PowerPC: Optimized isnan/isnanf for POWER8

This patch add a optimized isnan/isnanf implementation for POWER8
using the new Move From VSR Doubleword instruction to gains some
cycles from FP to GRP register move.

1 files changed, 53 insertions, 0 deletions

diff --git a/sysdeps/powerpc/powerpc64/power8/fpu/s_isnan.S b/sysdeps/powerpc/powerpc64/power8/fpu/s_isnan.S
new file mode 100644
index 0000000000..c1ca9a5b89
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/power8/fpu/s_isnan.S
@@ -0,0 +1,53 @@
+/* isnan().  PowerPC64/POWER8 version.
+   Copyright (C) 2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#include <math_ldbl_opt.h>
+
+#define MFVSRD_R3_V1  .byte 0x7c,0x23,0x00,0x66     /* mfvsrd  r3,vs1  */
+
+/* int [r3] __isnan([f1] x)  */
+
+EALIGN (__isnan, 4, 0)
+	CALL_MCOUNT 0
+	MFVSRD_R3_V1
+	lis     r9,0x7ff0
+	clrldi  r3,r3,1       /* r3 = r3 & 0x8000000000000000  */
+	rldicr  r9,r9,32,31   /* r9 = (r9 << 32) & 0xffffffff  */
+	subf    r3,r3,r9
+	rldicl  r3,r3,1,63
+	blr
+END (__isnan)
+
+/* It turns out that the 'double' version will also always work for
+   single-precision.  */
+strong_alias (__isnan, __isnanf)
+hidden_def (__isnanf)
+weak_alias (__isnanf, isnanf)
+
+#ifdef NO_LONG_DOUBLE
+strong_alias (__isnan, __isnanl)
+weak_alias (__isnan, isnanl)
+#endif
+
+#ifndef IS_IN_libm
+# if LONG_DOUBLE_COMPAT(libc, GLIBC_2_0)
+compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
+compat_symbol (libc, isnan, isnanl, GLIBC_2_0);
+# endif
+#endif