Merge pull request #11107 from ethereum/extendedLowlevelInliner

Inline ordinary jumps to small blocks and jumps to terminating control flow.

Changelog.md

@@ -4,6 +4,7 @@ Language Features:
  * Possibility to use ``bytes.concat`` with variable number of ``bytes`` and ``bytesNN`` arguments which behaves as a restricted version of `abi.encodePacked` with a more descriptive name.
 
 Compiler Features:
+ * Low-Level Inliner: Inline ordinary jumps to small blocks and jumps to small blocks that terminate.
 
 
 Bugfixes:

libevmasm/Inliner.cpp

@@ -82,9 +82,7 @@ bool Inliner::isInlineCandidate(size_t _tag, ranges::span<AssemblyItem const> _i
 {
 	assertThrow(_items.size() > 0, OptimizerException, "");
 
-	// Only consider blocks that end in a JUMP for now. This can e.g. be extended to include transaction terminating
+	if (_items.back() != Instruction::JUMP && !SemanticInformation::terminatesControlFlow(_items.back()))
-	// instructions as well in the future.
-	if (_items.back() != Instruction::JUMP)
 		return false;
 
 	// Never inline tags that reference themselves.
@@ -196,19 +194,38 @@ bool Inliner::shouldInlineFullFunctionBody(size_t _tag, ranges::span<AssemblyIte
 	return false;
 }
 
-
+optional<AssemblyItem> Inliner::shouldInline(size_t _tag, AssemblyItem const& _jump, InlinableBlock const& _block) const
-optional<AssemblyItem::JumpType> Inliner::shouldInline(size_t _tag, AssemblyItem const& _jump, InlinableBlock const& _block) const
 {
-	AssemblyItem exitJump = _block.items.back();
+	assertThrow(_jump == Instruction::JUMP, OptimizerException, "");
-	assertThrow(_jump == Instruction::JUMP && exitJump == Instruction::JUMP, OptimizerException, "");
+	AssemblyItem blockExit = _block.items.back();
 
 	if (
 		_jump.getJumpType() == AssemblyItem::JumpType::IntoFunction &&
-		exitJump.getJumpType() == AssemblyItem::JumpType::OutOfFunction
+		blockExit == Instruction::JUMP &&
+		blockExit.getJumpType() == AssemblyItem::JumpType::OutOfFunction &&
+		shouldInlineFullFunctionBody(_tag, _block.items, _block.pushTagCount)
 	)
-		return
+	{
-			shouldInlineFullFunctionBody(_tag, _block.items, _block.pushTagCount) ?
+		blockExit.setJumpType(AssemblyItem::JumpType::Ordinary);
-			make_optional(AssemblyItem::JumpType::Ordinary) : nullopt;
+		return blockExit;
+	}
+
+	// Inline small blocks, if the jump to it is ordinary or the blockExit is a terminating instruction.
+	if (
+		_jump.getJumpType() == AssemblyItem::JumpType::Ordinary ||
+		SemanticInformation::terminatesControlFlow(blockExit)
+	)
+	{
+		static AssemblyItems const jumpPattern = {
+			AssemblyItem{PushTag},
+			AssemblyItem{Instruction::JUMP},
+		};
+		if (
+			GasMeter::dataGas(codeSize(_block.items), m_isCreation, m_evmVersion) <=
+			GasMeter::dataGas(codeSize(jumpPattern), m_isCreation, m_evmVersion)
+		)
+			return blockExit;
+	}
 
 	return nullopt;
 }
@@ -232,10 +249,10 @@ void Inliner::optimise()
 			{
 				if (optional<size_t> tag = getLocalTag(item))
 					if (auto* inlinableBlock = util::valueOrNullptr(inlinableBlocks, *tag))
-						if (auto exitJumpType = shouldInline(*tag, nextItem, *inlinableBlock))
+						if (auto exitItem = shouldInline(*tag, nextItem, *inlinableBlock))
 						{
-							newItems += inlinableBlock->items;
+							newItems += inlinableBlock->items | ranges::views::drop_last(1);
-							newItems.back().setJumpType(*exitJumpType);
+							newItems.emplace_back(move(*exitItem));
 
 							// We are removing one push tag to the block we inline.
 							--inlinableBlock->pushTagCount;

libevmasm/Inliner.h

@@ -61,8 +61,8 @@ private:
 		uint64_t pushTagCount = 0;
 	};
 
-	/// @returns the exit jump type for the block to be inlined, if a particular jump to it should be inlined, otherwise nullopt.
+	/// @returns the exit item for the block to be inlined, if a particular jump to it should be inlined, otherwise nullopt.
-	std::optional<AssemblyItem::JumpType> shouldInline(size_t _tag, AssemblyItem const& _jump, InlinableBlock const& _block) const;
+	std::optional<AssemblyItem> shouldInline(size_t _tag, AssemblyItem const& _jump, InlinableBlock const& _block) const;
 	/// @returns true, if the full function at tag @a _tag with body @a _block that is referenced @a _pushTagCount times
 	/// should be inlined, false otherwise. @a _block should start at the first instruction after the function entry tag
 	/// up to and including the return jump.

test/cmdlineTests/optimizer_BlockDeDuplicator/output

@@ -10,7 +10,7 @@ EVM assembly:
   not(sub(shl(0x40, 0x01), 0x01))
   and
     /* "optimizer_BlockDeDuplicator/input.sol":201:206  fun_x */
-  or(tag_0_7, shl(0x20, tag_4))
+  or(tag_0_7, shl(0x20, tag_2))
   sub(shl(0x40, 0x01), 0x01)
     /* "optimizer_BlockDeDuplicator/input.sol":179:210  function() r = true ? fun_x : f */
   and
@@ -29,8 +29,8 @@ EVM assembly:
 tag_5:
   pop
   jump(tag_6)
-    /* "optimizer_BlockDeDuplicator/input.sol":77:103  function fun_x() public {} */
+    /* "optimizer_BlockDeDuplicator/input.sol":138:174  function f() public { true ? 1 : 3;} */
-tag_4:
+tag_2:
   jump	// out
     /* "optimizer_BlockDeDuplicator/input.sol":60:213  contract C {... */
 tag_6:
@@ -66,12 +66,12 @@ sub_0: assembly {
       dup1
       0x2e1fb2bc
       eq
-      tag_4
+      tag_3
       jumpi
       dup1
       0x4753a67d
       eq
-      tag_4
+      tag_3
       jumpi
     tag_2:
       0x00
@@ -80,10 +80,6 @@ sub_0: assembly {
         /* "optimizer_BlockDeDuplicator/input.sol":138:174  function f() public { true ? 1 : 3;} */
     tag_3:
       stop
-        /* "optimizer_BlockDeDuplicator/input.sol":108:133  function fun_() public {} */
-    tag_4:
-      jump(tag_3)
-        /* "optimizer_BlockDeDuplicator/input.sol":138:174  function f() public { true ? 1 : 3;} */
     tag_7:
       jump	// out
 

test/cmdlineTests/optimizer_inliner_dynamic_reference/output

@@ -58,9 +58,9 @@ sub_0: assembly {
       revert
         /* "optimizer_inliner_dynamic_reference/input.sol":160:215  function a() public pure returns (uint) { return f(); } */
     tag_3:
-      tag_6
+        /* "optimizer_inliner_dynamic_reference/input.sol":361:362  6 */
-      tag_7
+      0x06
-      jump	// in
+        /* "optimizer_inliner_dynamic_reference/input.sol":160:215  function a() public pure returns (uint) { return f(); } */
     tag_6:
       mload(0x40)
         /* "#utility.yul":160:185   */
@@ -100,12 +100,6 @@ sub_0: assembly {
       sstore
         /* "optimizer_inliner_dynamic_reference/input.sol":125:155  function g() public { x = f; } */
       stop
-        /* "optimizer_inliner_dynamic_reference/input.sol":160:215  function a() public pure returns (uint) { return f(); } */
-    tag_7:
-        /* "optimizer_inliner_dynamic_reference/input.sol":194:198  uint */
-      0x00
-        /* "optimizer_inliner_dynamic_reference/input.sol":361:362  6 */
-      0x06
         /* "optimizer_inliner_dynamic_reference/input.sol":209:212  f() */
     tag_16:
         /* "optimizer_inliner_dynamic_reference/input.sol":202:212  return f() */
@@ -147,8 +141,8 @@ sub_0: assembly {
     tag_17:
         /* "optimizer_inliner_dynamic_reference/input.sol":361:362  6 */
       0x06
-        /* "optimizer_inliner_dynamic_reference/input.sol":310:365  function f() internal pure returns (uint) { return 6; } */
       swap1
+        /* "optimizer_inliner_dynamic_reference/input.sol":310:365  function f() internal pure returns (uint) { return 6; } */
       jump	// out
     tag_20:
       mstore(0x00, shl(0xe0, 0x4e487b71))

test/cmdlineTests/optimizer_inliner_dynamic_reference_constructor/output

@@ -35,8 +35,8 @@ tag_1:
 tag_4:
     /* "optimizer_inliner_dynamic_reference_constructor/input.sol":355:356  6 */
   0x06
-    /* "optimizer_inliner_dynamic_reference_constructor/input.sol":304:359  function f() internal pure returns (uint) { return 6; } */
   swap1
+    /* "optimizer_inliner_dynamic_reference_constructor/input.sol":304:359  function f() internal pure returns (uint) { return 6; } */
   jump	// out
     /* "optimizer_inliner_dynamic_reference_constructor/input.sol":60:361  contract C {... */
 tag_5:
@@ -80,9 +80,9 @@ sub_0: assembly {
       revert
         /* "optimizer_inliner_dynamic_reference_constructor/input.sol":154:209  function a() public pure returns (uint) { return f(); } */
     tag_3:
-      tag_5
+        /* "optimizer_inliner_dynamic_reference_constructor/input.sol":355:356  6 */
-      tag_6
+      0x06
-      jump	// in
+        /* "optimizer_inliner_dynamic_reference_constructor/input.sol":154:209  function a() public pure returns (uint) { return f(); } */
     tag_5:
       mload(0x40)
         /* "#utility.yul":160:185   */
@@ -105,12 +105,6 @@ sub_0: assembly {
       tag_5
       tag_10
       jump	// in
-        /* "optimizer_inliner_dynamic_reference_constructor/input.sol":154:209  function a() public pure returns (uint) { return f(); } */
-    tag_6:
-        /* "optimizer_inliner_dynamic_reference_constructor/input.sol":188:192  uint */
-      0x00
-        /* "optimizer_inliner_dynamic_reference_constructor/input.sol":355:356  6 */
-      0x06
         /* "optimizer_inliner_dynamic_reference_constructor/input.sol":203:206  f() */
     tag_14:
         /* "optimizer_inliner_dynamic_reference_constructor/input.sol":196:206  return f() */
@@ -152,8 +146,8 @@ sub_0: assembly {
     tag_12:
         /* "optimizer_inliner_dynamic_reference_constructor/input.sol":355:356  6 */
       0x06
-        /* "optimizer_inliner_dynamic_reference_constructor/input.sol":304:359  function f() internal pure returns (uint) { return 6; } */
       swap1
+        /* "optimizer_inliner_dynamic_reference_constructor/input.sol":304:359  function f() internal pure returns (uint) { return 6; } */
       jump	// out
     tag_17:
       mstore(0x00, shl(0xe0, 0x4e487b71))

test/libevmasm/Optimiser.cpp

@@ -1637,6 +1637,113 @@ BOOST_AUTO_TEST_CASE(inliner_cse_break)
 	);
 }
 
+BOOST_AUTO_TEST_CASE(inliner_stop)
+{
+	AssemblyItems items{
+		AssemblyItem(PushTag, 1),
+		Instruction::JUMP,
+		AssemblyItem(Tag, 1),
+		Instruction::STOP
+	};
+	AssemblyItems expectation{
+		Instruction::STOP,
+		AssemblyItem(Tag, 1),
+		Instruction::STOP
+	};
+	Inliner{items, {}, 200, false, {}}.optimise();
+	BOOST_CHECK_EQUAL_COLLECTIONS(
+		items.begin(), items.end(),
+		expectation.begin(), expectation.end()
+	);
+}
+
+BOOST_AUTO_TEST_CASE(inliner_stop_jumpi)
+{
+	// Because of `jumpi`, will not be inlined.
+	AssemblyItems items{
+		u256(1),
+		AssemblyItem(PushTag, 1),
+		Instruction::JUMPI,
+		AssemblyItem(Tag, 1),
+		Instruction::STOP
+	};
+	AssemblyItems expectation = items;
+	Inliner{items, {}, 200, false, {}}.optimise();
+	BOOST_CHECK_EQUAL_COLLECTIONS(
+		items.begin(), items.end(),
+		expectation.begin(), expectation.end()
+	);
+}
+
+BOOST_AUTO_TEST_CASE(inliner_revert)
+{
+	AssemblyItems items{
+		AssemblyItem(PushTag, 1),
+		Instruction::JUMP,
+		AssemblyItem(Tag, 1),
+		u256(0),
+		Instruction::DUP1,
+		Instruction::REVERT
+	};
+	AssemblyItems expectation{
+		u256(0),
+		Instruction::DUP1,
+		Instruction::REVERT,
+		AssemblyItem(Tag, 1),
+		u256(0),
+		Instruction::DUP1,
+		Instruction::REVERT
+	};
+
+	Inliner{items, {}, 200, false, {}}.optimise();
+	BOOST_CHECK_EQUAL_COLLECTIONS(
+		items.begin(), items.end(),
+		expectation.begin(), expectation.end()
+	);
+}
+
+BOOST_AUTO_TEST_CASE(inliner_revert_increased_datagas)
+{
+	// Inlining this would increase data gas (5 bytes v/s 4 bytes), therefore, skipped.
+	AssemblyItems items{
+		AssemblyItem(PushTag, 1),
+		Instruction::JUMP,
+		AssemblyItem(Tag, 1),
+		u256(0),
+		u256(0),
+		Instruction::REVERT
+	};
+
+	AssemblyItems expectation = items;
+	Inliner{items, {}, 200, false, {}}.optimise();
+	BOOST_CHECK_EQUAL_COLLECTIONS(
+		items.begin(), items.end(),
+		expectation.begin(), expectation.end()
+	);
+}
+
+BOOST_AUTO_TEST_CASE(inliner_invalid)
+{
+	AssemblyItems items{
+		AssemblyItem(PushTag, 1),
+		Instruction::JUMP,
+		AssemblyItem(Tag, 1),
+		Instruction::INVALID
+	};
+
+	AssemblyItems expectation = {
+		Instruction::INVALID,
+		AssemblyItem(Tag, 1),
+		Instruction::INVALID
+	};
+	Inliner{items, {}, 200, false, {}}.optimise();
+	BOOST_CHECK_EQUAL_COLLECTIONS(
+		items.begin(), items.end(),
+		expectation.begin(), expectation.end()
+	);
+}
+
+
 BOOST_AUTO_TEST_SUITE_END()
 
 } // end namespaces

test/libsolidity/Assembly.cpp

@@ -210,7 +210,7 @@ BOOST_AUTO_TEST_CASE(jump_type)
 			jumpTypes += item.getJumpTypeAsString() + "\n";
 
 	if (solidity::test::CommonOptions::get().optimize)
-		BOOST_CHECK_EQUAL(jumpTypes, "[in]\n[out]\n[in]\n[out]\n");
+		BOOST_CHECK_EQUAL(jumpTypes, "[in]\n[out]\n[out]\n[in]\n[out]\n");
 	else
 		BOOST_CHECK_EQUAL(jumpTypes, "[in]\n[out]\n[in]\n[out]\n");
 }

test/libsolidity/semanticTests/array/byte_array_transitional_2.sol

@@ -21,4 +21,4 @@ contract c {
 // test() -> 0
 // gas irOptimized: 312322
 // gas legacy: 483915
-// gas legacyOptimized: 478673
+// gas legacyOptimized: 478672

test/libsolidity/semanticTests/array/copying/arrays_from_and_to_storage.sol

@@ -14,7 +14,7 @@ contract Test {
 // set(uint24[]): 0x20, 18, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 -> 18
 // gas irOptimized: 121109
 // gas legacy: 125815
-// gas legacyOptimized: 123615
+// gas legacyOptimized: 123614
 // data(uint256): 7 -> 8
 // data(uint256): 15 -> 16
 // data(uint256): 18 -> FAILURE

test/libsolidity/semanticTests/array/copying/copy_byte_array_to_storage.sol

@@ -50,4 +50,4 @@ contract C {
 // f() -> 0xff
 // gas irOptimized: 137415
 // gas legacy: 137645
-// gas legacyOptimized: 134377
+// gas legacyOptimized: 134376

test/libsolidity/semanticTests/array/push/byte_array_push_transition.sol

@@ -19,4 +19,4 @@ contract c {
 // test() -> 0
 // gas irOptimized: 397892
 // gas legacy: 565428
-// gas legacyOptimized: 552525
+// gas legacyOptimized: 552524

test/libsolidity/semanticTests/constructor/arrays_in_constructors.sol

@@ -28,4 +28,4 @@ contract Creator {
 // f(uint256,address[]): 7, 0x40, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 -> 7, 8
 // gas irOptimized: 472714
 // gas legacy: 570900
-// gas legacyOptimized: 436360
+// gas legacyOptimized: 435524

test/libsolidity/semanticTests/externalContracts/snark.sol

@@ -298,4 +298,4 @@ contract Test {
 // verifyTx() -> true
 // gas irOptimized: 145824
 // gas legacy: 130571
-// gas legacyOptimized: 100187
+// gas legacyOptimized: 100147

test/libsolidity/semanticTests/salted_create/salted_create.sol

@@ -24,4 +24,4 @@ contract A {
 // same_salt() -> true
 // gas irOptimized: 98439083
 // gas legacy: 98439116
-// gas legacyOptimized: 98438982
+// gas legacyOptimized: 98438970

test/libsolidity/semanticTests/various/destructuring_assignment.sol

@@ -38,4 +38,4 @@ contract C {
 // f(bytes): 0x20, 0x5, "abcde" -> 0
 // gas irOptimized: 248997
 // gas legacy: 239258
-// gas legacyOptimized: 238578
+// gas legacyOptimized: 238577

test/libsolidity/semanticTests/viaYul/array_memory_index_access.sol

@@ -30,7 +30,7 @@ contract C {
 // index(uint256): 0xFF -> true
 // gas irOptimized: 167533
 // gas legacy: 248854
-// gas legacyOptimized: 152640
+// gas legacyOptimized: 152638
 // accessIndex(uint256,int256): 10, 1 -> 2
 // accessIndex(uint256,int256): 10, 0 -> 1
 // accessIndex(uint256,int256): 10, 11 -> FAILURE, hex"4e487b71", 0x32