[mlir] Add basic block arguments
This patch adds support for basic block arguments including parsing and printing.
In doing so noticed that `ssa-id-and-type` is undefined in the MLIR spec; suggested an implementation in the spec doc.
PiperOrigin-RevId: 205593369
diff --git a/lib/IR/AsmPrinter.cpp b/lib/IR/AsmPrinter.cpp
index d811223..0d5610f 100644
--- a/lib/IR/AsmPrinter.cpp
+++ b/lib/IR/AsmPrinter.cpp
@@ -665,7 +665,9 @@
/// Number all of the SSA values in the specified basic block.
void CFGFunctionPrinter::numberValuesInBlock(const BasicBlock *block) {
- // TODO: basic block arguments.
+ for (auto *arg : block->getArguments()) {
+ numberValueID(arg);
+ }
for (auto &op : *block) {
// We number instruction that have results, and we only number the first
// result.
@@ -686,16 +688,26 @@
}
void CFGFunctionPrinter::print(const BasicBlock *block) {
- os << "bb" << getBBID(block) << ":\n";
+ os << "bb" << getBBID(block);
- // TODO Print arguments.
+ if (!block->args_empty()) {
+ os << '(';
+ interleaveComma(block->getArguments(), [&](const BBArgument *arg) {
+ printValueID(arg);
+ os << ": ";
+ ModulePrinter::print(arg->getType());
+ });
+ os << ')';
+ }
+ os << ":\n";
+
for (auto &inst : block->getOperations()) {
print(&inst);
- os << "\n";
+ os << '\n';
}
print(block->getTerminator());
- os << "\n";
+ os << '\n';
}
void CFGFunctionPrinter::print(const Instruction *inst) {
diff --git a/lib/IR/BasicBlock.cpp b/lib/IR/BasicBlock.cpp
index c2c865c..1aad430 100644
--- a/lib/IR/BasicBlock.cpp
+++ b/lib/IR/BasicBlock.cpp
@@ -19,12 +19,14 @@
#include "mlir/IR/CFGFunction.h"
using namespace mlir;
-BasicBlock::BasicBlock() {
-}
+BasicBlock::BasicBlock() {}
BasicBlock::~BasicBlock() {
if (terminator)
terminator->eraseFromBlock();
+ for (BBArgument *arg : arguments)
+ delete arg;
+ arguments.clear();
}
/// Unlink this BasicBlock from its CFGFunction and delete it.
@@ -84,3 +86,17 @@
for (; first != last; ++first)
first->function = curParent;
}
+
+BBArgument *BasicBlock::addArgument(Type *type) {
+ arguments.push_back(new BBArgument(type, this));
+ return arguments.back();
+}
+
+llvm::iterator_range<BasicBlock::BBArgListType::iterator>
+BasicBlock::addArguments(ArrayRef<Type *> types) {
+ auto initial_size = arguments.size();
+ for (auto *type : types) {
+ addArgument(type);
+ }
+ return {arguments.data() + initial_size, arguments.data() + arguments.size()};
+}
diff --git a/lib/IR/Verifier.cpp b/lib/IR/Verifier.cpp
index 3c3bb16..d1bb2ac 100644
--- a/lib/IR/Verifier.cpp
+++ b/lib/IR/Verifier.cpp
@@ -106,6 +106,26 @@
bool CFGFuncVerifier::verify() {
// TODO: Lots to be done here, including verifying dominance information when
// we have uses and defs.
+ // TODO: Verify the first block has no predecessors.
+
+ if (fn.empty())
+ return failure("cfgfunc must have at least one basic block", fn);
+
+ // Verify that the argument list of the function and the arg list of the first
+ // block line up.
+ auto *firstBB = &fn.front();
+ auto fnInputTypes = fn.getType()->getInputs();
+ if (fnInputTypes.size() != firstBB->getNumArguments())
+ return failure("first block of cfgfunc must have " +
+ Twine(fnInputTypes.size()) +
+ " arguments to match function signature",
+ fn);
+ for (unsigned i = 0, e = firstBB->getNumArguments(); i != e; ++i)
+ if (fnInputTypes[i] != firstBB->getArgument(i)->getType())
+ return failure(
+ "type of argument #" + Twine(i) +
+ " must match corresponding argument in function signature",
+ fn);
for (auto &block : fn) {
if (verifyBlock(block))
@@ -121,6 +141,11 @@
if (verifyTerminator(*block.getTerminator()))
return true;
+ for (auto *arg : block.getArguments()) {
+ if (arg->getOwner() != &block)
+ return failure("basic block argument not owned by block", block);
+ }
+
for (auto &inst : block) {
if (verifyOperation(inst))
return true;