diff --git a/include/nuttx/math.h b/include/nuttx/math.h
index 6ee91eab7e..d6963a5013 100644
--- a/include/nuttx/math.h
+++ b/include/nuttx/math.h
@@ -93,10 +93,15 @@
 #define NAN         (0.0/0.0)
 #define HUGE_VAL    INFINITY
 
+#define INFINITY_F  (1.0F/0.0F)
+#define NAN_F       (0.0F/0.0F)
+
 #define isnan(x)    ((x) != (x))
 #define isinf(x)    (((x) == INFINITY) || ((x) == -INFINITY))
 #define isfinite(x) (!(isinf(x)) && (x != NAN))
 
+#define isinf_f(x)  (((x) == INFINITY_F) || ((x) == -INFINITY_F))
+
 /* Exponential and Logarithmic constants ************************************/
 
 #define M_E        2.7182818284590452353602874713526625
@@ -116,6 +121,9 @@
 #define M_2_PI     0.6366197723675813430755350534900574
 #define M_2_SQRTPI 1.1283791670955125738961589031215452
 
+#define M_PI_F     ((float)M_PI)
+#define M_PI_2_F   ((float)M_PI_2)
+
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/
diff --git a/libc/libc.h b/libc/libc.h
index 9cb1974fa9..9e947009f2 100644
--- a/libc/libc.h
+++ b/libc/libc.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * libc/libc.h
  *
- *   Copyright (C) 2007-2014 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2014, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -211,6 +211,7 @@ int lib_checkbase(int base, const char **pptr);
 /* Defined in lib_expi.c */
 
 #ifdef CONFIG_LIBM
+float  lib_expif(size_t n);
 double lib_expi(size_t n);
 #endif
 
diff --git a/libc/math/Make.defs b/libc/math/Make.defs
index cf25a1ec76..a2acc7a93a 100644
--- a/libc/math/Make.defs
+++ b/libc/math/Make.defs
@@ -59,6 +59,7 @@ CSRCS += lib_tanhl.c lib_asinhl.c lib_acoshl.c lib_atanhl.c lib_erfl.c lib_copys
 CSRCS += lib_truncl.c
 
 CSRCS += lib_libexpi.c lib_libsqrtapprox.c
+CSRCS += lib_libexpif.c
 
 # Add the floating point math directory to the build
 
diff --git a/libc/math/lib_acosf.c b/libc/math/lib_acosf.c
index 6719e54a67..12fe68da67 100644
--- a/libc/math/lib_acosf.c
+++ b/libc/math/lib_acosf.c
@@ -37,5 +37,5 @@
 
 float acosf(float x)
 {
-  return (M_PI_2 - asinf(x));
+  return (M_PI_2_F - asinf(x));
 }
diff --git a/libc/math/lib_acoshf.c b/libc/math/lib_acoshf.c
index a676d6a40e..4b42e968d7 100644
--- a/libc/math/lib_acoshf.c
+++ b/libc/math/lib_acoshf.c
@@ -48,5 +48,5 @@
 
 float acoshf(float x)
 {
-  return logf(x + sqrtf(x * x - 1));
+  return logf(x + sqrtf(x * x - 1.0F));
 }
diff --git a/libc/math/lib_asinf.c b/libc/math/lib_asinf.c
index e22d32fe79..ac17a53944 100644
--- a/libc/math/lib_asinf.c
+++ b/libc/math/lib_asinf.c
@@ -47,9 +47,9 @@ float asinf(float x)
       y_sin = sinf(y);
       y_cos = cosf(y);
 
-      if (y > M_PI_2 || y < -M_PI_2)
+      if (y > M_PI_2_F || y < -M_PI_2_F)
         {
-          y = fmodf(y, M_PI);
+          y = fmodf(y, M_PI_F);
         }
 
       if (y_sin + FLT_EPSILON >= x && y_sin - FLT_EPSILON <= x)
diff --git a/libc/math/lib_asinhf.c b/libc/math/lib_asinhf.c
index ba749a6569..4c26d038ea 100644
--- a/libc/math/lib_asinhf.c
+++ b/libc/math/lib_asinhf.c
@@ -48,5 +48,5 @@
 
 float asinhf(float x)
 {
-  return logf(x + sqrtf(x * x + 1));
+  return logf(x + sqrtf(x * x + 1.0F));
 }
diff --git a/libc/math/lib_atan2f.c b/libc/math/lib_atan2f.c
index 5d766df99d..c600161408 100644
--- a/libc/math/lib_atan2f.c
+++ b/libc/math/lib_atan2f.c
@@ -43,22 +43,22 @@ float atan2f(float y, float x)
     }
   else if (y >= 0 && x < 0)
     {
-      return atanf(y / x) + M_PI;
+      return atanf(y / x) + M_PI_F;
     }
   else if (y < 0)
     {
       if (x == 0)
         {
-          return -M_PI_2;
+          return -M_PI_2_F;
         }
       else /* Can only be x < 0 */
         {
-          return atanf(y / x) - M_PI;
+          return atanf(y / x) - M_PI_F;
         }
     }
   else if (y > 0 && x == 0)
     {
-      return M_PI_2;
+      return M_PI_2_F;
     }
   else /* if (y == 0 && x == 0) Undefined but returns normally 0 */
     {
diff --git a/libc/math/lib_atanf.c b/libc/math/lib_atanf.c
index c9835c6f24..aef149ed9e 100644
--- a/libc/math/lib_atanf.c
+++ b/libc/math/lib_atanf.c
@@ -39,5 +39,5 @@
 
 float atanf(float x)
 {
-  return asinf(x / sqrtf(x * x + 1));
+  return asinf(x / sqrtf(x * x + 1.0F));
 }
diff --git a/libc/math/lib_atanhf.c b/libc/math/lib_atanhf.c
index 60a6696f73..a54090f517 100644
--- a/libc/math/lib_atanhf.c
+++ b/libc/math/lib_atanhf.c
@@ -48,5 +48,5 @@
 
 float atanhf(float x)
 {
-  return 0.5 * logf((1 + x) / (1 - x));
+  return 0.5F * logf((1.0F + x) / (1.0F - x));
 }
diff --git a/libc/math/lib_ceilf.c b/libc/math/lib_ceilf.c
index 8378141abd..830f2a4769 100644
--- a/libc/math/lib_ceilf.c
+++ b/libc/math/lib_ceilf.c
@@ -38,9 +38,9 @@
 float ceilf(float x)
 {
   modff(x, &x);
-  if (x > 0.0)
+  if (x > 0.0F)
     {
-      x += 1.0;
+      x += 1.0F;
     }
 
   return x;
diff --git a/libc/math/lib_cosf.c b/libc/math/lib_cosf.c
index 55ba93c1c8..5532894b02 100644
--- a/libc/math/lib_cosf.c
+++ b/libc/math/lib_cosf.c
@@ -37,5 +37,5 @@
 
 float cosf(float x)
 {
-  return sinf(x + M_PI_2);
+  return sinf(x + M_PI_2_F);
 }
diff --git a/libc/math/lib_coshf.c b/libc/math/lib_coshf.c
index 7cb575822f..37b4bf8e0f 100644
--- a/libc/math/lib_coshf.c
+++ b/libc/math/lib_coshf.c
@@ -38,5 +38,5 @@
 float coshf(float x)
 {
   x = expf(x);
-  return ((x + (1.0 / x)) / 2.0);
+  return ((x + (1.0F / x)) / 2.0F);
 }
diff --git a/libc/math/lib_erff.c b/libc/math/lib_erff.c
index 75199c828c..364b7fe03c 100644
--- a/libc/math/lib_erff.c
+++ b/libc/math/lib_erff.c
@@ -57,14 +57,14 @@ float erff(float x)
   float t;
   float a1, a2, a3, a4, a5, p;
 
-  a1 =  0.254829592;
-  a2 = -0.284496736;
-  a3 =  1.421413741;
-  a4 = -1.453152027;
-  a5 =  1.061405429;
-  p  =  0.3275911;
+  a1 =  0.254829592F;
+  a2 = -0.284496736F;
+  a3 =  1.421413741F;
+  a4 = -1.453152027F;
+  a5 =  1.061405429F;
+  p  =  0.3275911F;
 
   sign = (x >= 0 ? 1 : -1);
-  t = 1.0/(1.0 + p*x);
-  return sign * (1.0 - (((((a5 * t + a4) * t) + a3) * t + a2) * t + a1) * t * expf(-x * x));
+  t = 1.0F/(1.0F + p*x);
+  return sign * (1.0F - (((((a5 * t + a4) * t) + a3) * t + a2) * t + a1) * t * expf(-x * x));
 }
diff --git a/libc/math/lib_expf.c b/libc/math/lib_expf.c
index 4ce5208607..3e3cb02ed9 100644
--- a/libc/math/lib_expf.c
+++ b/libc/math/lib_expf.c
@@ -89,8 +89,8 @@ float expf(float x)
 
   /* Perform Taylor series approximation with eleven terms */
 
-  value = 0.0;
-  x0 = 1.0;
+  value = 0.0F;
+  x0 = 1.0F;
   for (i = 0; i < 10; i++)
     {
       value += x0 * _flt_inv_fact[i];
@@ -99,11 +99,11 @@ float expf(float x)
 
   /* Multiply by exp of the integer component */
 
-  value *= lib_expi(int_part);
+  value *= lib_expif(int_part);
 
   if (invert)
     {
-      return (1.0 / value);
+      return (1.0F / value);
     }
   else
     {
diff --git a/libc/math/lib_floorf.c b/libc/math/lib_floorf.c
index 4a4ef1a4f7..d2fac02d2d 100644
--- a/libc/math/lib_floorf.c
+++ b/libc/math/lib_floorf.c
@@ -38,9 +38,9 @@
 float floorf(float x)
 {
   modff(x, &x);
-  if (x < 0.0)
+  if (x < 0.0F)
     {
-      x -= 1.0;
+      x -= 1.0F;
     }
 
   return x;
diff --git a/libc/math/lib_frexpf.c b/libc/math/lib_frexpf.c
index 6ec5aa7442..2f0421ccb9 100644
--- a/libc/math/lib_frexpf.c
+++ b/libc/math/lib_frexpf.c
@@ -38,5 +38,5 @@
 float frexpf(float x, int *exponent)
 {
   *exponent = (int)ceilf(log2f(x));
-  return x / ldexpf(1.0, *exponent);
+  return x / ldexpf(1.0F, *exponent);
 }
diff --git a/libc/math/lib_ldexpf.c b/libc/math/lib_ldexpf.c
index 12503438b8..d24d1384e7 100644
--- a/libc/math/lib_ldexpf.c
+++ b/libc/math/lib_ldexpf.c
@@ -37,5 +37,5 @@
 
 float ldexpf(float x, int n)
 {
-  return (x * powf(2.0, (float)n));
+  return (x * powf(2.0F, (float)n));
 }
diff --git a/libc/math/lib_log10f.c b/libc/math/lib_log10f.c
index f0ec9b0589..aa810a0127 100644
--- a/libc/math/lib_log10f.c
+++ b/libc/math/lib_log10f.c
@@ -37,5 +37,5 @@
 
 float log10f(float x)
 {
-  return (logf(x) / M_LN10);
+  return (logf(x) / (float)M_LN10);
 }
diff --git a/libc/math/lib_log2f.c b/libc/math/lib_log2f.c
index a2d351bb12..025b5de3b1 100644
--- a/libc/math/lib_log2f.c
+++ b/libc/math/lib_log2f.c
@@ -37,5 +37,5 @@
 
 float log2f(float x)
 {
-  return (logf(x) / M_LN2);
+  return (logf(x) / (float)M_LN2);
 }
diff --git a/libc/math/lib_logf.c b/libc/math/lib_logf.c
index 80eff85c3c..2d097d228e 100644
--- a/libc/math/lib_logf.c
+++ b/libc/math/lib_logf.c
@@ -40,8 +40,8 @@ float logf(float x)
 {
   float y, y_old, ey, epsilon;
 
-  y = 0.0;
-  y_old = 1.0;
+  y = 0.0F;
+  y_old = 1.0F;
   epsilon = FLT_EPSILON;
 
   while (y > y_old + epsilon || y < y_old - epsilon)
@@ -50,25 +50,25 @@ float logf(float x)
       ey = exp(y);
       y -= (ey - x) / ey;
 
-      if (y > 700.0)
+      if (y > 700.0F)
         {
-          y = 700.0;
+          y = 700.0F;
         }
 
-      if (y < -700.0)
+      if (y < -700.0F)
         {
-          y = -700.0;
+          y = -700.0F;
         }
 
-      epsilon = (fabs(y) > 1.0) ? fabs(y) * FLT_EPSILON : FLT_EPSILON;
+      epsilon = (fabsf(y) > 1.0F) ? fabsf(y) * FLT_EPSILON : FLT_EPSILON;
     }
 
-  if (y == 700.0)
+  if (y == 700.0F)
     {
       return INFINITY;
     }
 
-  if (y == -700.0)
+  if (y == -700.0F)
     {
       return INFINITY;
     }
diff --git a/libc/math/lib_modff.c b/libc/math/lib_modff.c
index ad07a4f70c..5934782b7b 100644
--- a/libc/math/lib_modff.c
+++ b/libc/math/lib_modff.c
@@ -37,14 +37,14 @@
 
 float modff(float x, float *iptr)
 {
-  if (fabsf(x) >= 8388608.0)
+  if (fabsf(x) >= 8388608.0F)
     {
       *iptr = x;
-      return 0.0;
+      return 0.0F;
     }
-  else if (fabs(x) < 1.0)
+  else if (fabsf(x) < 1.0F)
     {
-      *iptr = 0.0;
+      *iptr = 0.0F;
       return x;
     }
   else
diff --git a/libc/math/lib_rintf.c b/libc/math/lib_rintf.c
index ca733e3d79..9a3c06df28 100644
--- a/libc/math/lib_rintf.c
+++ b/libc/math/lib_rintf.c
@@ -105,15 +105,15 @@ float rintf(float x)
   linteger  = (long)x;
   fremainder = x - (float)linteger;
 
-  if (x < 0.0)
+  if (x < 0.0F)
     {
       /* fremainder should be in range 0 .. -1 */
 
-      if (fremainder == -0.5)
+      if (fremainder == -0.5F)
         {
           linteger = ((linteger + 1) & ~1);
         }
-      else if (fremainder < -0.5)
+      else if (fremainder < -0.5F)
         {
           linteger--;
         }
@@ -122,11 +122,11 @@ float rintf(float x)
     {
       /* fremainder should be in range 0 .. 1 */
 
-      if (fremainder == 0.5)
+      if (fremainder == 0.5F)
         {
           linteger = ((linteger + 1) & ~1);
         }
-      else if (fremainder > 0.5)
+      else if (fremainder > 0.5F)
         {
           linteger++;
         }
diff --git a/libc/math/lib_sinf.c b/libc/math/lib_sinf.c
index 5f17eb212b..b7be087b90 100644
--- a/libc/math/lib_sinf.c
+++ b/libc/math/lib_sinf.c
@@ -58,31 +58,31 @@ float sinf(float x)
 
   /* Move x to [-pi, pi) */
 
-  x = fmodf(x, 2 * M_PI);
-  if (x >= M_PI)
+  x = fmodf(x, 2 * M_PI_F);
+  if (x >= M_PI_F)
     {
-      x -= 2 * M_PI;
+      x -= 2 * M_PI_F;
     }
 
-  if (x < -M_PI)
+  if (x < -M_PI_F)
     {
-      x += 2 * M_PI;
+      x += 2 * M_PI_F;
     }
 
   /* Move x to [-pi/2, pi/2) */
 
-  if (x >= M_PI_2)
+  if (x >= M_PI_2_F)
     {
-      x = M_PI - x;
+      x = M_PI_F - x;
     }
 
-  if (x < -M_PI_2)
+  if (x < -M_PI_2_F)
     {
-      x = -M_PI - x;
+      x = -M_PI_F - x;
     }
 
   x_squared = x * x;
-  sin_x = 0.0;
+  sin_x = 0.0F;
 
   /* Perform Taylor series approximation for sin(x) with six terms */
 
diff --git a/libc/math/lib_sinhf.c b/libc/math/lib_sinhf.c
index 6b27f59508..baf353f34d 100644
--- a/libc/math/lib_sinhf.c
+++ b/libc/math/lib_sinhf.c
@@ -38,5 +38,5 @@
 float sinhf(float x)
 {
   x = expf(x);
-  return ((x - (1.0 / x)) / 2.0);
+  return ((x - (1.0F / x)) / 2.0F);
 }
diff --git a/libc/math/lib_sqrtf.c b/libc/math/lib_sqrtf.c
index e1a107eb8b..918c1c9568 100644
--- a/libc/math/lib_sqrtf.c
+++ b/libc/math/lib_sqrtf.c
@@ -47,25 +47,25 @@ float sqrtf(float x)
 
   /* Filter out invalid/trivial inputs */
 
-  if (x < 0.0)
+  if (x < 0.0F)
     {
       set_errno(EDOM);
-      return NAN;
+      return NAN_F;
     }
 
   if (isnan(x))
     {
-      return NAN;
+      return NAN_F;
     }
 
-  if (isinf(x))
+  if (isinf_f(x))
     {
-      return INFINITY;
+      return INFINITY_F;
     }
 
-  if (x == 0.0)
+  if (x == 0.0F)
     {
-      return 0.0;
+      return 0.0F;
     }
 
   /* Guess square root (using bit manipulation) */
@@ -76,9 +76,9 @@ float sqrtf(float x)
    * definitely optimal
    */
 
-  y = 0.5 * (y + x / y);
-  y = 0.5 * (y + x / y);
-  y = 0.5 * (y + x / y);
+  y = 0.5F * (y + x / y);
+  y = 0.5F * (y + x / y);
+  y = 0.5F * (y + x / y);
 
   return y;
 }
diff --git a/libc/math/lib_tanhf.c b/libc/math/lib_tanhf.c
index 70edb57ec4..ef56b133dc 100644
--- a/libc/math/lib_tanhf.c
+++ b/libc/math/lib_tanhf.c
@@ -38,7 +38,7 @@
 float tanhf(float x)
 {
   float x0 = expf(x);
-  float x1 = 1.0 / x0;
+  float x1 = 1.0F / x0;
 
   return ((x0 + x1) / (x0 - x1));
 }