Make ConstantRange::makeICmpRegion handle all the edge cases properly. This

also fixes PR8250.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114972 91177308-0d34-0410-b5e6-96231b3b80d8

unittests/Support/ConstantRangeTest.cpp

@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/ConstantRange.h"
+#include "llvm/Instructions.h"
 
 #include "gtest/gtest.h"
 
@@ -429,4 +430,11 @@ TEST_F(ConstantRangeTest, Lshr) {
   EXPECT_EQ(Wrap.lshr(Wrap), Full);
 }
 
+TEST(ConstantRange, MakeICmpRegion) {
+  // PR8250
+  ConstantRange SMax = ConstantRange(APInt::getSignedMaxValue(32));
+  EXPECT_TRUE(ConstantRange::makeICmpRegion(ICmpInst::ICMP_SGT,
+                                            SMax).isEmptySet());
+}
+
 }  // anonymous namespace