Use STRICT_ASSIGN() for log1pf() and log1p() instead of a volatile cast

hack for log1pf() only.  The cast hack broke with gcc-4, resulting in
~1 million errors of more than 1 ulp, with a maximum error of ~1.5 ulps.
Now the maximum error for log1pf() on i386 is 0.5034 ulps again (this
depends on extra precision), and log1p() has a chance of working with
extra precision.

See s_log1pf.c 1.8 for the original hack.  (It claims only 62343 large
errors).

Convert to _FBSDID().  Another thing broken with gcc-4 is the static
const hack used for rcsids.

2 files changed, 10 insertions, 8 deletions

diff --git a/lib/msun/src/s_log1p.c b/lib/msun/src/s_log1p.c
index 0ee69a6..1af5892 100644
--- a/lib/msun/src/s_log1p.c
+++ b/lib/msun/src/s_log1p.c
@@ -10,9 +10,8 @@
  * ====================================================
  */
 
-#ifndef lint
-static char rcsid[] = "$FreeBSD$";
-#endif
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
 
 /* double log1p(double x)
  *
@@ -79,6 +78,8 @@ static char rcsid[] = "$FreeBSD$";
  *	 See HP-15C Advanced Functions Handbook, p.193.
  */
 
+#include <float.h>
+
 #include "math.h"
 #include "math_private.h"
 
@@ -124,7 +125,7 @@ log1p(double x)
 	if (hx >= 0x7ff00000) return x+x;
 	if(k!=0) {
 	    if(hx<0x43400000) {
-		u  = 1.0+x;
+		STRICT_ASSIGN(double,u,1.0+x);
 		GET_HIGH_WORD(hu,u);
 	        k  = (hu>>20)-1023;
 	        c  = (k>0)? 1.0-(u-x):x-(u-1.0);/* correction term */
diff --git a/lib/msun/src/s_log1pf.c b/lib/msun/src/s_log1pf.c
index eb0f4af..6b2fbc7 100644
--- a/lib/msun/src/s_log1pf.c
+++ b/lib/msun/src/s_log1pf.c
@@ -13,9 +13,10 @@
  * ====================================================
  */
 
-#ifndef lint
-static char rcsid[] = "$FreeBSD$";
-#endif
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <float.h>
 
 #include "math.h"
 #include "math_private.h"
@@ -62,7 +63,7 @@ log1pf(float x)
 	if (hx >= 0x7f800000) return x+x;
 	if(k!=0) {
 	    if(hx<0x5a000000) {
-		*(volatile float *)&u = (float)1.0+x;
+		STRICT_ASSIGN(float,u,(float)1.0+x);
 		GET_FLOAT_WORD(hu,u);
 	        k  = (hu>>23)-127;
 		/* correction term */