From ff79a72cc24d3723247501abd496babf34b2be24 Mon Sep 17 00:00:00 2001
From: "lperron@google.com"
 <lperron@google.com@59fed7e4-672f-1a80-1451-5ac2ff6d83f1>
Date: Fri, 7 Sep 2012 11:52:55 +0000
Subject: [PATCH] added Range on IntAbs()

---
 src/constraint_solver/expressions.cc | 64 ++++++++++++++++++++--------
 1 file changed, 47 insertions(+), 17 deletions(-)

diff --git a/src/constraint_solver/expressions.cc b/src/constraint_solver/expressions.cc
index 4e45f42264..9125cf0579 100644
--- a/src/constraint_solver/expressions.cc
+++ b/src/constraint_solver/expressions.cc
@@ -3441,6 +3441,20 @@ class SubIntExpr : public BaseIntExpr {
     right_->SetMax(left_->Max() - m);
   }
 
+  virtual int64 Max() const {
+    return left_->Max() - right_->Min();
+  }
+
+  virtual void SetMax(int64 m) {
+    left_->SetMax(m + right_->Max());
+    right_->SetMin(left_->Min() - m);
+  }
+
+  virtual void Range(int64* mi, int64* ma) {
+    *mi = left_->Min() - right_->Max();
+    *ma = left_->Max() - right_->Min();
+  }
+
   virtual void SetRange(int64 l, int64 u) {
     const int64 left_min = left_->Min();
     const int64 right_min = right_->Min();
@@ -3456,15 +3470,6 @@ class SubIntExpr : public BaseIntExpr {
     }
   }
 
-  virtual int64 Max() const {
-    return left_->Max() - right_->Min();
-  }
-
-  virtual void SetMax(int64 m) {
-    left_->SetMax(m + right_->Max());
-    right_->SetMin(left_->Min() - m);
-  }
-
   virtual bool Bound() const {
     return (left_->Bound() && right_->Bound());
   }
@@ -3532,6 +3537,11 @@ class SafeSubIntExpr : public SubIntExpr {
     }
   }
 
+  virtual void Range(int64* mi, int64* ma) {
+    *mi = CapSub(left_->Min(), right_->Max());
+    *ma = CapSub(left_->Max(), right_->Min());
+  }
+
   virtual int64 Max() const {
     return CapSub(left_->Max(), right_->Min());
   }
@@ -4687,8 +4697,9 @@ class IntAbs : public BaseIntExpr {
   virtual ~IntAbs() {}
 
   virtual int64 Min() const {
-    const int64 emin = expr_->Min();
-    const int64 emax = expr_->Max();
+    int64 emin = 0;
+    int64 emax = 0;
+    expr_->Range(&emin, &emax);
     if (emin >= 0) {
       return emin;
     }
@@ -4699,8 +4710,9 @@ class IntAbs : public BaseIntExpr {
   }
 
   virtual void SetMin(int64 m) {
-    const int64 emin = expr_->Min();
-    const int64 emax = expr_->Max();
+    int64 emin = 0;
+    int64 emax = 0;
+    expr_->Range(&emin, &emax);
     if (emin >= 0) {
       expr_->SetMin(m);
     } else if (emax <= 0) {
@@ -4709,8 +4721,9 @@ class IntAbs : public BaseIntExpr {
   }
 
   virtual int64 Max() const {
-    const int64 emin = expr_->Min();
-    const int64 emax = expr_->Max();
+    int64 emin = 0;
+    int64 emax = 0;
+    expr_->Range(&emin, &emax);
     if (emin >= 0) {
       return emax;
     }
@@ -4726,8 +4739,9 @@ class IntAbs : public BaseIntExpr {
 
   virtual void SetRange(int64 mi, int64 ma) {
     expr_->SetRange(-ma, ma);
-    const int64 emin = expr_->Min();
-    const int64 emax = expr_->Max();
+    int64 emin = 0;
+    int64 emax = 0;
+    expr_->Range(&emin, &emax);
     if (emin >= 0) {
       expr_->SetMin(mi);
     } else if (emax <= 0) {
@@ -4735,6 +4749,22 @@ class IntAbs : public BaseIntExpr {
     }
   }
 
+  virtual void Range(int64* mi, int64 *ma) {
+    int64 emin = 0;
+    int64 emax = 0;
+    expr_->Range(&emin, &emax);
+    if (emin >= 0) {
+      *mi = emin;
+      *ma = emax;
+    } else if (emax <= 0) {
+      *mi = -emax;
+      *ma = -emin;
+    } else {
+      *mi = 0;
+      *ma = std::max(-emin, emax);
+    }
+  }
+
   virtual bool Bound() const {
     return expr_->Bound();
   }