88 lines
1.7 KiB
ArmAsm
88 lines
1.7 KiB
ArmAsm
/**
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* This file has no copyright assigned and is placed in the Public Domain.
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* This file is part of the mingw-w64 runtime package.
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* No warranty is given; refer to the file DISCLAIMER.PD within this package.
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*/
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#include <_mingw_mac.h>
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.file "log2l.S"
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.text
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#ifdef __x86_64__
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.align 8
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#else
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.align 4
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#endif
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one: .double 1.0
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/* It is not important that this constant is precise. It is only
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a value which is known to be on the safe side for using the
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fyl2xp1 instruction. */
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limit: .double 0.29
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.globl __MINGW_USYMBOL(log2l)
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.def __MINGW_USYMBOL(log2l); .scl 2; .type 32; .endef
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__MINGW_USYMBOL(log2l):
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#ifdef __x86_64__
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fldl one(%rip)
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fldt (%rdx) // x : 1
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fxam
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fnstsw
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fld %st // x : x : 1
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sahf
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jc 3f // in case x is NaN or ±Inf
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4: fsub %st(2), %st // x-1 : x : 1
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fld %st // x-1 : x-1 : x : 1
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fabs // |x-1| : x-1 : x : 1
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fcompl limit(%rip) // x-1 : x : 1
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fnstsw // x-1 : x : 1
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andb $0x45, %ah
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jz 2f
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fstp %st(1) // x-1 : 1
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fyl2xp1 // log(x)
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movq %rcx,%rax
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movq $0,8(%rcx)
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fstpt (%rcx)
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ret
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2: fstp %st(0) // x : 1
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fyl2x // log(x)
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movq %rcx,%rax
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movq $0,8(%rcx)
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fstpt (%rcx)
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ret
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3: jp 4b // in case x is ±Inf
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fstp %st(1)
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fstp %st(1)
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movq %rcx,%rax
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movq $0,8(%rcx)
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fstpt (%rcx)
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ret
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#else
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fldl one
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fldt 4(%esp) // x : 1
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fxam
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fnstsw
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fld %st // x : x : 1
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sahf
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jc 3f // in case x is NaN or ±Inf
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4: fsub %st(2), %st // x-1 : x : 1
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fld %st // x-1 : x-1 : x : 1
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fabs // |x-1| : x-1 : x : 1
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fcompl limit // x-1 : x : 1
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fnstsw // x-1 : x : 1
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andb $0x45, %ah
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jz 2f
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fstp %st(1) // x-1 : 1
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fyl2xp1 // log(x)
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ret
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2: fstp %st(0) // x : 1
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fyl2x // log(x)
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ret
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3: jp 4b // in case x is ±Inf
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fstp %st(1)
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fstp %st(1)
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ret
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#endif
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