5 files changed, 75 insertions, 3 deletions

diff --git a/sysdeps/i386/fpu/s_log1p.S b/sysdeps/i386/fpu/s_log1p.S
index 8624249dba..c2559a3f18 100644
--- a/sysdeps/i386/fpu/s_log1p.S
+++ b/sysdeps/i386/fpu/s_log1p.S
@@ -17,6 +17,13 @@ RCSID("$NetBSD: s_log1p.S,v 1.7 1995/05/09 00:10:58 jtc Exp $")
 limit:	.double 0.29
 one:	.double 1.0
 
+	.section .rodata.cst8,"aM",@progbits,8
+
+	.p2align 3
+	.type dbl_min,@object
+dbl_min:	.byte 0, 0, 0, 0, 0, 0, 0x10, 0
+	ASM_SIZE_DIRECTIVE(dbl_min)
+
 /*
  * Use the fyl2xp1 function when the argument is in the range -0.29 to 0.29,
  * otherwise fyl2x with the needed extra computation.
@@ -55,7 +62,25 @@ ENTRY(__log1p)
 	ret
 
 2:	fyl2xp1
-	ret
+#ifdef PIC
+	fldl	dbl_min@GOTOFF(%edx)
+#else
+	fldl	dbl_min
+#endif
+	fld	%st(1)
+	fabs
+	fucompp
+	fnstsw
+	sahf
+	jnc	1f
+	subl	$8, %esp
+	cfi_adjust_cfa_offset (8)
+	fld	%st(0)
+	fmul	%st(0)
+	fstpl	(%esp)
+	addl	$8, %esp
+	cfi_adjust_cfa_offset (-8)
+1:	ret
 
 3:	jp	4b		// in case x is ħInf
 	fstp	%st(1)
diff --git a/sysdeps/i386/fpu/s_log1pf.S b/sysdeps/i386/fpu/s_log1pf.S
index b071e7372d..8fca22e4ff 100644
--- a/sysdeps/i386/fpu/s_log1pf.S
+++ b/sysdeps/i386/fpu/s_log1pf.S
@@ -17,6 +17,13 @@ RCSID("$NetBSD: s_log1pf.S,v 1.4 1995/05/09 00:13:05 jtc Exp $")
 limit:	.float 0.29
 one:	.float 1.0
 
+	.section .rodata.cst4,"aM",@progbits,4
+
+	.p2align 2
+	.type flt_min,@object
+flt_min:	.byte 0, 0, 0x80, 0
+	ASM_SIZE_DIRECTIVE(flt_min)
+
 /*
  * Use the fyl2xp1 function when the argument is in the range -0.29 to 0.29,
  * otherwise fyl2x with the needed extra computation.
@@ -55,7 +62,25 @@ ENTRY(__log1pf)
 	ret
 
 2:	fyl2xp1
-	ret
+#ifdef PIC
+	flds	flt_min@GOTOFF(%edx)
+#else
+	flds	flt_min
+#endif
+	fld	%st(1)
+	fabs
+	fucompp
+	fnstsw
+	sahf
+	jnc	1f
+	subl	$4, %esp
+	cfi_adjust_cfa_offset (4)
+	fld	%st(0)
+	fmul	%st(0)
+	fstps	(%esp)
+	addl	$4, %esp
+	cfi_adjust_cfa_offset (-4)
+1:	ret
 
 3:	jp	4b		// in case x is ħInf
 	fstp	%st(1)
diff --git a/sysdeps/ieee754/dbl-64/s_log1p.c b/sysdeps/ieee754/dbl-64/s_log1p.c
index 86bbfbacaf..cff555b0aa 100644
--- a/sysdeps/ieee754/dbl-64/s_log1p.c
+++ b/sysdeps/ieee754/dbl-64/s_log1p.c
@@ -78,6 +78,7 @@
  *	 See HP-15C Advanced Functions Handbook, p.193.
  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -118,7 +119,14 @@ __log1p (double x)
 	{
 	  math_force_eval (two54 + x);          /* raise inexact */
 	  if (ax < 0x3c900000)                  /* |x| < 2**-54 */
-	    return x;
+	    {
+	      if (fabs (x) < DBL_MIN)
+		{
+		  double force_underflow = x * x;
+		  math_force_eval (force_underflow);
+		}
+	      return x;
+	    }
 	  else
 	    return x - x * x * 0.5;
 	}
diff --git a/sysdeps/ieee754/flt-32/s_log1pf.c b/sysdeps/ieee754/flt-32/s_log1pf.c
index 94c33fca16..83a09f1414 100644
--- a/sysdeps/ieee754/flt-32/s_log1pf.c
+++ b/sysdeps/ieee754/flt-32/s_log1pf.c
@@ -13,6 +13,7 @@
  * ====================================================
  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -48,7 +49,14 @@ __log1pf(float x)
 	    if(ax<0x31000000) {			/* |x| < 2**-29 */
 		math_force_eval(two25+x);	/* raise inexact */
 		if (ax<0x24800000)		/* |x| < 2**-54 */
+		  {
+		    if (fabsf (x) < FLT_MIN)
+		      {
+			float force_underflow = x * x;
+			math_force_eval (force_underflow);
+		      }
 		    return x;
+		  }
 		else
 		    return x - x*x*(float)0.5;
 	    }
diff --git a/sysdeps/ieee754/ldbl-128/s_log1pl.c b/sysdeps/ieee754/ldbl-128/s_log1pl.c
index b70a55b758..ff759bc000 100644
--- a/sysdeps/ieee754/ldbl-128/s_log1pl.c
+++ b/sysdeps/ieee754/ldbl-128/s_log1pl.c
@@ -53,6 +53,7 @@
     <http://www.gnu.org/licenses/>.  */
 
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -140,6 +141,11 @@ __log1pl (long double xm1)
 
   if ((hx & 0x7fffffff) < 0x3f8e0000)
     {
+      if (fabsl (xm1) < LDBL_MIN)
+	{
+	  long double force_underflow = xm1 * xm1;
+	  math_force_eval (force_underflow);
+	}
       if ((int) xm1 == 0)
 	return xm1;
     }