diff --git a/hphp/runtime/base/string_data.cpp b/hphp/runtime/base/string_data.cpp
index 59ebe8eb5..10f876ff4 100644
--- a/hphp/runtime/base/string_data.cpp
+++ b/hphp/runtime/base/string_data.cpp
@@ -824,7 +824,7 @@ int64_t StringData::toInt64(int base /* = 10 */) const {
 
 double StringData::toDouble() const {
   StringSlice s = slice();
-  if (s.len) return zend_strtod(s.ptr, nullptr);
+  if (s.len) return folly::to<double>(s.ptr);
   return 0;
 }
 
diff --git a/hphp/runtime/base/variable_unserializer.cpp b/hphp/runtime/base/variable_unserializer.cpp
index 3cbd1300c..02aed7eab 100644
--- a/hphp/runtime/base/variable_unserializer.cpp
+++ b/hphp/runtime/base/variable_unserializer.cpp
@@ -46,7 +46,7 @@ int64_t VariableUnserializer::readInt() {
 double VariableUnserializer::readDouble() {
   check();
   char *newBuf;
-  double r = zend_strtod(m_buf, &newBuf);
+  double r = strtod(m_buf, &newBuf);
   m_buf = newBuf;
   return r;
 }
diff --git a/hphp/runtime/base/zend/zend_collator.cpp b/hphp/runtime/base/zend/zend_collator.cpp
index 6abaccf66..f143964d0 100644
--- a/hphp/runtime/base/zend/zend_collator.cpp
+++ b/hphp/runtime/base/zend/zend_collator.cpp
@@ -98,7 +98,7 @@ static double collator_u_strtod(const UChar *nptr, UChar **endptr) {
     }
 
     *bufpos = '\0';
-    value = zend_strtod(numbuf, nullptr);
+    value = folly::to<double>(numbuf);
 
     if (numbuf != buf) {
       free(numbuf);
diff --git a/hphp/runtime/base/zend/zend_functions.cpp b/hphp/runtime/base/zend/zend_functions.cpp
index 711da4706..e374b5269 100644
--- a/hphp/runtime/base/zend/zend_functions.cpp
+++ b/hphp/runtime/base/zend/zend_functions.cpp
@@ -17,6 +17,7 @@
 
 #include "hphp/runtime/base/zend/zend_functions.h"
 #include "hphp/runtime/base/zend/zend_strtod.h"
+#include "folly/Conv.h"
 
 namespace HPHP {
 
@@ -149,7 +150,7 @@ DataType is_numeric_string(const char *str, int length, int64_t *lval,
     } else if (!(digits < SIZEOF_LONG * 2 ||
                  (digits == SIZEOF_LONG * 2 && ptr[-digits] <= '7'))) {
       if (dval) {
-        local_dval = zend_strtod(str, (char **)&ptr);
+        local_dval = strtod(str, (char **)&ptr);
       }
       type = KindOfDouble;
     }
@@ -183,7 +184,7 @@ DataType is_numeric_string(const char *str, int length, int64_t *lval,
       int cmp = strcmp(&ptr[-digits], long_min_digits);
       if (!(cmp < 0 || (cmp == 0 && *str == '-'))) {
         if (dval) {
-          *dval = strtod(str, nullptr);
+          *dval = folly::to<double>(str);
         }
         return KindOfDouble;
       }
diff --git a/hphp/runtime/base/zend/zend_math.h b/hphp/runtime/base/zend/zend_math.h
index 0150eb042..8db7238b0 100644
--- a/hphp/runtime/base/zend/zend_math.h
+++ b/hphp/runtime/base/zend/zend_math.h
@@ -19,6 +19,7 @@
 #define incl_HPHP_ZEND_MATH_H_
 
 #include "hphp/util/base.h"
+#include "folly/Conv.h"
 
 namespace HPHP {
 ///////////////////////////////////////////////////////////////////////////////
@@ -115,7 +116,7 @@ inline double php_math_round(double value, int places,
     char buf[40];
     snprintf(buf, 39, "%15fe%d", tmp_value, -places);
     buf[39] = '\0';
-    tmp_value = strtod(buf, nullptr);
+    tmp_value = folly::to<double>(buf);
 
     /* couldn't convert to string and back */
     if (std::isinf(tmp_value)) {
diff --git a/hphp/runtime/base/zend/zend_scanf.cpp b/hphp/runtime/base/zend/zend_scanf.cpp
index 74a3a8814..b244c828d 100644
--- a/hphp/runtime/base/zend/zend_scanf.cpp
+++ b/hphp/runtime/base/zend/zend_scanf.cpp
@@ -1045,7 +1045,7 @@ int string_sscanf(const char *string, const char *format, int numVars,
       if (!(flags & SCAN_SUPPRESS)) {
         double dvalue;
         *end = '\0';
-        dvalue = strtod(buf, nullptr);
+        dvalue = folly::to<double>(buf);
         return_value.append(dvalue);
       }
       break;
diff --git a/hphp/runtime/base/zend/zend_strtod.cpp b/hphp/runtime/base/zend/zend_strtod.cpp
index 922bb1d99..94748078a 100644
--- a/hphp/runtime/base/zend/zend_strtod.cpp
+++ b/hphp/runtime/base/zend/zend_strtod.cpp
@@ -257,7 +257,6 @@ extern void *MALLOC(size_t);
 #define Emin (-1022)
 #define Exp_1  0x3ff00000
 #define Exp_11 0x3ff00000
-#define Ebits 11
 #define Frac_mask  0xfffff
 #define Frac_mask1 0xfffff
 #define Ten_pmax 22
@@ -285,7 +284,6 @@ extern void *MALLOC(size_t);
 #define Bias 65
 #define Exp_1  0x41000000
 #define Exp_11 0x41000000
-#define Ebits 8 /* exponent has 7 bits, but 8 is the right value in b2d */
 #define Frac_mask  0xffffff
 #define Frac_mask1 0xffffff
 #define Bletch 4
@@ -309,7 +307,6 @@ extern void *MALLOC(size_t);
 #define Bias 129
 #define Exp_1  0x40800000
 #define Exp_11 0x4080
-#define Ebits 8
 #define Frac_mask  0x7fffff
 #define Frac_mask1 0xffff007f
 #define Ten_pmax 24
@@ -663,39 +660,6 @@ static Bigint * mult(Bigint *a, Bigint *b)
   return c;
 }
 
-static Bigint * s2b (CONST char *s, int nd0, int nd, ULong y9)
-{
-  Bigint *b;
-  int i, k;
-  Long x, y;
-
-  x = (nd + 8) / 9;
-  for(k = 0, y = 1; x > y; y <<= 1, k++) ;
-#ifdef Pack_32
-  b = Balloc(k);
-  b->x[0] = y9;
-  b->wds = 1;
-#else
-  b = Balloc(k+1);
-  b->x[0] = y9 & 0xffff;
-  b->wds = (b->x[1] = y9 >> 16) ? 2 : 1;
-#endif
-
-  i = 9;
-  if (9 < nd0) {
-    s += 9;
-    do b = multadd(b, 10, *s++ - '0');
-    while(++i < nd0);
-    s++;
-  } else {
-    s += 10;
-  }
-  for(; i < nd; i++) {
-    b = multadd(b, 10, *s++ - '0');
-  }
-  return b;
-}
-
 static Bigint * pow5mult(Bigint *b, int k)
 {
   Bigint *b1, *p5, *p51;
@@ -892,108 +856,6 @@ static Bigint * diff(Bigint *a, Bigint *b)
   return c;
 }
 
-static double ulp (double _x)
-{
-  _double x;
-  register Long L;
-  _double a;
-
-  value(x) = _x;
-  L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1;
-#ifndef Sudden_Underflow
-  if (L > 0) {
-#endif
-#ifdef IBM
-    L |= Exp_msk1 >> 4;
-#endif
-    word0(a) = L;
-    word1(a) = 0;
-#ifndef Sudden_Underflow
-  }
-  else {
-    L = -L >> Exp_shift;
-    if (L < Exp_shift) {
-      word0(a) = 0x80000 >> L;
-      word1(a) = 0;
-    }
-    else {
-      word0(a) = 0;
-      L -= Exp_shift;
-      word1(a) = L >= 31 ? 1 : 1 << (31 - L);
-    }
-  }
-#endif
-  return value(a);
-}
-
-static double
-b2d
-#ifdef KR_headers
-(a, e) Bigint *a; int *e;
-#else
-(Bigint *a, int *e)
-#endif
-{
-  ULong *xa, *xa0, w, y, z;
-  int k;
-  _double d;
-#ifdef VAX
-  ULong d0, d1;
-#else
-#define d0 word0(d)
-#define d1 word1(d)
-#endif
-
-  xa0 = a->x;
-  xa = xa0 + a->wds;
-  y = *--xa;
-  k = hi0bits(y);
-  *e = 32 - k;
-#ifdef Pack_32
-  if (k < Ebits) {
-    d0 = Exp_1 | y >> (Ebits - k);
-    w = xa > xa0 ? *--xa : 0;
-    d1 = y << ((32-Ebits) + k) | w >> (Ebits - k);
-    goto ret_d;
-  }
-  z = xa > xa0 ? *--xa : 0;
-  if (k -= Ebits) {
-    d0 = Exp_1 | y << k | z >> (32 - k);
-    y = xa > xa0 ? *--xa : 0;
-    d1 = z << k | y >> (32 - k);
-  }
-  else {
-    d0 = Exp_1 | y;
-    d1 = z;
-  }
-#else
-  if (k < Ebits + 16) {
-    z = xa > xa0 ? *--xa : 0;
-    d0 = Exp_1 | y << k - Ebits | z >> Ebits + 16 - k;
-    w = xa > xa0 ? *--xa : 0;
-    y = xa > xa0 ? *--xa : 0;
-    d1 = z << k + 16 - Ebits | w << k - Ebits | y >> 16 + Ebits - k;
-    goto ret_d;
-  }
-  z = xa > xa0 ? *--xa : 0;
-  w = xa > xa0 ? *--xa : 0;
-  k -= Ebits + 16;
-  d0 = Exp_1 | y << k + 16 | z << k | w >> 16 - k;
-  y = xa > xa0 ? *--xa : 0;
-  d1 = w << k + 16 | y << k;
-#endif
-ret_d:
-#ifdef VAX
-  word0(d) = d0 >> 16 | d0 << 16;
-  word1(d) = d1 >> 16 | d1 << 16;
-#else
-#undef d0
-#undef d1
-#endif
-  return value(d);
-}
-
-
 static Bigint * d2b(double _d, int *e, int *bits)
 {
   Bigint *b;
@@ -1110,41 +972,6 @@ static Bigint * d2b(double _d, int *e, int *bits)
 #undef d1
 
 
-static double ratio (Bigint *a, Bigint *b)
-{
-  _double da, db;
-  int k, ka, kb;
-
-  value(da) = b2d(a, &ka);
-  value(db) = b2d(b, &kb);
-#ifdef Pack_32
-  k = ka - kb + 32*(a->wds - b->wds);
-#else
-  k = ka - kb + 16*(a->wds - b->wds);
-#endif
-#ifdef IBM
-  if (k > 0) {
-    word0(da) += (k >> 2)*Exp_msk1;
-    if (k &= 3) {
-      da *= 1 << k;
-    }
-  } else {
-    k = -k;
-    word0(db) += (k >> 2)*Exp_msk1;
-    if (k &= 3)
-      db *= 1 << k;
-  }
-#else
-  if (k > 0) {
-    word0(da) += k*Exp_msk1;
-  } else {
-    k = -k;
-    word0(db) += k*Exp_msk1;
-  }
-#endif
-  return value(da) / value(db);
-}
-
 static CONST double
 tens[] = {
   1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
@@ -1928,552 +1755,6 @@ ret1:
   return s0;
 }
 
-double zend_strtod (CONST char *s00, char **se)
-{
-  int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, dsign,
-    e, e1, esign, i, j, k, nd, nd0, nf, nz, nz0, sign;
-  CONST char *s, *s0, *s1;
-  double aadj, aadj1, adj;
-  _double rv, rv0;
-  Long L;
-  ULong y, z;
-  Bigint *bb = 0, *bb1, *bd = 0, *bd0, *bs = 0, *delta = 0, *tmp;
-  double result;
-
-  CONST char decimal_point = '.';
-
-  sign = nz0 = nz = 0;
-  value(rv) = 0.;
-
-
-  for(s = s00; isspace((unsigned char) *s); s++)
-    ;
-
-  if (*s == '-') {
-    sign = 1;
-    s++;
-  } else if (*s == '+') {
-    s++;
-  }
-
-  if (*s == '\0') {
-    s = s00;
-    goto ret;
-  }
-
-  if (*s == '0') {
-    nz0 = 1;
-    while(*++s == '0') ;
-    if (!*s)
-      goto ret;
-  }
-  s0 = s;
-  y = z = 0;
-  for(nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++)
-    if (nd < 9)
-      y = 10*y + c - '0';
-    else if (nd < 16)
-      z = 10*z + c - '0';
-  nd0 = nd;
-  if (c == decimal_point) {
-    c = *++s;
-    if (!nd) {
-      for(; c == '0'; c = *++s)
-        nz++;
-      if (c > '0' && c <= '9') {
-        s0 = s;
-        nf += nz;
-        nz = 0;
-        goto have_dig;
-      }
-      goto dig_done;
-    }
-    for(; c >= '0' && c <= '9'; c = *++s) {
-have_dig:
-      nz++;
-      if (c -= '0') {
-        nf += nz;
-        for(i = 1; i < nz; i++)
-          if (nd++ < 9)
-            y *= 10;
-          else if (nd <= DBL_DIG + 1)
-            z *= 10;
-        if (nd++ < 9)
-          y = 10*y + c;
-        else if (nd <= DBL_DIG + 1)
-          z = 10*z + c;
-        nz = 0;
-      }
-    }
-  }
-dig_done:
-  e = 0;
-  if (c == 'e' || c == 'E') {
-    if (!nd && !nz && !nz0) {
-      s = s00;
-      goto ret;
-    }
-    s00 = s;
-    esign = 0;
-    switch(c = *++s) {
-      case '-':
-        esign = 1;
-      case '+':
-        c = *++s;
-    }
-    if (c >= '0' && c <= '9') {
-      while(c == '0')
-        c = *++s;
-      if (c > '0' && c <= '9') {
-        L = c - '0';
-        s1 = s;
-        while((c = *++s) >= '0' && c <= '9')
-          L = 10*L + c - '0';
-        if (s - s1 > 8 || L > 19999)
-          /* Avoid confusion from exponents
-           * so large that e might overflow.
-           */
-          e = 19999; /* safe for 16 bit ints */
-        else
-          e = (int)L;
-        if (esign)
-          e = -e;
-      }
-      else
-        e = 0;
-    }
-    else
-      s = s00;
-  }
-  if (!nd) {
-    if (!nz && !nz0)
-      s = s00;
-    goto ret;
-  }
-  e1 = e -= nf;
-
-  /* Now we have nd0 digits, starting at s0, followed by a
-   * decimal point, followed by nd-nd0 digits.  The number we're
-   * after is the integer represented by those digits times
-   * 10**e */
-
-  if (!nd0)
-    nd0 = nd;
-  k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1;
-  value(rv) = y;
-  if (k > 9)
-    value(rv) = tens[k - 9] * value(rv) + z;
-  bd0 = 0;
-  if (nd <= DBL_DIG
-#ifndef RND_PRODQUOT
-      && FLT_ROUNDS == 1
-#endif
-     ) {
-    if (!e)
-      goto ret;
-    if (e > 0) {
-      if (e <= Ten_pmax) {
-#ifdef VAX
-        goto vax_ovfl_check;
-#else
-        /* value(rv) = */ rounded_product(value(rv),
-            tens[e]);
-        goto ret;
-#endif
-      }
-      i = DBL_DIG - nd;
-      if (e <= Ten_pmax + i) {
-        /* A fancier test would sometimes let us do
-         * this for larger i values.
-         */
-        e -= i;
-        value(rv) *= tens[i];
-#ifdef VAX
-        /* VAX exponent range is so narrow we must
-         * worry about overflow here...
-         */
-vax_ovfl_check:
-        word0(rv) -= P*Exp_msk1;
-        /* value(rv) = */ rounded_product(value(rv),
-            tens[e]);
-        if ((word0(rv) & Exp_mask)
-            > Exp_msk1*(DBL_MAX_EXP+Bias-1-P))
-          goto ovfl;
-        word0(rv) += P*Exp_msk1;
-#else
-        /* value(rv) = */ rounded_product(value(rv),
-            tens[e]);
-#endif
-        goto ret;
-      }
-    }
-#ifndef Inaccurate_Divide
-    else if (e >= -Ten_pmax) {
-      /* value(rv) = */ rounded_quotient(value(rv),
-          tens[-e]);
-      goto ret;
-    }
-#endif
-  }
-  e1 += nd - k;
-
-  /* Get starting approximation = rv * 10**e1 */
-
-  if (e1 > 0) {
-    if ((i = e1 & 15))
-      value(rv) *= tens[i];
-    if (e1 &= ~15) {
-      if (e1 > DBL_MAX_10_EXP) {
-ovfl:
-        errno = ERANGE;
-#ifndef Bad_float_h
-        value(rv) = HUGE_VAL;
-#else
-        /* Can't trust HUGE_VAL */
-#ifdef IEEE_Arith
-        word0(rv) = Exp_mask;
-        word1(rv) = 0;
-#else
-        word0(rv) = Big0;
-        word1(rv) = Big1;
-#endif
-#endif
-        if (bd0)
-          goto retfree;
-        goto ret;
-      }
-      if (e1 >>= 4) {
-        for(j = 0; e1 > 1; j++, e1 >>= 1)
-          if (e1 & 1)
-            value(rv) *= bigtens[j];
-        /* The last multiplication could overflow. */
-        word0(rv) -= P*Exp_msk1;
-        value(rv) *= bigtens[j];
-        if ((z = word0(rv) & Exp_mask)
-            > Exp_msk1*(DBL_MAX_EXP+Bias-P))
-          goto ovfl;
-        if (z > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) {
-          /* set to largest number */
-          /* (Can't trust DBL_MAX) */
-          word0(rv) = Big0;
-          word1(rv) = Big1;
-        }
-        else
-          word0(rv) += P*Exp_msk1;
-      }
-
-    }
-  }
-  else if (e1 < 0) {
-    e1 = -e1;
-    if ((i = e1 & 15))
-      value(rv) /= tens[i];
-    if (e1 &= ~15) {
-      e1 >>= 4;
-      if (e1 >= 1 << n_bigtens)
-        goto undfl;
-      for(j = 0; e1 > 1; j++, e1 >>= 1)
-        if (e1 & 1)
-          value(rv) *= tinytens[j];
-      /* The last multiplication could underflow. */
-      value(rv0) = value(rv);
-      value(rv) *= tinytens[j];
-      if (!value(rv)) {
-        value(rv) = 2.*value(rv0);
-        value(rv) *= tinytens[j];
-        if (!value(rv)) {
-undfl:
-          value(rv) = 0.;
-          errno = ERANGE;
-          if (bd0)
-            goto retfree;
-          goto ret;
-        }
-        word0(rv) = Tiny0;
-        word1(rv) = Tiny1;
-        /* The refinement below will clean
-         * this approximation up.
-         */
-      }
-    }
-  }
-
-  /* Now the hard part -- adjusting rv to the correct value.*/
-
-  /* Put digits into bd: true value = bd * 10^e */
-
-  bd0 = s2b(s0, nd0, nd, y);
-
-  for(;;) {
-    bd = Balloc(bd0->k);
-    Bcopy(bd, bd0);
-    bb = d2b(value(rv), &bbe, &bbbits);  /* rv = bb * 2^bbe */
-    bs = i2b(1);
-
-    if (e >= 0) {
-      bb2 = bb5 = 0;
-      bd2 = bd5 = e;
-    }
-    else {
-      bb2 = bb5 = -e;
-      bd2 = bd5 = 0;
-    }
-    if (bbe >= 0)
-      bb2 += bbe;
-    else
-      bd2 -= bbe;
-    bs2 = bb2;
-#ifdef Sudden_Underflow
-#ifdef IBM
-    j = 1 + 4*P - 3 - bbbits + ((bbe + bbbits - 1) & 3);
-#else
-    j = P + 1 - bbbits;
-#endif
-#else
-    i = bbe + bbbits - 1;  /* logb(rv) */
-    if (i < Emin)  /* denormal */
-      j = bbe + (P-Emin);
-    else
-      j = P + 1 - bbbits;
-#endif
-    bb2 += j;
-    bd2 += j;
-    i = bb2 < bd2 ? bb2 : bd2;
-    if (i > bs2)
-      i = bs2;
-    if (i > 0) {
-      bb2 -= i;
-      bd2 -= i;
-      bs2 -= i;
-    }
-    if (bb5 > 0) {
-      bs = pow5mult(bs, bb5);
-      bb1 = mult(bs, bb);
-      Bfree(bb);
-      bb = bb1;
-    }
-    if (bb2 > 0)
-      bb = lshift(bb, bb2);
-    if (bd5 > 0)
-      bd = pow5mult(bd, bd5);
-    if (bd2 > 0)
-      bd = lshift(bd, bd2);
-    if (bs2 > 0)
-      bs = lshift(bs, bs2);
-    delta = diff(bb, bd);
-    dsign = delta->sign;
-    delta->sign = 0;
-    i = cmp(delta, bs);
-    if (i < 0) {
-      /* Error is less than half an ulp -- check for
-       * special case of mantissa a power of two.
-       */
-      if (dsign || word1(rv) || word0(rv) & Bndry_mask)
-        break;
-      delta = lshift(delta,Log2P);
-      if (cmp(delta, bs) > 0)
-        goto drop_down;
-      break;
-    }
-    if (i == 0) {
-      /* exactly half-way between */
-      if (dsign) {
-        if ((word0(rv) & Bndry_mask1) == Bndry_mask1
-            &&  word1(rv) == 0xffffffff) {
-          /*boundary case -- increment exponent*/
-          word0(rv) = (word0(rv) & Exp_mask)
-            + Exp_msk1
-#ifdef IBM
-            | Exp_msk1 >> 4
-#endif
-            ;
-          word1(rv) = 0;
-          break;
-        }
-      }
-      else if (!(word0(rv) & Bndry_mask) && !word1(rv)) {
-drop_down:
-        /* boundary case -- decrement exponent */
-#ifdef Sudden_Underflow
-        L = word0(rv) & Exp_mask;
-#ifdef IBM
-        if (L <  Exp_msk1)
-#else
-          if (L <= Exp_msk1)
-#endif
-            goto undfl;
-        L -= Exp_msk1;
-#else
-        L = (word0(rv) & Exp_mask) - Exp_msk1;
-#endif
-        word0(rv) = L | Bndry_mask1;
-        word1(rv) = 0xffffffff;
-#ifdef IBM
-        goto cont;
-#else
-        break;
-#endif
-      }
-#ifndef ROUND_BIASED
-      if (!(word1(rv) & LSB))
-        break;
-#endif
-      if (dsign)
-        value(rv) += ulp(value(rv));
-#ifndef ROUND_BIASED
-      else {
-        value(rv) -= ulp(value(rv));
-#ifndef Sudden_Underflow
-        if (!value(rv))
-          goto undfl;
-#endif
-      }
-#endif
-      break;
-    }
-    if ((aadj = ratio(delta, bs)) <= 2.) {
-      if (dsign)
-        aadj = aadj1 = 1.;
-      else if (word1(rv) || word0(rv) & Bndry_mask) {
-#ifndef Sudden_Underflow
-        if (word1(rv) == Tiny1 && !word0(rv))
-          goto undfl;
-#endif
-        aadj = 1.;
-        aadj1 = -1.;
-      }
-      else {
-        /* special case -- power of FLT_RADIX to be */
-        /* rounded down... */
-
-        if (aadj < 2./FLT_RADIX)
-          aadj = 1./FLT_RADIX;
-        else
-          aadj *= 0.5;
-        aadj1 = -aadj;
-      }
-    }
-    else {
-      aadj *= 0.5;
-      aadj1 = dsign ? aadj : -aadj;
-#ifdef Check_FLT_ROUNDS
-      switch(FLT_ROUNDS) {
-        case 2: /* towards +infinity */
-          aadj1 -= 0.5;
-          break;
-        case 0: /* towards 0 */
-        case 3: /* towards -infinity */
-          aadj1 += 0.5;
-      }
-#else
-      if (FLT_ROUNDS == 0)
-        aadj1 += 0.5;
-#endif
-    }
-    y = word0(rv) & Exp_mask;
-
-    /* Check for overflow */
-
-    if (y == Exp_msk1*(DBL_MAX_EXP+Bias-1)) {
-      value(rv0) = value(rv);
-      word0(rv) -= P*Exp_msk1;
-      adj = aadj1 * ulp(value(rv));
-      value(rv) += adj;
-      if ((word0(rv) & Exp_mask) >=
-          Exp_msk1*(DBL_MAX_EXP+Bias-P)) {
-        if (word0(rv0) == Big0 && word1(rv0) == Big1)
-          goto ovfl;
-        word0(rv) = Big0;
-        word1(rv) = Big1;
-        goto cont;
-      }
-      else
-        word0(rv) += P*Exp_msk1;
-    }
-    else {
-#ifdef Sudden_Underflow
-      if ((word0(rv) & Exp_mask) <= P*Exp_msk1) {
-        value(rv0) = value(rv);
-        word0(rv) += P*Exp_msk1;
-        adj = aadj1 * ulp(value(rv));
-        value(rv) += adj;
-#ifdef IBM
-        if ((word0(rv) & Exp_mask) <  P*Exp_msk1)
-#else
-          if ((word0(rv) & Exp_mask) <= P*Exp_msk1)
-#endif
-          {
-            if (word0(rv0) == Tiny0
-                && word1(rv0) == Tiny1)
-              goto undfl;
-            word0(rv) = Tiny0;
-            word1(rv) = Tiny1;
-            goto cont;
-          }
-          else
-            word0(rv) -= P*Exp_msk1;
-      }
-      else {
-        adj = aadj1 * ulp(value(rv));
-        value(rv) += adj;
-      }
-#else
-      /* Compute adj so that the IEEE rounding rules will
-       * correctly round rv + adj in some half-way cases.
-       * If rv * ulp(rv) is denormalized (i.e.,
-       * y <= (P-1)*Exp_msk1), we must adjust aadj to avoid
-       * trouble from bits lost to denormalization;
-       * example: 1.2e-307 .
-       */
-      if (y <= (P-1)*Exp_msk1 && aadj >= 1.) {
-        aadj1 = (double)(int)(aadj + 0.5);
-        if (!dsign)
-          aadj1 = -aadj1;
-      }
-      adj = aadj1 * ulp(value(rv));
-      value(rv) += adj;
-#endif
-    }
-    z = word0(rv) & Exp_mask;
-    if (y == z) {
-      /* Can we stop now? */
-      L = (int32_t)aadj;
-      aadj -= L;
-      /* The tolerances below are conservative. */
-      if (dsign || word1(rv) || word0(rv) & Bndry_mask) {
-        if (aadj < .4999999 || aadj > .5000001)
-          break;
-      }
-      else if (aadj < .4999999/FLT_RADIX)
-        break;
-    }
-cont:
-    Bfree(bb);
-    Bfree(bd);
-    Bfree(bs);
-    Bfree(delta);
-  }
-retfree:
-  Bfree(bb);
-  Bfree(bd);
-  Bfree(bs);
-  Bfree(bd0);
-  Bfree(delta);
-ret:
-  if (se)
-    *se = (char *)s;
-  result = sign ? -value(rv) : value(rv);
-
-  Bigint *&p5s = s_bigint_data->p5s;
-  while (p5s) {
-    tmp = p5s;
-    p5s = p5s->next;
-    free(tmp);
-  }
-
-  return result;
-}
-
 double zend_hex_strtod(const char *str, char **endptr)
 {
   const char *s = str;
diff --git a/hphp/runtime/base/zend/zend_strtod.h b/hphp/runtime/base/zend/zend_strtod.h
index e0a86af9d..fc1f0fc4a 100644
--- a/hphp/runtime/base/zend/zend_strtod.h
+++ b/hphp/runtime/base/zend/zend_strtod.h
@@ -26,7 +26,6 @@ namespace HPHP {
 void zend_freedtoa(char *s);
 char * zend_dtoa(double _d, int mode, int ndigits, int *decpt, int *sign,
                  char **rve);
-double zend_strtod(const char *s00, char **se);
 double zend_hex_strtod(const char *str, char **endptr);
 double zend_oct_strtod(const char *str, char **endptr);
 int zend_startup_strtod(void);