diff --git a/src/dmd/root/ctfloat.d b/src/dmd/root/ctfloat.d
index ee3072122440..d09c83ab5f38 100644
--- a/src/dmd/root/ctfloat.d
+++ b/src/dmd/root/ctfloat.d
@@ -192,26 +192,39 @@ extern (C++) struct CTFloat
     {
         version(CRuntime_Microsoft)
         {
-            return cast(int)ld_sprint(str, fmt, longdouble_soft(x));
+            auto len = cast(int) ld_sprint(str, fmt, longdouble_soft(x));
         }
         else
         {
-            if (real_t(cast(ulong)x) == x)
+            char[4] sfmt = "%Lg\0";
+            sfmt[2] = fmt;
+            auto len = sprintf(str, sfmt.ptr, x);
+        }
+
+        if (fmt != 'a' && fmt != 'A')
+        {
+            assert(fmt == 'g');
+
+            // 1 => 1.0 to distinguish from integers
+            bool needsFPSuffix = true;
+            foreach (char c; str[0 .. len])
             {
-                // ((1.5 -> 1 -> 1.0) == 1.5) is false
-                // ((1.0 -> 1 -> 1.0) == 1.0) is true
-                // see http://en.cppreference.com/w/cpp/io/c/fprintf
-                char[5] sfmt = "%#Lg\0";
-                sfmt[3] = fmt;
-                return sprintf(str, sfmt.ptr, x);
+                // str might be `nan` or `inf`...
+                if (c != '-' && !(c >= '0' && c <= '9'))
+                {
+                    needsFPSuffix = false;
+                    break;
+                }
             }
-            else
+
+            if (needsFPSuffix)
             {
-                char[4] sfmt = "%Lg\0";
-                sfmt[2] = fmt;
-                return sprintf(str, sfmt.ptr, x);
+                str[len .. len+3] = ".0\0";
+                len += 2;
             }
         }
+
+        return len;
     }
 
     // Constant real values 0, 1, -1 and 0.5.
diff --git a/src/dmd/root/longdouble.d b/src/dmd/root/longdouble.d
index 0feb518f71da..8869b9e21260 100644
--- a/src/dmd/root/longdouble.d
+++ b/src/dmd/root/longdouble.d
@@ -746,13 +746,6 @@ size_t ld_sprint(char* str, int fmt, longdouble_soft x) @system
     // fmt is 'a','A','f' or 'g'
     if(fmt != 'a' && fmt != 'A')
     {
-        if (longdouble_soft(ld_readull(&x)) == x)
-        {   // ((1.5 -> 1 -> 1.0) == 1.5) is false
-            // ((1.0 -> 1 -> 1.0) == 1.0) is true
-            // see http://en.cppreference.com/w/cpp/io/c/fprintf
-            char[5] format = ['%', '#', 'L', cast(char)fmt, 0];
-            return sprintf(str, format.ptr, ld_read(&x));
-        }
         char[3] format = ['%', cast(char)fmt, 0];
         return sprintf(str, format.ptr, ld_read(&x));
     }
diff --git a/test/compilable/extra-files/header17125.di b/test/compilable/extra-files/header17125.di
index 3b68d19b56aa..343477d4255e 100644
--- a/test/compilable/extra-files/header17125.di
+++ b/test/compilable/extra-files/header17125.di
@@ -1,6 +1,6 @@
-void func1(real value = 103500L);
-void func2(real value = 520199F);
-void func3(real value = 970000);
-void func4(real value = 102450F);
-void func5(real value = 412502L);
+void func1(real value = 103500.0L);
+void func2(real value = 520199.0F);
+void func3(real value = 970000.0);
+void func4(real value = 102450.0F);
+void func5(real value = 412502.0L);
 int main();
diff --git a/test/compilable/extra-files/header2.di b/test/compilable/extra-files/header2.di
index 9f469b51a55f..11e882c760bf 100644
--- a/test/compilable/extra-files/header2.di
+++ b/test/compilable/extra-files/header2.di
@@ -74,7 +74,7 @@ template templateVariableBar(T) if (is(T == int))
 {
 	enum int templateVariableBar = T.stringof.length;
 }
-auto flit = 3 / 2.00000;
+auto flit = 3 / 2.0;
 void foo11217()(const int[] arr)
 {
 }
diff --git a/test/compilable/extra-files/header2i.di b/test/compilable/extra-files/header2i.di
index a8a1db04a7d9..313495c1bc60 100644
--- a/test/compilable/extra-files/header2i.di
+++ b/test/compilable/extra-files/header2i.di
@@ -87,7 +87,7 @@ template templateVariableBar(T) if (is(T == int))
 {
 	enum int templateVariableBar = T.stringof.length;
 }
-auto flit = 3 / 2.00000;
+auto flit = 3 / 2.0;
 void foo11217()(const int[] arr)
 {
 }
diff --git a/test/compilable/test5227.d b/test/compilable/test5227.d
index cbc2a99eb080..9748db3a9559 100644
--- a/test/compilable/test5227.d
+++ b/test/compilable/test5227.d
@@ -10,17 +10,17 @@ log2()
 log10()
 0.740363L
 round()
-6.00000L
+6.0L
 floor()
-5.00000F
-5.00000
-5.00000L
+5.0F
+5.0
+5.0L
 ceil()
-6.00000F
-6.00000
-6.00000L
+6.0F
+6.0
+6.0L
 trunc()
-5.00000L
+5.0L
 exp()
 244.692L
 expm1()
diff --git a/test/dub_package/frontend_file.d b/test/dub_package/frontend_file.d
index 41f3c6a106fe..952971602776 100755
--- a/test/dub_package/frontend_file.d
+++ b/test/dub_package/frontend_file.d
@@ -45,21 +45,12 @@ void main()
     t.module_.fullSemantic;
     auto generated = t.module_.prettyPrint.toUnixLineEndings();
 
-    // For some reason the floating point number in the pretty printed code  is
-    // different on Windows and on Posix. It might be due to different C
-    // standard libraries that are most likely used to convert the floating
-    // point number to a string.
-    version (Windows)
-        enum accumulator = "0.000000";
-    else
-        enum accumulator = "0.00000";
-
     enum expected =q{module foo;
 import object;
 double average(int[] array)
 {
     immutable immutable(uint) initialLength = array.length;
-    double accumulator = %s;
+    double accumulator = 0.0;
     for (; array.length;)
     {
         {
@@ -69,7 +60,7 @@ double average(int[] array)
     }
     return accumulator / cast(double)initialLength;
 }
-}.format(accumulator);
+};
 
     assert(generated.canFind(expected));
 }
diff --git a/test/fail_compilation/chkformat.d b/test/fail_compilation/chkformat.d
index a9fb395e54ef..7451b3f506bf 100644
--- a/test/fail_compilation/chkformat.d
+++ b/test/fail_compilation/chkformat.d
@@ -7,10 +7,10 @@ fail_compilation/chkformat.d(101): Deprecation: precision argument `1L` for form
 fail_compilation/chkformat.d(101): Deprecation: argument `2L` for format specification `"%*.*d"` must be `int`, not `long`
 fail_compilation/chkformat.d(104): Deprecation: argument `4` for format specification `"%lld"` must be `long`, not `int`
 fail_compilation/chkformat.d(105): Deprecation: argument `5` for format specification `"%jd"` must be `core.stdc.stdint.intmax_t`, not `int`
-fail_compilation/chkformat.d(106): Deprecation: argument `6.00000` for format specification `"%zd"` must be `size_t`, not `double`
-fail_compilation/chkformat.d(107): Deprecation: argument `7.00000` for format specification `"%td"` must be `ptrdiff_t`, not `double`
-fail_compilation/chkformat.d(108): Deprecation: argument `8.00000L` for format specification `"%g"` must be `double`, not `real`
-fail_compilation/chkformat.d(109): Deprecation: argument `9.00000` for format specification `"%Lg"` must be `real`, not `double`
+fail_compilation/chkformat.d(106): Deprecation: argument `6.0` for format specification `"%zd"` must be `size_t`, not `double`
+fail_compilation/chkformat.d(107): Deprecation: argument `7.0` for format specification `"%td"` must be `ptrdiff_t`, not `double`
+fail_compilation/chkformat.d(108): Deprecation: argument `8.0L` for format specification `"%g"` must be `double`, not `real`
+fail_compilation/chkformat.d(109): Deprecation: argument `9.0` for format specification `"%Lg"` must be `real`, not `double`
 fail_compilation/chkformat.d(110): Deprecation: argument `10` for format specification `"%p"` must be `void*`, not `int`
 fail_compilation/chkformat.d(111): Deprecation: argument `& u` for format specification `"%n"` must be `int*`, not `uint*`
 fail_compilation/chkformat.d(113): Deprecation: argument `& u` for format specification `"%lln"` must be `long*`, not `int*`
@@ -25,12 +25,12 @@ fail_compilation/chkformat.d(202): Deprecation: more format specifiers than 1 ar
 fail_compilation/chkformat.d(203): Deprecation: argument `0L` for format specification `"%d"` must be `int*`, not `long`
 fail_compilation/chkformat.d(204): Deprecation: argument `0L` for format specification `"%3u"` must be `uint*`, not `long`
 fail_compilation/chkformat.d(205): Deprecation: argument `u` for format specification `"%200u"` must be `uint*`, not `uint`
-fail_compilation/chkformat.d(206): Deprecation: argument `3.00000` for format specification `"%hhd"` must be `byte*`, not `double`
+fail_compilation/chkformat.d(206): Deprecation: argument `3.0` for format specification `"%hhd"` must be `byte*`, not `double`
 fail_compilation/chkformat.d(207): Deprecation: argument `4` for format specification `"%hd"` must be `short*`, not `int`
 fail_compilation/chkformat.d(209): Deprecation: argument `4` for format specification `"%lld"` must be `long*`, not `int`
 fail_compilation/chkformat.d(210): Deprecation: argument `5` for format specification `"%jd"` must be `core.stdc.stdint.intmax_t*`, not `int`
-fail_compilation/chkformat.d(211): Deprecation: argument `6.00000` for format specification `"%zd"` must be `size_t*`, not `double`
-fail_compilation/chkformat.d(212): Deprecation: argument `7.00000` for format specification `"%td"` must be `ptrdiff_t*`, not `double`
+fail_compilation/chkformat.d(211): Deprecation: argument `6.0` for format specification `"%zd"` must be `size_t*`, not `double`
+fail_compilation/chkformat.d(212): Deprecation: argument `7.0` for format specification `"%td"` must be `ptrdiff_t*`, not `double`
 fail_compilation/chkformat.d(213): Deprecation: format specifier `"%Ld"` is invalid
 fail_compilation/chkformat.d(214): Deprecation: argument `0` for format specification `"%u"` must be `uint*`, not `int`
 fail_compilation/chkformat.d(215): Deprecation: argument `0` for format specification `"%hhu"` must be `ubyte*`, not `int`
@@ -39,9 +39,9 @@ fail_compilation/chkformat.d(218): Deprecation: argument `0` for format specific
 fail_compilation/chkformat.d(219): Deprecation: argument `0` for format specification `"%ju"` must be `ulong*`, not `int`
 fail_compilation/chkformat.d(220): Deprecation: argument `0` for format specification `"%zu"` must be `size_t*`, not `int`
 fail_compilation/chkformat.d(221): Deprecation: argument `0` for format specification `"%tu"` must be `ptrdiff_t*`, not `int`
-fail_compilation/chkformat.d(222): Deprecation: argument `8.00000L` for format specification `"%g"` must be `float*`, not `real`
-fail_compilation/chkformat.d(223): Deprecation: argument `8.00000L` for format specification `"%lg"` must be `double*`, not `real`
-fail_compilation/chkformat.d(224): Deprecation: argument `9.00000` for format specification `"%Lg"` must be `real*`, not `double`
+fail_compilation/chkformat.d(222): Deprecation: argument `8.0L` for format specification `"%g"` must be `float*`, not `real`
+fail_compilation/chkformat.d(223): Deprecation: argument `8.0L` for format specification `"%lg"` must be `double*`, not `real`
+fail_compilation/chkformat.d(224): Deprecation: argument `9.0` for format specification `"%Lg"` must be `real*`, not `double`
 fail_compilation/chkformat.d(225): Deprecation: argument `& u` for format specification `"%s"` must be `char*`, not `int*`
 fail_compilation/chkformat.d(226): Deprecation: argument `& u` for format specification `"%ls"` must be `wchar_t*`, not `int*`
 fail_compilation/chkformat.d(227): Deprecation: argument `v` for format specification `"%p"` must be `void**`, not `void*`
diff --git a/test/fail_compilation/diag16499.d b/test/fail_compilation/diag16499.d
index 28b50fa29404..63b4b3c52795 100644
--- a/test/fail_compilation/diag16499.d
+++ b/test/fail_compilation/diag16499.d
@@ -2,7 +2,7 @@
 TEST_OUTPUT:
 ---
 fail_compilation/diag16499.d(22): Error: incompatible types for `(2) in (foo)`: `int` and `A`
-fail_compilation/diag16499.d(24): Error: incompatible types for `(1.00000) in (bar)`: `double` and `B`
+fail_compilation/diag16499.d(24): Error: incompatible types for `(1.0) in (bar)`: `double` and `B`
 ---
 */
 
diff --git a/test/fail_compilation/diag8101b.d b/test/fail_compilation/diag8101b.d
index f8e5cefd9b00..05a333264174 100644
--- a/test/fail_compilation/diag8101b.d
+++ b/test/fail_compilation/diag8101b.d
@@ -5,7 +5,7 @@ fail_compilation/diag8101b.d(28): Error: none of the overloads of `foo` are call
 fail_compilation/diag8101b.d(19):        `diag8101b.S.foo(int _param_0)`
 fail_compilation/diag8101b.d(20):        `diag8101b.S.foo(int _param_0, int _param_1)`
 fail_compilation/diag8101b.d(30): Error: function `diag8101b.S.bar(int _param_0)` is not callable using argument types `(double)`
-fail_compilation/diag8101b.d(30):        cannot pass argument `1.00000` of type `double` to parameter `int _param_0`
+fail_compilation/diag8101b.d(30):        cannot pass argument `1.0` of type `double` to parameter `int _param_0`
 fail_compilation/diag8101b.d(33): Error: none of the overloads of `foo` are callable using a `const` object, candidates are:
 fail_compilation/diag8101b.d(19):        `diag8101b.S.foo(int _param_0)`
 fail_compilation/diag8101b.d(20):        `diag8101b.S.foo(int _param_0, int _param_1)`
diff --git a/test/fail_compilation/diag9357.d b/test/fail_compilation/diag9357.d
index f26b1c4482e0..097c8dee2500 100644
--- a/test/fail_compilation/diag9357.d
+++ b/test/fail_compilation/diag9357.d
@@ -1,10 +1,10 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/diag9357.d(14): Error: cannot implicitly convert expression `1.00000` of type `double` to `int`
-fail_compilation/diag9357.d(15): Error: cannot implicitly convert expression `10.0000` of type `double` to `int`
-fail_compilation/diag9357.d(16): Error: cannot implicitly convert expression `11.0000` of type `double` to `int`
-fail_compilation/diag9357.d(17): Error: cannot implicitly convert expression `99.0000` of type `double` to `int`
+fail_compilation/diag9357.d(14): Error: cannot implicitly convert expression `1.0` of type `double` to `int`
+fail_compilation/diag9357.d(15): Error: cannot implicitly convert expression `10.0` of type `double` to `int`
+fail_compilation/diag9357.d(16): Error: cannot implicitly convert expression `11.0` of type `double` to `int`
+fail_compilation/diag9357.d(17): Error: cannot implicitly convert expression `99.0` of type `double` to `int`
 fail_compilation/diag9357.d(18): Error: cannot implicitly convert expression `1.04858e+06L` of type `real` to `int`
 fail_compilation/diag9357.d(19): Error: cannot implicitly convert expression `1.04858e+06L` of type `real` to `int`
 ---
diff --git a/test/fail_compilation/fail14304.d b/test/fail_compilation/fail14304.d
index 488802490a86..7c0015db246c 100644
--- a/test/fail_compilation/fail14304.d
+++ b/test/fail_compilation/fail14304.d
@@ -7,7 +7,7 @@ fail_compilation/fail14304.d(35): Error: cannot modify read-only constant `[1:1,
 fail_compilation/fail14304.d(61):        called from here: `modify14304(aae14304)`
 fail_compilation/fail14304.d(41): Error: cannot modify read-only constant `[1, 2, 3]`
 fail_compilation/fail14304.d(64):        called from here: `modify14304(cast(const(int)[])index14304)`
-fail_compilation/fail14304.d(47): Error: cannot modify read-only constant `[1.414, 1.732, 2.00000]`
+fail_compilation/fail14304.d(47): Error: cannot modify read-only constant `[1.414, 1.732, 2.0]`
 fail_compilation/fail14304.d(67):        called from here: `modify14304(cast(const(double)[])slice14304)`
 fail_compilation/fail14304.d(53): Error: cannot modify read-only string literal `"abc"`
 fail_compilation/fail14304.d(70):        called from here: `modify14304(cast(const(char)[])str14304)`
diff --git a/test/fail_compilation/fail340.d b/test/fail_compilation/fail340.d
index 83be09c57e48..3d83e6896ed8 100644
--- a/test/fail_compilation/fail340.d
+++ b/test/fail_compilation/fail340.d
@@ -2,7 +2,7 @@
 TEST_OUTPUT:
 ---
 fail_compilation/fail340.d(18): Error: variable `fail340.w` of type struct `const(CopyTest)` uses `this(this)`, which is not allowed in static initialization
-fail_compilation/fail340.d(19):        while evaluating: `static assert(w.x == 55.0000)`
+fail_compilation/fail340.d(19):        while evaluating: `static assert(w.x == 55.0)`
 ---
 */
 
diff --git a/test/fail_compilation/fail5435.d b/test/fail_compilation/fail5435.d
index 731e30b69857..5d1b6591268b 100644
--- a/test/fail_compilation/fail5435.d
+++ b/test/fail_compilation/fail5435.d
@@ -7,7 +7,7 @@ cast(Enum5435)1
 cast(Enum5435)2
 fail_compilation/fail5435.d(38): Error: cannot implicitly convert expression `"foo"` of type `string` to `Enum5435`
 fail_compilation/fail5435.d(38):        while evaluating `pragma(msg, foo)`
-fail_compilation/fail5435.d(38): Error: cannot implicitly convert expression `3.00000` of type `double` to `Enum5435`
+fail_compilation/fail5435.d(38): Error: cannot implicitly convert expression `3.0` of type `double` to `Enum5435`
 fail_compilation/fail5435.d(38):        while evaluating `pragma(msg, foo)`
 fail_compilation/fail5435.d(39): Error: cannot implicitly convert expression `cast(Enum5435)0` of type `Enum5435` to `string`
 fail_compilation/fail5435.d(39):        while evaluating `pragma(msg, foo)`
@@ -16,14 +16,14 @@ fail_compilation/fail5435.d(39):        while evaluating `pragma(msg, foo)`
 fail_compilation/fail5435.d(39): Error: cannot implicitly convert expression `cast(Enum5435)2` of type `Enum5435` to `string`
 fail_compilation/fail5435.d(39):        while evaluating `pragma(msg, foo)`
 foo
-fail_compilation/fail5435.d(39): Error: cannot implicitly convert expression `3.00000` of type `double` to `string`
+fail_compilation/fail5435.d(39): Error: cannot implicitly convert expression `3.0` of type `double` to `string`
 fail_compilation/fail5435.d(39):        while evaluating `pragma(msg, foo)`
 0
 1
 2
 fail_compilation/fail5435.d(40): Error: cannot implicitly convert expression `"foo"` of type `string` to `int`
 fail_compilation/fail5435.d(40):        while evaluating `pragma(msg, foo)`
-fail_compilation/fail5435.d(40): Error: cannot implicitly convert expression `3.00000` of type `double` to `int`
+fail_compilation/fail5435.d(40): Error: cannot implicitly convert expression `3.0` of type `double` to `int`
 fail_compilation/fail5435.d(40):        while evaluating `pragma(msg, foo)`
 ---
 */
diff --git a/test/fail_compilation/ice20042.d b/test/fail_compilation/ice20042.d
index 7ba9309c0772..7fc3313cdfd8 100644
--- a/test/fail_compilation/ice20042.d
+++ b/test/fail_compilation/ice20042.d
@@ -2,8 +2,8 @@
 DISABLED: freebsd32 linux32 osx32 win32
 TEST_OUTPUT:
 ---
-fail_compilation/ice20042.d(18): Error: slice operation `cast(__vector(float[4]))nanF = [1.00000F, 2.00000F, 3.00000F, 4.00000F][0..4]` cannot be evaluated at compile time
-fail_compilation/ice20042.d(25):        called from here: `Vec4(cast(__vector(float[4]))[nanF, nanF, nanF, nanF]).this([1.00000F, 2.00000F, 3.00000F, 4.00000F])`
+fail_compilation/ice20042.d(18): Error: slice operation `cast(__vector(float[4]))nanF = [1.0F, 2.0F, 3.0F, 4.0F][0..4]` cannot be evaluated at compile time
+fail_compilation/ice20042.d(25):        called from here: `Vec4(cast(__vector(float[4]))[nanF, nanF, nanF, nanF]).this([1.0F, 2.0F, 3.0F, 4.0F])`
 ---
 */
 void write(T...)(T t){}