llvm-toolchain-9/clang/tools/clang-fuzzer/proto-to-llvm/loop_proto_to_llvm.cpp

210 lines
6.1 KiB
C++

//==-- loop_proto_to_llvm.cpp - Protobuf-C++ 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
//
//===----------------------------------------------------------------------===//
//
// Implements functions for converting between protobufs and LLVM IR.
//
//
//===----------------------------------------------------------------------===//
#include "loop_proto_to_llvm.h"
#include "cxx_loop_proto.pb.h"
#include "../handle-llvm/input_arrays.h"
// The following is needed to convert protos in human-readable form
#include <google/protobuf/text_format.h>
#include <ostream>
#include <sstream>
namespace clang_fuzzer {
// Forward decls
std::string BinopToString(std::ostream &os, const BinaryOp &x);
std::string StateSeqToString(std::ostream &os, const StatementSeq &x);
// Counter variable to generate new LLVM IR variable names and wrapper function
static std::string get_var() {
static int ctr = 0;
return "%var" + std::to_string(ctr++);
}
static bool inner_loop = false;
class InnerLoop {
public:
InnerLoop() {
inner_loop = true;
}
~InnerLoop() {
inner_loop = false;
}
};
// Proto to LLVM.
std::string ConstToString(const Const &x) {
return std::to_string(x.val());
}
std::string VarRefToString(std::ostream &os, const VarRef &x) {
std::string which_loop = inner_loop ? "inner" : "outer";
std::string arr;
switch(x.arr()) {
case VarRef::ARR_A:
arr = "%a";
break;
case VarRef::ARR_B:
arr = "%b";
break;
case VarRef::ARR_C:
arr = "%c";
break;
}
std::string ptr_var = get_var();
os << ptr_var << " = getelementptr inbounds i32, i32* " << arr
<< ", i64 %" << which_loop << "_ct\n";
return ptr_var;
}
std::string RvalueToString(std::ostream &os, const Rvalue &x) {
if(x.has_cons())
return ConstToString(x.cons());
if(x.has_binop())
return BinopToString(os, x.binop());
if(x.has_varref()) {
std::string var_ref = VarRefToString(os, x.varref());
std::string val_var = get_var();
os << val_var << " = load i32, i32* " << var_ref << "\n";
return val_var;
}
return "1";
}
std::string BinopToString(std::ostream &os, const BinaryOp &x) {
std::string left = RvalueToString(os, x.left());
std::string right = RvalueToString(os, x.right());
std::string op;
switch (x.op()) {
case BinaryOp::PLUS:
op = "add";
break;
case BinaryOp::MINUS:
op = "sub";
break;
case BinaryOp::MUL:
op = "mul";
break;
case BinaryOp::XOR:
op = "xor";
break;
case BinaryOp::AND:
op = "and";
break;
case BinaryOp::OR:
op = "or";
break;
// Support for Boolean operators will be added later
case BinaryOp::EQ:
case BinaryOp::NE:
case BinaryOp::LE:
case BinaryOp::GE:
case BinaryOp::LT:
case BinaryOp::GT:
op = "add";
break;
}
std::string val_var = get_var();
os << val_var << " = " << op << " i32 " << left << ", " << right << "\n";
return val_var;
}
std::ostream &operator<<(std::ostream &os, const AssignmentStatement &x) {
std::string rvalue = RvalueToString(os, x.rvalue());
std::string var_ref = VarRefToString(os, x.varref());
return os << "store i32 " << rvalue << ", i32* " << var_ref << "\n";
}
std::ostream &operator<<(std::ostream &os, const Statement &x) {
return os << x.assignment();
}
std::ostream &operator<<(std::ostream &os, const StatementSeq &x) {
for (auto &st : x.statements()) {
os << st;
}
return os;
}
void NestedLoopToString(std::ostream &os, const LoopFunction &x) {
os << "target triple = \"x86_64-unknown-linux-gnu\"\n"
<< "define void @foo(i32* %a, i32* %b, i32* noalias %c, i64 %s) {\n"
<< "outer_loop_start:\n"
<< "%cmp = icmp sgt i64 %s, 0\n"
<< "br i1 %cmp, label %inner_loop_start, label %end\n"
<< "outer_loop:\n"
<< x.outer_statements()
<< "%o_ct_new = add i64 %outer_ct, 1\n"
<< "%jmp_outer = icmp eq i64 %o_ct_new, %s\n"
<< "br i1 %jmp_outer, label %end, label %inner_loop_start\n"
<< "inner_loop_start:\n"
<< "%outer_ct = phi i64 [%o_ct_new, %outer_loop], [0, %outer_loop_start]\n"
<< "br label %inner_loop\n"
<< "inner_loop:\n"
<< "%inner_ct = phi i64 [0, %inner_loop_start], [%i_ct_new, %inner_loop]\n";
{
InnerLoop IL;
os << x.inner_statements();
}
os << "%i_ct_new = add i64 %inner_ct, 1\n"
<< "%jmp_inner = icmp eq i64 %i_ct_new, %s\n"
<< "br i1 %jmp_inner, label %outer_loop, label %inner_loop, !llvm.loop !0\n"
<< "end:\n"
<< "ret void\n"
<< "}\n"
<< "!0 = distinct !{!0, !1, !2}\n"
<< "!1 = !{!\"llvm.loop.vectorize.enable\", i1 true}\n"
<< "!2 = !{!\"llvm.loop.vectorize.width\", i32 " << kArraySize << "}\n";
}
void SingleLoopToString(std::ostream &os, const LoopFunction &x) {
os << "target triple = \"x86_64-unknown-linux-gnu\"\n"
<< "define void @foo(i32* %a, i32* %b, i32* noalias %c, i64 %s) {\n"
<< "%cmp = icmp sgt i64 %s, 0\n"
<< "br i1 %cmp, label %start, label %end\n"
<< "start:\n"
<< "br label %loop\n"
<< "end:\n"
<< "ret void\n"
<< "loop:\n"
<< "%outer_ct = phi i64 [ %ctnew, %loop ], [ 0, %start ]\n"
<< x.outer_statements()
<< "%ctnew = add i64 %outer_ct, 1\n"
<< "%j = icmp eq i64 %ctnew, %s\n"
<< "br i1 %j, label %end, label %loop, !llvm.loop !0\n}\n"
<< "!0 = distinct !{!0, !1, !2}\n"
<< "!1 = !{!\"llvm.loop.vectorize.enable\", i1 true}\n"
<< "!2 = !{!\"llvm.loop.vectorize.width\", i32 " << kArraySize << "}\n";
}
std::ostream &operator<<(std::ostream &os, const LoopFunction &x) {
if (x.has_inner_statements())
NestedLoopToString(os, x);
else
SingleLoopToString(os, x);
return os;
}
// ---------------------------------
std::string LoopFunctionToLLVMString(const LoopFunction &input) {
std::ostringstream os;
os << input;
return os.str();
}
std::string LoopProtoToLLVM(const uint8_t *data, size_t size) {
LoopFunction message;
if (!message.ParsePartialFromArray(data, size))
return "#error invalid proto\n";
return LoopFunctionToLLVMString(message);
}
} // namespace clang_fuzzer