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path: root/src/math/x86_64/exp2l.s
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Diffstat (limited to 'src/math/x86_64/exp2l.s')
-rw-r--r--src/math/x86_64/exp2l.s75
1 files changed, 40 insertions, 35 deletions
diff --git a/src/math/x86_64/exp2l.s b/src/math/x86_64/exp2l.s
index 1f8ed7bb..e7145881 100644
--- a/src/math/x86_64/exp2l.s
+++ b/src/math/x86_64/exp2l.s
@@ -26,44 +26,32 @@ expm1l:
.type exp2l,@function
exp2l:
fldt 8(%rsp)
-1: mov $0x467ff000,%eax
- mov %eax,-16(%rsp)
- mov $0x80000000,%eax
- mov %eax,-20(%rsp)
- xor %eax,%eax
- mov %eax,-24(%rsp)
- flds -16(%rsp) # 16380
+1: fld %st(0)
+ sub $16,%rsp
+ fstpt (%rsp)
+ mov 8(%rsp),%ax
+ and $0x7fff,%ax
+ cmp $0x3fff+13,%ax
+ jb 4f # |x| < 8192
+ cmp $0x3fff+15,%ax
+ jae 3f # |x| >= 32768
+ fsts (%rsp)
+ cmpl $0xc67ff800,(%rsp)
+ jb 2f # x > -16382
+ movl $0x5f000000,(%rsp)
+ flds (%rsp) # 0x1p63
fld %st(1)
- fabs
- fucom %st(1)
+ fsub %st(1)
+ faddp
+ fucomp %st(1)
fnstsw
- fstp %st(0)
- fstp %st(0)
sahf
- ja 3f # |x| > 16380
- jp 2f # x is nan (avoid invalid except in fistp)
- fld %st(0)
- fistpl -16(%rsp)
- fildl -16(%rsp)
- fxch %st(1)
- fsub %st(1)
- mov $0x3fff,%eax
- add %eax,-16(%rsp)
- f2xm1
- fld1
- faddp # 2^(x-rint(x))
- fldt -24(%rsp) # 2^rint(x)
- fmulp
-2: fstp %st(1)
- ret
-
-3: fld %st(0)
- fstpt -24(%rsp)
- fld1
- mov -15(%rsp),%ax
- and $0x7fff,%ax
- cmp $0x7fff,%ax
- je 1f # x = +-inf
+ je 2f # x - 0x1p63 + 0x1p63 == x
+ movl $1,(%rsp)
+ flds (%rsp) # 0x1p-149
+ fdiv %st(1)
+ fstps (%rsp) # raise underflow
+2: fld1
fld %st(1)
frndint
fxch %st(2)
@@ -72,4 +60,21 @@ exp2l:
faddp # 2^(x-rint(x))
1: fscale
fstp %st(1)
+ add $16,%rsp
+ ret
+3: xor %eax,%eax
+4: cmp $0x3fff-64,%ax
+ fld1
+ jb 1b # |x| < 0x1p-64
+ fstpt (%rsp)
+ fistl 8(%rsp)
+ fildl 8(%rsp)
+ fsubrp %st(1)
+ addl $0x3fff,8(%rsp)
+ f2xm1
+ fld1
+ faddp # 2^(x-rint(x))
+ fldt (%rsp) # 2^rint(x)
+ fmulp
+ add $16,%rsp
ret