diff options
Diffstat (limited to 'src/math/i386/exp.s')
| -rw-r--r-- | src/math/i386/exp.s | 37 |
1 files changed, 35 insertions, 2 deletions
diff --git a/src/math/i386/exp.s b/src/math/i386/exp.s index e3b42af5..e5f54588 100644 --- a/src/math/i386/exp.s +++ b/src/math/i386/exp.s @@ -2,7 +2,18 @@ .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 @@ -14,10 +25,32 @@ expm1l: .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 |