fibonacci

benchmarks/wasm/fib.rs

@@ -0,0 +1,12 @@
+#[no_mangle]
+#[inline(never)]
+fn fibonacci(n: i32) -> i32 {
+    if n == 0 { 0 }
+    else if n == 1 { 1 }
+    else { fibonacci(n - 1) + fibonacci(n - 2) }
+}
+
+#[no_mangle]
+fn real_main() -> i32 {
+    fibonacci(12)
+}

benchmarks/wasm/fib.wat

@@ -0,0 +1,59 @@
+(module
+  (type (;0;) (func (param i32) (result i32)))
+  (type (;1;) (func (result i32)))
+  (func (;0;) (type 0) (param i32) (result i32)
+    (local i32)
+    i32.const 0
+    local.set 1
+    local.get 0
+    local.set 0
+    block  ;; label = @1
+      loop  ;; label = @2
+        local.get 1
+        local.set 1
+        block  ;; label = @3
+          block  ;; label = @4
+            block  ;; label = @5
+              local.get 0
+              local.tee 0
+              br_table 0 (;@5;) 1 (;@4;) 2 (;@3;)
+            end
+            local.get 0
+            local.set 0
+            br 3 (;@1;)
+          end
+          i32.const 1
+          local.set 0
+          br 2 (;@1;)
+        end
+        local.get 1
+        local.get 0
+        i32.const -1
+        i32.add
+        call 0
+        i32.add
+        local.set 1
+        local.get 0
+        i32.const -2
+        i32.add
+        local.set 0
+        br 0 (;@2;)
+      end
+    end
+    local.get 1
+    local.get 0
+    i32.add)
+  (func (;1;) (type 1) (result i32)
+    i32.const 12
+    call 0)
+  (start 1)
+  (table (;0;) 1 1 funcref)
+  (memory (;0;) 16)
+  (global (;0;) (mut i32) (i32.const 1048576))
+  (global (;1;) i32 (i32.const 1048576))
+  (global (;2;) i32 (i32.const 1048576))
+  (export "memory" (memory 0))
+  (export "fibonacci" (func 0))
+  (export "real_main" (func 1))
+  (export "__data_end" (global 1))
+  (export "__heap_base" (global 2)))

build.sbt

@@ -33,13 +33,15 @@ autoCompilerPlugins := true
 
 //https://www.scala-sbt.org/release/docs/Running-Project-Code.html
 fork := true
-run / javaOptions ++= Seq(
+val commonJavaOptions = Seq(
   "-Xms4G",
   "-Xmx32G",
   "-Xss1024M",
   "-XX:MaxMetaspaceSize=8G",
   "-XX:ReservedCodeCacheSize=2048M"
 )
+run / javaOptions ++= commonJavaOptions
+Test / javaOptions ++= commonJavaOptions
 
 val paradiseVersion = "2.1.0"
 addCompilerPlugin("org.scalamacros" % "paradise" % paradiseVersion cross CrossVersion.full)

src/main/scala/wasm/MiniWasm.scala

@@ -287,6 +287,10 @@ object Evaluator {
         val I32V(cond) :: newStack = stack
         if (cond != 0) trail(label)(newStack)
         else eval(rest, newStack, frame, kont, trail, ret)
+      case BrTable(labels, default) =>
+        val I32V(cond) :: newStack = stack
+        val goto = if (cond < labels.length) labels(cond) else default
+        trail(goto)(newStack)
       case Return => trail(ret)(stack)
       case Call(f) if frame.module.funcs(f).isInstanceOf[FuncDef] =>
         val FuncDef(_, FuncBodyDef(ty, _, locals, body)) = frame.module.funcs(f)

src/test/scala/genwasym/TestEval.scala

@@ -40,6 +40,8 @@ class TestEval extends FunSuite {
   test("even-odd") { testFile("./benchmarks/wasm/even_odd.wat", None, Some(1)) }
   test("return") { testFile("./benchmarks/wasm/return.wat", None, None) }
 
+  test("fib") { testFile("./benchmarks/wasm/fib.wat", None, Some(144)) }
+
   // Parser works, but the memory issue remains
   // test("btree") { testFile("./benchmarks/wasm/btree/2o1u-no-label-for-real.wat") }