Fix asin missing underflows (bug 16351).

Similar to various other bugs in this area, some asin implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact.  This patch forces the exception in a
similar way to previous fixes.

Tested for x86_64, x86, powerpc and mips64.

	[BZ #16351]
	* sysdeps/i386/fpu/e_asin.S (dbl_min): New object.
	(MO): New macro.
	(__ieee754_asin): Force underflow exception for results with small
	absolute value.
	* sysdeps/i386/fpu/e_asinf.S (flt_min): New object.
	(MO): New macro.
	(__ieee754_asinf): Force underflow exception for results with
	small absolute value.
	* sysdeps/ieee754/dbl-64/e_asin.c: Include <float.h> and <math.h>.
	(__ieee754_asin): Force underflow exception for results with small
	absolute value.
	* sysdeps/ieee754/flt-32/e_asinf.c: Include <float.h>.
	(__ieee754_asinf): Force underflow exception for results with
	small absolute value.
	* sysdeps/ieee754/ldbl-128/e_asinl.c: Include <float.h>.
	(__ieee754_asinl): Force underflow exception for results with
	small absolute value.
	* sysdeps/ieee754/ldbl-128ibm/e_asinl.c: Include <float.h>.
	(__ieee754_asinl): Force underflow exception for results with
	small absolute value.
	* sysdeps/ieee754/ldbl-96/e_asinl.c: Include <float.h>.
	(__ieee754_asinl): Force underflow exception for results with
	small absolute value.
	* sysdeps/x86_64/fpu/multiarch/e_asin.c [HAVE_FMA4_SUPPORT]:
	Include <math.h>.
	* math/auto-libm-test-in: Do not mark underflow exceptions as
	possibly missing for bug 16351.
	* math/auto-libm-test-out: Regenerated.

2 files changed, 66 insertions, 2 deletions

diff --git a/sysdeps/i386/fpu/e_asin.S b/sysdeps/i386/fpu/e_asin.S
index 9a44cb62ac..ea8cb6f1b2 100644
--- a/sysdeps/i386/fpu/e_asin.S
+++ b/sysdeps/i386/fpu/e_asin.S
@@ -7,8 +7,26 @@
 
 RCSID("$NetBSD: e_asin.S,v 1.4 1995/05/08 23:45:40 jtc Exp $")
 
+	.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)
+
+#ifdef PIC
+# define MO(op) op##@GOTOFF(%ecx)
+#else
+# define MO(op) op
+#endif
+
+	.text
+
 /* asin = atan (x / sqrt((1-x) (1+x))) */
 ENTRY(__ieee754_asin)
+#ifdef  PIC
+	LOAD_PIC_REG (cx)
+#endif
 	fldl	4(%esp)			/* x */
 	fld	%st
 	fld1				/* 1 : x : x */
@@ -18,6 +36,20 @@ ENTRY(__ieee754_asin)
 	fmulp				/* 1 - x^2 */
 	fsqrt				/* sqrt (1 - x^2) */
 	fpatan
-	ret
+	fldl	MO(dbl_min)
+	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
 END (__ieee754_asin)
 strong_alias (__ieee754_asin, __asin_finite)
diff --git a/sysdeps/i386/fpu/e_asinf.S b/sysdeps/i386/fpu/e_asinf.S
index 5c1065dd4d..f7bda77fa6 100644
--- a/sysdeps/i386/fpu/e_asinf.S
+++ b/sysdeps/i386/fpu/e_asinf.S
@@ -8,8 +8,26 @@
 
 RCSID("$NetBSD: $")
 
+	.section .rodata.cst4,"aM",@progbits,4
+
+	.p2align 2
+	.type flt_min,@object
+flt_min:	.byte 0, 0, 0x80, 0
+	ASM_SIZE_DIRECTIVE(flt_min)
+
+#ifdef PIC
+# define MO(op) op##@GOTOFF(%ecx)
+#else
+# define MO(op) op
+#endif
+
+	.text
+
 /* asin = atan (x / sqrt(1 - x^2)) */
 ENTRY(__ieee754_asinf)
+#ifdef  PIC
+	LOAD_PIC_REG (cx)
+#endif
 	flds	4(%esp)			/* x */
 	fld	%st
 	fmul	%st(0)			/* x^2 */
@@ -17,6 +35,20 @@ ENTRY(__ieee754_asinf)
 	fsubp				/* 1 - x^2 */
 	fsqrt				/* sqrt (1 - x^2) */
 	fpatan
-	ret
+	flds	MO(flt_min)
+	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
 END (__ieee754_asinf)
 strong_alias (__ieee754_asinf, __asinf_finite)