From 4cd6a4a5d7e49d54d53dcf4a6f3393d50bd88e8b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Gwenol=C3=A9=20Beauchesne?= Date: Wed, 4 Jun 2003 18:44:09 +0000 Subject: Import dietlibc 0.22 + other fixes for AMD64 --- mdk-stage1/dietlibc/i386/tanh.S | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 mdk-stage1/dietlibc/i386/tanh.S (limited to 'mdk-stage1/dietlibc/i386/tanh.S') diff --git a/mdk-stage1/dietlibc/i386/tanh.S b/mdk-stage1/dietlibc/i386/tanh.S new file mode 100644 index 000000000..61d3f3376 --- /dev/null +++ b/mdk-stage1/dietlibc/i386/tanh.S @@ -0,0 +1,32 @@ + +.text +.type tanh,@function +.global tanh + +tanh: # note: exp(x) = 2^(x*log2(e)) + fldl2e + fmull 4(%esp) # x*log2(e) + fld %st(0) # x*log2(e) x*log2(e) + frndint # int(x*log2(e)) x*log2(e) + fxch # x*log2(e) int(x*log2(e)) + fsub %st(1),%st(0) # frac(x*log2(e)) int(x*log2(e)) + f2xm1 # 2^(fract(x*log2(e)))-1 int(x*log2(e)) + fld1 # 1 2^(fract(x*log2(e)))-1 int(x*log2(e)) + faddp %st(0),%st(1) # 2^(fract(x*log2(e))) int(x*log2(e)) + fscale # 2^(x*log2(e)) int(x*log2(e)) + fstp %st(1) # 2^(x*log2(e)) + +# now we have y = exp(x), but tanh(x) = (y - 1/y) / (y + 1/y) + + fld1 + fdiv %st(1),%st(0) # 1/y y + fld %st(0) # 1/y 1/y y + fadd %st(2) # y+1/y 1/y y + fxch %st(2) # y 1/y y+1/y + fsubp # y-1/y y+1/y + fdivp # (y-1/y)/(y+1/y) + ret + +.Lende: + +.size tanh,.ende-tanh -- cgit v1.2.1