ConstantRange: add query for isAllPositive (llvm#97420)

ConstantRange has queries for isAllNegative and isAllNonNegative, but
misses a query for isAllPositive. Add this function.

Author: artagnon

llvm/include/llvm/IR/ConstantRange.h

@@ -277,6 +277,9 @@ class [[nodiscard]] ConstantRange {
   /// Return true if all values in this range are non-negative.
   bool isAllNonNegative() const;
 
+  /// Return true if all values in this range are positive.
+  bool isAllPositive() const;
+
   /// Return the largest unsigned value contained in the ConstantRange.
   APInt getUnsignedMax() const;
 

llvm/lib/IR/ConstantRange.cpp

@@ -440,6 +440,16 @@ bool ConstantRange::isAllNonNegative() const {
   return !isSignWrappedSet() && Lower.isNonNegative();
 }
 
+bool ConstantRange::isAllPositive() const {
+  // Empty set is all positive, full set is not.
+  if (isEmptySet())
+    return true;
+  if (isFullSet())
+    return false;
+
+  return !isSignWrappedSet() && Lower.isStrictlyPositive();
+}
+
 APInt ConstantRange::getUnsignedMax() const {
   if (isFullSet() || isUpperWrapped())
     return APInt::getMaxValue(getBitWidth());

llvm/unittests/IR/ConstantRangeTest.cpp

@@ -2398,23 +2398,31 @@ TEST_F(ConstantRangeTest, Negative) {
   // they are also covered by the exhaustive test below.
   EXPECT_TRUE(Empty.isAllNegative());
   EXPECT_TRUE(Empty.isAllNonNegative());
+  EXPECT_TRUE(Empty.isAllPositive());
   EXPECT_FALSE(Full.isAllNegative());
   EXPECT_FALSE(Full.isAllNonNegative());
+  EXPECT_FALSE(Full.isAllPositive());
 
   EnumerateInterestingConstantRanges([](const ConstantRange &CR) {
     bool AllNegative = true;
     bool AllNonNegative = true;
+    bool AllPositive = true;
     ForeachNumInConstantRange(CR, [&](const APInt &N) {
       if (!N.isNegative())
         AllNegative = false;
       if (!N.isNonNegative())
         AllNonNegative = false;
+      if (!N.isStrictlyPositive())
+        AllPositive = false;
     });
-    assert((CR.isEmptySet() || !AllNegative || !AllNonNegative) &&
-           "Only empty set can be both all negative and all non-negative");
+    assert(
+        (CR.isEmptySet() || !AllNegative || !AllNonNegative || !AllPositive) &&
+        "Only empty set can be all negative, all non-negative, and all "
+        "positive");
 
     EXPECT_EQ(AllNegative, CR.isAllNegative());
     EXPECT_EQ(AllNonNegative, CR.isAllNonNegative());
+    EXPECT_EQ(AllPositive, CR.isAllPositive());
   });
 }