Merge pull request #10454 from ethereum/ewasm-cleanup

[ewasm] Clean up some builtins and fix text representation of `select`
2023-10-03 13:03:40 +00:00 · 2020-12-01 17:34:48 +01:00 · 2020-12-01 17:34:48 +01:00 · e10712c173
commit e10712c173
parent 33ca90c284 04cf4867fe
8 changed files with 36 additions and 47 deletions
--- a/libyul/backends/wasm/BinaryTransform.cpp
+++ b/libyul/backends/wasm/BinaryTransform.cpp
@ -107,33 +107,24 @@ bytes toBytes(Export _export)
 	return toBytes(uint8_t(_export));
 }

+// NOTE: This is a subset of WebAssembly opcodes.
+//       Those available as a builtin are listed further down.
 enum class Opcode: uint8_t
 {
-	Unreachable = 0x00,
-	Nop = 0x01,
 	Block = 0x02,
 	Loop = 0x03,
 	If = 0x04,
 	Else = 0x05,
-	Try = 0x06,
-	Catch = 0x07,
-	Throw = 0x08,
-	Rethrow = 0x09,
-	BrOnExn = 0x0a,
 	End = 0x0b,
 	Br = 0x0c,
 	BrIf = 0x0d,
-	BrTable = 0x0e,
+	BrTable = 0x0e, // Not used yet.
 	Return = 0x0f,
 	Call = 0x10,
-	CallIndirect = 0x11,
-	ReturnCall = 0x12,
-	ReturnCallIndirect = 0x13,
-	Drop = 0x1a,
-	Select = 0x1b,
+	CallIndirect = 0x11, // Not used yet.
 	LocalGet = 0x20,
 	LocalSet = 0x21,
-	LocalTee = 0x22,
+	LocalTee = 0x22, // Not used yet.
 	GlobalGet = 0x23,
 	GlobalSet = 0x24,
 	I32Const = 0x41,
@ -156,6 +147,10 @@ Opcode constOpcodeFor(ValueType _type)
 }

 static map<string, uint8_t> const builtins = {
+	{"unreachable", 0x00},
+	{"nop", 0x01},
+	{"i32.drop", 0x1a},
+	{"i64.drop", 0x1a},
 	{"i32.select", 0x1b},
 	{"i64.select", 0x1b},
 	{"i32.load", 0x28},
@ -381,30 +376,21 @@ bytes BinaryTransform::operator()(BuiltinCall const& _call)
 		return toBytes(Opcode::I64Const) + lebEncodeSigned(static_cast<int64_t>(m_subModulePosAndSize.at(name).second));
 	}

+	yulAssert(builtins.count(_call.functionName), "Builtin " + _call.functionName + " not found");
+	// NOTE: the dialect ensures we have the right amount of arguments
 	bytes args = visit(_call.arguments);
+	bytes ret = move(args) + toBytes(builtins.at(_call.functionName));
+	if (
+		_call.functionName.find(".load") != string::npos ||
+		_call.functionName.find(".store") != string::npos
+	)
+		// Alignment hint and offset. Interpreters ignore the alignment. JITs/AOTs can take it
+		// into account to generate more efficient code but if the hint is invalid it could
+		// actually be more expensive. It's best to hint at 1-byte alignment if we don't plan
+		// to control the memory layout accordingly.
+		ret += bytes{{0, 0}}; // 2^0 == 1-byte alignment

-	if (_call.functionName == "unreachable")
-		return toBytes(Opcode::Unreachable);
-	else if (_call.functionName == "nop")
-		return toBytes(Opcode::Nop);
-	else if (_call.functionName == "i32.drop" || _call.functionName == "i64.drop")
-		return toBytes(Opcode::Drop);
-	else
-	{
-		yulAssert(builtins.count(_call.functionName), "Builtin " + _call.functionName + " not found");
-		bytes ret = move(args) + toBytes(builtins.at(_call.functionName));
-		if (
-			_call.functionName.find(".load") != string::npos ||
-			_call.functionName.find(".store") != string::npos
-		)
-			// Alignment hint and offset. Interpreters ignore the alignment. JITs/AOTs can take it
-			// into account to generate more efficient code but if the hint is invalid it could
-			// actually be more expensive. It's best to hint at 1-byte alignment if we don't plan
-			// to control the memory layout accordingly.
-			ret += bytes{{0, 0}}; // 2^0 == 1-byte alignment
-
-		return ret;
-	}
+	return ret;
 }

 bytes BinaryTransform::operator()(FunctionCall const& _call)
--- a/libyul/backends/wasm/TextTransform.cpp
+++ b/libyul/backends/wasm/TextTransform.cpp
@ -122,8 +122,11 @@ string TextTransform::operator()(wasm::BuiltinCall const& _builtinCall)
 {
 	string args = joinTransformed(_builtinCall.arguments);
 	string funcName = _builtinCall.functionName;
+	// These are prefixed in the dialect, but are actually overloaded instructions in WebAssembly.
 	if (funcName == "i32.drop" || funcName == "i64.drop")
 		funcName = "drop";
+	else if (funcName == "i32.select" || funcName == "i64.select")
+		funcName = "select";
 	return "(" + funcName + (args.empty() ? "" : " " + args) + ")";
 }

--- a/libyul/backends/wasm/WasmDialect.h
+++ b/libyul/backends/wasm/WasmDialect.h
@ -38,7 +38,7 @@ struct Object;
 *
 * Builtin functions are a subset of the wasm instructions.
 *
- * There is a builtin function `i32.drop` that takes an i32, while `drop` takes i64.
+ * There is a builtin function `i32.drop` that takes an i32, while `i64.drop` takes i64.
 *
 */
 struct WasmDialect: public Dialect
--- a/test/cmdlineTests/evm_to_wasm_break/output
+++ b/test/cmdlineTests/evm_to_wasm_break/output
@ -412,13 +412,13 @@ Text representation:
        (local.set $z (i32.const 0))
        (local.set $_1 (i32.const 4294967295))
        (block
-            (local.set $condition (i32.select (local.get $_1) (i64.ne (local.get $x1) (local.get $y1)) (i64.lt_u (local.get $x1) (local.get $y1))))
+            (local.set $condition (select (local.get $_1) (i64.ne (local.get $x1) (local.get $y1)) (i64.lt_u (local.get $x1) (local.get $y1))))
            (if (i32.eq (local.get $condition) (i32.const 0)) (then
                (block
-                    (local.set $condition_11 (i32.select (local.get $_1) (i64.ne (local.get $x2) (local.get $y2)) (i64.lt_u (local.get $x2) (local.get $y2))))
+                    (local.set $condition_11 (select (local.get $_1) (i64.ne (local.get $x2) (local.get $y2)) (i64.lt_u (local.get $x2) (local.get $y2))))
                    (if (i32.eq (local.get $condition_11) (i32.const 0)) (then
                        (block
-                            (local.set $condition_12 (i32.select (local.get $_1) (i64.ne (local.get $x3) (local.get $y3)) (i64.lt_u (local.get $x3) (local.get $y3))))
+                            (local.set $condition_12 (select (local.get $_1) (i64.ne (local.get $x3) (local.get $y3)) (i64.lt_u (local.get $x3) (local.get $y3))))
                            (if (i32.eq (local.get $condition_12) (i32.const 0)) (then
                                (local.set $z (i64.lt_u (local.get $x4) (local.get $y4)))
                            )(else
--- a/test/libyul/objectCompiler/wasm/no_main_function.yul
+++ b/test/libyul/objectCompiler/wasm/no_main_function.yul
@ -19,4 +19,4 @@
 // )
 //
 // Binary:
-// 0061736d01000000010401600000020100030201000503010001060100070a01066d656d6f727902000a0801060002401a0b0b
+// 0061736d01000000010401600000020100030201000503010001060100070a01066d656d6f727902000a0d010b000240420042017c1a0b0b
--- a/test/libyul/objectCompiler/wasm/simple.yul
+++ b/test/libyul/objectCompiler/wasm/simple.yul
@ -20,4 +20,4 @@
 // )
 //
 // Binary:
-// 0061736d01000000010401600000020100030201000503010001060100071102066d656d6f72790200046d61696e00000a0801060002401a0b0b
+// 0061736d01000000010401600000020100030201000503010001060100071102066d656d6f72790200046d61696e00000a0d010b000240420042017c1a0b0b
--- a/test/libyul/objectCompiler/wasm/subObject.yul
+++ b/test/libyul/objectCompiler/wasm/subObject.yul
@ -11,7 +11,7 @@ object "a" {
 // (module
 //     ;; custom section for sub-module
 //     ;; The Keccak-256 hash of the text representation of "sub": 78ac3419d75c8d6f42f663717b8e964eeb994d77ff175145133084422dbd23d7
-//     ;; (@custom "sub" "0061736d01000000010401600000020100030201000503010001060100071102066d656d6f72790200046d61696e00000a0801060002401a0b0b")
+//     ;; (@custom "sub" "0061736d01000000010401600000020100030201000503010001060100071102066d656d6f72790200046d61696e00000a0a0108000240420b1a0b0b")
 //     ;; custom section for data
 //     ;; (@custom "str" "48656c6c6f2c20576f726c6421")
 //     (memory $memory (export "memory") 1)
@ -19,4 +19,4 @@ object "a" {
 // )
 //
 // Binary:
-// 0061736d010000000101000201000301000503010001060100070a01066d656d6f72790200003e037375620061736d01000000010401600000020100030201000503010001060100071102066d656d6f72790200046d61696e00000a0801060002401a0b0b00110373747248656c6c6f2c20576f726c64210a0100
+// 0061736d010000000101000201000301000503010001060100070a01066d656d6f727902000040037375620061736d01000000010401600000020100030201000503010001060100071102066d656d6f72790200046d61696e00000a0a0108000240420b1a0b0b00110373747248656c6c6f2c20576f726c64210a0100
--- a/test/libyul/objectCompiler/wasm/subObjectAccess.yul
+++ b/test/libyul/objectCompiler/wasm/subObjectAccess.yul
@ -59,8 +59,8 @@ object "A" {
 // Text:
 // (module
 //     ;; custom section for sub-module
-//     ;; The Keccak-256 hash of the text representation of "B": 1eeffe5bc8d8819350ead60cc71ccd92c223cf52a908330db53461eb9ac89b62
-//     ;; (@custom "B" "0061736d01000000010401600000020100030201000503010001060100071102066d656d6f72790200046d61696e0000007b01430061736d01000000010401600000020100030201000503010001060100071102066d656d6f72790200046d61696e0000003c01440061736d01000000010401600000020100030201000503010001060100071102066d656d6f72790200046d61696e00000a080106000240000b0b0a0901070002401a1a0b0b003c01450061736d01000000010401600000020100030201000503010001060100071102066d656d6f72790200046d61696e00000a080106000240000b0b0a0b01090002401a1a1a1a0b0b")
+//     ;; The Keccak-256 hash of the text representation of "B": ccfc48ce1c0d0542ffd25ae6858777b2f7b8a6d2b6608f679458182e719f5434
+//     ;; (@custom "B" "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")
 //     ;; custom section for data
 //     ;; (@custom "data1" "48656c6c6f2c20576f726c6421")
 //     (memory $memory (export "memory") 1)
@ -76,4 +76,4 @@ object "A" {
 // )
 //
 // Binary:
-// 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
+// 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