mirror of
https://github.com/RPCSX/llvm.git
synced 2024-12-16 00:16:50 +00:00
ae9f3a3b7c
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47367 91177308-0d34-0410-b5e6-96231b3b80d8
498 lines
16 KiB
C++
498 lines
16 KiB
C++
//===-- PerfectShuffle.cpp - Perfect Shuffle Generator --------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file computes an optimal sequence of instructions for doing all shuffles
|
|
// of two 4-element vectors. With a release build and when configured to emit
|
|
// an altivec instruction table, this takes about 30s to run on a 2.7Ghz
|
|
// PowerPC G5.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include <iostream>
|
|
#include <vector>
|
|
#include <cassert>
|
|
#include <cstdlib>
|
|
struct Operator;
|
|
|
|
// Masks are 4-nibble hex numbers. Values 0-7 in any nibble means that it takes
|
|
// an element from that value of the input vectors. A value of 8 means the
|
|
// entry is undefined.
|
|
|
|
// Mask manipulation functions.
|
|
static inline unsigned short MakeMask(unsigned V0, unsigned V1,
|
|
unsigned V2, unsigned V3) {
|
|
return (V0 << (3*4)) | (V1 << (2*4)) | (V2 << (1*4)) | (V3 << (0*4));
|
|
}
|
|
|
|
/// getMaskElt - Return element N of the specified mask.
|
|
static unsigned getMaskElt(unsigned Mask, unsigned Elt) {
|
|
return (Mask >> ((3-Elt)*4)) & 0xF;
|
|
}
|
|
|
|
static unsigned setMaskElt(unsigned Mask, unsigned Elt, unsigned NewVal) {
|
|
unsigned FieldShift = ((3-Elt)*4);
|
|
return (Mask & ~(0xF << FieldShift)) | (NewVal << FieldShift);
|
|
}
|
|
|
|
// Reject elements where the values are 9-15.
|
|
static bool isValidMask(unsigned short Mask) {
|
|
unsigned short UndefBits = Mask & 0x8888;
|
|
return (Mask & ((UndefBits >> 1)|(UndefBits>>2)|(UndefBits>>3))) == 0;
|
|
}
|
|
|
|
/// hasUndefElements - Return true if any of the elements in the mask are undefs
|
|
///
|
|
static bool hasUndefElements(unsigned short Mask) {
|
|
return (Mask & 0x8888) != 0;
|
|
}
|
|
|
|
/// isOnlyLHSMask - Return true if this mask only refers to its LHS, not
|
|
/// including undef values..
|
|
static bool isOnlyLHSMask(unsigned short Mask) {
|
|
return (Mask & 0x4444) == 0;
|
|
}
|
|
|
|
/// getLHSOnlyMask - Given a mask that refers to its LHS and RHS, modify it to
|
|
/// refer to the LHS only (for when one argument value is passed into the same
|
|
/// function twice).
|
|
#if 0
|
|
static unsigned short getLHSOnlyMask(unsigned short Mask) {
|
|
return Mask & 0xBBBB; // Keep only LHS and Undefs.
|
|
}
|
|
#endif
|
|
|
|
/// getCompressedMask - Turn a 16-bit uncompressed mask (where each elt uses 4
|
|
/// bits) into a compressed 13-bit mask, where each elt is multiplied by 9.
|
|
static unsigned getCompressedMask(unsigned short Mask) {
|
|
return getMaskElt(Mask, 0)*9*9*9 + getMaskElt(Mask, 1)*9*9 +
|
|
getMaskElt(Mask, 2)*9 + getMaskElt(Mask, 3);
|
|
}
|
|
|
|
static void PrintMask(unsigned i, std::ostream &OS) {
|
|
OS << "<" << (char)(getMaskElt(i, 0) == 8 ? 'u' : ('0'+getMaskElt(i, 0)))
|
|
<< "," << (char)(getMaskElt(i, 1) == 8 ? 'u' : ('0'+getMaskElt(i, 1)))
|
|
<< "," << (char)(getMaskElt(i, 2) == 8 ? 'u' : ('0'+getMaskElt(i, 2)))
|
|
<< "," << (char)(getMaskElt(i, 3) == 8 ? 'u' : ('0'+getMaskElt(i, 3)))
|
|
<< ">";
|
|
}
|
|
|
|
/// ShuffleVal - This represents a shufflevector operation.
|
|
struct ShuffleVal {
|
|
unsigned Cost; // Number of instrs used to generate this value.
|
|
Operator *Op; // The Operation used to generate this value.
|
|
unsigned short Arg0, Arg1; // Input operands for this value.
|
|
|
|
ShuffleVal() : Cost(1000000) {}
|
|
};
|
|
|
|
|
|
/// ShufTab - This is the actual shuffle table that we are trying to generate.
|
|
///
|
|
static ShuffleVal ShufTab[65536];
|
|
|
|
/// TheOperators - All of the operators that this target supports.
|
|
static std::vector<Operator*> TheOperators;
|
|
|
|
/// Operator - This is a vector operation that is available for use.
|
|
struct Operator {
|
|
unsigned short ShuffleMask;
|
|
unsigned short OpNum;
|
|
const char *Name;
|
|
|
|
Operator(unsigned short shufflemask, const char *name, unsigned opnum)
|
|
: ShuffleMask(shufflemask), OpNum(opnum), Name(name) {
|
|
TheOperators.push_back(this);
|
|
}
|
|
~Operator() {
|
|
assert(TheOperators.back() == this);
|
|
TheOperators.pop_back();
|
|
}
|
|
|
|
bool isOnlyLHSOperator() const {
|
|
return isOnlyLHSMask(ShuffleMask);
|
|
}
|
|
|
|
const char *getName() const { return Name; }
|
|
|
|
unsigned short getTransformedMask(unsigned short LHSMask, unsigned RHSMask) {
|
|
// Extract the elements from LHSMask and RHSMask, as appropriate.
|
|
unsigned Result = 0;
|
|
for (unsigned i = 0; i != 4; ++i) {
|
|
unsigned SrcElt = (ShuffleMask >> (4*i)) & 0xF;
|
|
unsigned ResElt;
|
|
if (SrcElt < 4)
|
|
ResElt = getMaskElt(LHSMask, SrcElt);
|
|
else if (SrcElt < 8)
|
|
ResElt = getMaskElt(RHSMask, SrcElt-4);
|
|
else {
|
|
assert(SrcElt == 8 && "Bad src elt!");
|
|
ResElt = 8;
|
|
}
|
|
Result |= ResElt << (4*i);
|
|
}
|
|
return Result;
|
|
}
|
|
};
|
|
|
|
static const char *getZeroCostOpName(unsigned short Op) {
|
|
if (ShufTab[Op].Arg0 == 0x0123)
|
|
return "LHS";
|
|
else if (ShufTab[Op].Arg0 == 0x4567)
|
|
return "RHS";
|
|
else {
|
|
assert(0 && "bad zero cost operation");
|
|
abort();
|
|
}
|
|
}
|
|
|
|
static void PrintOperation(unsigned ValNo, unsigned short Vals[]) {
|
|
unsigned short ThisOp = Vals[ValNo];
|
|
std::cerr << "t" << ValNo;
|
|
PrintMask(ThisOp, std::cerr);
|
|
std::cerr << " = " << ShufTab[ThisOp].Op->getName() << "(";
|
|
|
|
if (ShufTab[ShufTab[ThisOp].Arg0].Cost == 0) {
|
|
std::cerr << getZeroCostOpName(ShufTab[ThisOp].Arg0);
|
|
PrintMask(ShufTab[ThisOp].Arg0, std::cerr);
|
|
} else {
|
|
// Figure out what tmp # it is.
|
|
for (unsigned i = 0; ; ++i)
|
|
if (Vals[i] == ShufTab[ThisOp].Arg0) {
|
|
std::cerr << "t" << i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!ShufTab[Vals[ValNo]].Op->isOnlyLHSOperator()) {
|
|
std::cerr << ", ";
|
|
if (ShufTab[ShufTab[ThisOp].Arg1].Cost == 0) {
|
|
std::cerr << getZeroCostOpName(ShufTab[ThisOp].Arg1);
|
|
PrintMask(ShufTab[ThisOp].Arg1, std::cerr);
|
|
} else {
|
|
// Figure out what tmp # it is.
|
|
for (unsigned i = 0; ; ++i)
|
|
if (Vals[i] == ShufTab[ThisOp].Arg1) {
|
|
std::cerr << "t" << i;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
std::cerr << ") ";
|
|
}
|
|
|
|
static unsigned getNumEntered() {
|
|
unsigned Count = 0;
|
|
for (unsigned i = 0; i != 65536; ++i)
|
|
Count += ShufTab[i].Cost < 100;
|
|
return Count;
|
|
}
|
|
|
|
static void EvaluateOps(unsigned short Elt, unsigned short Vals[],
|
|
unsigned &NumVals) {
|
|
if (ShufTab[Elt].Cost == 0) return;
|
|
|
|
// If this value has already been evaluated, it is free. FIXME: match undefs.
|
|
for (unsigned i = 0, e = NumVals; i != e; ++i)
|
|
if (Vals[i] == Elt) return;
|
|
|
|
// Otherwise, get the operands of the value, then add it.
|
|
unsigned Arg0 = ShufTab[Elt].Arg0, Arg1 = ShufTab[Elt].Arg1;
|
|
if (ShufTab[Arg0].Cost)
|
|
EvaluateOps(Arg0, Vals, NumVals);
|
|
if (Arg0 != Arg1 && ShufTab[Arg1].Cost)
|
|
EvaluateOps(Arg1, Vals, NumVals);
|
|
|
|
Vals[NumVals++] = Elt;
|
|
}
|
|
|
|
|
|
int main() {
|
|
// Seed the table with accesses to the LHS and RHS.
|
|
ShufTab[0x0123].Cost = 0;
|
|
ShufTab[0x0123].Op = 0;
|
|
ShufTab[0x0123].Arg0 = 0x0123;
|
|
ShufTab[0x4567].Cost = 0;
|
|
ShufTab[0x4567].Op = 0;
|
|
ShufTab[0x4567].Arg0 = 0x4567;
|
|
|
|
// Seed the first-level of shuffles, shuffles whose inputs are the input to
|
|
// the vectorshuffle operation.
|
|
bool MadeChange = true;
|
|
unsigned OpCount = 0;
|
|
while (MadeChange) {
|
|
MadeChange = false;
|
|
++OpCount;
|
|
std::cerr << "Starting iteration #" << OpCount << " with "
|
|
<< getNumEntered() << " entries established.\n";
|
|
|
|
// Scan the table for two reasons: First, compute the maximum cost of any
|
|
// operation left in the table. Second, make sure that values with undefs
|
|
// have the cheapest alternative that they match.
|
|
unsigned MaxCost = ShufTab[0].Cost;
|
|
for (unsigned i = 1; i != 0x8889; ++i) {
|
|
if (!isValidMask(i)) continue;
|
|
if (ShufTab[i].Cost > MaxCost)
|
|
MaxCost = ShufTab[i].Cost;
|
|
|
|
// If this value has an undef, make it be computed the cheapest possible
|
|
// way of any of the things that it matches.
|
|
if (hasUndefElements(i)) {
|
|
// This code is a little bit tricky, so here's the idea: consider some
|
|
// permutation, like 7u4u. To compute the lowest cost for 7u4u, we
|
|
// need to take the minimum cost of all of 7[0-8]4[0-8], 81 entries. If
|
|
// there are 3 undefs, the number rises to 729 entries we have to scan,
|
|
// and for the 4 undef case, we have to scan the whole table.
|
|
//
|
|
// Instead of doing this huge amount of scanning, we process the table
|
|
// entries *in order*, and use the fact that 'u' is 8, larger than any
|
|
// valid index. Given an entry like 7u4u then, we only need to scan
|
|
// 7[0-7]4u - 8 entries. We can get away with this, because we already
|
|
// know that each of 704u, 714u, 724u, etc contain the minimum value of
|
|
// all of the 704[0-8], 714[0-8] and 724[0-8] entries respectively.
|
|
unsigned UndefIdx;
|
|
if (i & 0x8000)
|
|
UndefIdx = 0;
|
|
else if (i & 0x0800)
|
|
UndefIdx = 1;
|
|
else if (i & 0x0080)
|
|
UndefIdx = 2;
|
|
else if (i & 0x0008)
|
|
UndefIdx = 3;
|
|
else
|
|
abort();
|
|
|
|
unsigned MinVal = i;
|
|
unsigned MinCost = ShufTab[i].Cost;
|
|
|
|
// Scan the 8 entries.
|
|
for (unsigned j = 0; j != 8; ++j) {
|
|
unsigned NewElt = setMaskElt(i, UndefIdx, j);
|
|
if (ShufTab[NewElt].Cost < MinCost) {
|
|
MinCost = ShufTab[NewElt].Cost;
|
|
MinVal = NewElt;
|
|
}
|
|
}
|
|
|
|
// If we found something cheaper than what was here before, use it.
|
|
if (i != MinVal) {
|
|
MadeChange = true;
|
|
ShufTab[i] = ShufTab[MinVal];
|
|
}
|
|
}
|
|
}
|
|
|
|
for (unsigned LHS = 0; LHS != 0x8889; ++LHS) {
|
|
if (!isValidMask(LHS)) continue;
|
|
if (ShufTab[LHS].Cost > 1000) continue;
|
|
|
|
// If nothing involving this operand could possibly be cheaper than what
|
|
// we already have, don't consider it.
|
|
if (ShufTab[LHS].Cost + 1 >= MaxCost)
|
|
continue;
|
|
|
|
for (unsigned opnum = 0, e = TheOperators.size(); opnum != e; ++opnum) {
|
|
Operator *Op = TheOperators[opnum];
|
|
|
|
// Evaluate op(LHS,LHS)
|
|
unsigned ResultMask = Op->getTransformedMask(LHS, LHS);
|
|
|
|
unsigned Cost = ShufTab[LHS].Cost + 1;
|
|
if (Cost < ShufTab[ResultMask].Cost) {
|
|
ShufTab[ResultMask].Cost = Cost;
|
|
ShufTab[ResultMask].Op = Op;
|
|
ShufTab[ResultMask].Arg0 = LHS;
|
|
ShufTab[ResultMask].Arg1 = LHS;
|
|
MadeChange = true;
|
|
}
|
|
|
|
// If this is a two input instruction, include the op(x,y) cases. If
|
|
// this is a one input instruction, skip this.
|
|
if (Op->isOnlyLHSOperator()) continue;
|
|
|
|
for (unsigned RHS = 0; RHS != 0x8889; ++RHS) {
|
|
if (!isValidMask(RHS)) continue;
|
|
if (ShufTab[RHS].Cost > 1000) continue;
|
|
|
|
// If nothing involving this operand could possibly be cheaper than
|
|
// what we already have, don't consider it.
|
|
if (ShufTab[RHS].Cost + 1 >= MaxCost)
|
|
continue;
|
|
|
|
|
|
// Evaluate op(LHS,RHS)
|
|
unsigned ResultMask = Op->getTransformedMask(LHS, RHS);
|
|
|
|
if (ShufTab[ResultMask].Cost <= OpCount ||
|
|
ShufTab[ResultMask].Cost <= ShufTab[LHS].Cost ||
|
|
ShufTab[ResultMask].Cost <= ShufTab[RHS].Cost)
|
|
continue;
|
|
|
|
// Figure out the cost to evaluate this, knowing that CSE's only need
|
|
// to be evaluated once.
|
|
unsigned short Vals[30];
|
|
unsigned NumVals = 0;
|
|
EvaluateOps(LHS, Vals, NumVals);
|
|
EvaluateOps(RHS, Vals, NumVals);
|
|
|
|
unsigned Cost = NumVals + 1;
|
|
if (Cost < ShufTab[ResultMask].Cost) {
|
|
ShufTab[ResultMask].Cost = Cost;
|
|
ShufTab[ResultMask].Op = Op;
|
|
ShufTab[ResultMask].Arg0 = LHS;
|
|
ShufTab[ResultMask].Arg1 = RHS;
|
|
MadeChange = true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
std::cerr << "Finished Table has " << getNumEntered()
|
|
<< " entries established.\n";
|
|
|
|
unsigned CostArray[10] = { 0 };
|
|
|
|
// Compute a cost histogram.
|
|
for (unsigned i = 0; i != 65536; ++i) {
|
|
if (!isValidMask(i)) continue;
|
|
if (ShufTab[i].Cost > 9)
|
|
++CostArray[9];
|
|
else
|
|
++CostArray[ShufTab[i].Cost];
|
|
}
|
|
|
|
for (unsigned i = 0; i != 9; ++i)
|
|
if (CostArray[i])
|
|
std::cout << "// " << CostArray[i] << " entries have cost " << i << "\n";
|
|
if (CostArray[9])
|
|
std::cout << "// " << CostArray[9] << " entries have higher cost!\n";
|
|
|
|
|
|
// Build up the table to emit.
|
|
std::cout << "\n// This table is 6561*4 = 26244 bytes in size.\n";
|
|
std::cout << "static const unsigned PerfectShuffleTable[6561+1] = {\n";
|
|
|
|
for (unsigned i = 0; i != 0x8889; ++i) {
|
|
if (!isValidMask(i)) continue;
|
|
|
|
// CostSat - The cost of this operation saturated to two bits.
|
|
unsigned CostSat = ShufTab[i].Cost;
|
|
if (CostSat > 4) CostSat = 4;
|
|
if (CostSat == 0) CostSat = 1;
|
|
--CostSat; // Cost is now between 0-3.
|
|
|
|
unsigned OpNum = ShufTab[i].Op ? ShufTab[i].Op->OpNum : 0;
|
|
assert(OpNum < 16 && "Too few bits to encode operation!");
|
|
|
|
unsigned LHS = getCompressedMask(ShufTab[i].Arg0);
|
|
unsigned RHS = getCompressedMask(ShufTab[i].Arg1);
|
|
|
|
// Encode this as 2 bits of saturated cost, 4 bits of opcodes, 13 bits of
|
|
// LHS, and 13 bits of RHS = 32 bits.
|
|
unsigned Val = (CostSat << 30) | (OpNum << 26) | (LHS << 13) | RHS;
|
|
|
|
std::cout << " " << Val << "U,\t// ";
|
|
PrintMask(i, std::cout);
|
|
std::cout << ": Cost " << ShufTab[i].Cost;
|
|
std::cout << " " << (ShufTab[i].Op ? ShufTab[i].Op->getName() : "copy");
|
|
std::cout << " ";
|
|
if (ShufTab[ShufTab[i].Arg0].Cost == 0) {
|
|
std::cout << getZeroCostOpName(ShufTab[i].Arg0);
|
|
} else {
|
|
PrintMask(ShufTab[i].Arg0, std::cout);
|
|
}
|
|
|
|
if (ShufTab[i].Op && !ShufTab[i].Op->isOnlyLHSOperator()) {
|
|
std::cout << ", ";
|
|
if (ShufTab[ShufTab[i].Arg1].Cost == 0) {
|
|
std::cout << getZeroCostOpName(ShufTab[i].Arg1);
|
|
} else {
|
|
PrintMask(ShufTab[i].Arg1, std::cout);
|
|
}
|
|
}
|
|
std::cout << "\n";
|
|
}
|
|
std::cout << " 0\n};\n";
|
|
|
|
if (0) {
|
|
// Print out the table.
|
|
for (unsigned i = 0; i != 0x8889; ++i) {
|
|
if (!isValidMask(i)) continue;
|
|
if (ShufTab[i].Cost < 1000) {
|
|
PrintMask(i, std::cerr);
|
|
std::cerr << " - Cost " << ShufTab[i].Cost << " - ";
|
|
|
|
unsigned short Vals[30];
|
|
unsigned NumVals = 0;
|
|
EvaluateOps(i, Vals, NumVals);
|
|
|
|
for (unsigned j = 0, e = NumVals; j != e; ++j)
|
|
PrintOperation(j, Vals);
|
|
std::cerr << "\n";
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
#define GENERATE_ALTIVEC
|
|
|
|
#ifdef GENERATE_ALTIVEC
|
|
|
|
///===---------------------------------------------------------------------===//
|
|
/// The altivec instruction definitions. This is the altivec-specific part of
|
|
/// this file.
|
|
///===---------------------------------------------------------------------===//
|
|
|
|
// Note that the opcode numbers here must match those in the PPC backend.
|
|
enum {
|
|
OP_COPY = 0, // Copy, used for things like <u,u,u,3> to say it is <0,1,2,3>
|
|
OP_VMRGHW,
|
|
OP_VMRGLW,
|
|
OP_VSPLTISW0,
|
|
OP_VSPLTISW1,
|
|
OP_VSPLTISW2,
|
|
OP_VSPLTISW3,
|
|
OP_VSLDOI4,
|
|
OP_VSLDOI8,
|
|
OP_VSLDOI12
|
|
};
|
|
|
|
struct vmrghw : public Operator {
|
|
vmrghw() : Operator(0x0415, "vmrghw", OP_VMRGHW) {}
|
|
} the_vmrghw;
|
|
|
|
struct vmrglw : public Operator {
|
|
vmrglw() : Operator(0x2637, "vmrglw", OP_VMRGLW) {}
|
|
} the_vmrglw;
|
|
|
|
template<unsigned Elt>
|
|
struct vspltisw : public Operator {
|
|
vspltisw(const char *N, unsigned Opc)
|
|
: Operator(MakeMask(Elt, Elt, Elt, Elt), N, Opc) {}
|
|
};
|
|
|
|
vspltisw<0> the_vspltisw0("vspltisw0", OP_VSPLTISW0);
|
|
vspltisw<1> the_vspltisw1("vspltisw1", OP_VSPLTISW1);
|
|
vspltisw<2> the_vspltisw2("vspltisw2", OP_VSPLTISW2);
|
|
vspltisw<3> the_vspltisw3("vspltisw3", OP_VSPLTISW3);
|
|
|
|
template<unsigned N>
|
|
struct vsldoi : public Operator {
|
|
vsldoi(const char *Name, unsigned Opc)
|
|
: Operator(MakeMask(N&7, (N+1)&7, (N+2)&7, (N+3)&7), Name, Opc) {
|
|
}
|
|
};
|
|
|
|
vsldoi<1> the_vsldoi1("vsldoi4" , OP_VSLDOI4);
|
|
vsldoi<2> the_vsldoi2("vsldoi8" , OP_VSLDOI8);
|
|
vsldoi<3> the_vsldoi3("vsldoi12", OP_VSLDOI12);
|
|
|
|
#endif
|