diff --git a/e_exp.cpp b/e_exp.cpp
--- a/e_exp.cpp
+++ b/e_exp.cpp
@@ -146,14 +146,17 @@ __ieee754_exp(double x)	/* default IEEE double exp */
 	if(k >= -1021)
 	    INSERT_WORDS(twopk,((u_int32_t)(0x3ff+k))<<20, 0);
 	else
 	    INSERT_WORDS(twopk,((u_int32_t)(0x3ff+(k+1000)))<<20, 0);
 	c  = x - t*(P1+t*(P2+t*(P3+t*(P4+t*P5))));
 	if(k==0) 	return one-((x*c)/(c-2.0)-x); 
 	else 		y = one-((lo-(x*c)/(2.0-c))-hi);
 	if(k >= -1021) {
-	    if (k==1024) return y*2.0*0x1p1023;
+	    if (k==1024) {
+	        double const_0x1p1023 = pow(2, 1023);
+	        return y*2.0*const_0x1p1023;
+	    }
 	    return y*twopk;
 	} else {
 	    return y*twopk*twom1000;
 	}
 }
diff --git a/s_expm1.cpp b/s_expm1.cpp
--- a/s_expm1.cpp
+++ b/s_expm1.cpp
@@ -192,17 +192,20 @@ expm1(double x)
 	    e -= hxs;
 	    if(k== -1) return 0.5*(x-e)-0.5;
 	    if(k==1) {
 	       	if(x < -0.25) return -2.0*(e-(x+0.5));
 	       	else 	      return  one+2.0*(x-e);
 	    }
 	    if (k <= -2 || k>56) {   /* suffice to return exp(x)-1 */
 	        y = one-(e-x);
-		if (k == 1024) y = y*2.0*0x1p1023;
+		if (k == 1024) {
+		    double const_0x1p1023 = pow(2, 1023);
+		    y = y*2.0*const_0x1p1023;
+		}
 		else y = y*twopk;
 	        return y-one;
 	    }
 	    t = one;
 	    if(k<20) {
 	        SET_HIGH_WORD(t,0x3ff00000 - (0x200000>>k));  /* t=1-2^-k */
 	       	y = t-(e-x);
 		y = y*twopk;
--- a/s_exp2.cpp	2022-12-11 21:26:36.045643147 -0500
+++ b/s_exp2.cpp_new	2022-12-11 21:28:42.058769925 -0500
@@ -381,14 +381,16 @@
 		INSERT_WORDS(twopk, 0x3ff00000 + k, 0);
 	else
 		INSERT_WORDS(twopkp1000, 0x3ff00000 + k + (1000 << 20), 0);
 	r = t + t * z * (P1 + z * (P2 + z * (P3 + z * (P4 + z * P5))));
 
 	/* Scale by 2**(k>>20). */
 	if(k >= -(1021 << 20)) {
-		if (k == 1024 << 20)
-			return (r * 2.0 * 0x1p1023);
+		if (k == 1024 << 20) {
+			double const_0x1p1023 = pow(2, 1023);
+			return (r * 2.0 * const_0x1p1023);
+		}
 		return (r * twopk);
 	} else {
 		return (r * twopkp1000 * twom1000);
 	}
 }