/* * 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(1) andl $0x80000000, %edx andl $8, %eax fstp %st(1) 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)