.type expm1f,@function
expm1f:
flds 4(%esp)
- jmp 1f
+ mov 4(%esp),%eax
+ add %eax,%eax
+ cmp $0x01000000,%eax
+ jae 1f
+ # subnormal x, return x with underflow
+ fnstsw %ax
+ and $16,%ax
+ jnz 2f
+ fld %st(0)
+ fmul %st(1)
+ fstps 4(%esp)
+2: ret
.global expm1l
.type expm1l,@function
.type expm1,@function
expm1:
fldl 4(%esp)
+ mov 8(%esp),%eax
+ add %eax,%eax
+ cmp $0x00200000,%eax
+ jae 1f
+ # subnormal x, return x with underflow
+ fnstsw %ax
+ and $16,%ax
+ jnz 2f
+ fsts 4(%esp)
+2: ret
1: fldl2e
fmulp
+ mov $0xc2820000,%eax
+ push %eax
+ flds (%esp)
+ pop %eax
+ fucomp %st(1)
+ fnstsw %ax
+ sahf
fld1
- fld %st(1)
+ jb 1f
+ # x*log2e < -65, return -1 without underflow
+ fstp %st(1)
+ fchs
+ ret
+1: fld %st(1)
fabs
fucom %st(1)
fnstsw %ax
flds 4(%esp)
jmp 2f
-.global expl
-.type expl,@function
-expl:
- fldt 4(%esp)
- jmp 2f
-
.global exp
.type exp,@function
exp:
.type exp2,@function
exp2:
fldl 4(%esp)
-1: mov $0x47000000,%eax
- push %eax
- flds (%esp)
- shl $7,%eax
- push %eax
- add %eax,%eax
- push %eax
+1: sub $12,%esp
+ fld %st(0)
+ fstpt (%esp)
+ mov 8(%esp),%ax
+ and $0x7fff,%ax
+ cmp $0x3fff+13,%ax
+ jb 4f # |x| < 8192
+ cmp $0x3fff+15,%ax
+ jae 3f # |x| >= 32768
+ fsts (%esp)
+ cmpl $0xc67ff800,(%esp)
+ jb 2f # x > -16382
+ movl $0x5f000000,(%esp)
+ flds (%esp) # 0x1p63
fld %st(1)
- fabs
- fucom %st(1)
+ fsub %st(1)
+ faddp
+ fucomp %st(1)
fnstsw
sahf
- ja 2f
- fstp %st(0)
- fstp %st(0)
- fld %st(0)
- fistpl 8(%esp)
- fildl 8(%esp)
- fxch %st(1)
- fsub %st(1)
- mov $0x3fff,%eax
- add %eax,8(%esp)
+ je 2f # x - 0x1p63 + 0x1p63 == x
+ movl $1,(%esp)
+ flds (%esp) # 0x1p-149
+ fdiv %st(1)
+ fstps (%esp) # raise underflow
+2: fld1
+ fld %st(1)
+ frndint
+ fxch %st(2)
+ fsub %st(2) # st(0)=x-rint(x), st(1)=1, st(2)=rint(x)
f2xm1
- fld1
- faddp
- fldt (%esp)
- fmulp
+ faddp # 2^(x-rint(x))
+1: fscale
fstp %st(1)
add $12,%esp
ret
-
-2: fstp %st(0)
- fstp %st(0)
- fsts 8(%esp)
- mov 8(%esp),%eax
- lea (%eax,%eax),%ecx
- cmp $0xff000000,%ecx
- ja 2f
- fstp %st(0)
- xor %ecx,%ecx
- inc %ecx
- add %eax,%eax
- jc 1f
- mov $0x7ffe,%ecx
-1: mov %ecx,8(%esp)
- fldt (%esp)
- fld %st(0)
+3: xor %eax,%eax
+4: cmp $0x3fff-64,%ax
+ fld1
+ jb 1b # |x| < 0x1p-64
+ fstpt (%esp)
+ fistl 8(%esp)
+ fildl 8(%esp)
+ fsubrp %st(1)
+ addl $0x3fff,8(%esp)
+ f2xm1
+ fld1
+ faddp # 2^(x-rint(x))
+ fldt (%esp) # 2^rint(x)
fmulp
-2: add $12,%esp
+ add $12,%esp
ret