From e1dce1a8f90aee8c6922ca12cba99cc22c4122f8 Mon Sep 17 00:00:00 2001
From: Walter Bright <walter@walterbright.com>
Date: Thu, 13 Dec 2018 00:58:41 -0800
Subject: [PATCH] fix Issue 19227 - S.init is S.init failing for struct with
 float member

---
 src/dmd/ctfeexpr.d          | 34 ++++++++++++++++++++++++++--------
 test/compilable/test19227.d | 21 +++++++++++++++++++++
 2 files changed, 47 insertions(+), 8 deletions(-)
 create mode 100644 test/compilable/test19227.d

diff --git a/src/dmd/ctfeexpr.d b/src/dmd/ctfeexpr.d
index bf0e08908e9a..cdca312a245d 100644
--- a/src/dmd/ctfeexpr.d
+++ b/src/dmd/ctfeexpr.d
@@ -1170,10 +1170,17 @@ private bool isArray(Expression e)
     return e.op == TOK.arrayLiteral || e.op == TOK.string_ || e.op == TOK.slice || e.op == TOK.null_;
 }
 
-/* For strings, return <0 if e1 < e2, 0 if e1==e2, >0 if e1 > e2.
+/*****
+ * Params:
+ *      loc = source file location
+ *      e1 = left operand
+ *      e2 = right operand
+ *      identity = true for `is` identity comparisons
+ * Returns:
+ * For strings, return <0 if e1 < e2, 0 if e1==e2, >0 if e1 > e2.
  * For all other types, return 0 if e1 == e2, !=0 if e1 != e2.
  */
-private int ctfeRawCmp(const ref Loc loc, Expression e1, Expression e2)
+private int ctfeRawCmp(const ref Loc loc, Expression e1, Expression e2, bool identity = false)
 {
     if (e1.op == TOK.classReference || e2.op == TOK.classReference)
     {
@@ -1254,9 +1261,11 @@ private int ctfeRawCmp(const ref Loc loc, Expression e1, Expression e2)
     {
         real_t r1 = e1.type.isreal() ? e1.toReal() : e1.toImaginary();
         real_t r2 = e1.type.isreal() ? e2.toReal() : e2.toImaginary();
+        if (identity)
+            return !RealEquals(r1, r2);
         if (CTFloat.isNaN(r1) || CTFloat.isNaN(r2)) // if unordered
         {
-            return 1;
+            return 1;   // they are not equal
         }
         else
         {
@@ -1265,7 +1274,13 @@ private int ctfeRawCmp(const ref Loc loc, Expression e1, Expression e2)
     }
     else if (e1.type.iscomplex())
     {
-        return e1.toComplex() != e2.toComplex();
+        auto c1 = e1.toComplex();
+        auto c2 = e2.toComplex();
+        if (identity)
+        {
+            return !RealEquals(c1.re, c2.re) && !RealEquals(c1.im, c2.im);
+        }
+        return c1 != c2;
     }
     if (e1.op == TOK.structLiteral && e2.op == TOK.structLiteral)
     {
@@ -1290,7 +1305,7 @@ private int ctfeRawCmp(const ref Loc loc, Expression e1, Expression e2)
                     continue;
                 if (!ee1 || !ee2)
                     return 1;
-                int cmp = ctfeRawCmp(loc, ee1, ee2);
+                const int cmp = ctfeRawCmp(loc, ee1, ee2, identity);
                 if (cmp)
                     return 1;
             }
@@ -1316,13 +1331,13 @@ private int ctfeRawCmp(const ref Loc loc, Expression e1, Expression e2)
                 if (used[j])
                     continue;
                 Expression k2 = (*es2.keys)[j];
-                if (ctfeRawCmp(loc, k1, k2))
+                if (ctfeRawCmp(loc, k1, k2, identity))
                     continue;
                 used[j] = true;
                 v2 = (*es2.values)[j];
                 break;
             }
-            if (!v2 || ctfeRawCmp(loc, v1, v2))
+            if (!v2 || ctfeRawCmp(loc, v1, v2, identity))
             {
                 mem.xfree(used);
                 return 1;
@@ -1347,6 +1362,7 @@ extern (C++) int ctfeEqual(const ref Loc loc, TOK op, Expression e1, Expression
 /// Evaluate is, !is.  Resolves slices before comparing. Returns 0 or 1
 extern (C++) int ctfeIdentity(const ref Loc loc, TOK op, Expression e1, Expression e2)
 {
+    //printf("ctfeIdentity %s %s\n", e1.toChars(), e2.toChars());
     //printf("ctfeIdentity op = '%s', e1 = %s %s, e2 = %s %s\n", Token::toChars(op),
     //    Token::toChars(e1.op), e1.toChars(), Token::toChars(e2.op), e1.toChars());
     int cmp;
@@ -1375,7 +1391,9 @@ extern (C++) int ctfeIdentity(const ref Loc loc, TOK op, Expression e1, Expressi
         cmp = RealEquals(creall(v1), creall(v2)) && RealEquals(cimagl(v1), cimagl(v1));
     }
     else
-        cmp = !ctfeRawCmp(loc, e1, e2);
+    {
+        cmp = !ctfeRawCmp(loc, e1, e2, true);
+    }
     if (op == TOK.notIdentity || op == TOK.notEqual)
         cmp ^= 1;
     return cmp;
diff --git a/test/compilable/test19227.d b/test/compilable/test19227.d
new file mode 100644
index 000000000000..5bcf47d35c99
--- /dev/null
+++ b/test/compilable/test19227.d
@@ -0,0 +1,21 @@
+// https://issues.dlang.org/show_bug.cgi?id=19227
+
+struct S
+{
+    float f;
+}
+
+struct T
+{
+    cfloat cf;
+}
+
+void main()
+{
+    static assert(S.init is S.init);
+    static assert(S.init != S.init);
+
+    static assert(T.init is T.init);
+    static assert(T.init != T.init);
+}
+