Merge pull request #3332 from ethereum/elimination_descirption

Rematerialisation step.

1 files changed, 179 insertions, 0 deletions

diff --git a/test/libjulia/Rematerialiser.cpp b/test/libjulia/Rematerialiser.cpp
new file mode 100644
index 00000000..8f928f8e
--- /dev/null
+++ b/test/libjulia/Rematerialiser.cpp
@@ -0,0 +1,179 @@
+/*
+    This file is part of solidity.
+
+    solidity is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    solidity is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @date 2017
+ * Unit tests for the rematerialiser optimizer stage.
+ */
+
+#include <test/libjulia/Common.h>
+
+#include <libjulia/optimiser/Rematerialiser.h>
+
+#include <libsolidity/inlineasm/AsmPrinter.h>
+
+#include <boost/test/unit_test.hpp>
+
+#include <boost/range/adaptors.hpp>
+#include <boost/algorithm/string/join.hpp>
+
+using namespace std;
+using namespace dev;
+using namespace dev::julia;
+using namespace dev::julia::test;
+using namespace dev::solidity;
+
+
+#define CHECK(_original, _expectation)\
+do\
+{\
+	assembly::AsmPrinter p;\
+	Block b = disambiguate(_original, false);\
+	(Rematerialiser{})(b);\
+	string result = p(b);\
+	BOOST_CHECK_EQUAL(result, format(_expectation, false));\
+}\
+while(false)
+
+BOOST_AUTO_TEST_SUITE(IuliaRematerialiser)
+
+BOOST_AUTO_TEST_CASE(smoke_test)
+{
+	CHECK("{ }", "{ }");
+}
+
+BOOST_AUTO_TEST_CASE(trivial)
+{
+	CHECK(
+		"{ let a := 1 let b := a mstore(0, b) }",
+		"{ let a := 1 let b := 1 mstore(0, 1) }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(expression)
+{
+	CHECK(
+		"{ let a := add(mul(calldatasize(), 2), number()) let b := add(a, a) }",
+		"{ let a := add(mul(calldatasize(), 2), number()) let b := add("
+			"add(mul(calldatasize(), 2), number()),"
+			"add(mul(calldatasize(), 2), number())"
+		") }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(reassign)
+{
+	CHECK(
+		"{ let a := extcodesize(0) let b := a let c := b a := 2 let d := add(b, c) pop(a) pop(b) pop(c) pop(d) }",
+		"{ let a := extcodesize(0) let b := a let c := a a := 2 let d := add(b, c) pop(2) pop(b) pop(c) pop(add(b, c)) }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(non_movable_instr)
+{
+	CHECK(
+		"{ let a := 1 let b := mload(a) let c := a mstore(add(a, b), c) }",
+		"{ let a := 1 let b := mload(1) let c := 1 mstore(add(1, b), 1) }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(non_movable_fun)
+{
+	CHECK(
+		"{ function f(x) -> y {} let a := 1 let b := f(a) let c := a mstore(add(a, b), c) }",
+		"{ function f(x) -> y {} let a := 1 let b := f(1) let c := 1 mstore(add(1, b), 1) }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(branches_if)
+{
+	CHECK(
+		"{ let a := 1 let b := 2 if b { pop(b) b := a } let c := b }",
+		"{ let a := 1 let b := 2 if 2 { pop(2) b := 1 } let c := b }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(branches_switch)
+{
+	CHECK(
+		"{ let a := 1 let b := 2 switch number() case 1 { b := a } default { let x := a let y := b b := a } pop(add(a, b)) }",
+		"{ let a := 1 let b := 2 switch number() case 1 { b := 1 } default { let x := 1 let y := b b := 1 } pop(add(1, b)) }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(branches_for)
+{
+	CHECK(
+		"{ let a := 1 for { pop(a) } a { pop(a) } { pop(a) } }",
+		"{ let a := 1 for { pop(1) } 1 { pop(1) } { pop(1) } }"
+	);
+	CHECK(
+		"{ let a := 1 for { pop(a) } a { pop(a) } { a := 7 let c := a } let x := a }",
+		"{ let a := 1 for { pop(1) } a { pop(7) } { a := 7 let c := 7 } let x := a }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(branches_for_declared_in_init)
+{
+	CHECK(
+		"{ let b := 0 for { let a := 1 pop(a) } a { pop(a) } { b := 1 pop(a) } }",
+		"{ let b := 0 for { let a := 1 pop(1) } 1 { pop(1) } { b := 1 pop(1) } }"
+	);
+	CHECK(
+		"{ let b := 0 for { let a := 1 pop(a) } lt(a, 0) { pop(a) a := add(a, 3) } { b := 1 pop(a) } }",
+		"{ let b := 0 for { let a := 1 pop(1) } lt(a, 0) { pop(a) a := add(a, 3) } { b := 1 pop(a) } }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(reassignment)
+{
+	CHECK(
+		"{ let a := 1 pop(a) if a { a := 2 } let b := mload(a) pop(b) }",
+		"{ let a := 1 pop(1) if 1 { a := 2 } let b := mload(a) pop(b) }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(update_assignment_remat)
+{
+	// We cannot substitute `a` in `let b := a`
+	CHECK(
+		"{ let a := extcodesize(0) a := mul(a, 2) let b := a }",
+		"{ let a := extcodesize(0) a := mul(a, 2) let b := a }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(do_not_move_out_of_scope)
+{
+	// Cannot replace by `let b := x` by `let b := a` since a is out of scope.
+	CHECK(
+		"{ let x { let a := sload(0) x := a } let b := x }",
+		"{ let x { let a := sload(0) x := a } let b := x }"
+	);
+}
+
+BOOST_AUTO_TEST_CASE(do_not_remat_large_amounts_of_code)
+{
+	CHECK(
+		"{ let x := add(mul(calldataload(2), calldataload(4)), mul(2, calldatasize())) let b := x }",
+		"{ let x := add(mul(calldataload(2), calldataload(4)), mul(2, calldatasize())) let b := x }"
+	);
+	CHECK(
+		"{ let x := add(mul(calldataload(2), calldataload(4)), calldatasize()) let b := x }",
+		"{ let x := add(mul(calldataload(2), calldataload(4)), calldatasize()) let b := add(mul(calldataload(2), calldataload(4)), calldatasize()) }"
+	);
+}
+
+BOOST_AUTO_TEST_SUITE_END()