MC: Calculate intra-section symbol differences correctly for COFF

This fixes PR22060.

llvm-svn: 228565

1 files changed, 11 insertions, 6 deletions

diff --git a/llvm/lib/MC/WinCOFFObjectWriter.cpp b/llvm/lib/MC/WinCOFFObjectWriter.cpp
index bd750af..e398581 100644
--- a/llvm/lib/MC/WinCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -706,17 +706,22 @@ void WinCOFFObjectWriter::RecordRelocation(
     CrossSection = &Symbol.getSection() != &B->getSection();
 
     // Offset of the symbol in the section
-    int64_t a = Layout.getSymbolOffset(&B_SD);
+    int64_t OffsetOfB = Layout.getSymbolOffset(&B_SD);
 
-    // Offset of the relocation in the section
-    int64_t b = Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
-
-    FixedValue = b - a;
     // In the case where we have SymbA and SymB, we just need to store the delta
     // between the two symbols.  Update FixedValue to account for the delta, and
     // skip recording the relocation.
-    if (!CrossSection)
+    if (!CrossSection) {
+      int64_t OffsetOfA = Layout.getSymbolOffset(&A_SD);
+      FixedValue = (OffsetOfA - OffsetOfB) + Target.getConstant();
       return;
+    }
+
+    // Offset of the relocation in the section
+    int64_t OffsetOfRelocation =
+        Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
+
+    FixedValue = OffsetOfRelocation - OffsetOfB;
   } else {
     FixedValue = Target.getConstant();
   }