This patch detects the AVG pattern in vectorized code, which is simply
c = (a + b + 1) / 2, where a, b, and c have the same type which are vectors of
either unsigned i8 or unsigned i16. In the IR, i8/i16 will be promoted to
i32 before any arithmetic operations. The following IR shows such an example:
%1 = zext <N x i8> %a to <N x i32>
%2 = zext <N x i8> %b to <N x i32>
%3 = add nuw nsw <N x i32> %1, <i32 1 x N>
%4 = add nuw nsw <N x i32> %3, %2
%5 = lshr <N x i32> %N, <i32 1 x N>
%6 = trunc <N x i32> %5 to <N x i8>
and with this patch it will be converted to a X86ISD::AVG instruction.
The pattern recognition is done when combining instructions just before type
legalization during instruction selection. We do it here because after type
legalization, it is much more difficult to do pattern recognition based
on many instructions that are doing type conversions. Therefore, for
target-specific instructions (like X86ISD::AVG), we need to take care of type
legalization by ourselves. However, as X86ISD::AVG behaves similarly to
ISD::ADD, I am wondering if there is a way to legalize operands and result
types of X86ISD::AVG together with ISD::ADD. It seems that the current design
doesn't support this idea.
Tests are added for SSE2, AVX2, and AVX512BW and both i8 and i16 types of
variant vector sizes.
Differential revision: http://reviews.llvm.org/D14761
llvm-svn: 253952
convert float to half with mask/maskz for the reg to reg version and mask for the reg to mem version (there is no maskz version for reg to mem).
Differential Revision: http://reviews.llvm.org/D14113
llvm-svn: 251409
The XOP vector integer comparisons can deal with all signed/unsigned comparison cases directly and can be easily commuted as well (D7646).
llvm-svn: 249976
The XOP shifts just have logical/arithmetic versions and the left/right shifts are controlled by whether the value is positive/negative. Because of this I've added new X86ISD nodes instead of trying to force them to use the existing shift nodes.
Additionally Excavator cores (bdver4) support XOP and AVX2 - meaning that it should use the AVX2 shifts when it can and fall back to XOP in other cases.
Differential Revision: http://reviews.llvm.org/D8690
llvm-svn: 248878
This patches removes the x86.sse41.pmovsx* intrinsics, provides a suitable upgrade path and updates relevant tests to sign extend a subvector instead.
LLVM counterpart to D12835
Differential Revision: http://reviews.llvm.org/D13002
llvm-svn: 248368
This commit broke the build. Numerous build bots broken, and it was
blocking my progress so reverting.
It should be trivial to reproduce -- enable the BPF backend and it
should fail when running llvm-tblgen.
llvm-svn: 242992
This patch adds support for v8i16 and v16i8 shuffle lowering using the immediate versions of the SSE4A EXTRQ and INSERTQ instructions. Although rather limited (they can only act on the lower 64-bits of the source vectors, leave the upper 64-bits of the result vector undefined and don't have VEX encoded variants), the instructions are still useful for the zero extension of any lane (EXTRQ) or inserting a lane into another vector (INSERTQ). Testing demonstrated that it wasn't typically worth it to use these instructions for v2i64 or v4i32 vector shuffles although they are capable of it.
As well as adding specific pattern matching for the shuffles, the patch uses EXTRQ for zero extension cases where SSE41 isn't available and its more efficient than the SSE2 'unpack' default approach. It also adds shuffle decode support for the EXTRQ / INSERTQ cases when the instructions are handling full byte-sized extractions / insertions.
From this foundation, future patches will be able to make use of the instructions for situations that use their ability to extract/insert at the bit level.
Differential Revision: http://reviews.llvm.org/D10146
llvm-svn: 241508
With the completion of D9746 there is now a common implementation of integer signed/unsigned min/max nodes, removing the need for the equivalent X86 specific implementations.
This patch removes the old X86ISD nodes, legalizes the relevant SSE2/SSE41/AVX2/AVX512 instructions for the ISD versions and converts the small amount of existing X86 code.
Differential Revision: http://reviews.llvm.org/D10947
llvm-svn: 241506
Cong Hou