diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -537,7 +537,17 @@
   path_list Paths;
   auto addPathForTriple = [this, &Paths](const llvm::Triple &Triple) {
     SmallString<128> P(D.ResourceDir);
-    llvm::sys::path::append(P, "lib", Triple.str());
+    llvm::Triple CanonicalTriple;
+    if (Triple.hasEnvironment())
+      CanonicalTriple =
+          llvm::Triple(llvm::Triple::getArchTypeName(Triple.getArch()),
+                       Triple.getVendorName(), Triple.getOSName(),
+                       Triple.getEnvironmentName());
+    else
+      CanonicalTriple =
+          llvm::Triple(llvm::Triple::getArchTypeName(Triple.getArch()),
+                       Triple.getVendorName(), Triple.getOSName());
+    llvm::sys::path::append(P, "lib", CanonicalTriple.str());
     Paths.push_back(std::string(P.str()));
   };
 
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/lib/sparc64-linux-gnu/Scrt1.o b/clang/test/Driver/Inputs/debian_sparc64_tree/lib/sparc64-linux-gnu/Scrt1.o
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/lib/sparc64-linux-gnu/crti.o b/clang/test/Driver/Inputs/debian_sparc64_tree/lib/sparc64-linux-gnu/crti.o
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/lib/sparc64-linux-gnu/crtn.o b/clang/test/Driver/Inputs/debian_sparc64_tree/lib/sparc64-linux-gnu/crtn.o
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/gcc/sparc64-linux-gnu/12/crtbeginS.o b/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/gcc/sparc64-linux-gnu/12/crtbeginS.o
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/gcc/sparc64-linux-gnu/12/crtendS.o b/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/gcc/sparc64-linux-gnu/12/crtendS.o
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/gcc/sparc64-linux-gnu/12/libgcc.a b/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/gcc/sparc64-linux-gnu/12/libgcc.a
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/gcc/sparc64-linux-gnu/12/libgcc_s.so b/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/gcc/sparc64-linux-gnu/12/libgcc_s.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/libc.so b/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/libc.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/libdl.so b/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/libdl.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/libm.so b/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/libm.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/libpthread.so b/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/libpthread.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/libresolv.so b/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/libresolv.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/librt.so b/clang/test/Driver/Inputs/debian_sparc64_tree/usr/lib/sparc64-linux-gnu/librt.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/resource_dir_with_per_target_subdir/lib/sparcv9-unknown-linux-gnu/libclang_rt.ubsan_standalone.a b/clang/test/Driver/Inputs/resource_dir_with_per_target_subdir/lib/sparcv9-unknown-linux-gnu/libclang_rt.ubsan_standalone.a
new file mode 100644
diff --git a/clang/test/Driver/Inputs/resource_dir_with_per_target_subdir/lib/x86_64-pc-solaris2.11/libclang_rt.ubsan_standalone.a b/clang/test/Driver/Inputs/resource_dir_with_per_target_subdir/lib/x86_64-pc-solaris2.11/libclang_rt.ubsan_standalone.a
new file mode 100644
diff --git a/clang/test/Driver/noncanon-per-target-runtime-dir.c b/clang/test/Driver/noncanon-per-target-runtime-dir.c
new file mode 100644
--- /dev/null
+++ b/clang/test/Driver/noncanon-per-target-runtime-dir.c
@@ -0,0 +1,20 @@
+/// Check that clang's and compiler-rt's ideas of per-target runtime dirs match.
+
+// RUN: %clang -### %s 2>&1 \
+// RUN:     --target=amd64-pc-solaris2.11 -fsanitize=undefined \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
+// RUN:     --sysroot=%S/Inputs/solaris_x86_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-SOLARIS-AMD64 %s
+
+// CHECK-SOLARIS-AMD64: x86_64-pc-solaris2.11/libclang_rt.ubsan_standalone.a
+// CHECK-SOLARIS-AMD64-NOT: lib/sunos/libclang_rt.ubsan_standalone-x86_64.a"
+
+// RUN: %clang -### %s 2>&1 \
+// RUN:     --target=sparc64-unknown-linux-gnu -fsanitize=undefined \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
+// RUN:     --sysroot=%S/Inputs/debian_sparc64_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-DEBIAN-SPARC64 %s
+
+// CHECK-DEBIAN-SPARC64: sparcv9-unknown-linux-gnu/libclang_rt.ubsan_standalone.a
+// CHECK-DEBIAN-SPARC64-NOT: lib/linux/libclang_rt.ubsan_standalone-sparcv9.a"
+
diff --git a/clang/test/Driver/runtime-layout.c b/clang/test/Driver/runtime-layout.c
new file mode 100644
--- /dev/null
+++ b/clang/test/Driver/runtime-layout.c
@@ -0,0 +1,56 @@
+/// Check that clang's idea of runtime dir layout matches e.g. compiler-rt's.
+
+/// Classical runtime layout.
+// RUN: mkdir -p %t-classic/lib/sunos
+
+/// Canonical triple, 64-bit.
+// RUN: %clang -print-runtime-dir --target=x86_64-pc-solaris2.11 \
+// RUN:   -resource-dir=%t-classic \
+// RUN:   | FileCheck --check-prefix=RUNTIME-DIR-CLASSIC %s
+
+/// Non-canonical triple, 64-bit.
+// RUN: %clang -print-runtime-dir --target=amd64-pc-solaris2.11 \
+// RUN:   -resource-dir=%t-classic \
+// RUN:   | FileCheck --check-prefix=RUNTIME-DIR-CLASSIC %s
+
+/// Canonical triple, 32-bit.
+// RUN: %clang -print-runtime-dir --target=i386-pc-solaris2.11 \
+// RUN:   -resource-dir=%t-classic \
+// RUN:   | FileCheck --check-prefix=RUNTIME-DIR-CLASSIC %s
+
+/// Non-canonical triple, 32-bit.
+// RUN: %clang -print-runtime-dir --target=i686-pc-solaris2.11 \
+// RUN:   -resource-dir=%t-classic \
+// RUN:   | FileCheck --check-prefix=RUNTIME-DIR-CLASSIC %s
+
+// RUNTIME-DIR-CLASSIC: {{.*}}/lib/sunos
+
+/// New runtime layout.
+
+// RUN: mkdir -p %t-runtime/lib/x86_64-pc-solaris2.11
+
+/// Canonical triple, 64-bit.
+// RUN: %clang -print-runtime-dir --target=x86_64-pc-solaris2.11 \
+// RUN:   -resource-dir=%t-runtime \
+// RUN:   | FileCheck --check-prefix=RUNTIME-DIR-X86_64 %s
+
+/// Non-canonical triple, 64-bit.
+// RUN: %clang -print-runtime-dir --target=amd64-pc-solaris2.11 \
+// RUN:   -resource-dir=%t-runtime \
+// RUN:   | FileCheck --check-prefix=RUNTIME-DIR-X86_64 %s
+
+// RUNTIME-DIR-X86_64: {{.*}}/lib/x86_64-pc-solaris2.11
+
+// RUN: mkdir -p %t-runtime/lib/i386-pc-solaris2.11
+
+/// Canonical triple, 32-bit.
+// RUN: %clang -print-runtime-dir --target=i386-pc-solaris2.11 \
+// RUN:   -resource-dir=%t-runtime \
+// RUN:   | FileCheck --check-prefix=RUNTIME-DIR-I386 %s
+
+/// Non-canonical triple, 32-bit.
+// RUN: %clang -print-runtime-dir --target=i686-pc-solaris2.11 \
+// RUN:   -resource-dir=%t-runtime \
+// RUN:   | FileCheck --check-prefix=RUNTIME-DIR-I386 %s
+
+// RUNTIME-DIR-I386: {{.*}}/lib/i386-pc-solaris2.11