llvm-6502/lib/Target/X86/X86ShuffleDecode.h

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//===-- X86ShuffleDecode.h - 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.
//
//===----------------------------------------------------------------------===//
#ifndef X86_SHUFFLE_DECODE_H
#define X86_SHUFFLE_DECODE_H
#include "llvm/ADT/SmallVector.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// Vector Mask Decoding
//===----------------------------------------------------------------------===//
enum {
SM_SentinelZero = ~0U
};
static inline
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>
static 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>
static 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);
}
static void DecodePSHUFMask(unsigned NElts, unsigned Imm,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts; ++i) {
ShuffleMask.push_back(Imm % NElts);
Imm /= NElts;
}
}
static 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;
}
}
static 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);
}
static void DecodePUNPCKLMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(i);
ShuffleMask.push_back(i+NElts);
}
}
static 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);
}
}
static 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;
}
}
static 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
}
}
/// DecodeUNPCKLPMask - This decodes the shuffle masks for unpcklps/unpcklpd
/// etc. NElts indicates the number of elements in the vector allowing it to
/// handle different datatypes and vector widths.
static void DecodeUNPCKLPMask(unsigned NElts,
SmallVectorImpl<unsigned> &ShuffleMask) {
for (unsigned i = 0; i != NElts/2; ++i) {
ShuffleMask.push_back(i); // Reads from dest
ShuffleMask.push_back(i+NElts); // Reads from src
}
}
#endif