replace it with a broadcast of that pattern.
For example:
"build_vector <0, 1, 2, 3, 0, 1, 2, 3>" would be replaced by "broadcast <0, 1, 2, 3>"

Differential Revision: https://reviews.llvm.org/D26802

llvm-svn: 288804
2016-12-06 12:24:14 +00:00
Simon Pilgrim 890b415902 [X86][SSE] Regenerate vector shift tests
llvm-svn: 274987
2016-07-09 20:55:20 +00:00
Sanjay Patel 7c6eaf03d7 fixed to test features, not CPUs
llvm-svn: 231512
2015-03-06 20:46:16 +00:00
Andrea Di Biagio 386d566395 [X86] Teach the backend how to lower vector shift left into multiply rather than scalarizing it.
Instead of expanding a packed shift into a sequence of scalar shifts,
the backend now tries (when possible) to convert the vector shift into a
vector multiply.

Before this change, a shift of a MVT::v8i16 vector by a
build_vector of constants was always scalarized into a long sequence of "vector
extracts + scalar shifts + vector insert".
With this change, if there is SSE2 support, we emit a single vector multiply.

This change also affects SSE4.1, AVX, AVX2 shifts:
 - A shift of a MVT::v4i32 vector by a build_vector of non uniform constants
is now lowered when possible into a single SSE4.1 vector multiply.
 - Packed v16i16 shift left by constant build_vector are now expanded when
possible into a single AVX2 vpmullw.
This change also improves the lowering of AVX512f vector shifts.

Added test CodeGen/X86/vec_shift6.ll with some code examples that are affected
by this change.

llvm-svn: 201271
2014-02-12 23:42:28 +00:00