llvm-6502/lib/Target/X86/Utils/X86ShuffleDecode.cpp
Bruno Cardoso Lopes 53cae1362d The VPERM2F128 is a AVX instruction which permutes between two 256-bit
vectors. It operates on 128-bit elements instead of regular scalar
types. Recognize shuffles that are suitable for VPERM2F128 and teach
the x86 legalizer how to handle them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137519 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-12 21:48:26 +00:00

244 lines
8.1 KiB
C++

//===-- X86ShuffleDecode.cpp - X86 shuffle decode logic -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Define several functions to decode x86 specific shuffle semantics into a
// generic vector mask.
//
//===----------------------------------------------------------------------===//
#include "X86ShuffleDecode.h"
//===----------------------------------------------------------------------===//
// Vector Mask Decoding
//===----------------------------------------------------------------------===//
namespace llvm {
void DecodeINSERTPSMask(unsigned Imm, SmallVectorImpl<unsigned> &ShuffleMask) {
// Defaults the copying the dest value.
ShuffleMask.push_back(0);
ShuffleMask.push_back(1);
ShuffleMask.push_back(2);
ShuffleMask.push_back(3);
// Decode the immediate.
unsigned ZMask = Imm & 15;
unsigned CountD = (Imm >> 4) & 3;
unsigned CountS = (Imm >> 6) & 3;
// CountS selects which input element to use.
unsigned InVal = 4+CountS;
// CountD specifies which element of destination to update.
ShuffleMask[CountD] = InVal;
// ZMask zaps values, potentially overriding the CountD elt.
if (ZMask & 1) ShuffleMask[0] = SM_SentinelZero;
if (ZMask & 2) ShuffleMask[1] = SM_SentinelZero;
if (ZMask & 4) ShuffleMask[2] = SM_SentinelZero;
if (ZMask & 8) ShuffleMask[3] = SM_SentinelZero;
}
// <3,1> or <6,7,2,3>
void DecodeMOVHLPSMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = NElts/2; i != NElts; ++i)
ShuffleMask.push_back(NElts+i);
for (unsigned i = NElts/2; i != NElts; ++i)
ShuffleMask.push_back(i);
}
// <0,2> or <0,1,4,5>
void DecodeMOVLHPSMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts/2; ++i)
ShuffleMask.push_back(i);
for (unsigned i = 0; i != NElts/2; ++i)
ShuffleMask.push_back(NElts+i);
}
void DecodePSHUFMask(unsigned NElts, unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts; ++i) {
ShuffleMask.push_back(Imm % NElts);
Imm /= NElts;
}
}
void DecodePSHUFHWMask(unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
ShuffleMask.push_back(0);
ShuffleMask.push_back(1);
ShuffleMask.push_back(2);
ShuffleMask.push_back(3);
for (unsigned i = 0; i != 4; ++i) {
ShuffleMask.push_back(4+(Imm & 3));
Imm >>= 2;
}
}
void DecodePSHUFLWMask(unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != 4; ++i) {
ShuffleMask.push_back((Imm & 3));
Imm >>= 2;
}
ShuffleMask.push_back(4);
ShuffleMask.push_back(5);
ShuffleMask.push_back(6);
ShuffleMask.push_back(7);
}
void DecodePUNPCKLBWMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
DecodeUNPCKLPMask(MVT::getVectorVT(MVT::i8, NElts), ShuffleMask);
}
void DecodePUNPCKLWDMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
DecodeUNPCKLPMask(MVT::getVectorVT(MVT::i16, NElts), ShuffleMask);
}
void DecodePUNPCKLDQMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
DecodeUNPCKLPMask(MVT::getVectorVT(MVT::i32, NElts), ShuffleMask);
}
void DecodePUNPCKLQDQMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
DecodeUNPCKLPMask(MVT::getVectorVT(MVT::i64, NElts), ShuffleMask);
}
void DecodePUNPCKLMask(EVT VT,
SmallVectorImpl<unsigned> &ShuffleMask) {
DecodeUNPCKLPMask(VT, ShuffleMask);
}
void DecodePUNPCKHMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(i+NElts/2);
ShuffleMask.push_back(i+NElts+NElts/2);
}
}
void DecodeSHUFPSMask(unsigned NElts, unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
// Part that reads from dest.
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(Imm % NElts);
Imm /= NElts;
}
// Part that reads from src.
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(Imm % NElts + NElts);
Imm /= NElts;
}
}
void DecodeUNPCKHPMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(i+NElts/2); // Reads from dest
ShuffleMask.push_back(i+NElts+NElts/2); // Reads from src
}
}
void DecodeUNPCKLPSMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
DecodeUNPCKLPMask(MVT::getVectorVT(MVT::i32, NElts), ShuffleMask);
}
void DecodeUNPCKLPDMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
DecodeUNPCKLPMask(MVT::getVectorVT(MVT::i64, NElts), ShuffleMask);
}
/// DecodeUNPCKLPMask - This decodes the shuffle masks for unpcklps/unpcklpd
/// etc. VT indicates the type of the vector allowing it to handle different
/// datatypes and vector widths.
void DecodeUNPCKLPMask(EVT VT,
SmallVectorImpl<unsigned> &ShuffleMask) {
unsigned NumElts = VT.getVectorNumElements();
// Handle 128 and 256-bit vector lengths. AVX defines UNPCK* to operate
// independently on 128-bit lanes.
unsigned NumLanes = VT.getSizeInBits() / 128;
if (NumLanes == 0 ) NumLanes = 1; // Handle MMX
unsigned NumLaneElts = NumElts / NumLanes;
unsigned Start = 0;
unsigned End = NumLaneElts / 2;
for (unsigned s = 0; s < NumLanes; ++s) {
for (unsigned i = Start; i != End; ++i) {
ShuffleMask.push_back(i); // Reads from dest/src1
ShuffleMask.push_back(i+NumLaneElts); // Reads from src/src2
}
// Process the next 128 bits.
Start += NumLaneElts;
End += NumLaneElts;
}
}
// DecodeVPERMILPSMask - Decodes VPERMILPS permutes for any 128-bit 32-bit
// elements. For 256-bit vectors, it's considered as two 128 lanes, the
// referenced elements can't cross lanes and the mask of the first lane must
// be the same of the second.
void DecodeVPERMILPSMask(unsigned NumElts, unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
unsigned NumLanes = (NumElts*32)/128;
unsigned LaneSize = NumElts/NumLanes;
for (unsigned l = 0; l != NumLanes; ++l) {
for (unsigned i = 0; i != LaneSize; ++i) {
unsigned Idx = (Imm >> (i*2)) & 0x3 ;
ShuffleMask.push_back(Idx+(l*LaneSize));
}
}
}
// DecodeVPERMILPDMask - Decodes VPERMILPD permutes for any 128-bit 64-bit
// elements. For 256-bit vectors, it's considered as two 128 lanes, the
// referenced elements can't cross lanes but the mask of the first lane can
// be the different of the second (not like VPERMILPS).
void DecodeVPERMILPDMask(unsigned NumElts, unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
unsigned NumLanes = (NumElts*64)/128;
unsigned LaneSize = NumElts/NumLanes;
for (unsigned l = 0; l < NumLanes; ++l) {
for (unsigned i = l*LaneSize; i < LaneSize*(l+1); ++i) {
unsigned Idx = (Imm >> i) & 0x1;
ShuffleMask.push_back(Idx+(l*LaneSize));
}
}
}
void DecodeVPERM2F128Mask(EVT VT, unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
unsigned HalfSize = VT.getVectorNumElements()/2;
unsigned FstHalfBegin = (Imm & 0x3) * HalfSize;
unsigned SndHalfBegin = ((Imm >> 4) & 0x3) * HalfSize;
for (int i = FstHalfBegin, e = FstHalfBegin+HalfSize; i != e; ++i)
ShuffleMask.push_back(i);
for (int i = SndHalfBegin, e = SndHalfBegin+HalfSize; i != e; ++i)
ShuffleMask.push_back(i);
}
void DecodeVPERM2F128Mask(unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
// VPERM2F128 is used by any 256-bit EVT, but X86InstComments only
// has information about the instruction and not the types. So for
// instruction comments purpose, assume the 256-bit vector is v4i64.
return DecodeVPERM2F128Mask(MVT::v4i64, Imm, ShuffleMask);
}
} // llvm namespace