diff options
Diffstat (limited to 'usr/src/lib/libm/i386/src/nextafterl.s')
| -rw-r--r-- | usr/src/lib/libm/i386/src/nextafterl.s | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/usr/src/lib/libm/i386/src/nextafterl.s b/usr/src/lib/libm/i386/src/nextafterl.s new file mode 100644 index 0000000000..cdf8647039 --- /dev/null +++ b/usr/src/lib/libm/i386/src/nextafterl.s @@ -0,0 +1,186 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright 2011 Nexenta Systems, Inc. All rights reserved. + */ +/* + * Copyright 2006 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + + .file "nextafterl.s" + +#include "libm.h" +LIBM_ANSI_PRAGMA_WEAK(nextafterl,function) +#include "libm_synonyms.h" + + .section .rodata + .align 4 +.LFmaxl: .long 0xffffffff,0xffffffff,0x00007ffe +.LFminl: .long 0x1,0x0,0x0 + + + ENTRY(nextafterl) + pushl %ebp + movl %esp,%ebp + fldt 20(%ebp) / y + subl $12,%esp + fldt 8(%ebp) / load x + fucom / x : y + fstsw %ax + sahf + jp .LNaN + je .Lequal + fstp %st(1) / x + ja .Lbigger + / x < y + ftst + movl $1,-12(%ebp) /// -12(%ebp) contains Fminl + movl $0,-8(%ebp) + movl $0,%ecx /// final needs this + movl %ecx,-4(%ebp) + fnstsw %ax + sahf + je .Lfinal + ja .Laddulp + jb .Lsubulp +.Lbigger: + / x > y + ftst + movl $1,-12(%ebp) /// -12(%ebp) contains -Fminl + movl $0,-8(%ebp) + movl $0x00008000,%ecx /// final needs this + movl %ecx,-4(%ebp) + fnstsw %ax + sahf + je .Lfinal + jb .Laddulp +.Lsubulp: + movl 12(%ebp),%edx / high word of significand of x + movl 16(%ebp),%ecx / x's exponent + andl $0x0000ffff,%ecx + movl %edx,%eax + not %eax + andl $0x80000000,%eax / look at explicit leading bit + orl %ecx,%eax + andl $0x80007fff,%eax + jnz .Lnot_pseudonormal / zero value implies pseudonormal + addl $1,%ecx / if pseudonormal, turn into equivalent normal +.Lnot_pseudonormal: + movl 8(%ebp),%eax / low x + subl $1,%eax / low x - ulp + movl %eax,-12(%ebp) + cmpl $0xffffffff,%eax / this means low x was 0 + jz .Lborrow + movl %edx,-8(%ebp) + movl %ecx,-4(%ebp) + jmp .Lfinal +.Lborrow: + cmpl $0x80000000,%edx / look at high x + je .Lsecond_borrow + subl $1,%edx + movl %edx,-8(%ebp) + movl %ecx,-4(%ebp) + jmp .Lfinal +.Lsecond_borrow: + movl %ecx,%eax + andl $0x7fff,%eax / look at exp x without sign bit + cmpl $1,%eax + jbe .Lsubnormal_result / exp > 1 ==> result will be normal + movl $0xffffffff,-8(%ebp) + subl $1,%ecx + movl %ecx,-4(%ebp) + jmp .Lfinal +.Lsubnormal_result: + movl $0x7fffffff,-8(%ebp) + movl %ecx,%eax + andl $0x8000,%eax / look at sign bit + jz .Lpositive + movl $0x8000,%ecx + movl %ecx,-4(%ebp) + jmp .Lfinal +.Lpositive: + movl $0,%ecx + movl %ecx,-4(%ebp) + jmp .Lfinal +.Laddulp: + movl 12(%ebp),%edx / high x + movl 16(%ebp),%ecx / x's exponent + andl $0x0000ffff,%ecx + movl %edx,%eax + not %eax + andl $0x80000000,%eax / look at explicit leading bit + orl %ecx,%eax + andl $0x80007fff,%eax + jnz .Lnot_pseudonormal_2 / zero value implies pseudonormal + addl $1,%ecx +.Lnot_pseudonormal_2: + movl 8(%ebp),%eax / low x + addl $1,%eax / low x + ulp + movl %eax,-12(%ebp) + jz .Lcarry / jump if the content of %eax is 0 + movl %edx,-8(%ebp) + movl %ecx,-4(%ebp) + jmp .Lfinal +.Lcarry: + movl %edx,%eax + andl $0x7fffffff,%eax + cmpl $0x7fffffff,%eax / look at high x + je .Lsecond_carry + addl $1,%edx + movl %edx,-8(%ebp) + movl %ecx,-4(%ebp) + jmp .Lfinal +.Lsecond_carry: + movl $0x80000000,-8(%ebp) + addl $1,%ecx + movl %ecx,-4(%ebp) +.Lfinal: + fstp %st(0) + fldt -12(%ebp) + andl $0x00007fff,%ecx + jz .Lunderflow + cmpw $0x7fff,%cx + je .Loverflow + jmp .Lreturn +.Loverflow: + PIC_SETUP(1) + fldt PIC_L(.LFmaxl) + PIC_WRAPUP + fmulp %st,%st(0) / create overflow signal + jmp .Lreturn +.Lunderflow: + PIC_SETUP(2) + fldt PIC_L(.LFminl) + PIC_WRAPUP + fmulp %st,%st(0) / create underflow signal + jmp .Lreturn +.Lequal: + fstp %st(0) / C99 says to return y when x == y + jmp .Lreturn +.LNaN: + faddp %st,%st(1) / x+y,x +.Lreturn: + fwait + leave + ret + .align 4 + SET_SIZE(nextafterl) |