[DebugInfo] Remove the restriction on the size of DIStringType

in DebugHandlerBase::isUnsignedDIType.

Differential Revision: https://reviews.llvm.org/D108559

1 files changed, 7 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp b/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
index c81288c..c957ca8 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
@@ -174,12 +174,16 @@ uint64_t DebugHandlerBase::getBaseTypeSize(const DIType *Ty) {
 }
 
 bool DebugHandlerBase::isUnsignedDIType(const DIType *Ty) {
-  // SROA may generate dbg value intrinsics to assign an unsigned value to a
-  // Fortran CHARACTER(1) type variables. Make them as unsigned.
   if (isa<DIStringType>(Ty)) {
-    assert((Ty->getSizeInBits()) == 8 && "Not a valid unsigned type!");
+    // Some transformations (e.g. instcombine) may decide to turn a Fortran
+    // character object into an integer, and later ones (e.g. SROA) may
+    // further inject a constant integer in a llvm.dbg.value call to track
+    // the object's value. Here we trust the transformations are doing the
+    // right thing, and treat the constant as unsigned to preserve that value
+    // (i.e. avoid sign extension).
     return true;
   }
+
   if (auto *CTy = dyn_cast<DICompositeType>(Ty)) {
     // FIXME: Enums without a fixed underlying type have unknown signedness
     // here, leading to incorrectly emitted constants.