circt/lib/Conversion/ImportVerilog/AssertionExpr.cpp

315 lines
12 KiB
C++

//===- AssertionExpr.cpp - Slang assertion expression conversion ----------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "slang/ast/expressions/AssertionExpr.h"
#include "ImportVerilogInternals.h"
#include "circt/Dialect/LTL/LTLOps.h"
#include "circt/Dialect/Moore/MooreOps.h"
#include "circt/Support/LLVM.h"
#include "mlir/IR/BuiltinAttributes.h"
#include "mlir/Support/LLVM.h"
#include <optional>
#include <utility>
using namespace circt;
using namespace ImportVerilog;
// NOLINTBEGIN(misc-no-recursion)
namespace {
struct AssertionExprVisitor {
Context &context;
Location loc;
OpBuilder &builder;
AssertionExprVisitor(Context &context, Location loc)
: context(context), loc(loc), builder(context.builder) {}
/// Helper to convert a range (min, optional max) to MLIR integer attributes
std::pair<mlir::IntegerAttr, mlir::IntegerAttr>
convertRangeToAttrs(uint32_t min,
std::optional<uint32_t> max = std::nullopt) {
auto minAttr = builder.getI64IntegerAttr(min);
mlir::IntegerAttr rangeAttr;
if (max.has_value()) {
rangeAttr = builder.getI64IntegerAttr(max.value() - min);
}
return {minAttr, rangeAttr};
}
/// Add repetition operation to a sequence
Value createRepetition(Location loc,
const slang::ast::SequenceRepetition &repetition,
Value &inputSequence) {
// Extract cycle range
auto [minRepetitions, repetitionRange] =
convertRangeToAttrs(repetition.range.min, repetition.range.max);
using slang::ast::SequenceRepetition;
// Check if repetition range is required
if ((repetition.kind == SequenceRepetition::Nonconsecutive ||
repetition.kind == SequenceRepetition::GoTo) &&
!repetitionRange) {
mlir::emitError(loc,
repetition.kind == SequenceRepetition::Nonconsecutive
? "Nonconsecutive repetition requires a maximum value"
: "GoTo repetition requires a maximum value");
return {};
}
switch (repetition.kind) {
case SequenceRepetition::Consecutive:
return ltl::RepeatOp::create(builder, loc, inputSequence, minRepetitions,
repetitionRange);
case SequenceRepetition::Nonconsecutive:
return ltl::NonConsecutiveRepeatOp::create(
builder, loc, inputSequence, minRepetitions, repetitionRange);
case SequenceRepetition::GoTo:
return ltl::GoToRepeatOp::create(builder, loc, inputSequence,
minRepetitions, repetitionRange);
}
llvm_unreachable("All enum values handled in switch");
}
Value visit(const slang::ast::SimpleAssertionExpr &expr) {
// Handle expression
auto value = context.convertRvalueExpression(expr.expr);
if (!value)
return {};
auto loc = context.convertLocation(expr.expr.sourceRange);
auto valueType = value.getType();
// For assertion instances the value is already the expected type, convert
// boolean value
if (!mlir::isa<ltl::SequenceType, ltl::PropertyType>(valueType)) {
value = context.convertToI1(value);
}
if (!value)
return {};
// Handle repetition
// The optional repetition is empty, return the converted expression
if (!expr.repetition.has_value()) {
return value;
}
// There is a repetition, embed the expression into the kind of given
// repetition
return createRepetition(loc, expr.repetition.value(), value);
}
Value visit(const slang::ast::SequenceConcatExpr &expr) {
// Create a sequence of delayed operations, combined with a concat operation
assert(!expr.elements.empty());
SmallVector<Value> sequenceElements;
for (const auto &concatElement : expr.elements) {
Value sequenceValue =
context.convertAssertionExpression(*concatElement.sequence, loc);
if (!sequenceValue)
return {};
Type valueType = sequenceValue.getType();
assert(valueType.isInteger(1) || mlir::isa<ltl::SequenceType>(valueType));
auto [delayMin, delayRange] =
convertRangeToAttrs(concatElement.delay.min, concatElement.delay.max);
auto delayedSequence = ltl::DelayOp::create(builder, loc, sequenceValue,
delayMin, delayRange);
sequenceElements.push_back(delayedSequence);
}
return builder.createOrFold<ltl::ConcatOp>(loc, sequenceElements);
}
Value visit(const slang::ast::UnaryAssertionExpr &expr) {
auto value = context.convertAssertionExpression(expr.expr, loc);
if (!value)
return {};
using slang::ast::UnaryAssertionOperator;
switch (expr.op) {
case UnaryAssertionOperator::Not:
return ltl::NotOp::create(builder, loc, value);
case UnaryAssertionOperator::SEventually:
if (expr.range.has_value()) {
mlir::emitError(loc, "Strong eventually with range not supported");
return {};
} else {
return ltl::EventuallyOp::create(builder, loc, value);
}
case UnaryAssertionOperator::Always: {
std::pair<mlir::IntegerAttr, mlir::IntegerAttr> attr = {
builder.getI64IntegerAttr(0), mlir::IntegerAttr{}};
if (expr.range.has_value()) {
attr =
convertRangeToAttrs(expr.range.value().min, expr.range.value().max);
}
return ltl::RepeatOp::create(builder, loc, value, attr.first,
attr.second);
}
case UnaryAssertionOperator::NextTime: {
auto minRepetitions = builder.getI64IntegerAttr(1);
if (expr.range.has_value()) {
minRepetitions = builder.getI64IntegerAttr(expr.range.value().min);
}
return ltl::DelayOp::create(builder, loc, value, minRepetitions,
builder.getI64IntegerAttr(0));
}
case UnaryAssertionOperator::Eventually:
case UnaryAssertionOperator::SNextTime:
case UnaryAssertionOperator::SAlways:
mlir::emitError(loc, "unsupported unary operator: ")
<< slang::ast::toString(expr.op);
return {};
}
llvm_unreachable("All enum values handled in switch");
}
Value visit(const slang::ast::BinaryAssertionExpr &expr) {
auto lhs = context.convertAssertionExpression(expr.left, loc);
auto rhs = context.convertAssertionExpression(expr.right, loc);
if (!lhs || !rhs)
return {};
SmallVector<Value, 2> operands = {lhs, rhs};
using slang::ast::BinaryAssertionOperator;
switch (expr.op) {
case BinaryAssertionOperator::And:
return ltl::AndOp::create(builder, loc, operands);
case BinaryAssertionOperator::Or:
return ltl::OrOp::create(builder, loc, operands);
case BinaryAssertionOperator::Intersect:
return ltl::IntersectOp::create(builder, loc, operands);
case BinaryAssertionOperator::Throughout: {
auto lhsRepeat = ltl::RepeatOp::create(
builder, loc, lhs, builder.getI64IntegerAttr(0), mlir::IntegerAttr{});
return ltl::IntersectOp::create(builder, loc,
SmallVector<Value, 2>{lhsRepeat, rhs});
}
case BinaryAssertionOperator::Within: {
auto constOne =
hw::ConstantOp::create(builder, loc, builder.getI1Type(), 1);
auto oneRepeat = ltl::RepeatOp::create(builder, loc, constOne,
builder.getI64IntegerAttr(0),
mlir::IntegerAttr{});
auto repeatDelay = ltl::DelayOp::create(builder, loc, oneRepeat,
builder.getI64IntegerAttr(1),
builder.getI64IntegerAttr(0));
auto lhsDelay =
ltl::DelayOp::create(builder, loc, lhs, builder.getI64IntegerAttr(1),
builder.getI64IntegerAttr(0));
auto combined = ltl::ConcatOp::create(
builder, loc, SmallVector<Value, 3>{repeatDelay, lhsDelay, constOne});
return ltl::IntersectOp::create(builder, loc,
SmallVector<Value, 2>{combined, rhs});
}
case BinaryAssertionOperator::Iff: {
auto ored = ltl::OrOp::create(builder, loc, operands);
auto notOred = ltl::NotOp::create(builder, loc, ored);
auto anded = ltl::AndOp::create(builder, loc, operands);
return ltl::OrOp::create(builder, loc,
SmallVector<Value, 2>{notOred, anded});
}
case BinaryAssertionOperator::Until:
return ltl::UntilOp::create(builder, loc, operands);
case BinaryAssertionOperator::UntilWith: {
auto untilOp = ltl::UntilOp::create(builder, loc, operands);
auto andOp = ltl::AndOp::create(builder, loc, operands);
auto notUntil = ltl::NotOp::create(builder, loc, untilOp);
return ltl::OrOp::create(builder, loc,
SmallVector<Value, 2>{notUntil, andOp});
}
case BinaryAssertionOperator::Implies: {
auto notLhs = ltl::NotOp::create(builder, loc, lhs);
return ltl::OrOp::create(builder, loc,
SmallVector<Value, 2>{notLhs, rhs});
}
case BinaryAssertionOperator::OverlappedImplication:
return ltl::ImplicationOp::create(builder, loc, operands);
case BinaryAssertionOperator::NonOverlappedImplication: {
auto constOne =
hw::ConstantOp::create(builder, loc, builder.getI1Type(), 1);
auto lhsDelay =
ltl::DelayOp::create(builder, loc, lhs, builder.getI64IntegerAttr(1),
builder.getI64IntegerAttr(0));
auto antecedent = ltl::ConcatOp::create(
builder, loc, SmallVector<Value, 2>{lhsDelay, constOne});
return ltl::ImplicationOp::create(builder, loc,
SmallVector<Value, 2>{antecedent, rhs});
}
case BinaryAssertionOperator::OverlappedFollowedBy: {
auto notRhs = ltl::NotOp::create(builder, loc, rhs);
auto implication = ltl::ImplicationOp::create(
builder, loc, SmallVector<Value, 2>{lhs, notRhs});
return ltl::NotOp::create(builder, loc, implication);
}
case BinaryAssertionOperator::NonOverlappedFollowedBy: {
auto constOne =
hw::ConstantOp::create(builder, loc, builder.getI1Type(), 1);
auto notRhs = ltl::NotOp::create(builder, loc, rhs);
auto lhsDelay =
ltl::DelayOp::create(builder, loc, lhs, builder.getI64IntegerAttr(1),
builder.getI64IntegerAttr(0));
auto antecedent = ltl::ConcatOp::create(
builder, loc, SmallVector<Value, 2>{lhsDelay, constOne});
auto implication = ltl::ImplicationOp::create(
builder, loc, SmallVector<Value, 2>{antecedent, notRhs});
return ltl::NotOp::create(builder, loc, implication);
}
case BinaryAssertionOperator::SUntil:
case BinaryAssertionOperator::SUntilWith:
mlir::emitError(loc, "unsupported binary operator: ")
<< slang::ast::toString(expr.op);
return {};
}
llvm_unreachable("All enum values handled in switch");
}
Value visit(const slang::ast::ClockingAssertionExpr &expr) {
auto assertionExpr = context.convertAssertionExpression(expr.expr, loc);
if (!assertionExpr)
return {};
return context.convertLTLTimingControl(expr.clocking, assertionExpr);
}
/// Emit an error for all other expressions.
template <typename T>
Value visit(T &&node) {
mlir::emitError(loc, "unsupported expression: ")
<< slang::ast::toString(node.kind);
return {};
}
Value visitInvalid(const slang::ast::AssertionExpr &expr) {
mlir::emitError(loc, "invalid expression");
return {};
}
};
} // namespace
Value Context::convertAssertionExpression(const slang::ast::AssertionExpr &expr,
Location loc) {
AssertionExprVisitor visitor{*this, loc};
return expr.visit(visitor);
}
// NOLINTEND(misc-no-recursion)
/// Helper function to convert a value to an i1 value.
Value Context::convertToI1(Value value) {
if (!value)
return {};
auto type = dyn_cast<moore::IntType>(value.getType());
if (!type || type.getBitSize() != 1) {
mlir::emitError(value.getLoc(), "expected a 1-bit integer");
return {};
}
return moore::ConversionOp::create(builder, value.getLoc(),
builder.getI1Type(), value);
}