about summary refs log tree commit diff
path: root/sysdeps/sparc/sparc64/strlen.S
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/sparc/sparc64/strlen.S')
-rw-r--r--sysdeps/sparc/sparc64/strlen.S172
1 files changed, 172 insertions, 0 deletions
diff --git a/sysdeps/sparc/sparc64/strlen.S b/sysdeps/sparc/sparc64/strlen.S
new file mode 100644
index 0000000000..3facf40746
--- /dev/null
+++ b/sysdeps/sparc/sparc64/strlen.S
@@ -0,0 +1,172 @@
+/* Determine the length of a string.  For SPARC v9.
+   Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+   Contributed by Jan Vondrak <jvon4518@ss1000.ms.mff.cuni.cz> and
+                  Jakub Jelinek <jj@ultra.linux.cz>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <sysdep.h>
+#include <asm/asi.h>
+
+	/* Normally, this uses
+	   ((xword - 0x0101010101010101) & 0x8080808080808080) test
+	   to find out if any byte in xword could be zero. This is fast, but
+	   also gives false alarm for any byte in range 0x81-0xff. It does
+	   not matter for correctness, as if this test tells us there could
+	   be some zero byte, we check it byte by byte, but if bytes with
+	   high bits set are common in the strings, then this will give poor
+	   performance. You can #define EIGHTBIT_NOT_RARE and the algorithm
+	   will use one tick slower, but more precise test
+	   ((xword - 0x0101010101010101) & (~xword) & 0x8080808080808080),
+	   which does not give any false alarms (but if some bits are set,
+	   one cannot assume from it which bytes are zero and which are not).
+	   It is yet to be measured, what is the correct default for glibc
+	   in these days for an average user.
+	 */
+
+	.text
+	.align		32
+ENTRY(strlen)
+	sethi		%hi(0x01010101), %g1		/* IEU0		Group		*/
+	ldub		[%o0], %o3			/* Load				*/
+	or		%g1, %lo(0x01010101), %g1	/* IEU0		Group		*/
+	mov		%o0, %o1			/* IEU1				*/
+
+	sllx		%g1, 32, %g2			/* IEU0		Group 		*/
+	andcc		%o0, 7, %g0			/* IEU1				*/
+	or		%g1, %g2, %g1			/* IEU0		Group		*/
+	brz,pn		%o3, 13f			/* CTI+IEU1			*/
+
+	 sllx		%g1, 7, %g2			/* IEU0		Group		*/
+	bne,a,pn	%icc, 15f			/* CTI				*/
+	 add		%o0, 1, %o0			/* IEU1				*/
+							/* %g1 = 0x0101010101010101	*
+							 * %g2 = 0x8080808080808080	*
+							 * %o0 = string pointer		*
+							 * %o1 = start of string	*/
+1:	ldx		[%o0], %o3			/* Load		Group		*/
+
+	add		%o0, 8, %o0			/* IEU1				*/
+2:	sub		%o3, %g1, %o2			/* IEU0		Group		*/
+#ifdef EIGHTBIT_NOT_RARE
+	andn		%o2, %o3, %g7			/* IEU0		Group		*/
+	ldxa		[%o0] ASI_PNF, %o3		/* Load				*/
+	andcc		%g7, %g2, %g0			/* IEU1		Group		*/
+#else
+	ldxa		[%o0] ASI_PNF, %o3		/* Load				*/
+	andcc		%o2, %g2, %g0			/* IEU1		Group		*/
+#endif
+
+	be,pt		%xcc, 2b			/* CTI				*/
+	 add		%o0, 8, %o0			/* IEU0				*/
+ 	addcc		%o2, %g1, %g3			/* IEU1		Group		*/
+#ifdef EIGHTBIT_NOT_RARE
+	srlx		%g7, 32, %g7			/* IEU0				*/
+
+3:	andcc		%g7, %g2, %g0			/* IEU1		Group		*/
+#else
+	srlx		%o2, 32, %o2			/* IEU0				*/
+
+3:	andcc		%o2, %g2, %g0			/* IEU1		Group		*/
+#endif
+	be,pn		%xcc, 4f			/* CTI				*/
+	 srlx		%g3, 56, %o2			/* IEU0				*/
+	andcc		%o2, 0xff, %g0			/* IEU1		Group		*/
+
+	be,pn		%icc, 12f			/* CTI				*/
+	 srlx		%g3, 48, %o2			/* IEU0				*/
+	andcc		%o2, 0xff, %g0			/* IEU1		Group		*/
+	be,pn		%icc, 11f			/* CTI				*/
+
+	 srlx		%g3, 40, %o2			/* IEU0				*/
+	andcc		%o2, 0xff, %g0			/* IEU1		Group		*/
+	be,pn		%icc, 10f			/* CTI				*/
+	 srlx		%g3, 32, %o2			/* IEU0				*/
+
+	andcc		%o2, 0xff, %g0			/* IEU1		Group		*/
+	be,pn		%icc, 9f			/* CTI				*/
+4:	 srlx		%g3, 24, %o2			/* IEU0				*/
+	andcc		%o2, 0xff, %g0			/* IEU1		Group		*/
+
+	be,pn		%icc, 8f			/* CTI				*/
+	 srlx		%g3, 16, %o2			/* IEU0				*/
+	andcc		%o2, 0xff, %g0			/* IEU1		Group		*/
+	be,pn		%icc, 7f			/* CTI				*/
+
+	 srlx		%g3, 8, %o2			/* IEU0				*/
+	andcc		%o2, 0xff, %g0			/* IEU1		Group		*/
+	be,pn		%icc, 6f			/* CTI				*/
+	 sub		%o3, %g1, %o2			/* IEU0				*/
+
+	andcc		%g3, 0xff, %g0			/* IEU1		Group		*/
+	be,pn		%icc, 5f			/* CTI				*/
+	 ldxa		[%o0] ASI_PNF, %o3		/* Load				*/
+	andcc		%o2, %g2, %g0			/* IEU1		Group		*/
+
+	be,pt		%xcc, 2b			/* CTI				*/
+	 add		%o0, 8, %o0			/* IEU0				*/
+	addcc		%o2, %g1, %g3			/* IEU1		Group		*/
+	ba,pt		%xcc, 3b			/* CTI				*/
+
+	 srlx		%o2, 32, %o2			/* IEU0				*/
+5:	add		%o0, -9, %o0			/* IEU0		Group		*/
+	retl						/* CTI+IEU1	Group		*/
+	 sub		%o0, %o1, %o0			/* IEU0				*/
+
+6:	add		%o0, -10, %o0			/* IEU0		Group		*/
+	retl						/* CTI+IEU1	Group		*/
+	 sub		%o0, %o1, %o0			/* IEU0				*/
+7:	add		%o0, -11, %o0			/* IEU0		Group		*/
+
+	retl						/* CTI+IEU1	Group		*/
+	 sub		%o0, %o1, %o0			/* IEU0				*/
+8:	add		%o0, -12, %o0			/* IEU0		Group		*/
+	retl						/* CTI+IEU1	Group		*/
+
+	 sub		%o0, %o1, %o0			/* IEU0				*/
+9:	add		%o0, -13, %o0			/* IEU0		Group		*/
+	retl						/* CTI+IEU1	Group		*/
+	 sub		%o0, %o1, %o0			/* IEU0				*/
+
+10:	add		%o0, -14, %o0			/* IEU0		Group		*/
+	retl						/* CTI+IEU1	Group		*/
+	 sub		%o0, %o1, %o0			/* IEU0				*/
+11:	add		%o0, -15, %o0			/* IEU0		Group		*/
+
+	retl						/* CTI+IEU1	Group		*/
+	 sub		%o0, %o1, %o0			/* IEU0				*/
+12:	add		%o0, -16, %o0			/* IEU0		Group		*/
+	retl						/* CTI+IEU1	Group		*/
+
+	 sub		%o0, %o1, %o0			/* IEU0				*/
+13:	retl						/* CTI+IEU1	Group		*/
+	 mov		0, %o0				/* IEU0				*/
+	nop
+
+15:	ldub		[%o0], %o3			/* Load		Group		*/
+16:	andcc		%o0, 7, %g0			/* IEU1				*/
+	be,pn		%icc, 1b			/* CTI				*/
+	 nop						/* IEU0		Group		*/
+
+	add		%o0, 1, %o0			/* IEU1				*/
+	andcc		%o3, 0xff, %g0			/* IEU1		Group		*/
+	bne,a,pt	%icc, 16b			/* CTI				*/
+	 lduba		[%o0] ASI_PNF, %o3		/* Load				*/
+
+	add		%o0, -1, %o0			/* IEU0		Group		*/
+	retl						/* CTI+IEU1	Group		*/
+	 sub		%o0, %o1, %o0			/* IEU0				*/
+END(strlen)