From 87e3fbee6c2790362902856762279817d1b89cf7 Mon Sep 17 00:00:00 2001
From: Alexander Arlt <alexander.arlt@arlt-labs.com>
Date: Sat, 21 Nov 2020 15:04:29 -0500
Subject: [PATCH] [ewasm] Polyfill: balance & address.

---
 libyul/backends/wasm/polyfill/Conversion.yul  | 21 ++++-----
 libyul/backends/wasm/polyfill/Interface.yul   | 45 +++++--------------
 libyul/backends/wasm/polyfill/Memory.yul      | 42 ++++++++++++++++-
 .../semanticTests/builtinFunctions/smoke.sol  |  0
 4 files changed, 63 insertions(+), 45 deletions(-)
 create mode 100644 test/libsolidity/semanticTests/builtinFunctions/smoke.sol

diff --git a/libyul/backends/wasm/polyfill/Conversion.yul b/libyul/backends/wasm/polyfill/Conversion.yul
index 3168b80ca..17d205ddd 100644
--- a/libyul/backends/wasm/polyfill/Conversion.yul
+++ b/libyul/backends/wasm/polyfill/Conversion.yul
@@ -59,20 +59,21 @@ function u256_to_address(x1, x2, x3, x4) -> r1, r2, r3 {
 	r3 := x4
 }
 
-function bswap16(x) -> y {
-	let hi := i64.and(i64.shl(x, 8), 0xff00)
-	let lo := i64.and(i64.shr_u(x, 8), 0xff)
-	y := i64.or(hi, lo)
+function bswap16(x:i32) -> y:i32 {
+	let hi:i32 := i32.and(i32.shl(x, 8:i32), 0xff00:i32)
+	let lo:i32 := i32.and(i32.shr_u(x, 8:i32), 0xff:i32)
+	y := i32.or(hi, lo)
 }
 
-function bswap32(x) -> y {
-	let hi := i64.shl(bswap16(x), 16)
-	let lo := bswap16(i64.shr_u(x, 16))
-	y := i64.or(hi, lo)
+function bswap32(x:i32) -> y:i32 {
+	let hi:i32 := i32.shl(bswap16(x), 16:i32)
+	let lo:i32 := bswap16(i32.shr_u(x, 16:i32))
+	y := i32.or(hi, lo)
 }
 
+
 function bswap64(x) -> y {
-	let hi := i64.shl(bswap32(x), 32)
-	let lo := bswap32(i64.shr_u(x, 32))
+	let hi := i64.shl(i64.extend_i32_u(bswap32(i32.wrap_i64(x))), 32)
+	let lo := i64.extend_i32_u(bswap32(i32.wrap_i64(i64.shr_u(x, 32))))
 	y := i64.or(hi, lo)
 }
diff --git a/libyul/backends/wasm/polyfill/Interface.yul b/libyul/backends/wasm/polyfill/Interface.yul
index 6251409bf..9c5fb59b4 100644
--- a/libyul/backends/wasm/polyfill/Interface.yul
+++ b/libyul/backends/wasm/polyfill/Interface.yul
@@ -19,14 +19,15 @@
 // NOTE: This file is used to generate `ewasmPolyfills/Interface.h`.
 
 function address() -> z1, z2, z3, z4 {
-	eth.getAddress(0:i32)
-	z1, z2, z3, z4 := mload_internal(0:i32)
+	eth.getAddress(12:i32)
+	z1, z2, z3, z4 := mload_address(0:i32)
 }
 
 function balance(x1, x2, x3, x4) -> z1, z2, z3, z4 {
 	mstore_address(0:i32, x1, x2, x3, x4)
-	eth.getExternalBalance(12:i32, 48:i32)
-	z1, z2, z3, z4 := mload_internal(32:i32)
+	eth.getExternalBalance(12:i32, 32:i32)
+	z3 := i64.load(40:i32)
+	z4 := i64.load(32:i32)
 }
 
 function selfbalance() -> z1, z2, z3, z4 {
@@ -40,13 +41,13 @@ function chainid() -> z1, z2, z3, z4 {
 }
 
 function origin() -> z1, z2, z3, z4 {
-	eth.getTxOrigin(0:i32)
-	z1, z2, z3, z4 := mload_internal(0:i32)
+	eth.getTxOrigin(12:i32)
+	z1, z2, z3, z4 := mload_address(0:i32)
 }
 
 function caller() -> z1, z2, z3, z4 {
-	eth.getCaller(0:i32)
-	z1, z2, z3, z4 := mload_internal(0:i32)
+	eth.getCaller(12:i32)
+	z1, z2, z3, z4 := mload_address(0:i32)
 }
 
 function callvalue() -> z1, z2, z3, z4 {
@@ -155,8 +156,8 @@ function blockhash(x1, x2, x3, x4) -> z1, z2, z3, z4 {
 }
 
 function coinbase() -> z1, z2, z3, z4 {
-	eth.getBlockCoinbase(0:i32)
-	z1, z2, z3, z4 := mload_internal(0:i32)
+	eth.getBlockCoinbase(12:i32)
+	z1, z2, z3, z4 := mload_address(0:i32)
 }
 
 function timestamp() -> z1, z2, z3, z4 {
@@ -180,34 +181,10 @@ function mload(x1, x2, x3, x4) -> z1, z2, z3, z4 {
 	z1, z2, z3, z4 := mload_internal(to_internal_i32ptr(x1, x2, x3, x4))
 }
 
-function mload_internal(pos:i32) -> z1, z2, z3, z4 {
-	z1 := bswap64(i64.load(pos))
-	z2 := bswap64(i64.load(i32.add(pos, 8:i32)))
-	z3 := bswap64(i64.load(i32.add(pos, 16:i32)))
-	z4 := bswap64(i64.load(i32.add(pos, 24:i32)))
-}
-
 function mstore(x1, x2, x3, x4, y1, y2, y3, y4) {
 	mstore_internal(to_internal_i32ptr(x1, x2, x3, x4), y1, y2, y3, y4)
 }
 
-function mstore_internal(pos:i32, y1, y2, y3, y4) {
-	i64.store(pos, bswap64(y1))
-	i64.store(i32.add(pos, 8:i32), bswap64(y2))
-	i64.store(i32.add(pos, 16:i32), bswap64(y3))
-	i64.store(i32.add(pos, 24:i32), bswap64(y4))
-}
-
-function mstore_address(pos:i32, a1, a2, a3, a4) {
-	a1, a2, a3 := u256_to_address(a1, a2, a3, a4)
-	mstore_internal(pos, 0, a1, a2, a3)
-}
-
-function mstore8(x1, x2, x3, x4, y1, y2, y3, y4) {
-	let v := u256_to_byte(y1, y2, y3, y4)
-	i64.store8(to_internal_i32ptr(x1, x2, x3, x4), v)
-}
-
 // Needed?
 function msize() -> z1, z2, z3, z4 {
 	// TODO implement
diff --git a/libyul/backends/wasm/polyfill/Memory.yul b/libyul/backends/wasm/polyfill/Memory.yul
index aec8e86c6..410c42d8f 100644
--- a/libyul/backends/wasm/polyfill/Memory.yul
+++ b/libyul/backends/wasm/polyfill/Memory.yul
@@ -61,9 +61,49 @@ function memoryguard(x:i64) -> y1, y2, y3, y4 {
 	y4 := x
 }
 
+// Fill `length` bytes starting from `ptr` with `value`.
 function memset(ptr:i32, value:i32, length:i32) {
 	for { let i:i32 := 0:i32 } i32.lt_u(i, length) { i := i32.add(i, 1:i32) }
 	{
 		i32.store8(i32.add(ptr, i), value)
 	}
-}
\ No newline at end of file
+}
+
+// Writes 256-bits from `pos`, but only set the bottom 160-bits.
+function mstore_address(pos:i32, a1, a2, a3, a4) {
+	a1, a2, a3 := u256_to_address(a1, a2, a3, a4)
+	i64.store(pos, 0:i64)
+	i32.store(i32.add(pos, 8:i32), 0:i32)
+	i32.store(i32.add(pos, 12:i32), bswap32(i32.wrap_i64(a1)))
+	i64.store(i32.add(pos, 16:i32), bswap64(a2))
+	i64.store(i32.add(pos, 24:i32), bswap64(a3))
+}
+
+// Reads 256-bits from `pos`, but only returns the bottom 160-bits.
+function mload_address(pos:i32) -> z1, z2, z3, z4 {
+	z2 := i64.extend_i32_u(bswap32(i32.load(i32.add(pos, 12:i32))))
+	z3 := bswap64(i64.load(i32.add(pos, 16:i32)))
+	z4 := bswap64(i64.load(i32.add(pos, 24:i32)))
+}
+
+// Writes 256-bits from `pos`.
+function mstore_internal(pos:i32, y1, y2, y3, y4) {
+	i64.store(pos, bswap64(y1))
+	i64.store(i32.add(pos, 8:i32), bswap64(y2))
+	i64.store(i32.add(pos, 16:i32), bswap64(y3))
+	i64.store(i32.add(pos, 24:i32), bswap64(y4))
+}
+
+// Reads 256-bits from `pos`.
+function mload_internal(pos:i32) -> z1, z2, z3, z4 {
+	z1 := bswap64(i64.load(pos))
+	z2 := bswap64(i64.load(i32.add(pos, 8:i32)))
+	z3 := bswap64(i64.load(i32.add(pos, 16:i32)))
+	z4 := bswap64(i64.load(i32.add(pos, 24:i32)))
+}
+
+// Stores one byte at position `x` of value `y`.
+function mstore8(x1, x2, x3, x4, y1, y2, y3, y4) {
+	let v := u256_to_byte(y1, y2, y3, y4)
+	i64.store8(to_internal_i32ptr(x1, x2, x3, x4), v)
+}
diff --git a/test/libsolidity/semanticTests/builtinFunctions/smoke.sol b/test/libsolidity/semanticTests/builtinFunctions/smoke.sol
new file mode 100644
index 000000000..e69de29bb