llvm-project/mlir/lib/Dialect/SparseTensor/Transforms/SparseBufferRewriting.cpp

801 lines
31 KiB
C++

//===- SparseBufferRewriting.cpp - Sparse buffer rewriting rules ----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements rewriting rules that are specific to sparse tensor
// primitives with memref operands.
//
//===----------------------------------------------------------------------===//
#include "CodegenUtils.h"
#include "mlir/Dialect/Arith/IR/Arith.h"
#include "mlir/Dialect/Func/IR/FuncOps.h"
#include "mlir/Dialect/Linalg/IR/Linalg.h"
#include "mlir/Dialect/MemRef/IR/MemRef.h"
#include "mlir/Dialect/SCF/IR/SCF.h"
#include "mlir/Dialect/SparseTensor/IR/SparseTensor.h"
#include "mlir/Dialect/SparseTensor/Transforms/Passes.h"
#include "mlir/Support/LLVM.h"
using namespace mlir;
using namespace mlir::sparse_tensor;
//===---------------------------------------------------------------------===//
// Helper methods for the actual rewriting rules.
//===---------------------------------------------------------------------===//
static constexpr uint64_t loIdx = 0;
static constexpr uint64_t hiIdx = 1;
static constexpr uint64_t xStartIdx = 2;
static constexpr const char kLessThanFuncNamePrefix[] = "_sparse_less_than_";
static constexpr const char kCompareEqFuncNamePrefix[] = "_sparse_compare_eq_";
static constexpr const char kPartitionFuncNamePrefix[] = "_sparse_partition_";
static constexpr const char kBinarySearchFuncNamePrefix[] =
"_sparse_binary_search_";
static constexpr const char kSortNonstableFuncNamePrefix[] =
"_sparse_sort_nonstable_";
static constexpr const char kSortStableFuncNamePrefix[] =
"_sparse_sort_stable_";
using FuncGeneratorType =
function_ref<void(OpBuilder &, ModuleOp, func::FuncOp, size_t)>;
/// Constructs a function name with this format to facilitate quick sort:
/// <namePrefix><dim>_<x type>_<y0 type>..._<yn type>
static void getMangledSortHelperFuncName(llvm::raw_svector_ostream &nameOstream,
StringRef namePrefix, size_t dim,
ValueRange operands) {
nameOstream
<< namePrefix << dim << "_"
<< operands[xStartIdx].getType().cast<MemRefType>().getElementType();
for (Value v : operands.drop_front(xStartIdx + dim))
nameOstream << "_" << v.getType().cast<MemRefType>().getElementType();
}
/// Looks up a function that is appropriate for the given operands being
/// sorted, and creates such a function if it doesn't exist yet.
static FlatSymbolRefAttr
getMangledSortHelperFunc(OpBuilder &builder, func::FuncOp insertPoint,
TypeRange resultTypes, StringRef namePrefix,
size_t dim, ValueRange operands,
FuncGeneratorType createFunc) {
SmallString<32> nameBuffer;
llvm::raw_svector_ostream nameOstream(nameBuffer);
getMangledSortHelperFuncName(nameOstream, namePrefix, dim, operands);
ModuleOp module = insertPoint->getParentOfType<ModuleOp>();
MLIRContext *context = module.getContext();
auto result = SymbolRefAttr::get(context, nameOstream.str());
auto func = module.lookupSymbol<func::FuncOp>(result.getAttr());
if (!func) {
// Create the function.
OpBuilder::InsertionGuard insertionGuard(builder);
builder.setInsertionPoint(insertPoint);
Location loc = insertPoint.getLoc();
func = builder.create<func::FuncOp>(
loc, nameOstream.str(),
FunctionType::get(context, operands.getTypes(), resultTypes));
func.setPrivate();
createFunc(builder, module, func, dim);
}
return result;
}
/// Creates a code block for swapping the values in index i and j for all the
/// buffers.
//
// The generated IR corresponds to this C like algorithm:
// swap(x0[i], x0[j]);
// swap(x1[i], x1[j]);
// ...
// swap(xn[i], xn[j]);
// swap(y0[i], y0[j]);
// ...
// swap(yn[i], yn[j]);
static void createSwap(OpBuilder &builder, Location loc, ValueRange args) {
Value i = args[0];
Value j = args[1];
for (auto arg : args.drop_front(xStartIdx)) {
Value vi = builder.create<memref::LoadOp>(loc, arg, i);
Value vj = builder.create<memref::LoadOp>(loc, arg, j);
builder.create<memref::StoreOp>(loc, vj, arg, i);
builder.create<memref::StoreOp>(loc, vi, arg, j);
}
}
/// Creates a function to compare all the (xs[i], xs[j]) pairs. The method to
/// compare each pair is create via `compareBuilder`.
static void createCompareFuncImplementation(
OpBuilder &builder, ModuleOp unused, func::FuncOp func, size_t dim,
function_ref<scf::IfOp(OpBuilder &, Location, Value, Value, Value, bool)>
compareBuilder) {
OpBuilder::InsertionGuard insertionGuard(builder);
Block *entryBlock = func.addEntryBlock();
builder.setInsertionPointToStart(entryBlock);
Location loc = func.getLoc();
ValueRange args = entryBlock->getArguments();
scf::IfOp topIfOp;
for (const auto &item : llvm::enumerate(args.slice(xStartIdx, dim))) {
scf::IfOp ifOp = compareBuilder(builder, loc, args[0], args[1],
item.value(), (item.index() == dim - 1));
if (item.index() == 0) {
topIfOp = ifOp;
} else {
OpBuilder::InsertionGuard insertionGuard(builder);
builder.setInsertionPointAfter(ifOp);
builder.create<scf::YieldOp>(loc, ifOp.getResult(0));
}
}
builder.setInsertionPointAfter(topIfOp);
builder.create<func::ReturnOp>(loc, topIfOp.getResult(0));
}
/// Generates an if-statement to compare whether x[i] is equal to x[j].
static scf::IfOp createEqCompare(OpBuilder &builder, Location loc, Value i,
Value j, Value x, bool isLastDim) {
Value f = constantI1(builder, loc, false);
Value t = constantI1(builder, loc, true);
Value vi = builder.create<memref::LoadOp>(loc, x, i);
Value vj = builder.create<memref::LoadOp>(loc, x, j);
Value cond =
builder.create<arith::CmpIOp>(loc, arith::CmpIPredicate::eq, vi, vj);
scf::IfOp ifOp =
builder.create<scf::IfOp>(loc, f.getType(), cond, /*else=*/true);
// x[1] != x[j]:
builder.setInsertionPointToStart(&ifOp.getElseRegion().front());
builder.create<scf::YieldOp>(loc, f);
// x[i] == x[j]:
builder.setInsertionPointToStart(&ifOp.getThenRegion().front());
if (isLastDim == 1) {
// Finish checking all dimensions.
builder.create<scf::YieldOp>(loc, t);
}
return ifOp;
}
/// Creates a function to compare whether xs[i] is equal to xs[j].
//
// The generate IR corresponds to this C like algorithm:
// if (x0[i] != x0[j])
// return false;
// else
// if (x1[i] != x1[j])
// return false;
// else if (x2[2] != x2[j]))
// and so on ...
static void createEqCompareFunc(OpBuilder &builder, ModuleOp unused,
func::FuncOp func, size_t dim) {
createCompareFuncImplementation(builder, unused, func, dim, createEqCompare);
}
/// Generates an if-statement to compare whether x[i] is less than x[j].
static scf::IfOp createLessThanCompare(OpBuilder &builder, Location loc,
Value i, Value j, Value x,
bool isLastDim) {
Value f = constantI1(builder, loc, false);
Value t = constantI1(builder, loc, true);
Value vi = builder.create<memref::LoadOp>(loc, x, i);
Value vj = builder.create<memref::LoadOp>(loc, x, j);
Value cond =
builder.create<arith::CmpIOp>(loc, arith::CmpIPredicate::ult, vi, vj);
scf::IfOp ifOp =
builder.create<scf::IfOp>(loc, f.getType(), cond, /*else=*/true);
// If (x[i] < x[j]).
builder.setInsertionPointToStart(&ifOp.getThenRegion().front());
builder.create<scf::YieldOp>(loc, t);
builder.setInsertionPointToStart(&ifOp.getElseRegion().front());
if (isLastDim == 1) {
// Finish checking all dimensions.
builder.create<scf::YieldOp>(loc, f);
} else {
cond =
builder.create<arith::CmpIOp>(loc, arith::CmpIPredicate::ult, vj, vi);
scf::IfOp ifOp2 =
builder.create<scf::IfOp>(loc, f.getType(), cond, /*else=*/true);
// Otherwise if (x[j] < x[i]).
builder.setInsertionPointToStart(&ifOp2.getThenRegion().front());
builder.create<scf::YieldOp>(loc, f);
// Otherwise check the remaining dimensions.
builder.setInsertionPointAfter(ifOp2);
builder.create<scf::YieldOp>(loc, ifOp2.getResult(0));
// Set up the insertion point for the nested if-stmt that checks the
// remaining dimensions.
builder.setInsertionPointToStart(&ifOp2.getElseRegion().front());
}
return ifOp;
}
/// Creates a function to compare whether xs[i] is less than xs[j].
//
// The generate IR corresponds to this C like algorithm:
// if (x0[i] < x0[j])
// return true;
// else if (x0[j] < x0[i])
// return false;
// else
// if (x1[i] < x1[j])
// return true;
// else if (x1[j] < x1[i]))
// and so on ...
static void createLessThanFunc(OpBuilder &builder, ModuleOp unused,
func::FuncOp func, size_t dim) {
createCompareFuncImplementation(builder, unused, func, dim,
createLessThanCompare);
}
/// Creates a function to use a binary search to find the insertion point for
/// inserting xs[hi] to the sorted values xs[lo..hi).
//
// The generate IR corresponds to this C like algorithm:
// p = hi
// while (lo < hi)
// mid = (lo + hi) >> 1
// if (xs[p] < xs[mid])
// hi = mid
// else
// lo = mid - 1
// return lo;
//
static void createBinarySearchFunc(OpBuilder &builder, ModuleOp module,
func::FuncOp func, size_t dim) {
OpBuilder::InsertionGuard insertionGuard(builder);
Block *entryBlock = func.addEntryBlock();
builder.setInsertionPointToStart(entryBlock);
Location loc = func.getLoc();
ValueRange args = entryBlock->getArguments();
Value p = args[hiIdx];
SmallVector<Type, 2> types(2, p.getType());
scf::WhileOp whileOp = builder.create<scf::WhileOp>(
loc, types, SmallVector<Value, 2>{args[loIdx], args[hiIdx]});
// The before-region of the WhileOp.
Block *before =
builder.createBlock(&whileOp.getBefore(), {}, types, {loc, loc});
builder.setInsertionPointToEnd(before);
Value cond1 = builder.create<arith::CmpIOp>(loc, arith::CmpIPredicate::ult,
before->getArgument(0),
before->getArgument(1));
builder.create<scf::ConditionOp>(loc, cond1, before->getArguments());
// The after-region of the WhileOp.
Block *after =
builder.createBlock(&whileOp.getAfter(), {}, types, {loc, loc});
builder.setInsertionPointToEnd(after);
Value lo = after->getArgument(0);
Value hi = after->getArgument(1);
// Compute mid = (lo + hi) >> 1.
Value c1 = constantIndex(builder, loc, 1);
Value mid = builder.create<arith::ShRUIOp>(
loc, builder.create<arith::AddIOp>(loc, lo, hi), c1);
Value midp1 = builder.create<arith::AddIOp>(loc, mid, c1);
// Compare xs[p] < xs[mid].
SmallVector<Value, 6> compareOperands{p, mid};
compareOperands.append(args.begin() + xStartIdx,
args.begin() + xStartIdx + dim);
Type i1Type = IntegerType::get(module.getContext(), 1, IntegerType::Signless);
FlatSymbolRefAttr lessThanFunc =
getMangledSortHelperFunc(builder, func, {i1Type}, kLessThanFuncNamePrefix,
dim, compareOperands, createLessThanFunc);
Value cond2 = builder
.create<func::CallOp>(loc, lessThanFunc, TypeRange{i1Type},
compareOperands)
.getResult(0);
// Update lo and hi for the WhileOp as follows:
// if (xs[p] < xs[mid]))
// hi = mid;
// else
// lo = mid + 1;
Value newLo = builder.create<arith::SelectOp>(loc, cond2, lo, midp1);
Value newHi = builder.create<arith::SelectOp>(loc, cond2, mid, hi);
builder.create<scf::YieldOp>(loc, ValueRange{newLo, newHi});
builder.setInsertionPointAfter(whileOp);
builder.create<func::ReturnOp>(loc, whileOp.getResult(0));
}
/// Creates code to advance i in a loop based on xs[p] as follows:
/// while (xs[i] < xs[p]) i += step (step > 0)
/// or
/// while (xs[i] > xs[p]) i += step (step < 0)
/// The routine returns i as well as a boolean value to indicate whether
/// xs[i] == xs[p].
static std::pair<Value, Value>
createScanLoop(OpBuilder &builder, ModuleOp module, func::FuncOp func,
ValueRange xs, Value i, Value p, size_t dim, int step) {
Location loc = func.getLoc();
scf::WhileOp whileOp =
builder.create<scf::WhileOp>(loc, TypeRange{i.getType()}, ValueRange{i});
Block *before =
builder.createBlock(&whileOp.getBefore(), {}, {i.getType()}, {loc});
builder.setInsertionPointToEnd(before);
SmallVector<Value, 6> compareOperands;
if (step > 0) {
compareOperands.push_back(before->getArgument(0));
compareOperands.push_back(p);
} else {
assert(step < 0);
compareOperands.push_back(p);
compareOperands.push_back(before->getArgument(0));
}
compareOperands.append(xs.begin(), xs.end());
MLIRContext *context = module.getContext();
Type i1Type = IntegerType::get(context, 1, IntegerType::Signless);
FlatSymbolRefAttr lessThanFunc =
getMangledSortHelperFunc(builder, func, {i1Type}, kLessThanFuncNamePrefix,
dim, compareOperands, createLessThanFunc);
Value cond = builder
.create<func::CallOp>(loc, lessThanFunc, TypeRange{i1Type},
compareOperands)
.getResult(0);
builder.create<scf::ConditionOp>(loc, cond, before->getArguments());
Block *after =
builder.createBlock(&whileOp.getAfter(), {}, {i.getType()}, {loc});
builder.setInsertionPointToEnd(after);
Value cs = constantIndex(builder, loc, step);
i = builder.create<arith::AddIOp>(loc, after->getArgument(0), cs);
builder.create<scf::YieldOp>(loc, ValueRange{i});
i = whileOp.getResult(0);
builder.setInsertionPointAfter(whileOp);
compareOperands[0] = i;
compareOperands[1] = p;
FlatSymbolRefAttr compareEqFunc = getMangledSortHelperFunc(
builder, func, {i1Type}, kCompareEqFuncNamePrefix, dim, compareOperands,
createEqCompareFunc);
Value compareEq =
builder
.create<func::CallOp>(loc, compareEqFunc, TypeRange{i1Type},
compareOperands)
.getResult(0);
return std::make_pair(whileOp.getResult(0), compareEq);
}
/// Creates a function to perform quick sort partition on the values in the
/// range of index [lo, hi), assuming lo < hi.
//
// The generated IR corresponds to this C like algorithm:
// int partition(lo, hi, xs) {
// p = (lo+hi)/2 // pivot index
// i = lo
// j = hi-1
// while (i < j) do {
// while (xs[i] < xs[p]) i ++;
// i_eq = (xs[i] == xs[p]);
// while (xs[j] > xs[p]) j --;
// j_eq = (xs[j] == xs[p]);
// if (i < j) {
// swap(xs[i], xs[j])
// if (i == p) {
// p = j;
// } else if (j == p) {
// p = i;
// }
// if (i_eq && j_eq) {
// ++i;
// --j;
// }
// }
// }
// return p
// }
static void createPartitionFunc(OpBuilder &builder, ModuleOp module,
func::FuncOp func, size_t dim) {
OpBuilder::InsertionGuard insertionGuard(builder);
Block *entryBlock = func.addEntryBlock();
builder.setInsertionPointToStart(entryBlock);
Location loc = func.getLoc();
ValueRange args = entryBlock->getArguments();
Value lo = args[loIdx];
Value hi = args[hiIdx];
Value sum = builder.create<arith::AddIOp>(loc, lo, hi);
Value c1 = constantIndex(builder, loc, 1);
Value p = builder.create<arith::ShRUIOp>(loc, sum, c1);
Value i = lo;
Value j = builder.create<arith::SubIOp>(loc, hi, c1);
SmallVector<Value, 4> operands{i, j, p};
SmallVector<Type, 4> types{i.getType(), j.getType(), p.getType()};
scf::WhileOp whileOp = builder.create<scf::WhileOp>(loc, types, operands);
// The before-region of the WhileOp.
Block *before =
builder.createBlock(&whileOp.getBefore(), {}, types, {loc, loc, loc});
builder.setInsertionPointToEnd(before);
Value cond = builder.create<arith::CmpIOp>(loc, arith::CmpIPredicate::ult,
before->getArgument(0),
before->getArgument(1));
builder.create<scf::ConditionOp>(loc, cond, before->getArguments());
// The after-region of the WhileOp.
Block *after =
builder.createBlock(&whileOp.getAfter(), {}, types, {loc, loc, loc});
builder.setInsertionPointToEnd(after);
i = after->getArgument(0);
j = after->getArgument(1);
p = after->getArgument(2);
auto [iresult, iCompareEq] = createScanLoop(
builder, module, func, args.slice(xStartIdx, dim), i, p, dim, 1);
i = iresult;
auto [jresult, jCompareEq] = createScanLoop(
builder, module, func, args.slice(xStartIdx, dim), j, p, dim, -1);
j = jresult;
// If i < j:
cond = builder.create<arith::CmpIOp>(loc, arith::CmpIPredicate::ult, i, j);
scf::IfOp ifOp = builder.create<scf::IfOp>(loc, types, cond, /*else=*/true);
builder.setInsertionPointToStart(&ifOp.getThenRegion().front());
SmallVector<Value, 6> swapOperands{i, j};
swapOperands.append(args.begin() + xStartIdx, args.end());
createSwap(builder, loc, swapOperands);
// If the pivot is moved, update p with the new pivot.
Value icond =
builder.create<arith::CmpIOp>(loc, arith::CmpIPredicate::eq, i, p);
scf::IfOp ifOpI = builder.create<scf::IfOp>(loc, TypeRange{p.getType()},
icond, /*else=*/true);
builder.setInsertionPointToStart(&ifOpI.getThenRegion().front());
builder.create<scf::YieldOp>(loc, ValueRange{j});
builder.setInsertionPointToStart(&ifOpI.getElseRegion().front());
Value jcond =
builder.create<arith::CmpIOp>(loc, arith::CmpIPredicate::eq, j, p);
scf::IfOp ifOpJ = builder.create<scf::IfOp>(loc, TypeRange{p.getType()},
jcond, /*else=*/true);
builder.setInsertionPointToStart(&ifOpJ.getThenRegion().front());
builder.create<scf::YieldOp>(loc, ValueRange{i});
builder.setInsertionPointToStart(&ifOpJ.getElseRegion().front());
builder.create<scf::YieldOp>(loc, ValueRange{p});
builder.setInsertionPointAfter(ifOpJ);
builder.create<scf::YieldOp>(loc, ifOpJ.getResults());
builder.setInsertionPointAfter(ifOpI);
Value compareEqIJ =
builder.create<arith::AndIOp>(loc, iCompareEq, jCompareEq);
scf::IfOp ifOp2 = builder.create<scf::IfOp>(
loc, TypeRange{i.getType(), j.getType()}, compareEqIJ, /*else=*/true);
builder.setInsertionPointToStart(&ifOp2.getThenRegion().front());
Value i2 = builder.create<arith::AddIOp>(loc, i, c1);
Value j2 = builder.create<arith::SubIOp>(loc, j, c1);
builder.create<scf::YieldOp>(loc, ValueRange{i2, j2});
builder.setInsertionPointToStart(&ifOp2.getElseRegion().front());
builder.create<scf::YieldOp>(loc, ValueRange{i, j});
builder.setInsertionPointAfter(ifOp2);
builder.create<scf::YieldOp>(
loc,
ValueRange{ifOp2.getResult(0), ifOp2.getResult(1), ifOpI.getResult(0)});
// False branch for if i < j:
builder.setInsertionPointToStart(&ifOp.getElseRegion().front());
builder.create<scf::YieldOp>(loc, ValueRange{i, j, p});
// Return for the whileOp.
builder.setInsertionPointAfter(ifOp);
builder.create<scf::YieldOp>(loc, ifOp.getResults());
// Return for the function.
builder.setInsertionPointAfter(whileOp);
builder.create<func::ReturnOp>(loc, whileOp.getResult(2));
}
/// Creates a function to perform quick sort on the value in the range of
/// index [lo, hi).
//
// The generate IR corresponds to this C like algorithm:
// void quickSort(lo, hi, data) {
// if (lo < hi) {
// p = partition(low, high, data);
// quickSort(lo, p, data);
// quickSort(p + 1, hi, data);
// }
// }
static void createSortNonstableFunc(OpBuilder &builder, ModuleOp module,
func::FuncOp func, size_t dim) {
OpBuilder::InsertionGuard insertionGuard(builder);
Block *entryBlock = func.addEntryBlock();
builder.setInsertionPointToStart(entryBlock);
MLIRContext *context = module.getContext();
Location loc = func.getLoc();
ValueRange args = entryBlock->getArguments();
Value lo = args[loIdx];
Value hi = args[hiIdx];
Value cond =
builder.create<arith::CmpIOp>(loc, arith::CmpIPredicate::ult, lo, hi);
scf::IfOp ifOp = builder.create<scf::IfOp>(loc, cond, /*else=*/false);
// The if-stmt true branch.
builder.setInsertionPointToStart(&ifOp.getThenRegion().front());
FlatSymbolRefAttr partitionFunc = getMangledSortHelperFunc(
builder, func, {IndexType::get(context)}, kPartitionFuncNamePrefix, dim,
args, createPartitionFunc);
auto p = builder.create<func::CallOp>(
loc, partitionFunc, TypeRange{IndexType::get(context)}, ValueRange(args));
SmallVector<Value, 6> lowOperands{lo, p.getResult(0)};
lowOperands.append(args.begin() + xStartIdx, args.end());
builder.create<func::CallOp>(loc, func, lowOperands);
SmallVector<Value, 6> highOperands{
builder.create<arith::AddIOp>(loc, p.getResult(0),
constantIndex(builder, loc, 1)),
hi};
highOperands.append(args.begin() + xStartIdx, args.end());
builder.create<func::CallOp>(loc, func, highOperands);
// After the if-stmt.
builder.setInsertionPointAfter(ifOp);
builder.create<func::ReturnOp>(loc);
}
/// Creates a function to perform insertion sort on the values in the range of
/// index [lo, hi).
//
// The generate IR corresponds to this C like algorithm:
// void insertionSort(lo, hi, data) {
// for (i = lo+1; i < hi; i++) {
// d = data[i];
// p = binarySearch(lo, i-1, data)
// for (j = 0; j > i - p; j++)
// data[i-j] = data[i-j-1]
// data[p] = d
// }
// }
static void createSortStableFunc(OpBuilder &builder, ModuleOp module,
func::FuncOp func, size_t dim) {
OpBuilder::InsertionGuard insertionGuard(builder);
Block *entryBlock = func.addEntryBlock();
builder.setInsertionPointToStart(entryBlock);
MLIRContext *context = module.getContext();
Location loc = func.getLoc();
ValueRange args = entryBlock->getArguments();
Value c1 = constantIndex(builder, loc, 1);
Value lo = args[loIdx];
Value hi = args[hiIdx];
Value lop1 = builder.create<arith::AddIOp>(loc, lo, c1);
// Start the outer for-stmt with induction variable i.
scf::ForOp forOpI = builder.create<scf::ForOp>(loc, lop1, hi, c1);
builder.setInsertionPointToStart(forOpI.getBody());
Value i = forOpI.getInductionVar();
// Binary search to find the insertion point p.
SmallVector<Value, 6> operands{lo, i};
operands.append(args.begin() + xStartIdx, args.begin() + xStartIdx + dim);
FlatSymbolRefAttr searchFunc = getMangledSortHelperFunc(
builder, func, {IndexType::get(context)}, kBinarySearchFuncNamePrefix,
dim, operands, createBinarySearchFunc);
Value p = builder
.create<func::CallOp>(loc, searchFunc, TypeRange{c1.getType()},
operands)
.getResult(0);
// Move the value at data[i] to a temporary location.
ValueRange data = args.drop_front(xStartIdx);
SmallVector<Value, 6> d;
for (Value v : data)
d.push_back(builder.create<memref::LoadOp>(loc, v, i));
// Start the inner for-stmt with induction variable j, for moving data[p..i)
// to data[p+1..i+1).
Value imp = builder.create<arith::SubIOp>(loc, i, p);
Value c0 = constantIndex(builder, loc, 0);
scf::ForOp forOpJ = builder.create<scf::ForOp>(loc, c0, imp, c1);
builder.setInsertionPointToStart(forOpJ.getBody());
Value j = forOpJ.getInductionVar();
Value imj = builder.create<arith::SubIOp>(loc, i, j);
Value imjm1 = builder.create<arith::SubIOp>(loc, imj, c1);
for (Value v : data) {
Value t = builder.create<memref::LoadOp>(loc, v, imjm1);
builder.create<memref::StoreOp>(loc, t, v, imj);
}
// Store the value at data[i] to data[p].
builder.setInsertionPointAfter(forOpJ);
for (auto it : llvm::zip(d, data))
builder.create<memref::StoreOp>(loc, std::get<0>(it), std::get<1>(it), p);
builder.setInsertionPointAfter(forOpI);
builder.create<func::ReturnOp>(loc);
}
//===---------------------------------------------------------------------===//
// The actual sparse buffer rewriting rules.
//===---------------------------------------------------------------------===//
namespace {
/// Sparse rewriting rule for the push_back operator.
struct PushBackRewriter : OpRewritePattern<PushBackOp> {
public:
using OpRewritePattern<PushBackOp>::OpRewritePattern;
PushBackRewriter(MLIRContext *context, bool enableInit)
: OpRewritePattern(context), enableBufferInitialization(enableInit) {}
LogicalResult matchAndRewrite(PushBackOp op,
PatternRewriter &rewriter) const override {
// Rewrite push_back(buffer, value, n) to:
// new_size = size(buffer) + n
// if (new_size > capacity(buffer))
// while new_size > new_capacity
// new_capacity = new_capacity*2
// new_buffer = realloc(buffer, new_capacity)
// buffer = new_buffer
// subBuffer = subviewof(buffer)
// linalg.fill subBuffer value
//
// size(buffer) += n
//
// The capacity check is skipped when the attribute inbounds is presented.
Location loc = op->getLoc();
Value c0 = constantIndex(rewriter, loc, 0);
Value buffer = op.getInBuffer();
Value capacity = rewriter.create<memref::DimOp>(loc, buffer, c0);
Value idx = constantIndex(rewriter, loc, op.getIdx().getZExtValue());
Value bufferSizes = op.getBufferSizes();
Value size = rewriter.create<memref::LoadOp>(loc, bufferSizes, idx);
Value value = op.getValue();
Value n = op.getN() ? op.getN() : constantIndex(rewriter, loc, 1);
Value newSize = rewriter.create<arith::AddIOp>(loc, size, n);
auto nValue = dyn_cast_or_null<arith::ConstantIndexOp>(n.getDefiningOp());
bool nIsOne = (nValue && nValue.value() == 1);
if (!op.getInbounds()) {
Value cond = rewriter.create<arith::CmpIOp>(
loc, arith::CmpIPredicate::ugt, newSize, capacity);
Value c2 = constantIndex(rewriter, loc, 2);
auto bufferType =
MemRefType::get({ShapedType::kDynamicSize}, value.getType());
scf::IfOp ifOp = rewriter.create<scf::IfOp>(loc, bufferType, cond,
/*else=*/true);
// True branch.
rewriter.setInsertionPointToStart(&ifOp.getThenRegion().front());
if (nIsOne) {
capacity = rewriter.create<arith::MulIOp>(loc, capacity, c2);
} else {
// Use a do-while loop to calculate the new capacity as follows:
// do { new_capacity *= 2 } while (size > new_capacity)
scf::WhileOp whileOp =
rewriter.create<scf::WhileOp>(loc, capacity.getType(), capacity);
// The before-region of the WhileOp.
Block *before = rewriter.createBlock(&whileOp.getBefore(), {},
{capacity.getType()}, {loc});
rewriter.setInsertionPointToEnd(before);
capacity =
rewriter.create<arith::MulIOp>(loc, before->getArgument(0), c2);
cond = rewriter.create<arith::CmpIOp>(loc, arith::CmpIPredicate::ugt,
newSize, capacity);
rewriter.create<scf::ConditionOp>(loc, cond, ValueRange{capacity});
// The after-region of the WhileOp.
Block *after = rewriter.createBlock(&whileOp.getAfter(), {},
{capacity.getType()}, {loc});
rewriter.setInsertionPointToEnd(after);
rewriter.create<scf::YieldOp>(loc, after->getArguments());
rewriter.setInsertionPointAfter(whileOp);
capacity = whileOp.getResult(0);
}
Value newBuffer =
rewriter.create<memref::ReallocOp>(loc, bufferType, buffer, capacity);
if (enableBufferInitialization) {
Value fillSize = rewriter.create<arith::SubIOp>(loc, capacity, newSize);
Value fillValue = rewriter.create<arith::ConstantOp>(
loc, value.getType(), rewriter.getZeroAttr(value.getType()));
Value subBuffer = rewriter.create<memref::SubViewOp>(
loc, newBuffer, /*offset=*/ValueRange{newSize},
/*size=*/ValueRange{fillSize},
/*step=*/ValueRange{constantIndex(rewriter, loc, 1)});
rewriter.create<linalg::FillOp>(loc, fillValue, subBuffer);
}
rewriter.create<scf::YieldOp>(loc, newBuffer);
// False branch.
rewriter.setInsertionPointToStart(&ifOp.getElseRegion().front());
rewriter.create<scf::YieldOp>(loc, buffer);
// Prepare for adding the value to the end of the buffer.
rewriter.setInsertionPointAfter(ifOp);
buffer = ifOp.getResult(0);
}
// Add the value to the end of the buffer.
if (nIsOne) {
rewriter.create<memref::StoreOp>(loc, value, buffer, size);
} else {
Value subBuffer = rewriter.create<memref::SubViewOp>(
loc, buffer, /*offset=*/ValueRange{size}, /*size=*/ValueRange{n},
/*step=*/ValueRange{constantIndex(rewriter, loc, 1)});
rewriter.create<linalg::FillOp>(loc, value, subBuffer);
}
// Update the buffer size.
rewriter.create<memref::StoreOp>(loc, newSize, bufferSizes, idx);
rewriter.replaceOp(op, buffer);
return success();
}
private:
bool enableBufferInitialization;
};
/// Sparse rewriting rule for the sort operator.
struct SortRewriter : public OpRewritePattern<SortOp> {
public:
using OpRewritePattern<SortOp>::OpRewritePattern;
LogicalResult matchAndRewrite(SortOp op,
PatternRewriter &rewriter) const override {
Location loc = op.getLoc();
SmallVector<Value, 6> operands{constantIndex(rewriter, loc, 0), op.getN()};
// Convert `values` to have dynamic shape and append them to `operands`.
auto addValues = [&](ValueRange values) {
for (Value v : values) {
auto mtp = v.getType().cast<MemRefType>();
if (!mtp.isDynamicDim(0)) {
auto newMtp =
MemRefType::get({ShapedType::kDynamicSize}, mtp.getElementType());
v = rewriter.create<memref::CastOp>(loc, newMtp, v);
}
operands.push_back(v);
}
};
ValueRange xs = op.getXs();
addValues(xs);
addValues(op.getYs());
auto insertPoint = op->getParentOfType<func::FuncOp>();
SmallString<32> funcName(op.getStable() ? kSortStableFuncNamePrefix
: kSortNonstableFuncNamePrefix);
FuncGeneratorType funcGenerator =
op.getStable() ? createSortStableFunc : createSortNonstableFunc;
FlatSymbolRefAttr func =
getMangledSortHelperFunc(rewriter, insertPoint, TypeRange(), funcName,
xs.size(), operands, funcGenerator);
rewriter.replaceOpWithNewOp<func::CallOp>(op, func, TypeRange(), operands);
return success();
}
};
} // namespace
//===---------------------------------------------------------------------===//
// Methods that add patterns described in this file to a pattern list.
//===---------------------------------------------------------------------===//
void mlir::populateSparseBufferRewriting(RewritePatternSet &patterns,
bool enableBufferInitialization) {
patterns.add<PushBackRewriter>(patterns.getContext(),
enableBufferInitialization);
patterns.add<SortRewriter>(patterns.getContext());
}