Create empty dynamic memory arrays more efficiently.

4 files changed, 66 insertions, 8 deletions

diff --git a/test/libsolidity/JSONCompiler.cpp b/test/libsolidity/JSONCompiler.cpp
index aed0a370..cdcc22a6 100644
--- a/test/libsolidity/JSONCompiler.cpp
+++ b/test/libsolidity/JSONCompiler.cpp
@@ -111,12 +111,12 @@ BOOST_AUTO_TEST_CASE(basic_compilation)
 	BOOST_CHECK(contract["bytecode"].isString());
 	BOOST_CHECK_EQUAL(
 		dev::test::bytecodeSansMetadata(contract["bytecode"].asString()),
-		"60606040523415600e57600080fd5b603580601b6000396000f3006060604052600080fd00"
+		"60806040523415600e57600080fd5b603580601b6000396000f3006080604052600080fd00"
 	);
 	BOOST_CHECK(contract["runtimeBytecode"].isString());
 	BOOST_CHECK_EQUAL(
 		dev::test::bytecodeSansMetadata(contract["runtimeBytecode"].asString()),
-		"6060604052600080fd00"
+		"6080604052600080fd00"
 	);
 	BOOST_CHECK(contract["functionHashes"].isObject());
 	BOOST_CHECK(contract["gasEstimates"].isObject());
@@ -153,12 +153,12 @@ BOOST_AUTO_TEST_CASE(single_compilation)
 	BOOST_CHECK(contract["bytecode"].isString());
 	BOOST_CHECK_EQUAL(
 		dev::test::bytecodeSansMetadata(contract["bytecode"].asString()),
-		"60606040523415600e57600080fd5b603580601b6000396000f3006060604052600080fd00"
+		"60806040523415600e57600080fd5b603580601b6000396000f3006080604052600080fd00"
 	);
 	BOOST_CHECK(contract["runtimeBytecode"].isString());
 	BOOST_CHECK_EQUAL(
 		dev::test::bytecodeSansMetadata(contract["runtimeBytecode"].asString()),
-		"6060604052600080fd00"
+		"6080604052600080fd00"
 	);
 	BOOST_CHECK(contract["functionHashes"].isObject());
 	BOOST_CHECK(contract["gasEstimates"].isObject());
diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
index 38d3ce4d..b58ebee4 100644
--- a/test/libsolidity/SolidityEndToEndTest.cpp
+++ b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -7687,7 +7687,6 @@ BOOST_AUTO_TEST_CASE(create_memory_array_allocation_size)
 	ABI_CHECK(callContractFunction("f()"), encodeArgs(0x40, 0x40, 0x20 + 256));
 }
 
-
 BOOST_AUTO_TEST_CASE(memory_arrays_of_various_sizes)
 {
 	// Computes binomial coefficients the chinese way
@@ -7710,6 +7709,41 @@ BOOST_AUTO_TEST_CASE(memory_arrays_of_various_sizes)
 	ABI_CHECK(callContractFunction("f(uint256,uint256)", encodeArgs(u256(9), u256(5))), encodeArgs(u256(70)));
 }
 
+BOOST_AUTO_TEST_CASE(create_multiple_dynamic_arrays)
+{
+	char const* sourceCode = R"(
+		contract C {
+			function f() returns (uint) {
+				uint[][] memory x = new uint[][](42);
+				assert(x[0].length == 0);
+				x[0] = new uint[](1);
+				x[0][0] = 1;
+				assert(x[4].length == 0);
+				x[4] = new uint[](1);
+				x[4][0] = 2;
+				assert(x[10].length == 0);
+				x[10] = new uint[](1);
+				x[10][0] = 44;
+				uint[][] memory y = new uint[][](24);
+				assert(y[0].length == 0);
+				y[0] = new uint[](1);
+				y[0][0] = 1;
+				assert(y[4].length == 0);
+				y[4] = new uint[](1);
+				y[4][0] = 2;
+				assert(y[10].length == 0);
+				y[10] = new uint[](1);
+				y[10][0] = 88;
+				if ((x[0][0] == y[0][0]) && (x[4][0] == y[4][0]) && (x[10][0] == 44) && (y[10][0] == 88))
+					return 7;
+				return 0;
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "C");
+	ABI_CHECK(callContractFunction("f()"), encodeArgs(u256(7)));
+}
+
 BOOST_AUTO_TEST_CASE(memory_overwrite)
 {
 	char const* sourceCode = R"(
diff --git a/test/libsolidity/SolidityOptimizer.cpp b/test/libsolidity/SolidityOptimizer.cpp
index cf4550c7..a0df76f3 100644
--- a/test/libsolidity/SolidityOptimizer.cpp
+++ b/test/libsolidity/SolidityOptimizer.cpp
@@ -93,8 +93,10 @@ public:
 	{
 		m_contractAddress = m_nonOptimizedContract;
 		bytes nonOptimizedOutput = callContractFunction(_sig, _arguments...);
+		m_gasUsedNonOptimized = m_gasUsed;
 		m_contractAddress = m_optimizedContract;
 		bytes optimizedOutput = callContractFunction(_sig, _arguments...);
+		m_gasUsedOptimized = m_gasUsed;
 		BOOST_CHECK_MESSAGE(!optimizedOutput.empty(), "No optimized output for " + _sig);
 		BOOST_CHECK_MESSAGE(!nonOptimizedOutput.empty(), "No un-optimized output for " + _sig);
 		BOOST_CHECK_MESSAGE(nonOptimizedOutput == optimizedOutput, "Computed values do not match."
@@ -120,6 +122,8 @@ public:
 	}
 
 protected:
+	u256 m_gasUsedOptimized;
+	u256 m_gasUsedNonOptimized;
 	bytes m_nonOptimizedBytecode;
 	bytes m_optimizedBytecode;
 	Address m_optimizedContract;
@@ -584,6 +588,26 @@ BOOST_AUTO_TEST_CASE(invalid_state_at_control_flow_join)
 	compareVersions("test()");
 }
 
+BOOST_AUTO_TEST_CASE(init_empty_dynamic_arrays)
+{
+	// This is not so much an optimizer test, but rather a test
+	// that allocating empty arrays is implemented efficiently.
+	// In particular, initializing a dynamic memory array does
+	// not use any memory.
+	char const* sourceCode = R"(
+		contract Test {
+			function f() pure returns (uint r) {
+				uint[][] memory x = new uint[][](20000);
+				return x.length;
+			}
+		}
+	)";
+	compileBothVersions(sourceCode);
+	compareVersions("f()");
+	BOOST_CHECK_LE(m_gasUsedNonOptimized, 1900000);
+	BOOST_CHECK_LE(1600000, m_gasUsedNonOptimized);
+}
+
 BOOST_AUTO_TEST_CASE(optimise_multi_stores)
 {
 	char const* sourceCode = R"(
diff --git a/test/libsolidity/StandardCompiler.cpp b/test/libsolidity/StandardCompiler.cpp
index dd6eb7c4..b285a2a0 100644
--- a/test/libsolidity/StandardCompiler.cpp
+++ b/test/libsolidity/StandardCompiler.cpp
@@ -261,14 +261,14 @@ BOOST_AUTO_TEST_CASE(basic_compilation)
 	BOOST_CHECK(contract["evm"]["bytecode"]["object"].isString());
 	BOOST_CHECK_EQUAL(
 		dev::test::bytecodeSansMetadata(contract["evm"]["bytecode"]["object"].asString()),
-		"60606040523415600e57600080fd5b603580601b6000396000f3006060604052600080fd00"
+		"60806040523415600e57600080fd5b603580601b6000396000f3006080604052600080fd00"
 	);
 	BOOST_CHECK(contract["evm"]["assembly"].isString());
 	BOOST_CHECK(contract["evm"]["assembly"].asString().find(
-		"    /* \"fileA\":0:14  contract A { } */\n  mstore(0x40, 0x60)\n  jumpi(tag_1, iszero(callvalue))\n"
+		"    /* \"fileA\":0:14  contract A { } */\n  mstore(0x40, 0x80)\n  jumpi(tag_1, iszero(callvalue))\n"
 		"  0x0\n  dup1\n  revert\ntag_1:\n  dataSize(sub_0)\n  dup1\n  dataOffset(sub_0)\n  0x0\n  codecopy\n  0x0\n"
 		"  return\nstop\n\nsub_0: assembly {\n        /* \"fileA\":0:14  contract A { } */\n"
-		"      mstore(0x40, 0x60)\n      0x0\n      dup1\n      revert\n\n"
+		"      mstore(0x40, 0x80)\n      0x0\n      dup1\n      revert\n\n"
 		"    auxdata: 0xa165627a7a7230582") == 0);
 	BOOST_CHECK(contract["evm"]["gasEstimates"].isObject());
 	BOOST_CHECK_EQUAL(