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.text
.global pow
.type pow,@function
# pow(x,y)
.global powf,pow,powl
.type powf,@function
.type pow,@function
.type powl,@function
powf:
flds 4(%esp) # x
flds 8(%esp) # y
jmp .L__pow
powl:
fldt 4(%esp)
fldt 16(%esp)
jmp .L__pow
pow:
fldl 4(%esp)
fldl 12(%esp)
# x^y; st(0)=y, st(1)=x
.L__pow:
ftst # y = 0 ?
fstsw %ax
fld1 # st(0)=1, st(1)=y, st(2)=x
sahf
jz 1f # return 1
fcomp %st(1) # y = 1 ?
fstsw %ax
fxch # st(0)=x, st(1)=y
sahf
jz 1f # return x
ftst # x = 0 ?
fstsw %ax
sahf
jz 1f
jnc .Lfinpow # x > 0
fxch # st(0)=y, st(1)=x
fld %st(0) # st(0)=y, st(1)=y, st(2)=x
frndint # st(0)=int(y)
fcomp %st(1) # y = int(y)?
fstsw %ax
fxch
sahf
jnz .Lfinpow # fyl2x -> st(0) = NaN
# y even or odd ?
fld1
fadd %st(0) # st(0) = 2
fdivr %st(2),%st(0) # st(0)=st(2)/2
frndint
fadd %st(0),%st(0)
fcomp %st(2) # st(0) = x, st(1) = y
fstsw %ax
fchs # st(0) = -x
sahf
jz .Lfinpow # y even
call .Lfinpow # y odd
fchs
1: ret
.Lfinpow:
fyl2x
jmp __finexp
.Lende:
.size pow,.Lende-pow
.size powf,.Lende-powf
.size powl,.Lende-powl
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