1 files changed, 32 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/wasm/tail-calls/litmus1.js b/js/src/jit-test/tests/wasm/tail-calls/litmus1.js
new file mode 100644
index 0000000000..7a86e3ce52
--- /dev/null
+++ b/js/src/jit-test/tests/wasm/tail-calls/litmus1.js
@@ -0,0 +1,32 @@
+// |jit-test| skip-if: !wasmTailCallsEnabled()
+
+// Mutually recursive functions implement a multi-entry loop using tail calls.
+// The functions do not have the same signatures, so if all arguments are stack
+// arguments then these use different amounts of stack space.
+//
+// The variable ballast is intended to test that we handle various combinations
+// of stack and register arguments properly.
+
+for ( let ballast=1; ballast < TailCallBallast; ballast++ ) {
+    let vals = iota(ballast,1);
+    let ps = vals.map(_ => 'i32').join(' ')
+    let es = vals.map(i => `(local.get ${i})`).join(' ')
+    let sum = vals.reduceRight((p,c) => `(i32.add (local.get ${c}) ${p})`, `(i32.const 0)`)
+    let sumv = vals.reduce((p,c) => p+c);
+    let text = `
+(module
+  (func $odd (export "odd") (param $n i32) (param ${ps}) (param $dummy i32) (result i32)
+    (if (result i32) (i32.eqz (local.get $n))
+        (then (return (i32.or (i32.shl ${sum} (i32.const 1)) (i32.const 0))))
+        (else (return_call $even (i32.sub (local.get $n) (i32.const 1)) ${es}))))
+
+  (func $even (export "even") (param $n i32) (param ${ps}) (result i32)
+    (if (result i32) (i32.eqz (local.get $n))
+        (then (return (i32.or (i32.shl ${sum} (i32.const 1)) (i32.const 1))))
+        (else (return_call $odd (i32.sub (local.get $n) (i32.const 1)) ${es} (i32.const 33))))))`;
+
+    let ins = wasmEvalText(text);
+    assertEq(ins.exports.even(TailCallIterations, ...vals), (sumv*2) + 1);
+    assertEq(ins.exports.odd(TailCallIterations, ...vals, 33), (sumv*2) + 0);
+}
+