From 54f3ac339a854dcfcedb2f964e9f4a1607d69375 Mon Sep 17 00:00:00 2001
From: Alon Zakai <azakai@google.com>
Date: Thu, 20 Aug 2026 15:55:12 -0700
Subject: [PATCH 1/2] fix

---
 src/ir/constraint.cpp                    |  4 +-
 test/lit/passes/constraint-analysis.wast | 86 ++++++++++++++++++++++++
 2 files changed, 88 insertions(+), 2 deletions(-)

diff --git a/src/ir/constraint.cpp b/src/ir/constraint.cpp
index a1516280deb..13d5891c4e4 100644
--- a/src/ir/constraint.cpp
+++ b/src/ir/constraint.cpp
@@ -420,7 +420,7 @@ std::optional<LocalConstraint> LocalConstraint::parse(Expression* curr) {
   };
 
   if (auto* unary = curr->dynCast<Unary>()) {
-    if (Abstract::getUnary(unary->type, Abstract::EqZ) == unary->op) {
+    if (Abstract::getUnary(unary->value->type, Abstract::EqZ) == unary->op) {
       return parseEqZArgument(unary->value);
     }
     return {};
@@ -467,7 +467,7 @@ std::optional<LocalConstraint> LocalConstraint::parse(Expression* curr) {
                     Abstract::GtU,
                     Abstract::GeS,
                     Abstract::GeU}) {
-      if (Abstract::getBinary(binary->type, op) == binary->op) {
+      if (Abstract::getBinary(binary->left->type, op) == binary->op) {
         return parseBinaryArguments(op, binary->left, binary->right);
       }
     }
diff --git a/test/lit/passes/constraint-analysis.wast b/test/lit/passes/constraint-analysis.wast
index 2dd26b27779..6222f24c157 100644
--- a/test/lit/passes/constraint-analysis.wast
+++ b/test/lit/passes/constraint-analysis.wast
@@ -4649,4 +4649,90 @@
       )
     )
   )
+
+  ;; CHECK:      (func $eqz-condition (type $0) (param $x i32)
+  ;; CHECK-NEXT:  (if
+  ;; CHECK-NEXT:   (i32.eqz
+  ;; CHECK-NEXT:    (local.get $x)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (then
+  ;; CHECK-NEXT:    (drop
+  ;; CHECK-NEXT:     (i32.const 1)
+  ;; CHECK-NEXT:    )
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  ;; OPTIN:      (func $eqz-condition (type $0) (param $x i32)
+  ;; OPTIN-NEXT:  (if
+  ;; OPTIN-NEXT:   (i32.eqz
+  ;; OPTIN-NEXT:    (local.get $x)
+  ;; OPTIN-NEXT:   )
+  ;; OPTIN-NEXT:   (then
+  ;; OPTIN-NEXT:    (drop
+  ;; OPTIN-NEXT:     (i32.const 1)
+  ;; OPTIN-NEXT:    )
+  ;; OPTIN-NEXT:   )
+  ;; OPTIN-NEXT:  )
+  ;; OPTIN-NEXT: )
+  (func $eqz-condition (param $x i32)
+    ;; Verify we parse an eqz condition and can optimize after it.
+    (if
+      (i32.eqz
+        (local.get $x)
+      )
+      (then
+        ;; Also test we parse this binary properly, and see it is equivalent to
+        ;; the eqz.
+        (drop
+          (i32.eq
+            (local.get $x)
+            (i32.const 0)
+          )
+        )
+      )
+    )
+  )
+
+  ;; CHECK:      (func $eqz-condition-64 (type $10) (param $x i64)
+  ;; CHECK-NEXT:  (if
+  ;; CHECK-NEXT:   (i64.eqz
+  ;; CHECK-NEXT:    (local.get $x)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (then
+  ;; CHECK-NEXT:    (drop
+  ;; CHECK-NEXT:     (i32.const 1)
+  ;; CHECK-NEXT:    )
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  ;; OPTIN:      (func $eqz-condition-64 (type $10) (param $x i64)
+  ;; OPTIN-NEXT:  (if
+  ;; OPTIN-NEXT:   (i64.eqz
+  ;; OPTIN-NEXT:    (local.get $x)
+  ;; OPTIN-NEXT:   )
+  ;; OPTIN-NEXT:   (then
+  ;; OPTIN-NEXT:    (drop
+  ;; OPTIN-NEXT:     (i32.const 1)
+  ;; OPTIN-NEXT:    )
+  ;; OPTIN-NEXT:   )
+  ;; OPTIN-NEXT:  )
+  ;; OPTIN-NEXT: )
+  (func $eqz-condition-64 (param $x i64)
+    ;; As above, but i64.
+    (if
+      (i64.eqz
+        (local.get $x)
+      )
+      (then
+        (drop
+          (i64.eq
+            (local.get $x)
+            (i64.const 0)
+          )
+        )
+      )
+    )
+  )
+
+  ;; binary
 )

From 6274e6853b89380d11866ef7af3d3126419b67c3 Mon Sep 17 00:00:00 2001
From: Alon Zakai <alonzakai@gmail.com>
Date: Fri, 21 Aug 2026 11:03:01 -0700
Subject: [PATCH 2/2] Apply suggestion from @kripken

---
 test/lit/passes/constraint-analysis.wast | 2 --
 1 file changed, 2 deletions(-)

diff --git a/test/lit/passes/constraint-analysis.wast b/test/lit/passes/constraint-analysis.wast
index 6222f24c157..6f04d3c882a 100644
--- a/test/lit/passes/constraint-analysis.wast
+++ b/test/lit/passes/constraint-analysis.wast
@@ -4733,6 +4733,4 @@
       )
     )
   )
-
-  ;; binary
 )