1 files changed, 89 insertions, 0 deletions
diff --git a/arch/x86/math-emu/shr_Xsig.S b/arch/x86/math-emu/shr_Xsig.S
new file mode 100644
index 000000000..96f4779aa
--- /dev/null
+++ b/arch/x86/math-emu/shr_Xsig.S
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+	.file	"shr_Xsig.S"
+/*---------------------------------------------------------------------------+
+ |  shr_Xsig.S                                                               |
+ |                                                                           |
+ | 12 byte right shift function                                              |
+ |                                                                           |
+ | Copyright (C) 1992,1994,1995                                              |
+ |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
+ |                       Australia.  E-mail billm@jacobi.maths.monash.edu.au |
+ |                                                                           |
+ | Call from C as:                                                           |
+ |   void shr_Xsig(Xsig *arg, unsigned nr)                                   |
+ |                                                                           |
+ |   Extended shift right function.                                          |
+ |   Fastest for small shifts.                                               |
+ |   Shifts the 12 byte quantity pointed to by the first arg (arg)           |
+ |   right by the number of bits specified by the second arg (nr).           |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+#include "fpu_emu.h"
+
+.text
+ENTRY(shr_Xsig)
+	push	%ebp
+	movl	%esp,%ebp
+	pushl	%esi
+	movl	PARAM2,%ecx
+	movl	PARAM1,%esi
+	cmpl	$32,%ecx	/* shrd only works for 0..31 bits */
+	jnc	L_more_than_31
+
+/* less than 32 bits */
+	pushl	%ebx
+	movl	(%esi),%eax	/* lsl */
+	movl	4(%esi),%ebx	/* midl */
+	movl	8(%esi),%edx	/* msl */
+	shrd	%cl,%ebx,%eax
+	shrd	%cl,%edx,%ebx
+	shr	%cl,%edx
+	movl	%eax,(%esi)
+	movl	%ebx,4(%esi)
+	movl	%edx,8(%esi)
+	popl	%ebx
+	popl	%esi
+	leave
+	ret
+
+L_more_than_31:
+	cmpl	$64,%ecx
+	jnc	L_more_than_63
+
+	subb	$32,%cl
+	movl	4(%esi),%eax	/* midl */
+	movl	8(%esi),%edx	/* msl */
+	shrd	%cl,%edx,%eax
+	shr	%cl,%edx
+	movl	%eax,(%esi)
+	movl	%edx,4(%esi)
+	movl	$0,8(%esi)
+	popl	%esi
+	leave
+	ret
+
+L_more_than_63:
+	cmpl	$96,%ecx
+	jnc	L_more_than_95
+
+	subb	$64,%cl
+	movl	8(%esi),%eax	/* msl */
+	shr	%cl,%eax
+	xorl	%edx,%edx
+	movl	%eax,(%esi)
+	movl	%edx,4(%esi)
+	movl	%edx,8(%esi)
+	popl	%esi
+	leave
+	ret
+
+L_more_than_95:
+	xorl	%eax,%eax
+	movl	%eax,(%esi)
+	movl	%eax,4(%esi)
+	movl	%eax,8(%esi)
+	popl	%esi
+	leave
+	ret
+ENDPROC(shr_Xsig)