newlib-cygwin/winsup/cygwin/math/ilogbl.S

80 lines
1.4 KiB
ArmAsm

/**
* This file has no copyright assigned and is placed in the Public Domain.
* This file is part of the mingw-w64 runtime package.
* No warranty is given; refer to the file DISCLAIMER.PD within this package.
*/
#include <_mingw_mac.h>
.file "ilogbl.S"
.text
#ifdef __x86_64__
.align 8
#else
.align 4
#endif
.globl __MINGW_USYMBOL(ilogbl)
.def __MINGW_USYMBOL(ilogbl); .scl 2; .type 32; .endef
__MINGW_USYMBOL(ilogbl):
#ifdef __x86_64__
fldt (%rcx)
fxam /* Is NaN or +-Inf? */
fstsw %ax
movb $0x45, %dh
andb %ah, %dh
cmpb $0x05, %dh
je 1f /* Is +-Inf, jump. */
cmpb $0x01, %dh
je 1f /* Is +-Inf, jump. */
cmpb $0x40, %dh
je 2f /* Is +-Inf, jump. */
fxtract
pushq %rax
fstp %st
fistpl (%rsp)
fwait
popq %rax
ret
1: fstp %st
movl $0x7fffffff, %eax
ret
2: fstp %st
movl $0x80000001, %eax /* FP_ILOGB0 */
ret
#else
fldt 4(%esp)
/* I added the following ugly construct because ilogb(+-Inf) is
required to return INT_MAX in ISO C99.
-- jakub@redhat.com. */
fxam /* Is NaN or +-Inf? */
fstsw %ax
movb $0x45, %dh
andb %ah, %dh
cmpb $0x05, %dh
je 1f /* Is +-Inf, jump. */
cmpb $0x01, %dh
je 1f /* Is +-Inf, jump. */
cmpb $0x40, %dh
je 2f /* Is +-Inf, jump. */
fxtract
pushl %eax
fstp %st
fistpl (%esp)
fwait
popl %eax
ret
1: fstp %st
movl $0x7fffffff, %eax
ret
2: fstp %st
movl $0x80000001, %eax /* FP_ILOGB0 */
ret
#endif