optimize if and select in the case their values are identical (#1013)

6 files changed, 151 insertions, 67 deletions

diff --git a/test/passes/O.bin.txt b/test/passes/O.bin.txt
index 7b80e0211..4c64af9c6 100644
--- a/test/passes/O.bin.txt
+++ b/test/passes/O.bin.txt
@@ -43,14 +43,7 @@
   )
  )
  (func $2 (type $0) (param $0 i64) (result i64)
-  (if
-   (i64.eq
-    (get_local $0)
-    (i64.const 0)
-   )
-   (unreachable)
-   (unreachable)
-  )
+  (unreachable)
  )
  (func $3 (type $0) (param $0 i64) (result i64)
   (local $1 i64)
diff --git a/test/passes/optimize-instructions.txt b/test/passes/optimize-instructions.txt
index 03edc6e4c..2b33bd700 100644
--- a/test/passes/optimize-instructions.txt
+++ b/test/passes/optimize-instructions.txt
@@ -406,7 +406,7 @@
    (if i32
     (i32.const 1)
     (call $ne0)
-    (call $ne0)
+    (call $ne1)
    )
    (nop)
   )
@@ -418,6 +418,9 @@
    (nop)
   )
  )
+ (func $ne1 (type $2) (result i32)
+  (unreachable)
+ )
  (func $load-off-2 (type $3) (param $0 i32) (result i32)
   (i32.store
    (i32.const 6)
@@ -1882,4 +1885,81 @@
    )
   )
  )
+ (func $if-parallel (type $4) (param $0 i32) (param $1 i32)
+  (drop
+   (i32.add
+    (get_local $1)
+    (i32.const 1)
+   )
+  )
+  (drop
+   (block i32
+    (drop
+     (tee_local $0
+      (get_local $1)
+     )
+    )
+    (i32.add
+     (get_local $1)
+     (i32.const 1)
+    )
+   )
+  )
+ )
+ (func $select-parallel (type $4) (param $0 i32) (param $1 i32)
+  (drop
+   (i32.add
+    (get_local $1)
+    (i32.const 1)
+   )
+  )
+  (drop
+   (select
+    (tee_local $0
+     (get_local $1)
+    )
+    (tee_local $0
+     (get_local $1)
+    )
+    (get_local $0)
+   )
+  )
+  (drop
+   (block i32
+    (drop
+     (tee_local $0
+      (get_local $1)
+     )
+    )
+    (i32.add
+     (get_local $1)
+     (i32.const 1)
+    )
+   )
+  )
+  (drop
+   (select
+    (tee_local $0
+     (get_local $1)
+    )
+    (tee_local $0
+     (get_local $1)
+    )
+    (tee_local $0
+     (get_local $1)
+    )
+   )
+  )
+  (drop
+   (select
+    (tee_local $0
+     (get_local $1)
+    )
+    (tee_local $0
+     (get_local $1)
+    )
+    (unreachable)
+   )
+  )
+ )
 )
diff --git a/test/passes/optimize-instructions.wast b/test/passes/optimize-instructions.wast
index eccbf1268..56defd648 100644
--- a/test/passes/optimize-instructions.wast
+++ b/test/passes/optimize-instructions.wast
@@ -319,7 +319,7 @@
       (if i32
         (i32.const 1)
         (i32.ne (call $ne0) (i32.const 0))
-        (i32.ne (call $ne0) (i32.const 0))
+        (i32.ne (call $ne1) (i32.const 0))
       )
       (nop)
     )
@@ -331,6 +331,9 @@
       (nop)
     )
   )
+  (func $ne1 (result i32)
+    (unreachable)
+  )
   (func $load-off-2 "load-off-2" (param $0 i32) (result i32)
     (i32.store offset=2
       (i32.add
@@ -2303,4 +2306,57 @@
       )
     )
   )
+  (func $if-parallel (param $0 i32) (param $1 i32)
+    (drop
+      (if i32
+        (get_local $0)
+        (i32.add (get_local $1) (i32.const 1))
+        (i32.add (get_local $1) (i32.const 1))
+      )
+    )
+    (drop
+      (if i32
+        (tee_local $0 (get_local $1)) ;; side effects!
+        (i32.add (get_local $1) (i32.const 1))
+        (i32.add (get_local $1) (i32.const 1))
+      )
+    )
+  )
+  (func $select-parallel (param $0 i32) (param $1 i32)
+    (drop
+      (select
+        (i32.add (get_local $1) (i32.const 1))
+        (i32.add (get_local $1) (i32.const 1))
+        (get_local $0)
+      )
+    )
+    (drop
+      (select
+        (tee_local $0 (get_local $1)) ;; side effects!
+        (tee_local $0 (get_local $1)) ;; side effects!
+        (get_local $0)
+      )
+    )
+    (drop
+      (select
+        (i32.add (get_local $1) (i32.const 1))
+        (i32.add (get_local $1) (i32.const 1))
+        (tee_local $0 (get_local $1)) ;; side effects! (but no interference with values)
+      )
+    )
+    (drop
+      (select
+        (tee_local $0 (get_local $1)) ;; side effects! interference!
+        (tee_local $0 (get_local $1)) ;; side effects! interference!
+        (tee_local $0 (get_local $1)) ;; side effects! interference!
+      )
+    )
+    (drop
+      (select
+        (tee_local $0 (get_local $1)) ;; side effects!
+        (tee_local $0 (get_local $1)) ;; side effects!
+        (unreachable) ;; side effects! (but no interference with values)
+      )
+    )
+  )
 )
diff --git a/test/wasm-only.fromasm b/test/wasm-only.fromasm
index b8d876711..6fa30ba12 100644
--- a/test/wasm-only.fromasm
+++ b/test/wasm-only.fromasm
@@ -306,29 +306,14 @@
   (i64.const 0)
  )
  (func $ifValue64 (param $0 i64) (param $1 i64) (result i64)
-  (if i64
-   (i32.wrap/i64
-    (get_local $1)
-   )
-   (call $call2
-    (get_local $0)
-   )
-   (call $call2
-    (get_local $0)
-   )
+  (call $call2
+   (get_local $0)
   )
  )
  (func $ifValue32 (param $0 i32) (param $1 i32) (result i32)
-  (if i32
+  (call $ifValue32
+   (get_local $0)
    (get_local $1)
-   (call $ifValue32
-    (get_local $0)
-    (get_local $1)
-   )
-   (call $ifValue32
-    (get_local $0)
-    (get_local $1)
-   )
   )
  )
  (func $switch64 (param $0 i64) (result i32)
diff --git a/test/wasm-only.fromasm.clamp b/test/wasm-only.fromasm.clamp
index b8d876711..6fa30ba12 100644
--- a/test/wasm-only.fromasm.clamp
+++ b/test/wasm-only.fromasm.clamp
@@ -306,29 +306,14 @@
   (i64.const 0)
  )
  (func $ifValue64 (param $0 i64) (param $1 i64) (result i64)
-  (if i64
-   (i32.wrap/i64
-    (get_local $1)
-   )
-   (call $call2
-    (get_local $0)
-   )
-   (call $call2
-    (get_local $0)
-   )
+  (call $call2
+   (get_local $0)
   )
  )
  (func $ifValue32 (param $0 i32) (param $1 i32) (result i32)
-  (if i32
+  (call $ifValue32
+   (get_local $0)
    (get_local $1)
-   (call $ifValue32
-    (get_local $0)
-    (get_local $1)
-   )
-   (call $ifValue32
-    (get_local $0)
-    (get_local $1)
-   )
   )
  )
  (func $switch64 (param $0 i64) (result i32)
diff --git a/test/wasm-only.fromasm.imprecise b/test/wasm-only.fromasm.imprecise
index ae68d6a66..11eedc71d 100644
--- a/test/wasm-only.fromasm.imprecise
+++ b/test/wasm-only.fromasm.imprecise
@@ -221,29 +221,14 @@
   (i64.const 0)
  )
  (func $ifValue64 (param $0 i64) (param $1 i64) (result i64)
-  (if i64
-   (i32.wrap/i64
-    (get_local $1)
-   )
-   (call $call2
-    (get_local $0)
-   )
-   (call $call2
-    (get_local $0)
-   )
+  (call $call2
+   (get_local $0)
   )
  )
  (func $ifValue32 (param $0 i32) (param $1 i32) (result i32)
-  (if i32
+  (call $ifValue32
+   (get_local $0)
    (get_local $1)
-   (call $ifValue32
-    (get_local $0)
-    (get_local $1)
-   )
-   (call $ifValue32
-    (get_local $0)
-    (get_local $1)
-   )
   )
  )
  (func $switch64 (param $0 i64) (result i32)