move check of empty/full range attribute to verifier

llvm/lib/AsmParser/LLParser.cpp

@@ -3109,8 +3109,9 @@ bool LLParser::parseRangeAttr(AttrBuilder &B) {
   if (ParseAPSInt(BitWidth, Lower) ||
       parseToken(lltok::comma, "expected ','") || ParseAPSInt(BitWidth, Upper))
     return true;
-  if (Lower == Upper)
-    return tokError("the range should not represent the full or empty set!");
+  if (Lower == Upper && !(Lower.isMaxValue() || Lower.isMinValue()))
+    return tokError("the range represent the full or empty set but they aren't "
+                    "min or max value!");
 
   if (parseToken(lltok::rparen, "expected ')'"))
     return true;

llvm/lib/IR/Verifier.cpp

@@ -2074,6 +2074,8 @@ void Verifier::verifyParameterAttrs(AttributeSet Attrs, Type *Ty,
         Attrs.getAttribute(Attribute::Range).getValueAsConstantRange();
     Check(Ty->isIntOrIntVectorTy(CR.getBitWidth()),
           "Range bit width must match type bit width!", V);
+    Check(!CR.isEmptySet(), "Range must not be empty!", V);
+    Check(!CR.isFullSet(), "Range must not be full!", V);
   }
 }
 

llvm/test/Assembler/range-attribute-invalid-range.ll

@@ -1,6 +1,6 @@
 ; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
 
-; CHECK: the range should not represent the full or empty set!
-define void @range_empty(i8 range(i8 0, 0) %a) {
+; CHECK: the range represent the full or empty set but they aren't min or max value!
+define void @range_empty(i8 range(i8 3, 3) %a) {
   ret void
 }

llvm/test/Verifier/range-attr.ll

@@ -17,3 +17,15 @@ define void @bit_widths_do_not_match_vector(<4 x i32> range(i8 1, 0) %a) {
 define void @not-integer-type(ptr range(i8 1, 0) %a) {
   ret void
 }
+
+; CHECK: Range must not be empty!
+; CHECK-NEXT: ptr @empty_range
+define void @empty_range(i8 range(i8 0, 0) %a) {
+  ret void
+}
+
+; CHECK: Range must not be full!
+; CHECK-NEXT: ptr @full_range
+define void @full_range(i8 range(i8 -1, -1) %a) {
+  ret void
+}