[llvm] [ConstantFPRange] Implement `ConstantFPRange::makeAllowedFCmpRegion` (PR #110082)

[Matt Arsenault via llvm-commits]

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@@ -425,4 +442,32 @@ TEST_F(ConstantFPRangeTest, MismatchedSemantics) {
 #endif
 #endif
 
+TEST_F(ConstantFPRangeTest, makeAllowedFCmpRegion) {
+  for (auto Pred : FCmpInst::predicates()) {
+    EnumerateConstantFPRanges(
+        [Pred](const ConstantFPRange &CR) {
+          ConstantFPRange Res =
+              ConstantFPRange::makeAllowedFCmpRegion(Pred, CR);
+          ConstantFPRange Optimal =
+              ConstantFPRange::getEmpty(CR.getSemantics());
+          EnumerateValuesInConstantFPRange(
+              ConstantFPRange::getFull(CR.getSemantics()),
+              [&](const APFloat &V) {
+                if (AnyOfValueInConstantFPRange(CR, [&](const APFloat &U) {
+                      return FCmpInst::compare(V, U, Pred);
+                    }))
+                  Optimal = Optimal.unionWith(ConstantFPRange(V));
+              });
+
+          ASSERT_TRUE(Res.contains(Optimal))
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arsenm wrote:

Not sure why this isn't EXPECT_TRUE 

https://github.com/llvm/llvm-project/pull/110082