[opt] Eliminate WhileControlStmt with non-zero const conditions

taichi-dev · Apr 20, 2020 · 24009bb · 24009bb
1 parent 1046995
commit 24009bb
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/taichi/transforms/alg_simp.cpp b/taichi/transforms/alg_simp.cpp
@@ -74,6 +74,17 @@ class AlgSimp : public BasicStmtVisitor {
     }
   }
 
+  void visit(WhileControlStmt *stmt) override {
+    auto cond = stmt->cond->cast<ConstStmt>();
+    if (!cond)
+      return;
+    if (!alg_is_zero(cond)) {
+      // this statement has no effect
+      stmt->parent->erase(stmt);
+      throw IRModified();
+    }
+  }
+
   static bool alg_is_zero(ConstStmt *stmt) {
     if (!stmt)
       return false;