i386: move math-emu

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 167 insertions, 0 deletions

diff --git a/arch/x86/math-emu/reg_u_add.S b/arch/x86/math-emu/reg_u_add.S
new file mode 100644
index 00000000000..47c4c2434d8
--- /dev/null
+++ b/arch/x86/math-emu/reg_u_add.S
@@ -0,0 +1,167 @@
+	.file	"reg_u_add.S"
+/*---------------------------------------------------------------------------+
+ |  reg_u_add.S                                                              |
+ |                                                                           |
+ | Add two valid (TAG_Valid) FPU_REG numbers, of the same sign, and put the  |
+ |   result in a destination FPU_REG.                                        |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1995,1997                                         |
+ |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
+ |                  E-mail   billm@suburbia.net                              |
+ |                                                                           |
+ | Call from C as:                                                           |
+ |   int  FPU_u_add(FPU_REG *arg1, FPU_REG *arg2, FPU_REG *answ,             |
+ |                                                int control_w)             |
+ |    Return value is the tag of the answer, or-ed with FPU_Exception if     |
+ |    one was raised, or -1 on internal error.                               |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+/*
+ |    Kernel addition routine FPU_u_add(reg *arg1, reg *arg2, reg *answ).
+ |    Takes two valid reg f.p. numbers (TAG_Valid), which are
+ |    treated as unsigned numbers,
+ |    and returns their sum as a TAG_Valid or TAG_Special f.p. number.
+ |    The returned number is normalized.
+ |    Basic checks are performed if PARANOID is defined.
+ */
+
+#include "exception.h"
+#include "fpu_emu.h"
+#include "control_w.h"
+
+.text
+ENTRY(FPU_u_add)
+	pushl	%ebp
+	movl	%esp,%ebp
+	pushl	%esi
+	pushl	%edi
+	pushl	%ebx
+
+	movl	PARAM1,%esi		/* source 1 */
+	movl	PARAM2,%edi		/* source 2 */
+
+	movl	PARAM6,%ecx
+	movl	%ecx,%edx
+	subl	PARAM7,%ecx			/* exp1 - exp2 */
+	jge	L_arg1_larger
+
+	/* num1 is smaller */
+	movl	SIGL(%esi),%ebx
+	movl	SIGH(%esi),%eax
+
+	movl	%edi,%esi
+	movl	PARAM7,%edx
+	negw	%cx
+	jmp	L_accum_loaded
+
+L_arg1_larger:
+	/* num1 has larger or equal exponent */
+	movl	SIGL(%edi),%ebx
+	movl	SIGH(%edi),%eax
+
+L_accum_loaded:
+	movl	PARAM3,%edi		/* destination */
+	movw	%dx,EXP(%edi)		/* Copy exponent to destination */
+
+	xorl	%edx,%edx		/* clear the extension */
+
+#ifdef PARANOID
+	testl	$0x80000000,%eax
+	je	L_bugged
+
+	testl	$0x80000000,SIGH(%esi)
+	je	L_bugged
+#endif /* PARANOID */
+
+/* The number to be shifted is in %eax:%ebx:%edx */
+	cmpw	$32,%cx		/* shrd only works for 0..31 bits */
+	jnc	L_more_than_31
+
+/* less than 32 bits */
+	shrd	%cl,%ebx,%edx
+	shrd	%cl,%eax,%ebx
+	shr	%cl,%eax
+	jmp	L_shift_done
+
+L_more_than_31:
+	cmpw	$64,%cx
+	jnc	L_more_than_63
+
+	subb	$32,%cl
+	jz	L_exactly_32
+
+	shrd	%cl,%eax,%edx
+	shr	%cl,%eax
+	orl	%ebx,%ebx
+	jz	L_more_31_no_low	/* none of the lowest bits is set */
+
+	orl	$1,%edx			/* record the fact in the extension */
+
+L_more_31_no_low:
+	movl	%eax,%ebx
+	xorl	%eax,%eax
+	jmp	L_shift_done
+
+L_exactly_32:
+	movl	%ebx,%edx
+	movl	%eax,%ebx
+	xorl	%eax,%eax
+	jmp	L_shift_done
+
+L_more_than_63:
+	cmpw	$65,%cx
+	jnc	L_more_than_64
+
+	movl	%eax,%edx
+	orl	%ebx,%ebx
+	jz	L_more_63_no_low
+
+	orl	$1,%edx
+	jmp	L_more_63_no_low
+
+L_more_than_64:
+	movl	$1,%edx		/* The shifted nr always at least one '1' */
+
+L_more_63_no_low:
+	xorl	%ebx,%ebx
+	xorl	%eax,%eax
+
+L_shift_done:
+	/* Now do the addition */
+	addl	SIGL(%esi),%ebx
+	adcl	SIGH(%esi),%eax
+	jnc	L_round_the_result
+
+	/* Overflow, adjust the result */
+	rcrl	$1,%eax
+	rcrl	$1,%ebx
+	rcrl	$1,%edx
+	jnc	L_no_bit_lost
+
+	orl	$1,%edx
+
+L_no_bit_lost:
+	incw	EXP(%edi)
+
+L_round_the_result:
+	jmp	fpu_reg_round	/* Round the result */
+
+
+
+#ifdef PARANOID
+/* If we ever get here then we have problems! */
+L_bugged:
+	pushl	EX_INTERNAL|0x201
+	call	EXCEPTION
+	pop	%ebx
+	movl	$-1,%eax
+	jmp	L_exit
+
+L_exit:
+	popl	%ebx
+	popl	%edi
+	popl	%esi
+	leave
+	ret
+#endif /* PARANOID */