handle unary and binary nodes that have implicit traps in vacuum

Author: kripken

src/passes/Vacuum.cpp

@@ -93,15 +93,26 @@ struct Vacuum : public WalkerPass<PostWalker<Vacuum>> {
           if (resultUsed) {
             return curr; // used, keep it
           }
-          // for unary, binary, and select, we need to check their arguments for side effects
+          // for unary, binary, and select, we need to check their arguments for side effects,
+          // as well as the node itself, as some unaries and binaries have implicit traps
           if (auto* unary = curr->dynCast<Unary>()) {
+            EffectAnalyzer tester(getPassOptions());
+            tester.visitUnary(unary);
+            if (tester.hasSideEffects()) {
+              return curr;
+            }
             if (EffectAnalyzer(getPassOptions(), unary->value).hasSideEffects()) {
               curr = unary->value;
               continue;
             } else {
               return nullptr;
             }
           } else if (auto* binary = curr->dynCast<Binary>()) {
+            EffectAnalyzer tester(getPassOptions());
+            tester.visitBinary(binary);
+            if (tester.hasSideEffects()) {
+              return curr;
+            }
             if (EffectAnalyzer(getPassOptions(), binary->left).hasSideEffects()) {
               if (EffectAnalyzer(getPassOptions(), binary->right).hasSideEffects()) {
                 return curr; // leave them

test/passes/vacuum.txt

@@ -260,4 +260,17 @@
    (i64.const 0)
   )
  )
+ (func $unary-binary-may-trap (type $0)
+  (drop
+   (i64.div_s
+    (i64.const -1)
+    (i64.const 729618461987467893)
+   )
+  )
+  (drop
+   (i64.trunc_u/f32
+    (f32.const 70847791997969805621592064)
+   )
+  )
+ )
 )

test/passes/vacuum.wast

@@ -580,4 +580,17 @@
     (i64.const 0)
    )
   )
+  (func $unary-binary-may-trap
+   (drop
+    (i64.div_s
+     (i64.const 70847791997969805621592064)
+     (i64.const 729618461987467893)
+    )
+   )
+   (drop
+    (i64.trunc_u/f32
+     (f32.const 70847791997969805621592064)
+    )
+   )
+  )
 )

test/passes/vacuum_ignore-implicit-traps.txt

@@ -1,10 +1,14 @@
 (module
  (type $0 (func (result i32)))
+ (type $1 (func))
  (memory $0 0)
  (func $load-would-normally-have-side-effects (type $0) (result i32)
   (i64.ge_s
    (i64.const 2912825531628789796)
    (i64.const 0)
   )
  )
+ (func $unary-binary-may-trap (type $1)
+  (nop)
+ )
 )

test/passes/vacuum_ignore-implicit-traps.wast

@@ -15,5 +15,18 @@
     (i64.const 0)
    )
   )
+  (func $unary-binary-may-trap
+   (drop
+    (i64.div_s
+     (i64.const 70847791997969805621592064)
+     (i64.const 729618461987467893)
+    )
+   )
+   (drop
+    (i64.trunc_u/f32
+     (f32.const 70847791997969805621592064)
+    )
+   )
+  )
 )