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, 377 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/powerpc/powerpc64/power8/strchr.S b/REORG.TODO/sysdeps/powerpc/powerpc64/power8/strchr.S
new file mode 100644
index 0000000000..e0c185c162
--- /dev/null
+++ b/REORG.TODO/sysdeps/powerpc/powerpc64/power8/strchr.S
@@ -0,0 +1,377 @@
+/* Optimized strchr implementation for PowerPC64/POWER8.
+   Copyright (C) 2016-2017 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/>.  */
+
+#include <sysdep.h>
+
+#ifdef USE_AS_STRCHRNUL
+# ifndef STRCHRNUL
+#   define FUNC_NAME __strchrnul
+# else
+#   define FUNC_NAME STRCHRNUL
+# endif
+#else
+# ifndef STRCHR
+#  define FUNC_NAME strchr
+# else
+#  define FUNC_NAME STRCHR
+# endif
+#endif  /* !USE_AS_STRCHRNUL  */
+
+/* int [r3] strchr (char *s [r3], int c [r4])  */
+/* TODO: change these to the actual instructions when the minimum required
+   binutils allows it.  */
+#define MTVRD(v,r) .long (0x7c000167 | ((v)<<(32-11)) | ((r)<<(32-16)))
+#define MFVRD(r,v) .long (0x7c000067 | ((v)<<(32-11)) | ((r)<<(32-16)))
+#define VBPERMQ(t,a,b)  .long (0x1000054c \
+			| ((t)<<(32-11)) \
+			| ((a)<<(32-16)) \
+			| ((b)<<(32-21)) )
+/* TODO: change this to .machine power8 when the minimum required binutils
+   allows it.  */
+	.machine  power7
+ENTRY (FUNC_NAME)
+	CALL_MCOUNT 2
+	dcbt	0,r3
+	clrrdi	r8,r3,3	      /* Align the address to doubleword boundary.  */
+	cmpdi	cr7,r4,0
+	ld	r12,0(r8)     /* Load doubleword from memory.  */
+	li	r0,0	      /* Doubleword with null chars to use
+				 with cmpb.  */
+
+	rlwinm	r6,r3,3,26,28 /* Calculate padding.  */
+
+	beq	cr7,L(null_match)
+
+	/* Replicate byte to doubleword.  */
+	insrdi	r4,r4,8,48
+	insrdi	r4,r4,16,32
+	insrdi  r4,r4,32,0
+
+	/* Now r4 has a doubleword of c bytes and r0 has
+	   a doubleword of null bytes.  */
+
+	cmpb	r10,r12,r4     /* Compare each byte against c byte.  */
+	cmpb	r11,r12,r0     /* Compare each byte against null byte.  */
+
+	/* Move the doublewords left and right to discard the bits that are
+	   not part of the string and bring them back as zeros.  */
+#ifdef __LITTLE_ENDIAN__
+	srd	r10,r10,r6
+	srd	r11,r11,r6
+	sld	r10,r10,r6
+	sld	r11,r11,r6
+#else
+	sld	r10,r10,r6
+	sld	r11,r11,r6
+	srd	r10,r10,r6
+	srd	r11,r11,r6
+#endif
+	or	r5,r10,r11    /* OR the results to speed things up.  */
+	cmpdi	cr7,r5,0      /* If r5 == 0, no c or null bytes
+				 have been found.  */
+	bne	cr7,L(done)
+
+	mtcrf   0x01,r8
+
+	/* Are we now aligned to a doubleword boundary?  If so, skip to
+	   the main loop.  Otherwise, go through the alignment code.  */
+
+	bt	28,L(loop)
+
+	/* Handle WORD2 of pair.  */
+	ldu	r12,8(r8)
+	cmpb    r10,r12,r4
+	cmpb	r11,r12,r0
+	or	r5,r10,r11
+	cmpdi	cr7,r5,0
+	bne	cr7,L(done)
+	b	L(loop)	      /* We branch here (rather than falling through)
+				 to skip the nops due to heavy alignment
+				 of the loop below.  */
+
+	.p2align  5
+L(loop):
+	/* Load two doublewords, compare and merge in a
+	   single register for speed.  This is an attempt
+	   to speed up the null-checking process for bigger strings.  */
+	ld	r12,8(r8)
+	ldu	r9,16(r8)
+	cmpb	r10,r12,r4
+	cmpb	r11,r12,r0
+	cmpb	r6,r9,r4
+	cmpb	r7,r9,r0
+	or	r5,r10,r11
+	or	r9,r6,r7
+	or	r12,r5,r9
+	cmpdi	cr7,r12,0
+	beq	cr7,L(vector)
+	/* OK, one (or both) of the doublewords contains a c/null byte.  Check
+	   the first doubleword and decrement the address in case the first
+	   doubleword really contains a c/null byte.  */
+
+	cmpdi	cr6,r5,0
+	addi	r8,r8,-8
+	bne	cr6,L(done)
+
+	/* The c/null byte must be in the second doubleword.  Adjust the
+	   address again and move the result of cmpb to r10 so we can calculate
+	   the pointer.  */
+
+	mr	r10,r6
+	mr	r11,r7
+	addi	r8,r8,8
+#ifdef USE_AS_STRCHRNUL
+	mr	r5, r9
+#endif
+	/* r10/r11 have the output of the cmpb instructions, that is,
+	   0xff in the same position as the c/null byte in the original
+	   doubleword from the string.  Use that to calculate the pointer.  */
+L(done):
+#ifdef USE_AS_STRCHRNUL
+	mr	r10, r5
+#endif
+#ifdef __LITTLE_ENDIAN__
+	addi    r3,r10,-1
+	andc    r3,r3,r10
+	popcntd	r0,r3
+# ifndef USE_AS_STRCHRNUL
+	addi    r4,r11,-1
+	andc    r4,r4,r11
+	cmpld	cr7,r3,r4
+	bgt	cr7,L(no_match)
+# endif
+#else
+	cntlzd	r0,r10	      /* Count leading zeros before c matches.  */
+# ifndef USE_AS_STRCHRNUL
+	cmpld	cr7,r11,r10
+	bgt	cr7,L(no_match)
+# endif
+#endif
+	srdi	r0,r0,3	      /* Convert leading zeros to bytes.  */
+	add	r3,r8,r0      /* Return address of the matching c byte
+				 or null in case c was not found.  */
+	blr
+
+	/* Check the first 32B in GPR's and move to vectorized loop.  */
+	.p2align  5
+L(vector):
+	addi	r3, r8, 8
+	andi.	r10, r3, 31
+	bne	cr0, L(loop)
+	vspltisb	v0, 0
+	/* Precompute vbpermq constant.  */
+	vspltisb	v10, 3
+	lvsl	v11, r0, r0
+	vslb	v10, v11, v10
+	MTVRD(v1,r4)
+	li	r5, 16
+	vspltb	v1, v1, 7
+	/* Compare 32 bytes in each loop.  */
+L(continue):
+	lvx	v4, 0, r3
+	lvx	v5, r3, r5
+	vcmpequb	v2, v0, v4
+	vcmpequb	v3, v0, v5
+	vcmpequb	v6, v1, v4
+	vcmpequb	v7, v1, v5
+	vor	v8, v2, v3
+	vor	v9, v6, v7
+	vor	v11, v8, v9
+	vcmpequb.	v11, v0, v11
+	addi	r3, r3, 32
+	blt	cr6, L(continue)
+	/* One (or both) of the quadwords contains a c/null byte.  */
+	addi	r3, r3, -32
+#ifndef USE_AS_STRCHRNUL
+	vcmpequb.	v11, v0, v9
+	blt	cr6, L(no_match)
+#endif
+	/* Permute the first bit of each byte into bits 48-63.  */
+	VBPERMQ(v2, v2, v10)
+	VBPERMQ(v3, v3, v10)
+	VBPERMQ(v6, v6, v10)
+	VBPERMQ(v7, v7, v10)
+	/* Shift each component into its correct position for merging.  */
+#ifdef __LITTLE_ENDIAN__
+	vsldoi	v3, v3, v3, 2
+	vsldoi	v7, v7, v7, 2
+#else
+	vsldoi	v2, v2, v2, 6
+	vsldoi	v3, v3, v3, 4
+	vsldoi	v6, v6, v6, 6
+	vsldoi	v7, v7, v7, 4
+#endif
+
+        /* Merge the results and move to a GPR.  */
+        vor     v1, v3, v2
+        vor     v2, v6, v7
+        vor     v4, v1, v2
+	MFVRD(r5, v4)
+#ifdef __LITTLE_ENDIAN__
+	addi	r6, r5, -1
+	andc	r6, r6, r5
+	popcntd	r6, r6
+#else
+	cntlzd	r6, r5	/* Count leading zeros before the match.  */
+#endif
+	add	r3, r3, r6	/* Compute final length.  */
+	/* Return NULL if null found before c.  */
+#ifndef USE_AS_STRCHRNUL
+	lbz	r4, 0(r3)
+	cmpdi	cr7, r4, 0
+	beq	cr7, L(no_match)
+#endif
+	blr
+
+#ifndef USE_AS_STRCHRNUL
+	.align	4
+L(no_match):
+	li	r3,0
+	blr
+#endif
+
+/* We are here because strchr was called with a null byte.  */
+	.align	4
+L(null_match):
+	/* r0 has a doubleword of null bytes.  */
+
+	cmpb	r5,r12,r0     /* Compare each byte against null bytes.  */
+
+	/* Move the doublewords left and right to discard the bits that are
+	   not part of the string and bring them back as zeros.  */
+#ifdef __LITTLE_ENDIAN__
+	srd	r5,r5,r6
+	sld	r5,r5,r6
+#else
+	sld	r5,r5,r6
+	srd	r5,r5,r6
+#endif
+	cmpdi	cr7,r5,0      /* If r10 == 0, no c or null bytes
+				 have been found.  */
+	bne	cr7,L(done_null)
+
+	mtcrf   0x01,r8
+
+	/* Are we now aligned to a quadword boundary?  If so, skip to
+	   the main loop.  Otherwise, go through the alignment code.  */
+
+	bt	28,L(loop_null)
+
+	/* Handle WORD2 of pair.  */
+	ldu	r12,8(r8)
+	cmpb    r5,r12,r0
+	cmpdi	cr7,r5,0
+	bne	cr7,L(done_null)
+	b	L(loop_null)  /* We branch here (rather than falling through)
+				 to skip the nops due to heavy alignment
+				 of the loop below.  */
+
+	/* Main loop to look for the end of the string.  Since it's a
+	   small loop (< 8 instructions), align it to 32-bytes.  */
+	.p2align  5
+L(loop_null):
+	/* Load two doublewords, compare and merge in a
+	   single register for speed.  This is an attempt
+	   to speed up the null-checking process for bigger strings.  */
+	ld	r12,8(r8)
+	ldu     r11,16(r8)
+	cmpb	r5,r12,r0
+	cmpb	r10,r11,r0
+	or	r6,r5,r10
+	cmpdi	cr7,r6,0
+	beq	cr7,L(vector1)
+
+	/* OK, one (or both) of the doublewords contains a null byte.  Check
+	   the first doubleword and decrement the address in case the first
+	   doubleword really contains a null byte.  */
+
+	cmpdi	cr6,r5,0
+	addi	r8,r8,-8
+	bne	cr6,L(done_null)
+
+	/* The null byte must be in the second doubleword.  Adjust the address
+	   again and move the result of cmpb to r10 so we can calculate the
+	   pointer.  */
+
+	mr	r5,r10
+	addi	r8,r8,8
+
+	/* r5 has the output of the cmpb instruction, that is, it contains
+	   0xff in the same position as the null byte in the original
+	   doubleword from the string.  Use that to calculate the pointer.  */
+L(done_null):
+#ifdef __LITTLE_ENDIAN__
+	addi    r0,r5,-1
+	andc    r0,r0,r5
+	popcntd	r0,r0
+#else
+	cntlzd	r0,r5	      /* Count leading zeros before the match.  */
+#endif
+	srdi	r0,r0,3	      /* Convert leading zeros to bytes.  */
+	add	r3,r8,r0      /* Return address of the matching null byte.  */
+	blr
+	.p2align  5
+L(vector1):
+	addi    r3, r8, 8
+	andi.	r10, r3, 31
+	bne	cr0, L(loop_null)
+	vspltisb	v8, -1
+	vspltisb	v0, 0
+	vspltisb	v10, 3
+	lvsl	v11, r0, r0
+	vslb	v10, v11, v10
+	li	r5, 16
+L(continue1):
+	lvx	v4, 0, r3
+	lvx	v5, r3, r5
+	vcmpequb	v2, v0, v4
+	vcmpequb	v3, v0, v5
+	vor	v8, v2, v3
+	vcmpequb.	v11, v0, v8
+	addi	r3, r3, 32
+	blt	cr6, L(continue1)
+	addi	r3, r3, -32
+L(end1):
+	VBPERMQ(v2, v2, v10)
+	VBPERMQ(v3, v3, v10)
+	/* Shift each component into its correct position for merging.  */
+#ifdef __LITTLE_ENDIAN__
+	vsldoi	v3, v3, v3, 2
+#else
+	vsldoi	v2, v2, v2, 6
+	vsldoi	v3, v3, v3, 4
+#endif
+
+        /* Merge the results and move to a GPR.  */
+        vor     v4, v3, v2
+	MFVRD(r5, v4)
+#ifdef __LITTLE_ENDIAN__
+	addi	r6, r5, -1
+	andc	r6, r6, r5
+	popcntd	r6, r6
+#else
+	cntlzd	r6, r5	/* Count leading zeros before the match.  */
+#endif
+	add	r3, r3, r6	/* Compute final length.  */
+	blr
+END (FUNC_NAME)
+
+#ifndef USE_AS_STRCHRNUL
+weak_alias (strchr, index)
+libc_hidden_builtin_def (strchr)
+#endif