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Diffstat (limited to 'sysdeps/x86_64/fpu/e_logl.S')
-rw-r--r--sysdeps/x86_64/fpu/e_logl.S12
1 files changed, 11 insertions, 1 deletions
diff --git a/sysdeps/x86_64/fpu/e_logl.S b/sysdeps/x86_64/fpu/e_logl.S
index a0bed663c8..2ba91eedfd 100644
--- a/sysdeps/x86_64/fpu/e_logl.S
+++ b/sysdeps/x86_64/fpu/e_logl.S
@@ -38,8 +38,12 @@ limit: .double 0.29
ENTRY(__ieee754_logl)
fldln2 // log(2)
fldt 8(%rsp) // x : log(2)
+ fxam
+ fnstsw
fld %st // x : x : log(2)
- fsubl MO(one) // x-1 : x : log(2)
+ testb $1, %ah
+ jnz 3f // in case x is NaN or +-Inf
+4: fsubl MO(one) // x-1 : x : log(2)
fld %st // x-1 : x-1 : x : log(2)
fabs // |x-1| : x-1 : x : log(2)
fcompl MO(limit) // x-1 : x : log(2)
@@ -53,4 +57,10 @@ ENTRY(__ieee754_logl)
2: fstp %st(0) // x : log(2)
fyl2x // log(x)
ret
+
+3: testb $4, %ah
+ jnz 4b // in case x is +-Inf
+ fstp %st(1)
+ fstp %st(1)
+ ret
END (__ieee754_logl)