From b8cdc234c67d883b7e9d6e4caf4ba15972ac7788 Mon Sep 17 00:00:00 2001 From: Danny Smith Date: Mon, 29 Jul 2002 03:00:10 +0000 Subject: Add incomplet long double math support to libmingwex.a --- winsup/mingw/mingwex/math/log2l.S | 48 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 winsup/mingw/mingwex/math/log2l.S (limited to 'winsup/mingw/mingwex/math/log2l.S') diff --git a/winsup/mingw/mingwex/math/log2l.S b/winsup/mingw/mingwex/math/log2l.S new file mode 100644 index 000000000..52503fc52 --- /dev/null +++ b/winsup/mingw/mingwex/math/log2l.S @@ -0,0 +1,48 @@ +/* + * Written by J.T. Conklin . + * Adapted for use as log2 by Ulrich Drepper . + * Public domain. + * + * Changed to use fyl2xp1 for values near 1, . + */ + + .file "log2l.S" + .text + .align 4 +one: .double 1.0 + /* It is not important that this constant is precise. It is only + a value which is known to be on the safe side for using the + fyl2xp1 instruction. */ +limit: .double 0.29 + + .text + .align 4 +.globl _log2l + .def _log2l; .scl 2; .type 32; .endef +_log2l: + fldl one + fldt 4(%esp) // x : 1 + fxam + fnstsw + fld %st // x : x : 1 + sahf + jc 3f // in case x is NaN or ħInf +4: fsub %st(2), %st // x-1 : x : 1 + fld %st // x-1 : x-1 : x : 1 + fabs // |x-1| : x-1 : x : 1 + fcompl limit // x-1 : x : 1 + fnstsw // x-1 : x : 1 + andb $0x45, %ah + jz 2f + fstp %st(1) // x-1 : 1 + fyl2xp1 // log(x) + ret + +2: fstp %st(0) // x : 1 + fyl2x // log(x) + ret + +3: jp 4b // in case x is ħInf + fstp %st(1) + fstp %st(1) + ret -- cgit v1.2.3