This was a fix suggested by Kiran Chandramohan (ARM) to force the subrange values to be signed integral values.

schweitzpgi · schweitzpgi · commit 796ae24489c4 · 2018-10-29T12:03:39.000-07:00
diff --git a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1441,12 +1441,12 @@ void DwarfUnit::constructFortranSubrangeDIE(DIE &Buffer,
 
   if (!SR->getLowerBound()) {
     int64_t BVC = SR->getCLowerBound();
-    addSInt(DW_Subrange, dwarf::DW_AT_lower_bound, None, BVC);
+    addSInt(DW_Subrange, dwarf::DW_AT_lower_bound, dwarf::DW_FORM_sdata, BVC);
   }
 
   if ((!SR->getUpperBound()) && (!SR->noUpperBound())) {
     int64_t BVC = SR->getCUpperBound();
-    addSInt(DW_Subrange, dwarf::DW_AT_upper_bound, None, BVC);
+    addSInt(DW_Subrange, dwarf::DW_AT_upper_bound, dwarf::DW_FORM_sdata, BVC);
   }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -1441,12 +1441,12 @@ void DwarfUnit::constructFortranSubrangeDIE(DIE &Buffer,`
`1441`	`1441`
`1442`	`1442`	`if (!SR->getLowerBound()) {`
`1443`	`1443`	`int64_t BVC = SR->getCLowerBound();`
`1444`		`- addSInt(DW_Subrange, dwarf::DW_AT_lower_bound, None, BVC);`
	`1444`	`+ addSInt(DW_Subrange, dwarf::DW_AT_lower_bound, dwarf::DW_FORM_sdata, BVC);`
`1445`	`1445`	`}`
`1446`	`1446`
`1447`	`1447`	`if ((!SR->getUpperBound()) && (!SR->noUpperBound())) {`
`1448`	`1448`	`int64_t BVC = SR->getCUpperBound();`
`1449`		`- addSInt(DW_Subrange, dwarf::DW_AT_upper_bound, None, BVC);`
	`1449`	`+ addSInt(DW_Subrange, dwarf::DW_AT_upper_bound, dwarf::DW_FORM_sdata, BVC);`
`1450`	`1450`	`}`
`1451`	`1451`	`}`
`1452`	`1452`