Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 168 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/powerpc/powerpc64/power7/strcmp.S b/REORG.TODO/sysdeps/powerpc/powerpc64/power7/strcmp.S
new file mode 100644
index 0000000000..14e14f457e
--- /dev/null
+++ b/REORG.TODO/sysdeps/powerpc/powerpc64/power7/strcmp.S
@@ -0,0 +1,168 @@
+/* Optimized strcmp implementation for Power7 using 'cmpb' instruction
+   Copyright (C) 2014-2017 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/>.  */
+
+/* The optimization is achieved here through cmpb instruction.
+   8byte aligned strings are processed with double word comparision
+   and unaligned strings are handled effectively with loop unrolling
+   technique  */
+
+#include <sysdep.h>
+
+#ifndef STRCMP
+# define STRCMP strcmp
+#endif
+
+/* int [r3] strcmp (const char *s1 [r3], const char *s2 [r4])  */
+
+	.machine	power7
+EALIGN (STRCMP, 4, 0)
+	CALL_MCOUNT 2
+
+	or r9, r3, r4
+	rldicl. r10, r9, 0, 61	/* are s1 and s2 8 byte aligned..?  */
+	bne cr0, L(process_unaligned_bytes)
+	li	r5, 0
+
+	.align 4
+/* process input parameters on double word aligned boundary  */
+L(unrollDword):
+	ld	r8,0(r3)
+	ld	r10,0(r4)
+	cmpb	r7,r8,r5
+	cmpdi	cr7,r7,0
+	mr	r9,r7
+	bne 	cr7,L(null_found)
+	cmpld	cr7,r8,r10
+	bne	cr7,L(different)
+
+	ld	r8,8(r3)
+	ld	r10,8(r4)
+	cmpb	r7,r8,r5
+	cmpdi	cr7,r7,0
+	mr	r9,r7
+	bne 	cr7,L(null_found)
+	cmpld	cr7,r8,r10
+	bne	cr7,L(different)
+
+	ld	r8,16(r3)
+	ld	r10,16(r4)
+	cmpb	r7,r8,r5
+	cmpdi	cr7,r7,0
+	mr	r9,r7
+	bne 	cr7,L(null_found)
+	cmpld	cr7,r8,r10
+	bne	cr7,L(different)
+
+	ld	r8,24(r3)
+	ld	r10,24(r4)
+	cmpb	r7,r8,r5
+	cmpdi	cr7,r7,0
+	mr	r9,r7
+	bne 	cr7,L(null_found)
+	cmpld	cr7,r8,r10
+	bne	cr7,L(different)
+
+	addi r3, r3, 32
+	addi r4, r4, 32
+	beq cr7, L(unrollDword)
+
+	.align 4
+L(null_found):
+#ifdef __LITTLE_ENDIAN__
+	neg	r7,r9
+	and	r9,r9,r7
+	li	r7,-1
+	cntlzd	r9,r9
+	subfic	r9,r9,71
+	sld	r9,r7,r9
+#else
+	cntlzd	r9,r9
+	li	r7,-1
+	addi	r9,r9,8
+	srd	r9,r7,r9
+#endif
+	or	r8,r8,r9
+	or	r10,r10,r9
+
+L(different):
+	cmpb	r9,r8,r10
+#ifdef __LITTLE_ENDIAN__
+	addi	r7,r9,1
+	andc	r9,r7,r9
+	cntlzd	r9,r9
+	subfic	r9,r9,63
+#else
+	not	r9,r9
+	cntlzd	r9,r9
+	subfic	r9,r9,56
+#endif
+	srd	r3,r8,r9
+	srd	r10,r10,r9
+	rldicl	r10,r10,0,56
+	rldicl	r3,r3,0,56
+	subf	r3,r10,r3
+	blr
+
+	.align 4
+L(process_unaligned_bytes):
+	lbz r9, 0(r3)		/* load byte from s1  */
+	lbz r10, 0(r4)		/* load byte from s2  */
+	cmpdi cr7, r9, 0	/* compare *s1 with NULL  */
+	beq cr7, L(diffOfNULL)	/* if *s1 is NULL , return *s1 - *s2  */
+	cmplw cr7, r9, r10	/* compare *s1 and *s2  */
+	bne cr7, L(ComputeDiff)	/* branch to compute difference and return  */
+
+	lbz r9, 1(r3)		/* load next byte from s1  */
+	lbz r10, 1(r4)		/* load next byte from s2  */
+	cmpdi cr7, r9, 0	/* compare *s1 with NULL  */
+	beq cr7, L(diffOfNULL)	/* if *s1 is NULL , return *s1 - *s2  */
+	cmplw cr7, r9, r10	/* compare *s1 and *s2  */
+	bne cr7, L(ComputeDiff)	/* branch to compute difference and return  */
+
+	lbz r9, 2(r3)		/* unroll 3rd byte here  */
+	lbz r10, 2(r4)
+	cmpdi cr7, r9, 0
+	beq cr7, L(diffOfNULL)
+	cmplw cr7, r9, r10
+	bne 7, L(ComputeDiff)
+
+	lbz r9, 3(r3)		/* unroll 4th byte now  */
+	lbz r10, 3(r4)
+	addi r3, r3, 4		/* increment s1 by unroll factor  */
+	cmpdi cr7, r9, 0
+	cmplw cr6, 9, r10
+	beq cr7, L(diffOfNULL)
+	addi r4, r4, 4		/* increment s2 by unroll factor  */
+	beq cr6, L(process_unaligned_bytes)	/* unroll byte processing  */
+
+	.align 4
+L(ComputeDiff):
+	extsw r9, r9
+	subf r10, r10, r9	/* compute s1 - s2  */
+	extsw r3, r10
+	blr			/* return  */
+
+	.align 4
+L(diffOfNULL):
+	li r9, 0
+	subf r10, r10, r9	/* compute s1 - s2  */
+	extsw r3, r10		/* sign extend result  */
+	blr			/* return  */
+
+END (STRCMP)
+libc_hidden_builtin_def (strcmp)