From f26cd009c75f0ef19468ef44a1fae065e43b0eae Mon Sep 17 00:00:00 2001
From: Andreas Rossberg <rossberg@chromium.org>
Date: Fri, 2 Sep 2016 13:07:11 +0200
Subject: [PATCH] Make br_if return its operands

---
 ml-proto/spec/check.ml           |  2 +-
 ml-proto/spec/eval.ml            |  2 +-
 ml-proto/test/br_if.wast         | 46 ++++++++++++--------------
 ml-proto/test/func.wast          |  2 +-
 ml-proto/test/labels.wast        | 57 ++++++++++++--------------------
 ml-proto/test/left-to-right.wast |  2 +-
 ml-proto/test/nop.wast           |  5 ++-
 7 files changed, 48 insertions(+), 68 deletions(-)

diff --git a/ml-proto/spec/check.ml b/ml-proto/spec/check.ml
index a15d3131fb..0c4be1655a 100644
--- a/ml-proto/spec/check.ml
+++ b/ml-proto/spec/check.ml
@@ -192,7 +192,7 @@ let rec check_instr (c : context) (e : instr) (stack : stack_type) : op_type =
     check_arity n e.at;
     let ts = List.tl (peek_n (n + 1) stack) in
     unify (label c x) ts e.at;
-    (ts @ [I32Type]) --> Stack []
+    (ts @ [I32Type]) --> Stack ts
 
   | BrTable (n, xs, x) ->
     check_arity n e.at;
diff --git a/ml-proto/spec/eval.ml b/ml-proto/spec/eval.ml
index 715d676abe..130a229a6c 100644
--- a/ml-proto/spec/eval.ml
+++ b/ml-proto/spec/eval.ml
@@ -140,7 +140,7 @@ let rec step_instr (c : config) (vs : value stack) (e : instr)
     assert false  (* abrupt *)
 
   | BrIf (n, x), I32 0l :: vs' ->
-    drop n vs' e.at, []
+    vs', []
 
   | BrIf (n, x), I32 i :: vs' ->
     vs', [Br (n, x) @@ e.at]
diff --git a/ml-proto/test/br_if.wast b/ml-proto/test/br_if.wast
index 957cec4a4b..2ad79088b4 100644
--- a/ml-proto/test/br_if.wast
+++ b/ml-proto/test/br_if.wast
@@ -7,23 +7,22 @@
     (block (br_if 0 (get_local 0)) (return (i32.const 2))) (i32.const 3)
   )
   (func "as-block-mid" (param i32) (result i32)
-    (block (call $dummy) (br_if 0 (get_local 0)) (return (i32.const 2))) (i32.const 3)
+    (block (call $dummy) (br_if 0 (get_local 0)) (return (i32.const 2)))
+    (i32.const 3)
   )
   (func "as-block-last" (param i32)
     (block (call $dummy) (call $dummy) (br_if 0 (get_local 0)))
   )
-  (func "as-block-first-value" (param i32) (result i32)
-    (block (br_if 0 (i32.const 10) (get_local 0)) (i32.const 11))
-  )
-  (func "as-block-mid-value" (param i32) (result i32)
-    (block (call $dummy) (br_if 0 (i32.const 20) (get_local 0)) (i32.const 21))
+  (func "as-block-last-value" (param i32) (result i32)
+    (block (call $dummy) (call $dummy) (br_if 0 (i32.const 11) (get_local 0)))
   )
 
   (func "as-loop-first" (param i32) (result i32)
-    (loop (br_if 1 (i32.const 3) (get_local 0)) (i32.const 2))
+    (block (loop (br_if 1 (get_local 0)) (return (i32.const 2)))) (i32.const 3)
   )
   (func "as-loop-mid" (param i32) (result i32)
-    (loop (call $dummy) (br_if 1 (i32.const 4) (get_local 0)) (i32.const 2))
+    (block (loop (call $dummy) (br_if 1 (get_local 0)) (return (i32.const 2))))
+    (i32.const 4)
   )
   (func "as-loop-last" (param i32)
     (loop (call $dummy) (br_if 1 (get_local 0)))
@@ -43,7 +42,7 @@
         (drop (i32.const 2))
         (i32.add
           (i32.const 4)
-          (block (br_if 1 (i32.const 8) (get_local 0)) (i32.const 16))
+          (block (drop (br_if 1 (i32.const 8) (get_local 0))) (i32.const 16))
         )
       )
     )
@@ -55,7 +54,7 @@
       (block
         (drop (i32.const 2))
         (br 0
-          (block (br_if 1 (i32.const 8) (get_local 0)) (i32.const 4))
+          (block (drop (br_if 1 (i32.const 8) (get_local 0))) (i32.const 4))
         )
         (i32.const 16)
       )
@@ -67,10 +66,10 @@
       (i32.const 1)
       (block
         (drop (i32.const 2))
-        (br_if 0
-          (block (br_if 1 (i32.const 8) (get_local 0)) (i32.const 4))
+        (drop (br_if 0
+          (block (drop (br_if 1 (i32.const 8) (get_local 0))) (i32.const 4))
           (i32.const 1)
-        )
+        ))
         (i32.const 16)
       )
     )
@@ -81,10 +80,10 @@
       (i32.const 1)
       (block
         (drop (i32.const 2))
-        (br_if 0
+        (drop (br_if 0
           (i32.const 4)
-          (block (br_if 1 (i32.const 8) (get_local 0)) (i32.const 1))
-        )
+          (block (drop (br_if 1 (i32.const 8) (get_local 0))) (i32.const 1))
+        ))
         (i32.const 16)
       )
     )
@@ -96,7 +95,7 @@
       (block
         (drop (i32.const 2))
         (br_table 0
-          (block (br_if 1 (i32.const 8) (get_local 0)) (i32.const 4))
+          (block (drop (br_if 1 (i32.const 8) (get_local 0))) (i32.const 4))
           (i32.const 1)
         )
         (i32.const 16)
@@ -111,7 +110,7 @@
         (drop (i32.const 2))
         (br_table 0
           (i32.const 4)
-          (block (br_if 1 (i32.const 8) (get_local 0)) (i32.const 1))
+          (block (drop (br_if 1 (i32.const 8) (get_local 0))) (i32.const 1))
         )
         (i32.const 16)
       )
@@ -125,11 +124,8 @@
 (assert_return (invoke "as-block-mid" (i32.const 1)) (i32.const 3))
 (assert_return (invoke "as-block-last" (i32.const 0)))
 (assert_return (invoke "as-block-last" (i32.const 1)))
-
-(assert_return (invoke "as-block-first-value" (i32.const 0)) (i32.const 11))
-(assert_return (invoke "as-block-first-value" (i32.const 1)) (i32.const 10))
-(assert_return (invoke "as-block-mid-value" (i32.const 0)) (i32.const 21))
-(assert_return (invoke "as-block-mid-value" (i32.const 1)) (i32.const 20))
+(assert_return (invoke "as-block-last-value" (i32.const 0)) (i32.const 11))
+(assert_return (invoke "as-block-last-value" (i32.const 1)) (i32.const 11))
 
 (assert_return (invoke "as-loop-first" (i32.const 0)) (i32.const 2))
 (assert_return (invoke "as-loop-first" (i32.const 1)) (i32.const 3))
@@ -259,13 +255,13 @@
 )
 (assert_invalid
   (module (func $type-false-arg-num-vs-num (result i32)
-    (block (br_if 0 (i64.const 1) (i32.const 0)) (i32.const 1))
+    (block (drop (br_if 0 (i64.const 1) (i32.const 0))) (i32.const 1))
   ))
   "type mismatch"
 )
 (assert_invalid
   (module (func $type-true-arg-num-vs-num (result i32)
-    (block (br_if 0 (i64.const 1) (i32.const 0)) (i32.const 1))
+    (block (drop (br_if 0 (i64.const 1) (i32.const 0))) (i32.const 1))
   ))
   "type mismatch"
 )
diff --git a/ml-proto/test/func.wast b/ml-proto/test/func.wast
index 5bbb40077e..442f2e70bb 100644
--- a/ml-proto/test/func.wast
+++ b/ml-proto/test/func.wast
@@ -120,7 +120,7 @@
     (br_if 0 (get_local 0))
   )
   (func "break-br_if-num" (param i32) (result i32)
-    (br_if 0 (i32.const 50) (get_local 0)) (i32.const 51)
+    (drop (br_if 0 (i32.const 50) (get_local 0))) (i32.const 51)
   )
 
   (func "break-br_table-empty" (param i32)
diff --git a/ml-proto/test/labels.wast b/ml-proto/test/labels.wast
index 3e511ac405..b13be54d03 100644
--- a/ml-proto/test/labels.wast
+++ b/ml-proto/test/labels.wast
@@ -193,39 +193,44 @@
         (br_if $inner (i32.const 1))
         (set_local $i (i32.or (get_local $i) (i32.const 0x2)))
       )
-      (br_if $outer
-        (block (set_local $i (i32.or (get_local $i) (i32.const 0x4))) (get_local $i)) (i32.const 0)
-      )
+      (drop (br_if $outer
+        (block (set_local $i (i32.or (get_local $i) (i32.const 0x4))) (get_local $i))
+        (i32.const 0)
+      ))
       (set_local $i (i32.or (get_local $i) (i32.const 0x8)))
-      (br_if $outer
-        (block (set_local $i (i32.or (get_local $i) (i32.const 0x10))) (get_local $i)) (i32.const 1)
-      )
+      (drop (br_if $outer
+        (block (set_local $i (i32.or (get_local $i) (i32.const 0x10))) (get_local $i))
+        (i32.const 1)
+      ))
       (set_local $i (i32.or (get_local $i) (i32.const 0x20))) (get_local $i)
     )
   )
 
   (func $br_if1 (result i32)
     (block $l0
-      (br_if $l0 (block $l1 (br $l1 (i32.const 1))) (i32.const 1))
-      (i32.const 1)))
+      (drop (br_if $l0 (block $l1 (br $l1 (i32.const 1))) (i32.const 1)))
+      (i32.const 1)
+    )
+  )
 
   (func $br_if2 (result i32)
     (block $l0
       (if (i32.const 1)
-        (br $l0
-          (block $l1
-            (br $l1 (i32.const 1)))))
-      (i32.const 1)))
+        (br $l0 (block $l1 (br $l1 (i32.const 1))))
+      )
+      (i32.const 1)
+    )
+  )
 
   (func $br_if3 (result i32)
     (local $i1 i32)
     (drop
       (i32.add
         (block $l0
-          (br_if $l0
+          (drop (br_if $l0
             (block (set_local $i1 (i32.const 1)) (get_local $i1))
             (block (set_local $i1 (i32.const 2)) (get_local $i1))
-          )
+          ))
           (i32.const 0)
         )
         (i32.const 0)
@@ -312,30 +317,10 @@
   "type mismatch"
 )
 (assert_invalid
-  (module (func (result f32) (block $l (br_if $l (f32.const 0) (i32.const 1)))))
+  (module (func (block $l (br_if $l (f32.const 0) (i32.const 1)))))
   "type mismatch"
 )
 (assert_invalid
-  (module (func (result i32) (block $l (br_if $l (f32.const 0) (i32.const 1)))))
-  "type mismatch"
-)
-(assert_invalid
-  (module (func (block $l (f32.neg (br_if $l (f32.const 0) (i32.const 1))))))
-  "type mismatch"
-)
-(assert_invalid
-  (module
-    (func (param i32) (result i32)
-      (block $l (f32.neg (br_if $l (f32.const 0) (get_local 0))))
-    )
-  )
-  "type mismatch"
-)
-(assert_invalid
-  (module
-    (func (param i32) (result f32)
-      (block $l (f32.neg (block $i (br_if $l (f32.const 3) (get_local 0)))))
-    )
-  )
+  (module (func (block $l (br_if $l (f32.const 0) (i32.const 1)))))
   "type mismatch"
 )
diff --git a/ml-proto/test/left-to-right.wast b/ml-proto/test/left-to-right.wast
index dc3ed2f623..b990e98b34 100644
--- a/ml-proto/test/left-to-right.wast
+++ b/ml-proto/test/left-to-right.wast
@@ -161,7 +161,7 @@
   (func $br_if (result i32)
     (block
       (call $reset)
-      (br_if 0 (call $i32_left) (i32.and (call $i32_right) (i32.const 0)))
+      (drop (br_if 0 (call $i32_left) (i32.and (call $i32_right) (i32.const 0))))
       (call $get)
     )
   )
diff --git a/ml-proto/test/nop.wast b/ml-proto/test/nop.wast
index bde3b7d63b..a6c2f729c6 100644
--- a/ml-proto/test/nop.wast
+++ b/ml-proto/test/nop.wast
@@ -86,15 +86,14 @@
   )
 
   (func "as-br_if-mid" (param i32) (result i32)
-    block (get_local 0) (nop) (get_local 0) br_if 1 0 (i32.const 0) end
+    block (get_local 0) (nop) (get_local 0) br_if 1 0 end
   )
   (func "as-br_if-last" (param i32) (result i32)
-    block (get_local 0) (get_local 0) (nop) br_if 1 0 (i32.const 0) end
+    block (get_local 0) (get_local 0) (nop) br_if 1 0 end
   )
   (func "as-br_if-everywhere" (param i32) (result i32)
     block
      (nop) (nop) (get_local 0) (nop) (nop) (get_local 0) (nop) (nop) br_if 1 0
-     (i32.const 0) 
     end
   )