handle unary and binary nodes that have implicit traps in vacuum

5 files changed, 55 insertions, 1 deletions

diff --git a/src/passes/Vacuum.cpp b/src/passes/Vacuum.cpp
index 70230e502..40f4a6e59 100644
--- a/src/passes/Vacuum.cpp
+++ b/src/passes/Vacuum.cpp
@@ -93,8 +93,14 @@ 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;
@@ -102,6 +108,11 @@ struct Vacuum : public WalkerPass<PostWalker<Vacuum>> {
               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
diff --git a/test/passes/vacuum.txt b/test/passes/vacuum.txt
index f17607734..e07357296 100644
--- a/test/passes/vacuum.txt
+++ b/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)
+   )
+  )
+ )
 )
diff --git a/test/passes/vacuum.wast b/test/passes/vacuum.wast
index 65e528621..77ffabd60 100644
--- a/test/passes/vacuum.wast
+++ b/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)
+    )
+   )
+  )
 )
diff --git a/test/passes/vacuum_ignore-implicit-traps.txt b/test/passes/vacuum_ignore-implicit-traps.txt
index 040a3dc1a..e5ff28583 100644
--- a/test/passes/vacuum_ignore-implicit-traps.txt
+++ b/test/passes/vacuum_ignore-implicit-traps.txt
@@ -1,5 +1,6 @@
 (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
@@ -7,4 +8,7 @@
    (i64.const 0)
   )
  )
+ (func $unary-binary-may-trap (type $1)
+  (nop)
+ )
 )
diff --git a/test/passes/vacuum_ignore-implicit-traps.wast b/test/passes/vacuum_ignore-implicit-traps.wast
index 08b41a141..21e87e10c 100644
--- a/test/passes/vacuum_ignore-implicit-traps.wast
+++ b/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)
+    )
+   )
+  )
 )