diff --git a/llvm/lib/TargetParser/Triple.cpp b/llvm/lib/TargetParser/Triple.cpp
index 4c1de09e91f21c2..855889ac05620d3 100644
--- a/llvm/lib/TargetParser/Triple.cpp
+++ b/llvm/lib/TargetParser/Triple.cpp
@@ -2024,6 +2024,10 @@ bool Triple::isLittleEndian() const {
 }
 
 bool Triple::isCompatibleWith(const Triple &Other) const {
+  // On MinGW, C code is usually built with a "w64" vendor, while Rust
+  // often uses a "pc" vendor.
+  bool IgnoreVendor = isWindowsGNUEnvironment();
+
   // ARM and Thumb triples are compatible, if subarch, vendor and OS match.
   if ((getArch() == Triple::thumb && Other.getArch() == Triple::arm) ||
       (getArch() == Triple::arm && Other.getArch() == Triple::thumb) ||
@@ -2034,17 +2038,24 @@ bool Triple::isCompatibleWith(const Triple &Other) const {
              getVendor() == Other.getVendor() && getOS() == Other.getOS();
     else
       return getSubArch() == Other.getSubArch() &&
-             getVendor() == Other.getVendor() && getOS() == Other.getOS() &&
+             (getVendor() == Other.getVendor() || IgnoreVendor) &&
+             getOS() == Other.getOS() &&
              getEnvironment() == Other.getEnvironment() &&
              getObjectFormat() == Other.getObjectFormat();
   }
 
-  // If vendor is apple, ignore the version number.
+  // If vendor is apple, ignore the version number (the environment field)
+  // and the object format.
   if (getVendor() == Triple::Apple)
     return getArch() == Other.getArch() && getSubArch() == Other.getSubArch() &&
-           getVendor() == Other.getVendor() && getOS() == Other.getOS();
-
-  return *this == Other;
+           (getVendor() == Other.getVendor() || IgnoreVendor) &&
+           getOS() == Other.getOS();
+
+  return getArch() == Other.getArch() && getSubArch() == Other.getSubArch() &&
+         (getVendor() == Other.getVendor() || IgnoreVendor) &&
+         getOS() == Other.getOS() &&
+         getEnvironment() == Other.getEnvironment() &&
+         getObjectFormat() == Other.getObjectFormat();
 }
 
 std::string Triple::merge(const Triple &Other) const {
diff --git a/llvm/unittests/TargetParser/TripleTest.cpp b/llvm/unittests/TargetParser/TripleTest.cpp
index 7fb7625f8c2d10a..3217014aa69af71 100644
--- a/llvm/unittests/TargetParser/TripleTest.cpp
+++ b/llvm/unittests/TargetParser/TripleTest.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/TargetParser/Triple.h"
+#include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/VersionTuple.h"
 #include "gtest/gtest.h"
 
@@ -2737,4 +2738,41 @@ TEST(TripleTest, DXILNormaizeWithVersion) {
   EXPECT_EQ("dxilv1.0-pc-shadermodel5.0-compute",
             Triple::normalize("dxil-shadermodel5.0-pc-compute"));
 }
+
+TEST(TripleTest, isCompatibleWith) {
+  struct {
+    const char *A;
+    const char *B;
+    bool Result;
+  } Cases[] = {
+      {"armv7-linux-gnueabihf", "thumbv7-linux-gnueabihf", true},
+      {"armv4-none-unknown-eabi", "thumbv6-unknown-linux-gnueabihf", false},
+      {"x86_64-apple-macosx10.9.0", "x86_64-apple-macosx10.10.0", true},
+      {"x86_64-apple-macosx10.9.0", "i386-apple-macosx10.9.0", false},
+      {"x86_64-apple-macosx10.9.0", "x86_64h-apple-macosx10.9.0", true},
+      {"x86_64-unknown-linux-gnu", "x86_64-unknown-linux-gnu", true},
+      {"x86_64-unknown-linux-gnu", "i386-unknown-linux-gnu", false},
+      {"x86_64-unknown-linux-gnu", "x86_64h-unknown-linux-gnu", true},
+      {"x86_64-pc-windows-gnu", "x86_64-pc-windows-msvc", false},
+      {"x86_64-pc-windows-msvc", "x86_64-pc-windows-msvc-elf", false},
+      {"i686-w64-windows-gnu", "i386-w64-windows-gnu", true},
+      {"x86_64-w64-windows-gnu", "x86_64-pc-windows-gnu", true},
+      {"armv7-w64-windows-gnu", "thumbv7-pc-windows-gnu", true},
+  };
+
+  auto DoTest = [](const char *A, const char *B,
+                   bool Result) -> testing::AssertionResult {
+    if (Triple(A).isCompatibleWith(Triple(B)) != Result) {
+      return testing::AssertionFailure()
+             << llvm::formatv("Triple {0} and {1} were expected to be {2}", A,
+                              B, Result ? "compatible" : "incompatible");
+    }
+    return testing::AssertionSuccess();
+  };
+  for (const auto &C : Cases) {
+    EXPECT_TRUE(DoTest(C.A, C.B, C.Result));
+    // Test that the comparison is commutative.
+    EXPECT_TRUE(DoTest(C.B, C.A, C.Result));
+  }
+}
 } // end anonymous namespace