Merge the relevant part of rev.1.14 of s_cbrt.c (a micro-optimization

involving moving the check for x == 0).  The savings in cycles are
smaller for cbrtf() than for cbrt(), and positive in all measured cases
with gcc-3.4.4, but still very machine/compiler-dependent.

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/msun/src/s_cbrtf.c b/lib/msun/src/s_cbrtf.c
index 5fcd795..ea7b3cd 100644
--- a/lib/msun/src/s_cbrtf.c
+++ b/lib/msun/src/s_cbrtf.c
@@ -41,11 +41,11 @@ cbrtf(float x)
 	sign=hx&0x80000000; 		/* sign= sign(x) */
 	hx  ^=sign;
 	if(hx>=0x7f800000) return(x+x); /* cbrt(NaN,INF) is itself */
-	if(hx==0)
-	    return(x);			/* cbrt(0) is itself */
 
     /* rough cbrt to 5 bits */
-	if(hx<0x00800000) { 		/* subnormal number */
+	if(hx<0x00800000) { 		/* zero or subnormal? */
+	    if(hx==0)
+		return(x);		/* cbrt(+-0) is itself */
 	    SET_FLOAT_WORD(t,0x4b800000); /* set t= 2**24 */
 	    t*=x;
 	    GET_FLOAT_WORD(high,t);