diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1142,6 +1142,10 @@
 def dsym_dir : JoinedOrSeparate<["-"], "dsym-dir">,
   Flags<[NoXarchOption, RenderAsInput]>,
   HelpText<"Directory to output dSYM's (if any) to">, MetaVarName<"<dir>">;
+// GCC style -dumpdir. We intentionally don't implement the less useful -dumpbase{,-ext}.
+def dumpdir : Separate<["-"], "dumpdir">, Flags<[CC1Option]>,
+  MetaVarName<"<dumppfx>">,
+  HelpText<"Use <dumpfpx> as a prefix to form auxiliary and dump file names">;
 def dumpmachine : Flag<["-"], "dumpmachine">;
 def dumpspecs : Flag<["-"], "dumpspecs">, Flags<[Unsupported]>;
 def dumpversion : Flag<["-"], "dumpversion">;
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -3875,6 +3875,16 @@
         !Args.getLastArgValue(options::OPT_fuse_ld_EQ)
              .equals_insensitive("lld"))
       Diag(clang::diag::err_drv_lto_without_lld);
+
+    // If -dumpdir is not specified, give a default prefix derived from the link
+    // output filename.
+    if (!Args.hasArg(options::OPT_dumpdir)) {
+      Arg *Arg = Args.MakeSeparateArg(
+          nullptr, getOpts().getOption(options::OPT_dumpdir),
+          Args.MakeArgString(Args.getLastArgValue(options::OPT_o, "a") + "-"));
+      Arg->claim();
+      Args.append(Arg);
+    }
   }
 
   if (FinalPhase == phases::Preprocess || Args.hasArg(options::OPT__SLASH_Y_)) {
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4837,6 +4837,8 @@
     }
   }
 
+  Args.AddLastArg(CmdArgs, options::OPT_dumpdir);
+
   if (const Arg *A = Args.getLastArg(options::OPT_fthinlto_index_EQ)) {
     if (!types::isLLVMIR(Input.getType()))
       D.Diag(diag::err_drv_arg_requires_bitcode_input) << A->getAsString(Args);
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1248,23 +1248,24 @@
     if (StringRef(A->getValue()) == "single")
       return Args.MakeArgString(Output.getFilename());
 
-  Arg *FinalOutput = Args.getLastArg(options::OPT_o);
-  if (FinalOutput && Args.hasArg(options::OPT_c)) {
-    SmallString<128> T(FinalOutput->getValue());
-    llvm::sys::path::remove_filename(T);
-    llvm::sys::path::append(T, llvm::sys::path::stem(FinalOutput->getValue()));
-    AddPostfix(T);
-    return Args.MakeArgString(T);
+  SmallString<128> T;
+  if (const Arg *A = Args.getLastArg(options::OPT_dumpdir)) {
+    T = A->getValue();
   } else {
-    // Use the compilation dir.
-    Arg *A = Args.getLastArg(options::OPT_ffile_compilation_dir_EQ,
-                             options::OPT_fdebug_compilation_dir_EQ);
-    SmallString<128> T(A ? A->getValue() : "");
-    SmallString<128> F(llvm::sys::path::stem(Input.getBaseInput()));
-    AddPostfix(F);
-    T += F;
-    return Args.MakeArgString(T);
+    Arg *FinalOutput = Args.getLastArg(options::OPT_o);
+    if (FinalOutput && Args.hasArg(options::OPT_c)) {
+      T = FinalOutput->getValue();
+      llvm::sys::path::remove_filename(T);
+      llvm::sys::path::append(T,
+                              llvm::sys::path::stem(FinalOutput->getValue()));
+      AddPostfix(T);
+      return Args.MakeArgString(T);
+    }
   }
+
+  T += llvm::sys::path::stem(Input.getBaseInput());
+  AddPostfix(T);
+  return Args.MakeArgString(T);
 }
 
 void tools::SplitDebugInfo(const ToolChain &TC, Compilation &C, const Tool &T,
diff --git a/clang/test/Driver/hip-gsplit-dwarf-options.hip b/clang/test/Driver/hip-gsplit-dwarf-options.hip
--- a/clang/test/Driver/hip-gsplit-dwarf-options.hip
+++ b/clang/test/Driver/hip-gsplit-dwarf-options.hip
@@ -13,13 +13,17 @@
 // RUN: %clang -### --target=x86_64-unknown-linux-gnu \
 // RUN:   --offload-arch=gfx906:xnack+ %s -nogpulib -nogpuinc \
 // RUN:   --offload-arch=gfx900 \
-// RUN:   -ggdb -gsplit-dwarf 2>&1 | FileCheck %s
+// RUN:   -ggdb -gsplit-dwarf 2>&1 | FileCheck %s --check-prefix=LINK
 
 // RUN: %clang -### --target=x86_64-unknown-linux-gnu \
 // RUN:   -fgpu-rdc --offload-arch=gfx906:xnack+ %s -nogpulib -nogpuinc \
 // RUN:   --offload-arch=gfx900 \
-// RUN:   -ggdb -gsplit-dwarf 2>&1 | FileCheck %s
+// RUN:   -ggdb -gsplit-dwarf 2>&1 | FileCheck %s --check-prefix=LINK
 
 // CHECK-DAG: {{".*clang.*".* "-target-cpu" "gfx906".* "-split-dwarf-output" "hip-gsplit-dwarf-options_gfx906:xnack\+.dwo"}}
 // CHECK-DAG: {{".*clang.*".* "-target-cpu" "gfx900".* "-split-dwarf-output" "hip-gsplit-dwarf-options_gfx900.dwo"}}
 // CHECK-DAG: {{".*clang.*".* "-target-cpu" "x86-64".* "-split-dwarf-output" "hip-gsplit-dwarf-options.dwo"}}
+
+// LINK-DAG: {{".*clang.*".* "-target-cpu" "gfx906".* "-split-dwarf-output" "a-hip-gsplit-dwarf-options_gfx906:xnack\+.dwo"}}
+// LINK-DAG: {{".*clang.*".* "-target-cpu" "gfx900".* "-split-dwarf-output" "a-hip-gsplit-dwarf-options_gfx900.dwo"}}
+// LINK-DAG: {{".*clang.*".* "-target-cpu" "x86-64".* "-split-dwarf-output" "a-hip-gsplit-dwarf-options.dwo"}}
diff --git a/clang/test/Driver/split-debug.c b/clang/test/Driver/split-debug.c
--- a/clang/test/Driver/split-debug.c
+++ b/clang/test/Driver/split-debug.c
@@ -9,6 +9,7 @@
 
 // INLINE:     "-fsplit-dwarf-inlining"
 // NOINLINE-NOT: "-fsplit-dwarf-inlining"
+// SPLIT-NOT:  "-dumpdir"
 // SPLIT:      "-debug-info-kind=constructor"
 // SPLIT-SAME: "-ggnu-pubnames"
 // SPLIT-SAME: "-split-dwarf-file" "split-debug.dwo" "-split-dwarf-output" "split-debug.dwo"
@@ -54,8 +55,29 @@
 // SINGLE_WITH_FILENAME: "-split-dwarf-file" "{{.*}}foo.o"
 // SINGLE_WITH_FILENAME-NOT: "-split-dwarf-output"
 
-/// Without -c, clang performs linking as well. The output is unchanged.
-// RUN: %clang -### -target x86_64-unknown-linux-gnu -gsplit-dwarf -g %s -o ignore.d 2>&1 | FileCheck %s --check-prefix=SPLIT
+/// If linking is the final phase, the .dwo filename is derived from -o (if specified) or "a".
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -gsplit-dwarf -g %s -o obj/out 2>&1 | FileCheck %s --check-prefix=SPLIT_LINK
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -gsplit-dwarf -g %s 2>&1 | FileCheck %s --check-prefix=SPLIT_LINK_A
+
+// SPLIT_LINK:      "-dumpdir" "obj/out-"
+// SPLIT_LINK:      "-debug-info-kind=constructor"
+// SPLIT_LINK-SAME: "-split-dwarf-file" "obj/out-split-debug.dwo" "-split-dwarf-output" "obj/out-split-debug.dwo"
+// SPLIT_LINK_A:      "-dumpdir" "a-"
+// SPLIT_LINK_A-SAME: "-split-dwarf-file" "a-split-debug.dwo" "-split-dwarf-output" "a-split-debug.dwo"
+
+/// GCC special cases /dev/null (HOST_BIT_BUCKET) but not other special files like /dev/zero.
+/// We don't apply special rules at all.
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -gsplit-dwarf -g %s -o /dev/null 2>&1 | FileCheck %s --check-prefix=SPLIT_LINK_NULL
+
+// SPLIT_LINK_NULL:      "-dumpdir" "/dev/null-"
+// SPLIT_LINK_NULL-SAME: "-split-dwarf-output" "/dev/null-split-debug.dwo"
+
+/// If -dumpdir is specified, use its value to derive the .dwo filename.
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -gsplit-dwarf -g %s -o obj/out -dumpdir pf/x -c 2>&1 | FileCheck %s --check-prefix=DUMPDIR
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -gsplit-dwarf -g %s -o obj/out -dumpdir pf/x 2>&1 | FileCheck %s --check-prefix=DUMPDIR
+
+// DUMPDIR:      "-dumpdir" "pf/x"
+// DUMPDIR-SAME: "-split-dwarf-output" "pf/xsplit-debug.dwo"
 
 /// -fsplit-dwarf-inlining
 // RUN: %clang -### -c -target x86_64 -gsplit-dwarf=split -g -fsplit-dwarf-inlining %s 2>&1 | FileCheck %s --check-prefixes=INLINE,SPLIT