diff --git a/cfg/std.cfg b/cfg/std.cfg
index 9f30fccf9..f6387689e 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -1138,49 +1138,133 @@
     </arg>
   </function>
   <!-- double erf(double x); -->
-  <!-- float erff(float f); -->
-  <!-- long double erfl(long double x); -->
-  <function name="erf,std::erf,erff,std::erff,erfl,std::erfl">
+  <function name="erf,std::erf">
     <use-retval/>
     <pure/>
     <noreturn>false</noreturn>
+    <returnValue type="double"/>
+    <leak-ignore/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- float erff(float f); -->
+  <function name="erff,std::erff">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="float"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- long double erfl(long double x); -->
+  <function name="erfl,std::erfl">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <returnValue type="long double"/>
     <leak-ignore/>
     <arg nr="1">
       <not-uninit/>
     </arg>
   </function>
   <!-- double erfc(double x); -->
-  <!-- float erfcf(float x); -->
-  <!-- long double erfcl(long double x); -->
-  <function name="erfc,std::erfc,erfcf,std::erfcf,erfcl,std::erfcl">
+  <function name="erfc,std::erfc">
     <use-retval/>
     <pure/>
     <noreturn>false</noreturn>
     <leak-ignore/>
+    <returnValue type="double"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- float erfcf(float x); -->
+  <function name="erfcf,std::erfcf">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="float"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- long double erfcl(long double x); -->
+  <function name="erfcl,std::erfcl">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="long double"/>
     <arg nr="1">
       <not-uninit/>
     </arg>
   </function>
   <!-- double carg(double complex z);-->
-  <!-- float cargf(float complex z);-->
-  <!-- long double cargl(long double complex z);-->
-  <function name="carg,cargf,cargl">
+  <function name="carg">
     <use-retval/>
     <pure/>
     <noreturn>false</noreturn>
     <leak-ignore/>
+    <returnValue type="double"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- float cargf(float complex z);-->
+  <function name="cargf">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="float"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- long double cargl(long double complex z);-->
+  <function name="cargl">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="long double"/>
     <arg nr="1">
       <not-uninit/>
     </arg>
   </function>
   <!-- double exp(double x); -->
-  <!-- float expf(float x); -->
-  <!-- long double expl(long double x); -->
-  <function name="exp,std::exp,expf,expl">
+  <function name="exp,std::exp">
     <use-retval/>
     <pure/>
     <noreturn>false</noreturn>
     <leak-ignore/>
+    <returnValue type="double"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- float expf(float x); -->
+  <function name="expf,std::expf">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="float"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- long double expl(long double x); -->
+  <function name="expl,std::expl">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="long double"/>
     <arg nr="1">
       <not-uninit/>
     </arg>
@@ -1210,25 +1294,67 @@
     </arg>
   </function>
   <!-- double exp2(double x); -->
-  <!-- float exp2f(float x); -->
-  <!-- long double exp2l(long double x);-->
-  <function name="exp2,std::exp2,exp2f,std::exp2f,exp2l,std::exp2l">
+  <function name="exp2,std::exp2">
     <use-retval/>
     <pure/>
     <noreturn>false</noreturn>
     <leak-ignore/>
+    <returnValue type="double"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- float exp2f(float x); -->
+  <function name="exp2f,std::exp2f">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="float"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- long double exp2l(long double x);-->
+  <function name="exp2l,std::exp2l">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="long double"/>
     <arg nr="1">
       <not-uninit/>
     </arg>
   </function>
   <!-- double expm1(double x); -->
-  <!-- float expm1f(float x); -->
-  <!-- long double expm1l(long double x); -->
-  <function name="expm1,std::expm1,expm1f,std::expm1f,expm1l,std::expm1l">
+  <function name="expm1,std::expm1">
     <use-retval/>
     <pure/>
     <noreturn>false</noreturn>
     <leak-ignore/>
+    <returnValue type="double"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- float expm1f(float x); -->
+  <function name="expm1f,std::expm1f">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="float"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- long double expm1l(long double x); -->
+  <function name="expm1l,std::expm1l">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="long double"/>
     <arg nr="1">
       <not-uninit/>
     </arg>
@@ -1241,25 +1367,73 @@
     </arg>
   </function>
   <!-- double fabs(double x); -->
-  <!-- float fabsf(float x); -->
-  <!-- long double fabsl(long double x); -->
-  <function name="fabs,std::fabs,fabsf,fabsl">
+  <function name="fabs,std::fabs">
     <use-retval/>
     <pure/>
     <noreturn>false</noreturn>
     <leak-ignore/>
+    <returnValue type="double"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- float fabsf(float x); -->
+  <function name="fabsf,std::fabsf">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="float"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- long double fabsl(long double x); -->
+  <function name="fabsl,std::fabsl">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="long double"/>
     <arg nr="1">
       <not-uninit/>
     </arg>
   </function>
   <!-- double fdim(double x, double y); -->
-  <!-- float fdimf(float x, float y); -->
-  <!-- long double fdiml(long double x, long double y); -->
-  <function name="fdim,std::fdim,fdimf,std::fdimf,fdiml,std::fdiml">
+  <function name="fdim,std::fdim">
     <use-retval/>
     <pure/>
     <noreturn>false</noreturn>
     <leak-ignore/>
+    <returnValue type="double"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+    <arg nr="2">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- float fdimf(float x, float y); -->
+  <function name="fdimf,std::fdimf">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="float"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+    <arg nr="2">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- long double fdiml(long double x, long double y); -->
+  <function name="fdiml,std::fdiml">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="long double"/>
     <arg nr="1">
       <not-uninit/>
     </arg>
@@ -1308,12 +1482,22 @@
     </arg>
   </function>
   <!-- int fgetc(FILE *stream); -->
-  <!-- wint_t fgetwc(FILE * stream); -->
   <!-- int getc(FILE *stream); -->
-  <!-- wint_t getwc(FILE* stream); -->
-  <function name="fgetc,std::fgetc,fgetwc,std::fgetwc,getc,std::getc,getwc,std::getwc">
+  <function name="fgetc,std::fgetc,getc,std::getc">
     <noreturn>false</noreturn>
     <leak-ignore/>
+    <returnValue type="int"/>
+    <arg nr="1">
+      <not-null/>
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- wint_t fgetwc(FILE * stream); -->
+  <!-- wint_t getwc(FILE* stream); -->
+  <function name="fgetwc,std::fgetwc,getc,getwc,std::getwc">
+    <noreturn>false</noreturn>
+    <returnValue type="wint_t"/>
+    <leak-ignore/>
     <arg nr="1">
       <not-null/>
       <not-uninit/>
@@ -1333,13 +1517,34 @@
     </arg>
   </function>
   <!-- double floor(double x); -->
-  <!-- float floorf(float x); -->
-  <!-- long double floorl(long double x); -->
-  <function name="floor,std::floor,floorf,floorl">
+  <function name="floor,std::floor">
     <use-retval/>
     <pure/>
     <noreturn>false</noreturn>
     <leak-ignore/>
+    <returnValue type="double"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- float floorf(float x); -->
+  <function name="floorf,std::floorf">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="float"/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- long double floorl(long double x); -->
+  <function name="floorl,std::floorl">
+    <use-retval/>
+    <pure/>
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="long double"/>
     <arg nr="1">
       <not-uninit/>
     </arg>