Extend getConstantTripCount to deal with a larger subset of loop bounds; make loop
unroll/unroll-and-jam more powerful; add additional affine expr builder methods
- use previously added analysis/simplification to infer multiple of unroll
factor trip counts, making loop unroll/unroll-and-jam more general.
- for loop unroll, support bounds that are single result affine map's with the
same set of operands. For unknown loop bounds, loop unroll will now work as
long as trip count can be determined to be a multiple of unroll factor.
- extend getConstantTripCount to deal with single result affine map's with the
same operands. move it to mlir/Analysis/LoopAnalysis.cpp
- add additional builder utility methods for affine expr arithmetic
(difference, mod/floordiv/ceildiv w.r.t postitive constant). simplify code to
use the utility methods.
- move affine analysis routines to AffineAnalysis.cpp/.h from
AffineStructures.cpp/.h.
- Rename LoopUnrollJam to LoopUnrollAndJam to match class name.
- add an additional simplification for simplifyFloorDiv, simplifyCeilDiv
- Rename AffineMap::getNumOperands() getNumInputs: an affine map by itself does
not have operands. Operands are passed to it through affine_apply, from loop
bounds/if condition's, etc., operands are stored in the latter.
This should be sufficiently powerful for now as far as unroll/unroll-and-jam go for TPU
code generation, and can move to other analyses/transformations.
Loop nests like these are now unrolled without any cleanup loop being generated.
for %i = 1 to 100 {
// unroll factor 4: no cleanup loop will be generated.
for %j = (d0) -> (d0) (%i) to (d0) -> (5*d0 + 3) (%i) {
%x = "foo"(%j) : (affineint) -> i32
}
}
for %i = 1 to 100 {
// unroll factor 4: no cleanup loop will be generated.
for %j = (d0) -> (d0) (%i) to (d0) -> (d0 - d mod 4 - 1) (%i) {
%y = "foo"(%j) : (affineint) -> i32
}
}
for %i = 1 to 100 {
for %j = (d0) -> (d0) (%i) to (d0) -> (d0 + 128) (%i) {
%x = "foo"() : () -> i32
}
}
TODO(bondhugula): extend this to LoopUnrollAndJam as well in the next CL (with minor
changes).
PiperOrigin-RevId: 212661212
diff --git a/include/mlir/IR/AffineExpr.h b/include/mlir/IR/AffineExpr.h
index dccbe91..f2f3a9f 100644
--- a/include/mlir/IR/AffineExpr.h
+++ b/include/mlir/IR/AffineExpr.h
@@ -70,8 +70,8 @@
/// floordiv, ceildiv, and mod is only allowed w.r.t constants.
bool isPureAffine() const;
- /// Returns the greatest known common divisor of this affine expression.
- uint64_t getKnownGcd() const;
+ /// Returns the greatest known integral divisor of this affine expression.
+ uint64_t getLargestKnownDivisor() const;
/// Return true if the affine expression is a multiple of 'factor'.
bool isMultipleOf(int64_t factor) const;
@@ -107,6 +107,11 @@
MLIRContext *context) {
return get(AffineExpr::Kind::Add, lhs, rhs, context);
}
+ static AffineExpr *getAdd(AffineExpr *expr, int64_t rhs,
+ MLIRContext *context);
+ static AffineExpr *getSub(AffineExpr *lhs, AffineExpr *rhs,
+ MLIRContext *context);
+
static AffineExpr *getMul(AffineExpr *lhs, AffineExpr *rhs,
MLIRContext *context) {
return get(AffineExpr::Kind::Mul, lhs, rhs, context);
@@ -119,6 +124,8 @@
MLIRContext *context) {
return get(AffineExpr::Kind::CeilDiv, lhs, rhs, context);
}
+ static AffineExpr *getCeilDiv(AffineExpr *lhs, uint64_t rhs,
+ MLIRContext *context);
static AffineExpr *getMod(AffineExpr *lhs, AffineExpr *rhs,
MLIRContext *context) {
return get(AffineExpr::Kind::Mod, lhs, rhs, context);
diff --git a/include/mlir/IR/AffineMap.h b/include/mlir/IR/AffineMap.h
index 9f3ffee..1f5d497 100644
--- a/include/mlir/IR/AffineMap.h
+++ b/include/mlir/IR/AffineMap.h
@@ -69,7 +69,7 @@
unsigned getNumDims() const { return numDims; }
unsigned getNumSymbols() const { return numSymbols; }
unsigned getNumResults() const { return numResults; }
- unsigned getNumOperands() const { return numDims + numSymbols; }
+ unsigned getNumInputs() const { return numDims + numSymbols; }
ArrayRef<AffineExpr *> getResults() const {
return ArrayRef<AffineExpr *>(results, numResults);
diff --git a/include/mlir/IR/Builders.h b/include/mlir/IR/Builders.h
index f6cd245..7cd0dd5 100644
--- a/include/mlir/IR/Builders.h
+++ b/include/mlir/IR/Builders.h
@@ -106,9 +106,13 @@
AffineExpr *getAddExpr(AffineExpr *lhs, AffineExpr *rhs);
AffineExpr *getSubExpr(AffineExpr *lhs, AffineExpr *rhs);
AffineExpr *getMulExpr(AffineExpr *lhs, AffineExpr *rhs);
+ AffineExpr *getMulExpr(AffineExpr *lhs, int64_t rhs);
AffineExpr *getModExpr(AffineExpr *lhs, AffineExpr *rhs);
+ AffineExpr *getModExpr(AffineExpr *lhs, uint64_t rhs);
AffineExpr *getFloorDivExpr(AffineExpr *lhs, AffineExpr *rhs);
+ AffineExpr *getFloorDivExpr(AffineExpr *lhs, uint64_t rhs);
AffineExpr *getCeilDivExpr(AffineExpr *lhs, AffineExpr *rhs);
+ AffineExpr *getCeilDivExpr(AffineExpr *lhs, uint64_t rhs);
// Integer set.
IntegerSet *getIntegerSet(unsigned dimCount, unsigned symbolCount,
diff --git a/include/mlir/IR/Statement.h b/include/mlir/IR/Statement.h
index 55a0aec..3b2bbeb 100644
--- a/include/mlir/IR/Statement.h
+++ b/include/mlir/IR/Statement.h
@@ -110,6 +110,7 @@
return operand_iterator(this, getNumOperands());
}
+ /// Returns an iterator on the underlying MLValue's (MLValue *).
llvm::iterator_range<operand_iterator> getOperands() {
return {operand_begin(), operand_end()};
}
@@ -126,6 +127,7 @@
return const_operand_iterator(this, getNumOperands());
}
+ /// Returns a const iterator on the underlying MLValue's (MLValue *).
llvm::iterator_range<const_operand_iterator> getOperands() const {
return {operand_begin(), operand_end()};
}
diff --git a/include/mlir/IR/Statements.h b/include/mlir/IR/Statements.h
index 513bc08..c0de576 100644
--- a/include/mlir/IR/Statements.h
+++ b/include/mlir/IR/Statements.h
@@ -81,6 +81,7 @@
return operand_iterator(this, getNumOperands());
}
+ /// Returns an iterator on the underlying MLValue's (MLValue *).
llvm::iterator_range<operand_iterator> getOperands() {
return {operand_begin(), operand_end()};
}
@@ -97,6 +98,7 @@
return const_operand_iterator(this, getNumOperands());
}
+ /// Returns a const iterator on the underlying MLValue's (MLValue *).
llvm::iterator_range<const_operand_iterator> getOperands() const {
return {operand_begin(), operand_end()};
}
@@ -244,6 +246,13 @@
void setLowerBound(ArrayRef<MLValue *> operands, AffineMap *map);
/// Set upper bound.
void setUpperBound(ArrayRef<MLValue *> operands, AffineMap *map);
+
+ /// Set the lower bound map without changing operands.
+ void setLowerBoundMap(AffineMap *map);
+
+ /// Set the upper bound map without changing operands.
+ void setUpperBoundMap(AffineMap *map);
+
/// Set loop step.
void setStep(int64_t step) { this->step = step; }
@@ -266,9 +275,6 @@
/// Sets the upper bound to the given constant value.
void setConstantUpperBound(int64_t value);
- /// Returns the trip count if it's a constant.
- Optional<uint64_t> getConstantTripCount() const;
-
//===--------------------------------------------------------------------===//
// Operands
//===--------------------------------------------------------------------===//
@@ -361,16 +367,19 @@
return stmt.getStmtOperand(opStart + idx);
}
- using operand_iterator = ForStmt::const_operand_iterator;
- using operand_range = ForStmt::const_operand_range;
+ using operand_iterator = ForStmt::operand_iterator;
+ using operand_range = ForStmt::operand_range;
operand_iterator operand_begin() const {
- return operand_iterator(&stmt, opStart);
+ // These are iterators over MLValue *. Not casting away const'ness would
+ // require the caller to use const MLValue *.
+ return operand_iterator(const_cast<ForStmt *>(&stmt), opStart);
}
operand_iterator operand_end() const {
- return operand_iterator(&stmt, opEnd);
+ return operand_iterator(const_cast<ForStmt *>(&stmt), opEnd);
}
+ /// Returns an iterator on the underlying MLValue's (MLValue *).
operand_range getOperands() const { return {operand_begin(), operand_end()}; }
ArrayRef<StmtOperand> getStmtOperands() const {
auto ops = stmt.getStmtOperands();