From bfbe97811bca316b63f61e7bee77921d990846f6 Mon Sep 17 00:00:00 2001
From: Walter Bright <walter@walterbright.com>
Date: Wed, 2 Sep 2020 22:46:54 -0700
Subject: [PATCH] fix Issue 14203 - Return of floating point values from
 extern(C++) member functions does not match dmc

---
 src/dmd/target.d                         | 10 ++++++++++
 test/runnable_cxx/extra-files/c14203.cpp |  2 ++
 test/runnable_cxx/test14203.d            | 22 ++++++++++++++++++++++
 3 files changed, 34 insertions(+)
 create mode 100644 test/runnable_cxx/extra-files/c14203.cpp
 create mode 100644 test/runnable_cxx/test14203.d

diff --git a/src/dmd/target.d b/src/dmd/target.d
index 8e7bc0bc9c..e19e7f3593 100644
--- a/src/dmd/target.d
+++ b/src/dmd/target.d
@@ -715,6 +715,16 @@ extern (C++) struct Target
             else
                 return true;
         }
+        else if (global.params.isWindows &&
+                 !global.params.is64bit &&
+                 (tf.linkage == LINK.cpp || tf.linkage == LINK.pascal) &&
+                 tf.isfloating())
+        {
+            /* See DMC++ function exp2_retmethod()
+             * https://github.com/DigitalMars/Compiler/blob/master/dm/src/dmc/dexp2.d#L149
+             */
+            return true;
+        }
         else
         {
             //assert(sz <= 16);
diff --git a/test/runnable_cxx/extra-files/c14203.cpp b/test/runnable_cxx/extra-files/c14203.cpp
new file mode 100644
index 0000000000..059d0eeff5
--- /dev/null
+++ b/test/runnable_cxx/extra-files/c14203.cpp
@@ -0,0 +1,2 @@
+
+float func1() { return 73; }
diff --git a/test/runnable_cxx/test14203.d b/test/runnable_cxx/test14203.d
new file mode 100644
index 0000000000..3b29c66203
--- /dev/null
+++ b/test/runnable_cxx/test14203.d
@@ -0,0 +1,22 @@
+// EXTRA_CPP_SOURCES: c14203.cpp
+
+
+/************************************************/
+
+// https://issues.dlang.org/show_bug.cgi?id=14203
+
+extern (C++) float func1();
+
+void test14203()
+{
+    assert(func1() == 73);
+}
+
+/************************************************/
+
+int main()
+{
+    test14203();
+
+    return 0;
+}