diff --git a/compiler/src/dmd/backend/arm/cod1.d b/compiler/src/dmd/backend/arm/cod1.d
index 1643d460da..70a23197c3 100644
--- a/compiler/src/dmd/backend/arm/cod1.d
+++ b/compiler/src/dmd/backend/arm/cod1.d
@@ -1314,6 +1314,146 @@ void fixresult(ref CodeBuilder cdb, elem* e, regm_t retregs, ref regm_t outretre
     }
 }
 
+/*******************************
+ * Extra information about each CLIB_A runtime library function.
+ */
+
+private
+enum CLIB_A
+{
+    realToDouble,
+    doubleToReal,
+}
+
+private
+struct ClibInfo
+{
+    regm_t retregs;     // registers that 32 bit result is returned in
+}
+
+__gshared int clib_inited = false;          // true if initialized
+
+@trusted private
+Symbol* symboly(string name, regm_t desregs)
+{
+    Symbol* s = symbol_calloc(name);
+    s.Stype = tsclib;
+    s.Sclass = SC.extern_;
+    s.Sfl = FL.func;
+    s.Ssymnum = 0;
+    s.Sregsaved = fregsaved;  // assume C conventions
+    return s;
+}
+
+private
+void initClibInfo(ref Symbol*[CLIB_A.max + 1] clibsyms, ref ClibInfo[CLIB_A.max + 1] clibinfo)
+{
+    foreach (s; clibsyms[])
+    {
+        if (s)
+        {
+            s.Sxtrnnum = 0;
+            s.Stypidx = 0;
+        }
+    }
+}
+
+private
+void getClibFunction(uint clib, ref Symbol* s, ref ClibInfo* cinfo, objfmt_t objfmt, exefmt_t exe)
+{
+    switch (clib)
+    {
+        case CLIB_A.realToDouble:
+        {
+            string name = "__trunctfdf2";
+            s = symboly(name, mask(32));
+            cinfo.retregs = mask(32);
+            break;
+        }
+
+        case CLIB_A.doubleToReal:
+        {
+            string name = "__extenddftf2";
+            s = symboly(name, mask(32));
+            cinfo.retregs = mask(32);
+            break;
+        }
+
+        default:
+            assert(0);
+    }
+}
+
+@trusted private
+void getClibInfo(uint clib, Symbol** ps, ClibInfo** pinfo, objfmt_t objfmt, exefmt_t exe)
+{
+    static Symbol*[CLIB_A.max + 1] clibsyms;
+    static ClibInfo[CLIB_A.max + 1] clibinfo;
+
+    if (!clib_inited)
+    {
+        initClibInfo(clibsyms, clibinfo);
+        clib_inited = true;
+    }
+
+    ClibInfo* cinfo = &clibinfo[clib];
+    Symbol* s = clibsyms[clib];
+    if (!s)
+    {
+        getClibFunction(clib, s, cinfo, objfmt, exe);
+        clibsyms[clib] = s;
+    }
+
+    *ps = s;
+    *pinfo = cinfo;
+}
+
+/********************************
+ * Generate code sequence to call C runtime library support routine.
+ *      clib = CLIB_A.xxxx
+ *      keepmask = mask of registers not to destroy. Currently can
+ *              handle only 1. Should use a temporary rather than
+ *              push/pop for speed.
+ */
+
+@trusted
+void callclib(ref CodeBuilder cdb, elem* e, uint clib, ref regm_t pretregs, regm_t keepmask)
+{
+    //printf("callclib(e = %p, clib = %d, pretregs = %s, keepmask = %s\n", e, clib, regm_str(pretregs), regm_str(keepmask));
+    //elem_print(e);
+
+    Symbol* s;
+    ClibInfo* cinfo;
+    getClibInfo(clib, &s, &cinfo, config.objfmt, config.exe);
+
+    getregs(cdb,(~s.Sregsaved & (cgstate.allregs | INSTR.FLOATREGS | mask(cgstate.BP)) & ~keepmask)); // mask of regs destroyed
+    keepmask &= ~s.Sregsaved;
+    int npushed = popcnt(keepmask);
+    CodeBuilder cdbpop;
+    cdbpop.ctor();
+    gensaverestore(keepmask, cdb, cdbpop);
+
+    makeitextern(s);
+    int nalign = 0;
+    if (STACKALIGN >= 16)
+    {   // Align the stack (assume no args on stack)
+        int npush = npushed * REGSIZE + cgstate.stackpush;
+        if (npush & (STACKALIGN - 1))
+        {   nalign = STACKALIGN - (npush & (STACKALIGN - 1));
+            cod3_stackadj(cdb, nalign);
+        }
+    }
+
+    cdb.gencs1(INSTR.branch_imm(1,0),0,FL.func,s);  // CALL s
+    if (nalign)
+        cod3_stackadj(cdb, -nalign);
+    cgstate.calledafunc = 1;
+
+    cdb.append(cdbpop);
+    fixresult(cdb, e, cinfo.retregs, pretregs);
+}
+
+
 /*******************************
  * Generate code sequence for function call.
  */
diff --git a/compiler/src/dmd/backend/arm/cod3.d b/compiler/src/dmd/backend/arm/cod3.d
index e60f4dfba3..7b2bbf55a8 100644
--- a/compiler/src/dmd/backend/arm/cod3.d
+++ b/compiler/src/dmd/backend/arm/cod3.d
@@ -68,7 +68,7 @@ nothrow:
 @trusted
 void REGSAVE_save(ref REGSAVE regsave, ref CodeBuilder cdb, reg_t reg, out uint idx)
 {
-    // TODO AArch64 floating point registers
+    assert(reg < 32);    // TODO AArch64 floating point registers
     if (!regsave.alignment)
         regsave.alignment = REGSIZE;
     idx = regsave.idx;
@@ -96,7 +96,7 @@ void REGSAVE_save(ref REGSAVE regsave, ref CodeBuilder cdb, reg_t reg, out uint
 @trusted
 void REGSAVE_restore(const ref REGSAVE regsave, ref CodeBuilder cdb, reg_t reg, uint idx)
 {
-    // TODO AArch64 floating point registers
+    assert(reg < 32);   // TODO AArch64 floating point registers
     // LDR reg,[BP, #idx]
     code cs;
     cs.reg = reg;
diff --git a/compiler/src/dmd/backend/x86/cod1.d b/compiler/src/dmd/backend/x86/cod1.d
index 657ab62757..51c20d5c18 100644
--- a/compiler/src/dmd/backend/x86/cod1.d
+++ b/compiler/src/dmd/backend/x86/cod1.d
@@ -37,6 +37,7 @@ import dmd.backend.ty;
 import dmd.backend.type;
 import dmd.backend.x86.xmm;
 import dmd.backend.arm.cod1;
+import dmd.backend.arm.instr : INSTR;
 
 import dmd.backend.cg : segfl, stackfl;
 
@@ -349,7 +350,7 @@ uint gensaverestore(regm_t regm,ref CodeBuilder cdbsave,ref CodeBuilder cdbresto
 
     if (cgstate.AArch64)
     {
-        regm &= cgstate.allregs | mask(cgstate.BP);
+        regm &= cgstate.allregs | mask(cgstate.BP) | INSTR.FLOATREGS;
         if (!regm)
             return 0;
 
@@ -2092,6 +2093,7 @@ void fixresult(ref CodeBuilder cdb, elem* e, regm_t retregs, ref regm_t outretre
  * Extra information about each CLIB runtime library function.
  */
 
+private
 enum
 {
     INF32         = 1,      /// if 32 bit only
@@ -2102,6 +2104,7 @@ enum
     INFpusheabcdx = 0x20,   /// pass EAX/EBX/ECX/EDX on stack, callee does ret 16
 }
 
+private
 struct ClibInfo
 {
     regm_t retregs16;   /* registers that 16 bit result is returned in  */
@@ -2114,6 +2117,7 @@ struct ClibInfo
 
 int clib_inited = false;          // true if initialized
 
+private
 Symbol* symboly(string name, regm_t desregs)
 {
     Symbol* s = symbol_calloc(name);
@@ -2125,6 +2129,7 @@ Symbol* symboly(string name, regm_t desregs)
     return s;
 }
 
+private
 void initClibInfo(ref Symbol*[CLIB.MAX] clibsyms, ref ClibInfo[CLIB.MAX] clibinfo)
 {
     for (size_t i = 0; i < CLIB.MAX; ++i)
@@ -2139,6 +2144,7 @@ void initClibInfo(ref Symbol*[CLIB.MAX] clibsyms, ref ClibInfo[CLIB.MAX] clibinf
     }
 }
 
+private
 void getClibFunction(uint clib, ref Symbol* s, ref ClibInfo* cinfo, objfmt_t objfmt, exefmt_t exe)
 {
     const uint ex_unix = (EX_LINUX   | EX_LINUX64   |
@@ -2805,6 +2811,7 @@ void getClibFunction(uint clib, ref Symbol* s, ref ClibInfo* cinfo, objfmt_t obj
     }
 }
 
+private
 void getClibInfo(uint clib, Symbol** ps, ClibInfo** pinfo, objfmt_t objfmt, exefmt_t exe)
 {
     static Symbol*[CLIB.MAX] clibsyms;