From 67fbfe63051274850cfd20f6d9baec4b762fe579 Mon Sep 17 00:00:00 2001
From: Seth Junot <xsetech@gmail.com>
Date: Thu, 17 Jan 2019 17:51:58 -0800
Subject: [PATCH] runtime/wasm: add memset()

Copied from the ARM runtime and modified to return a pointer.
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memset.html
---
 src/runtime/runtime_wasm.go | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/runtime/runtime_wasm.go b/src/runtime/runtime_wasm.go
index 8212d859..4abc1cd7 100644
--- a/src/runtime/runtime_wasm.go
+++ b/src/runtime/runtime_wasm.go
@@ -2,6 +2,10 @@
 
 package runtime
 
+import (
+	"unsafe"
+)
+
 type timeUnit int64
 
 const tickMicros = 1
@@ -48,3 +52,11 @@ func ticks() timeUnit {
 func abort() {
 	trap()
 }
+
+//go:export memset
+func memset(ptr unsafe.Pointer, c byte, size uintptr) unsafe.Pointer {
+	for i := uintptr(0); i < size; i++ {
+		*(*byte)(unsafe.Pointer(uintptr(ptr) + i)) = c
+	}
+	return ptr
+}