Use native shift instructions in ABIFunctions on Constantinople

3 files changed, 70 insertions, 26 deletions

diff --git a/libsolidity/codegen/ABIFunctions.cpp b/libsolidity/codegen/ABIFunctions.cpp
index 8e890854..f6aa714d 100644
--- a/libsolidity/codegen/ABIFunctions.cpp
+++ b/libsolidity/codegen/ABIFunctions.cpp
@@ -1401,37 +1401,74 @@ string ABIFunctions::copyToMemoryFunction(bool _fromCalldata)
 
 string ABIFunctions::shiftLeftFunction(size_t _numBits)
 {
+	solAssert(_numBits < 256, "");
+
 	string functionName = "shift_left_" + to_string(_numBits);
-	return createFunction(functionName, [&]() {
-		solAssert(_numBits < 256, "");
-		return
-			Whiskers(R"(
-			function <functionName>(value) -> newValue {
-				newValue := mul(value, <multiplier>)
-			}
-			)")
-			("functionName", functionName)
-			("multiplier", toCompactHexWithPrefix(u256(1) << _numBits))
-			.render();
-	});
+	if (m_evmVersion.hasBitwiseShifting())
+	{
+		return createFunction(functionName, [&]() {
+			return
+				Whiskers(R"(
+				function <functionName>(value) -> newValue {
+					newValue := shl(<numBits>, value)
+				}
+				)")
+				("functionName", functionName)
+				("numBits", to_string(_numBits))
+				.render();
+		});
+	}
+	else
+	{
+		return createFunction(functionName, [&]() {
+			return
+				Whiskers(R"(
+				function <functionName>(value) -> newValue {
+					newValue := mul(value, <multiplier>)
+				}
+				)")
+				("functionName", functionName)
+				("multiplier", toCompactHexWithPrefix(u256(1) << _numBits))
+				.render();
+		});
+	}
 }
 
 string ABIFunctions::shiftRightFunction(size_t _numBits, bool _signed)
 {
+	solAssert(_numBits < 256, "");
+
 	string functionName = "shift_right_" + to_string(_numBits) + (_signed ? "_signed" : "_unsigned");
-	return createFunction(functionName, [&]() {
-		solAssert(_numBits < 256, "");
-		return
-			Whiskers(R"(
-			function <functionName>(value) -> newValue {
-				newValue := <div>(value, <multiplier>)
-			}
-			)")
-			("functionName", functionName)
-			("div", _signed ? "sdiv" : "div")
-			("multiplier", toCompactHexWithPrefix(u256(1) << _numBits))
-			.render();
-	});
+	if (m_evmVersion.hasBitwiseShifting())
+	{
+		return createFunction(functionName, [&]() {
+			return
+				Whiskers(R"(
+				function <functionName>(value) -> newValue {
+					newValue := <shiftOp>(<numBits>, value)
+				}
+				)")
+				("functionName", functionName)
+				("shiftOp", _signed ? "sar" : "shr")
+				("numBits", to_string(_numBits))
+				.render();
+		});
+	}
+	else
+	{
+		return createFunction(functionName, [&]() {
+			return
+				Whiskers(R"(
+				function <functionName>(value) -> newValue {
+					newValue := <div>(value, <multiplier>)
+				}
+				)")
+				("functionName", functionName)
+				("div", _signed ? "sdiv" : "div")
+				("multiplier", toCompactHexWithPrefix(u256(1) << _numBits))
+				.render();
+		});
+	}
 }
 
 string ABIFunctions::roundUpFunction()
diff --git a/libsolidity/codegen/ABIFunctions.h b/libsolidity/codegen/ABIFunctions.h
index 2b582e84..41bb70b2 100644
--- a/libsolidity/codegen/ABIFunctions.h
+++ b/libsolidity/codegen/ABIFunctions.h
@@ -22,6 +22,8 @@
 
 #pragma once
 
+#include <libsolidity/interface/EVMVersion.h>
+
 #include <libsolidity/ast/ASTForward.h>
 
 #include <vector>
@@ -48,6 +50,8 @@ using TypePointers = std::vector<TypePointer>;
 class ABIFunctions
 {
 public:
+	explicit ABIFunctions(EVMVersion _evmVersion = EVMVersion{}) : m_evmVersion(_evmVersion) {}
+
 	/// @returns name of an assembly function to ABI-encode values of @a _givenTypes
 	/// into memory, converting the types to @a _targetTypes on the fly.
 	/// Parameters are: <headStart> <value_n> ... <value_1>, i.e.
@@ -225,6 +229,8 @@ private:
 
 	/// Map from function name to code for a multi-use function.
 	std::map<std::string, std::string> m_requestedFunctions;
+
+	EVMVersion m_evmVersion;
 };
 
 }
diff --git a/libsolidity/codegen/CompilerContext.h b/libsolidity/codegen/CompilerContext.h
index 098472f7..5776b5d1 100644
--- a/libsolidity/codegen/CompilerContext.h
+++ b/libsolidity/codegen/CompilerContext.h
@@ -55,7 +55,8 @@ public:
 	explicit CompilerContext(EVMVersion _evmVersion = EVMVersion{}, CompilerContext* _runtimeContext = nullptr):
 		m_asm(std::make_shared<eth::Assembly>()),
 		m_evmVersion(_evmVersion),
-		m_runtimeContext(_runtimeContext)
+		m_runtimeContext(_runtimeContext),
+		m_abiFunctions(m_evmVersion)
 	{
 		if (m_runtimeContext)
 			m_runtimeSub = size_t(m_asm->newSub(m_runtimeContext->m_asm).data());