Index: COFF/InputFiles.h
===================================================================
--- COFF/InputFiles.h
+++ COFF/InputFiles.h
@@ -157,6 +157,11 @@
       COFFSymbolRef COFFSym,
       const llvm::object::coff_aux_section_definition *Def);
 
+  void readAssociativeDefinition(
+      COFFSymbolRef COFFSym,
+      const llvm::object::coff_aux_section_definition *Def,
+      uint32_t ParentSection);
+
   llvm::Optional<Symbol *>
   createDefined(COFFSymbolRef Sym,
                 std::vector<const llvm::object::coff_aux_section_definition *>
Index: COFF/InputFiles.cpp
===================================================================
--- COFF/InputFiles.cpp
+++ COFF/InputFiles.cpp
@@ -205,7 +205,13 @@
 
 void ObjFile::readAssociativeDefinition(
     COFFSymbolRef Sym, const coff_aux_section_definition *Def) {
-  SectionChunk *Parent = SparseChunks[Def->getNumber(Sym.isBigObj())];
+  readAssociativeDefinition(Sym, Def, Def->getNumber(Sym.isBigObj()));
+}
+
+void ObjFile::readAssociativeDefinition(
+    COFFSymbolRef Sym, const coff_aux_section_definition *Def,
+    uint32_t ParentSection) {
+  SectionChunk *Parent = SparseChunks[ParentSection];
 
   // If the parent is pending, it probably means that its section definition
   // appears after us in the symbol table. Leave the associated section as
@@ -254,6 +260,7 @@
   std::vector<uint32_t> PendingIndexes;
   PendingIndexes.reserve(NumSymbols);
 
+  std::map<StringRef, uint32_t> SymbolSectionIndexes;
   std::vector<const coff_aux_section_definition *> ComdatDefs(
       COFFObj->getNumberOfSections() + 1);
 
@@ -267,6 +274,11 @@
       WeakAliases.emplace_back(Symbols[I], TagIndex);
     } else if (Optional<Symbol *> OptSym = createDefined(COFFSym, ComdatDefs)) {
       Symbols[I] = *OptSym;
+      if (Config->MinGW) {
+        StringRef Name;
+        COFFObj->getSymbolName(COFFSym, Name);
+        SymbolSectionIndexes[Name] = COFFSym.getSectionNumber();
+      }
     } else {
       // createDefined() returns None if a symbol belongs to a section that
       // was pending at the point when the symbol was read. This can happen in
@@ -284,9 +296,21 @@
 
   for (uint32_t I : PendingIndexes) {
     COFFSymbolRef Sym = check(COFFObj->getSymbol(I));
-    if (auto *Def = Sym.getSectionDefinition())
+    if (auto *Def = Sym.getSectionDefinition()) {
       if (Def->Selection == IMAGE_COMDAT_SELECT_ASSOCIATIVE)
         readAssociativeDefinition(Sym, Def);
+      else if (Config->MinGW) {
+        StringRef Name;
+        COFFObj->getSymbolName(Sym, Name);
+        if (Name.consume_front(".xdata$") || Name.consume_front(".pdata$")) {
+          // For MinGW, treat .xdata$foo as implicitly associative to the symbol
+          // foo.
+          auto ParentSym = SymbolSectionIndexes.find(Name);
+          if (ParentSym != SymbolSectionIndexes.end())
+            readAssociativeDefinition(Sym, Def, ParentSym->second);
+        }
+      }
+    }
     Symbols[I] = createRegular(Sym);
   }
 
Index: test/COFF/Inputs/associative-comdat-mingw-2.s
===================================================================
--- /dev/null
+++ test/COFF/Inputs/associative-comdat-mingw-2.s
@@ -0,0 +1,34 @@
+        .section        .xdata$foo,"dr"
+        .linkonce       discard
+        .p2align        3
+        .long           42
+
+        .section        .xdata$bar,"dr"
+        .linkonce       discard
+        .p2align        3
+        .long           43
+
+        .section        .xdata$baz,"dr"
+        .linkonce       discard
+        .p2align        3
+        .long           44
+
+        .def            foo;
+        .scl            2;
+        .type           32;
+        .endef
+        .section        .text$foo,"xr",discard,foo
+        .globl          foo
+        .p2align        4
+foo:
+        ret
+
+        .def            bar;
+        .scl            2;
+        .type           32;
+        .endef
+        .section        .text$bar,"xr",discard,bar
+        .globl          bar
+        .p2align        4
+bar:
+        ret
Index: test/COFF/associative-comdat-mingw.s
===================================================================
--- /dev/null
+++ test/COFF/associative-comdat-mingw.s
@@ -0,0 +1,73 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -triple=x86_64-windows-gnu %s -filetype=obj -o %t1.obj
+# RUN: llvm-mc -triple=x86_64-windows-gnu %S/Inputs/associative-comdat-mingw-2.s -filetype=obj -o %t2.obj
+
+# RUN: lld-link -lldmingw -entry:main %t1.obj %t2.obj -out:%t.gc.exe -verbose
+# RUN: llvm-readobj -sections %t.gc.exe | FileCheck %s
+
+# CHECK: Sections [
+# CHECK:   Section {
+# CHECK:     Number: 2
+# CHECK-LABEL:     Name: .rdata (2E 72 64 61 74 61 00 00)
+#             This is the critical check to show that only *one* definition of
+#             .xdata$foo was retained. This *must* be 4.
+#             Make sure that no other .xdata sections get included, which would
+#             increase the size here.
+# CHECK-NEXT:     VirtualSize: 0x4
+
+        .text
+        .def            main;
+        .scl            2;
+        .type           32;
+        .endef
+        .globl          main
+        .p2align        4, 0x90
+main:
+        call            foo
+        retq
+
+# Defines .text$foo (which has a leader symbol and is referenced like
+# normally), and .xdata$foo (which lacks a leader symbol, which normally
+# would be declared associative to the symbol foo).
+# .xdata$foo should be implicitly treated as associative to foo and brought
+# in, while .xdata$bar, implicitly associative to bar, not included, and
+# .xdata$baz not included since there's no symbol baz.
+
+# GNU binutils ld doesn't do this at all, but always includes all .xdata/.pdata
+# comdat sections, even if --gc-sections is used.
+
+        .section        .xdata$foo,"dr",associative,foo
+#        .linkonce       discard
+        .p2align        3
+        .long           42
+
+        .section        .xdata$bar,"dr"
+        .linkonce       discard
+        .p2align        3
+        .long           43
+
+        .section        .xdata$baz,"dr"
+        .linkonce       discard
+        .p2align        3
+        .long           44
+
+        .def            foo;
+        .scl            2;
+        .type           32;
+        .endef
+        .section        .text$foo,"xr",discard,foo
+        .globl          foo
+        .p2align        4
+foo:
+	ret
+
+        .def            bar;
+        .scl            2;
+        .type           32;
+        .endef
+        .section        .text$bar,"xr",discard,bar
+        .globl          bar
+        .p2align        4
+bar:
+	ret