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authorUlrich Drepper <drepper@redhat.com>2001-02-17 16:54:13 +0000
committerUlrich Drepper <drepper@redhat.com>2001-02-17 16:54:13 +0000
commit63640cb777a26b684f44a1786c1384d3a96a8825 (patch)
tree9ed7ce04cdc72dd2a25d903adfc5333514c68bb7 /sysdeps/i386/fpu/e_exp2f.S
parentd313277ad2a2a7a292705a5d9c9a47709e759f42 (diff)
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Update.
2001-02-17  Ulrich Drepper  <drepper@redhat.com>

	* sysdeps/generic/s_exp2l.c: Renamed to...
	* sysdeps/generic/s_exp2l.c: ...this.   New file.
	* sysdeps/i386/fpu/s_exp2.S: Renamed to...
	* sysdeps/i386/fpu/s_exp2.S: ...this.   New file.
	* sysdeps/i386/fpu/s_exp2f.S: Renamed to...
	* sysdeps/i386/fpu/s_exp2f.S: ...this.   New file.
	* sysdeps/i386/fpu/s_exp2l.S: Renamed to...
	* sysdeps/i386/fpu/s_exp2l.S: ...this.   New file.
	* sysdeps/ieee754/flt-32/s_exp2f.c: Renamed to...
	* sysdeps/ieee754/flt-32/s_exp2f.c: ...this.   New file.
	* sysdeps/ieee754/dbl-64/s_exp2.c: Renamed to...
	* sysdeps/ieee754/dbl-64/s_exp2.c: ...this.   New file.
	* sysdeps/m68k/fpu/s_exp2.c: Renamed to...
	* sysdeps/m68k/fpu/s_exp2.c: ...this.   New file.
	* sysdeps/m68k/fpu/s_exp2f.c: Renamed to...
	* sysdeps/m68k/fpu/s_exp2f.c: ...this.   New file.
	* sysdeps/m68k/fpu/s_exp2l.c: Renamed to...
	* sysdeps/m68k/fpu/s_exp2l.c: ...this.   New file.
Diffstat (limited to 'sysdeps/i386/fpu/e_exp2f.S')
-rw-r--r--sysdeps/i386/fpu/e_exp2f.S37
1 files changed, 37 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/e_exp2f.S b/sysdeps/i386/fpu/e_exp2f.S
new file mode 100644
index 0000000000..c2d1af1af1
--- /dev/null
+++ b/sysdeps/i386/fpu/e_exp2f.S
@@ -0,0 +1,37 @@
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Adapted for exp2 by Ulrich Drepper <drepper@cygnus.com>.
+ * Public domain.
+ */
+
+#include <machine/asm.h>
+
+ENTRY(__ieee754_exp2f)
+	flds	4(%esp)
+/* I added the following ugly construct because exp(+-Inf) resulted
+   in NaN.  The ugliness results from the bright minds at Intel.
+   For the i686 the code can be written better.
+   -- drepper@cygnus.com.  */
+	fxam				/* Is NaN or +-Inf?  */
+	fstsw	%ax
+	movb	$0x45, %dh
+	andb	%ah, %dh
+	cmpb	$0x05, %dh
+	je	1f			/* Is +-Inf, jump.  */
+	fld	%st
+	frndint				/* int(x) */
+	fsubr	%st,%st(1)		/* fract(x) */
+	fxch
+	f2xm1				/* 2^(fract(x)) - 1 */
+	fld1
+	faddp				/* 2^(fract(x)) */
+	fscale				/* e^x */
+	fstp	%st(1)
+	ret
+
+1:	testl	$0x200, %eax		/* Test sign.  */
+	jz	2f			/* If positive, jump.  */
+	fstp	%st
+	fldz				/* Set result to 0.  */
+2:	ret
+END (__ieee754_exp2f)