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authorUlrich Drepper <drepper@redhat.com>1999-07-14 00:54:57 +0000
committerUlrich Drepper <drepper@redhat.com>1999-07-14 00:54:57 +0000
commitabfbdde177c3a7155070dda1b2cdc8292054cc26 (patch)
treee021306b596381fbf8311d2b7eb294e918ff17c8 /sysdeps/i386/fpu/e_scalbf.S
parent86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff)
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Update.
Diffstat (limited to 'sysdeps/i386/fpu/e_scalbf.S')
-rw-r--r--sysdeps/i386/fpu/e_scalbf.S96
1 files changed, 96 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/e_scalbf.S b/sysdeps/i386/fpu/e_scalbf.S
new file mode 100644
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+++ b/sysdeps/i386/fpu/e_scalbf.S
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+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ * Adapted for float type by Ulrich Drepper <drepper@cygnus.com>.
+ *
+ * Correct handling of y==-inf <drepper@gnu>
+ */
+
+#include <machine/asm.h>
+
+RCSID("$NetBSD: $")
+
+#ifdef __ELF__
+	.section .rodata
+#else
+	.text
+#endif
+
+	.align ALIGNARG(4)
+	ASM_TYPE_DIRECTIVE(zero_nan,@object)
+zero_nan:
+	.double 0.0
+nan:	.byte 0, 0, 0, 0, 0, 0, 0xff, 0x7f
+minus_zero:
+	.byte 0, 0, 0, 0, 0, 0, 0, 0x80
+	.byte 0, 0, 0, 0, 0, 0, 0xff, 0x7f
+	ASM_SIZE_DIRECTIVE(zero_nan)
+
+
+#ifdef PIC
+#define MO(op) op##@GOTOFF(%ecx)
+#define MOX(op,x,f) op##@GOTOFF(%ecx,x,f)
+#else
+#define MO(op) op
+#define MOX(op,x,f) op(,x,f)
+#endif
+
+
+	.text
+ENTRY(__ieee754_scalbf)
+	flds	8(%esp)
+	fxam
+	fnstsw
+	flds	4(%esp)
+	andl	$0x4700, %eax
+	cmpl	$0x0700, %eax
+	je	1f
+	andl	$0x4500, %eax
+	cmpl	$0x0100, %eax
+	je	2f
+	fxam
+	fnstsw
+	andl	$0x4500, %eax
+	cmpl	$0x0100, %eax
+	je	2f
+	fld	%st(1)
+	frndint
+	fcomp	%st(2)
+	fnstsw
+	sahf
+	jne	2f
+	fscale
+	fstp	%st(1)
+	ret
+
+	/* y is -inf */
+1:	fxam
+#ifdef  PIC
+        call    1f
+1:      popl    %ecx
+        addl    $_GLOBAL_OFFSET_TABLE_+[.-1b], %ecx
+#endif
+	fnstsw
+	movl	4(%esp), %edx
+	shrl	$5, %eax
+	fstp	%st
+	fstp	%st
+	andl	$0x80000000, %edx
+	andl	$8, %eax
+	shrl	$27, %edx
+	addl	%edx, %eax
+	fldl	MOX(zero_nan, %eax, 1)
+	ret
+
+	/* The result is NaN, but we must not raise an exception.
+	   So use a variable.  */
+2:	fstp	%st
+	fstp	%st
+#ifdef  PIC
+        call    1f
+1:      popl    %ecx
+        addl    $_GLOBAL_OFFSET_TABLE_+[.-1b], %ecx
+#endif
+	fldl	MO(nan)
+	ret
+END(__ieee754_scalbf)