From 5244766b7b2b5750a719c78d438aa11471d2d5e5 Mon Sep 17 00:00:00 2001
From: Pawel Kojma <pkojma@internships.antmicro.com>
Date: Fri, 19 Dec 2025 18:37:20 +0100
Subject: [PATCH] Support reduction or in constraints (#6840)

---
 src/V3Randomize.cpp                             | 12 ++++++++++++
 test_regress/t/t_randomize_method_constraints.v |  7 +++++++
 2 files changed, 19 insertions(+)

diff --git a/src/V3Randomize.cpp b/src/V3Randomize.cpp
index 77bf43812..624176bc9 100644
--- a/src/V3Randomize.cpp
+++ b/src/V3Randomize.cpp
@@ -1050,6 +1050,18 @@ class ConstraintExprVisitor final : public VNVisitor {
         VL_DO_DANGLING(nodep->deleteTree(), nodep);
         iterate(sump);
     }
+    void visit(AstRedOr* nodep) override {
+        if (editFormat(nodep)) return;
+        // Convert to (x != 0)
+        FileLine* const fl = nodep->fileline();
+        AstNodeExpr* const argp = nodep->lhsp()->unlinkFrBack();
+        V3Number numZero{fl, argp->width(), 0};
+        AstNodeExpr* const neqp = new AstNeq{fl, argp, new AstConst{fl, numZero}};
+        neqp->user1(true);
+        nodep->replaceWith(neqp);
+        VL_DO_DANGLING(nodep->deleteTree(), nodep);
+        iterate(neqp);
+    }
     void visit(AstNodeBiop* nodep) override {
         if (editFormat(nodep)) return;
         editSMT(nodep, nodep->lhsp(), nodep->rhsp());
diff --git a/test_regress/t/t_randomize_method_constraints.v b/test_regress/t/t_randomize_method_constraints.v
index f7f310f3b..482f6ced8 100644
--- a/test_regress/t/t_randomize_method_constraints.v
+++ b/test_regress/t/t_randomize_method_constraints.v
@@ -15,6 +15,10 @@ class Cls;
    constraint A { v inside {ONE, THREE}; }
    constraint B { w == 5; x inside {1,2} || x inside {4,5}; }
    constraint C { z < 3 * 7; z > 5 + 8; u > 0; }
+   constraint D {
+      |redor == 1'b1;
+      redor[31:1] == 31'b0;
+   }
 
    rand logic[79:0] u;
    rand Enum v;
@@ -22,6 +26,7 @@ class Cls;
    rand logic[47:0] x;
    rand logic[31:0] y;
    rand logic[22:0] z;
+   rand logic[31:0] redor;
 
    function new;
       u = 0;
@@ -50,12 +55,14 @@ module t;
          $display("obj.x == %0d", obj.x);
          $display("obj.y == %0d", obj.y);
          $display("obj.z == %0d", obj.z);
+         $display("obj.redor == %0d", obj.redor);
          $display("rand_result == %0d", rand_result);
          $display("-------------------");
          if (!(obj.v inside {ONE, THREE})) $stop;
          if (obj.w != 5) $stop;
          if (!(obj.x inside {1,2,4,5})) $stop;
          if (obj.z <= 13 || obj.z >= 21) $stop;
+         if (obj.redor != 1) $stop;
       end
       //$display("===================\nUnsatisfiable constraints for obj.y:");
       //rand_result = obj.randomize() with { 256 < y && y < 256; };