diff options
Diffstat (limited to 'lib/libm/arch/vax/n_hypot.S')
| -rw-r--r-- | lib/libm/arch/vax/n_hypot.S | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/lib/libm/arch/vax/n_hypot.S b/lib/libm/arch/vax/n_hypot.S new file mode 100644 index 00000000000..bd5cbf49df1 --- /dev/null +++ b/lib/libm/arch/vax/n_hypot.S @@ -0,0 +1,117 @@ +/* $OpenBSD: n_hypot.S,v 1.1 2008/10/07 22:25:53 martynas Exp $ */ +/* $NetBSD: n_cabs.S,v 1.1 1995/10/10 23:40:26 ragge Exp $ */ +/* + * Copyright (c) 1985, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)cabs.s 8.1 (Berkeley) 6/4/93 + */ + +#include <machine/asm.h> + +/* + * double precision complex absolute value + * CABS by W. Kahan, 9/7/80. + * Revised for reserved operands by E. LeBlanc, 8/18/82 + * argument for complex absolute value by reference, *4(ap) + * argument for cabs and hypot (C fcns) by value, 4(ap) + * output is in r0:r1 (error less than 0.86 ulps) + */ + +/* entry for c functions cabs and hypot */ + .text + _ALIGN_TEXT +ENTRY(hypot, 0x8000|R2|R3|R4|R5|R6) # enable floating overflow + movq 4(ap),r0 # r0:1 = x + movq 12(ap),r2 # r2:3 = y + bicw3 $0x7f,r0,r4 # r4 has signed biased exp of x + cmpw $0x8000,r4 + jeql return # x is a reserved operand, so return it + bicw3 $0x7f,r2,r5 # r5 has signed biased exp of y + cmpw $0x8000,r5 + jneq cont /* y isn't a reserved operand */ + movq r2,r0 /* return y if it's reserved */ + ret + +cont: + bsbb regs_set # r0:1 = dsqrt(x^2+y^2)/2^r6 + addw2 r6,r0 # unscaled cdabs in r0:1 + jvc return # unless it overflows + subw2 $0x80,r0 # halve r0 to get meaningful overflow + addd2 r0,r0 # overflow; r0 is half of true abs value +return: + ret + +#if 0 /* apparently not used */ +_ALTENTRY(__libm_cdabs_r6) # ENTRY POINT for cdsqrt + # calculates a scaled (factor in r6) + # complex absolute value + + movq (r4)+,r0 # r0:r1 = x via indirect addressing + movq (r4),r2 # r2:r3 = y via indirect addressing + + bicw3 $0x7f,r0,r5 # r5 has signed biased exp of x + cmpw $0x8000,r5 + jeql cdreserved # x is a reserved operand + bicw3 $0x7f,r2,r5 # r5 has signed biased exp of y + cmpw $0x8000,r5 + jneq regs_set /* y isn't a reserved operand either? */ + +cdreserved: + movl *4(ap),r4 # r4 -> (u,v), if x or y is reserved + movq r0,(r4)+ # copy u and v as is and return + movq r2,(r4) # (again addressing is indirect) + ret +#endif + +regs_set: + bicw2 $0x8000,r0 # r0:r1 = dabs(x) + bicw2 $0x8000,r2 # r2:r3 = dabs(y) + cmpw r0,r2 + jgeq ordered + movq r0,r4 + movq r2,r0 + movq r4,r2 # force y's exp <= x's exp +ordered: + bicw3 $0x7f,r0,r6 # r6 = exponent(x) + bias(129) + jeql retsb # if x = y = 0 then cdabs(x,y) = 0 + subw2 $0x4780,r6 # r6 = exponent(x) - 14 + subw2 r6,r0 # 2^14 <= scaled x < 2^15 + bitw $0xff80,r2 + jeql retsb # if y = 0 return dabs(x) + subw2 r6,r2 + cmpw $0x3780,r2 # if scaled y < 2^-18 + jgtr retsb # return dabs(x) + emodd r0,$0,r0,r4,r0 # r4 + r0:1 = scaled x^2 + emodd r2,$0,r2,r5,r2 # r5 + r2:3 = scaled y^2 + addd2 r2,r0 + addl2 r5,r4 + cvtld r4,r2 + addd2 r2,r0 # r0:1 = scaled x^2 + y^2 + jmp __libm_dsqrt_r5 # r0:1 = dsqrt(x^2+y^2)/2^r6 +retsb: + rsb # error < 0.86 ulp |