replaced strlen with glibc optimized version i586 and powerpc32

if build fails, simply delete the object file posix_build.o manually


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16819 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/libroot/posix/glibc/arch/ppc/Jamfile

@@ -118,6 +118,7 @@ MergeObject posix_gnu_arch_$(TARGET_ARCH)_other.o :
 	ldbl2mpn.c
 	lshift.S rshift.S
 	mul_1.S
+	strlen.S
 	sub_n.S
 	submul_1.S
 

src/system/libroot/posix/glibc/arch/ppc/strlen.S

@@ -0,0 +1,159 @@
+/* Optimized strlen implementation for PowerPC.
+   Copyright (C) 1997, 1999, 2000 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+#include <bp-sym.h>
+#include <bp-asm.h>
+
+/* The algorithm here uses the following techniques:
+
+   1) Given a word 'x', we can test to see if it contains any 0 bytes
+      by subtracting 0x01010101, and seeing if any of the high bits of each
+      byte changed from 0 to 1. This works because the least significant
+      0 byte must have had no incoming carry (otherwise it's not the least
+      significant), so it is 0x00 - 0x01 == 0xff. For all other
+      byte values, either they have the high bit set initially, or when
+      1 is subtracted you get a value in the range 0x00-0x7f, none of which
+      have their high bit set. The expression here is
+      (x + 0xfefefeff) & ~(x | 0x7f7f7f7f), which gives 0x00000000 when
+      there were no 0x00 bytes in the word.
+
+   2) Given a word 'x', we can test to see _which_ byte was zero by
+      calculating ~(((x & 0x7f7f7f7f) + 0x7f7f7f7f) | x | 0x7f7f7f7f).
+      This produces 0x80 in each byte that was zero, and 0x00 in all
+      the other bytes. The '| 0x7f7f7f7f' clears the low 7 bits in each
+      byte, and the '| x' part ensures that bytes with the high bit set
+      produce 0x00. The addition will carry into the high bit of each byte
+      iff that byte had one of its low 7 bits set. We can then just see
+      which was the most significant bit set and divide by 8 to find how
+      many to add to the index.
+      This is from the book 'The PowerPC Compiler Writer's Guide',
+      by Steve Hoxey, Faraydon Karim, Bill Hay and Hank Warren.
+
+   We deal with strings not aligned to a word boundary by taking the
+   first word and ensuring that bytes not part of the string
+   are treated as nonzero. To allow for memory latency, we unroll the
+   loop a few times, being careful to ensure that we do not read ahead
+   across cache line boundaries.
+
+   Questions to answer:
+   1) How long are strings passed to strlen? If they're often really long,
+   we should probably use cache management instructions and/or unroll the
+   loop more. If they're often quite short, it might be better to use
+   fact (2) in the inner loop than have to recalculate it.
+   2) How popular are bytes with the high bit set? If they are very rare,
+   on some processors it might be useful to use the simpler expression
+   ~((x - 0x01010101) | 0x7f7f7f7f) (that is, on processors with only one
+   ALU), but this fails when any character has its high bit set.  */
+
+/* Some notes on register usage: Under the SVR4 ABI, we can use registers
+   0 and 3 through 12 (so long as we don't call any procedures) without
+   saving them. We can also use registers 14 through 31 if we save them.
+   We can't use r1 (it's the stack pointer), r2 nor r13 because the user
+   program may expect them to hold their usual value if we get sent
+   a signal. Integer parameters are passed in r3 through r10.
+   We can use condition registers cr0, cr1, cr5, cr6, and cr7 without saving
+   them, the others we must save.  */
+
+/* int [r3] strlen (char *s [r3])  */
+
+ENTRY (BP_SYM (strlen))
+
+#define rTMP1	r0
+#define rRTN	r3	/* incoming STR arg, outgoing result */
+#define rSTR	r4	/* current string position */
+#define rPADN	r5	/* number of padding bits we prepend to the
+			   string to make it start at a word boundary */
+#define rFEFE	r6	/* constant 0xfefefeff (-0x01010101) */
+#define r7F7F	r7	/* constant 0x7f7f7f7f */
+#define rWORD1	r8	/* current string word */
+#define rWORD2	r9	/* next string word */
+#define rMASK	r9	/* mask for first string word */
+#define rTMP2	r10
+#define rTMP3	r11
+#define rTMP4	r12
+
+	CHECK_BOUNDS_LOW (rRTN, rTMP1, rTMP2)
+
+	clrrwi	rSTR, rRTN, 2
+	lis	r7F7F, 0x7f7f
+	rlwinm	rPADN, rRTN, 3, 27, 28
+	lwz	rWORD1, 0(rSTR)
+	li	rMASK, -1
+	addi	r7F7F, r7F7F, 0x7f7f
+/* That's the setup done, now do the first pair of words.
+   We make an exception and use method (2) on the first two words, to reduce
+   overhead.  */
+	srw	rMASK, rMASK, rPADN
+	and	rTMP1, r7F7F, rWORD1
+	or	rTMP2, r7F7F, rWORD1
+	add	rTMP1, rTMP1, r7F7F
+	nor	rTMP1, rTMP2, rTMP1
+	and.	rWORD1, rTMP1, rMASK
+	mtcrf	0x01, rRTN
+	bne	L(done0)
+	lis	rFEFE, -0x101
+	addi	rFEFE, rFEFE, -0x101
+/* Are we now aligned to a doubleword boundary?  */
+	bt	29, L(loop)
+
+/* Handle second word of pair.  */
+	lwzu	rWORD1, 4(rSTR)
+	and	rTMP1, r7F7F, rWORD1
+	or	rTMP2, r7F7F, rWORD1
+	add	rTMP1, rTMP1, r7F7F
+	nor.	rWORD1, rTMP2, rTMP1
+	bne	L(done0)
+
+/* The loop.  */
+
+L(loop):
+	lwz	rWORD1, 4(rSTR)
+	lwzu	rWORD2, 8(rSTR)
+	add	rTMP1, rFEFE, rWORD1
+	nor	rTMP2, r7F7F, rWORD1
+	and.	rTMP1, rTMP1, rTMP2
+	add	rTMP3, rFEFE, rWORD2
+	nor	rTMP4, r7F7F, rWORD2
+	bne	L(done1)
+	and.	rTMP1, rTMP3, rTMP4
+	beq	L(loop)
+
+	and	rTMP1, r7F7F, rWORD2
+	add	rTMP1, rTMP1, r7F7F
+	andc	rWORD1, rTMP4, rTMP1
+	b	L(done0)
+
+L(done1):
+	and	rTMP1, r7F7F, rWORD1
+	subi	rSTR, rSTR, 4
+	add	rTMP1, rTMP1, r7F7F
+	andc	rWORD1, rTMP2, rTMP1
+
+/* When we get to here, rSTR points to the first word in the string that
+   contains a zero byte, and the most significant set bit in rWORD1 is in that
+   byte.  */
+L(done0):
+	cntlzw	rTMP3, rWORD1
+	subf	rTMP1, rRTN, rSTR
+	srwi	rTMP3, rTMP3, 3
+	add	rRTN, rTMP1, rTMP3
+	/* GKM FIXME: check high bound.  */
+	blr
+END (BP_SYM (strlen))

src/system/libroot/posix/glibc/arch/x86/Jamfile

@@ -101,6 +101,7 @@ MergeObject posix_gnu_arch_$(TARGET_ARCH)_other.o :
 	mplog.c
 	mul_1.S
 	lshift.S rshift.S
+	strlen.S
 	sub_n.S
 	submul_1.S
 ;

src/system/libroot/posix/glibc/arch/x86/strlen.S

@@ -0,0 +1,188 @@
+/* strlen -- Compute length of NUL terminated string.
+   Highly optimized version for ix86, x>=5.
+   Copyright (C) 1995, 1996, 1997, 2000, 2002 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu>.
+
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+#include "asm-syntax.h"
+#include "bp-sym.h"
+#include "bp-asm.h"
+
+/* This version is especially optimized for the i586 (and following?)
+   processors.  This is mainly done by using the two pipelines.  The
+   version optimized for i486 is weak in this aspect because to get
+   as much parallelism we have to execute some *more* instructions.
+
+   The code below is structured to reflect the pairing of the instructions
+   as *I think* it is.  I have no processor data book to verify this.
+   If you find something you think is incorrect let me know.  */
+
+
+/* The magic value which is used throughout in the whole code.  */
+#define magic 0xfefefeff
+
+#define PARMS	LINKAGE		/* no space for saved regs */
+#define STR	PARMS
+
+	.text
+ENTRY (BP_SYM (strlen))
+	ENTER
+
+	movl STR(%esp), %eax
+	CHECK_BOUNDS_LOW (%eax, STR(%esp))
+	movl $3, %edx		/* load mask (= 3) */
+
+	andl %eax, %edx		/* separate last two bits of address */
+
+	jz L(1)			/* aligned => start loop */
+	jp L(0)			/* exactly two bits set */
+
+	cmpb %dh, (%eax)	/* is byte NUL? */
+	je L(2)			/* yes => return */
+
+	incl %eax		/* increment pointer */
+	cmpb %dh, (%eax)	/* is byte NUL? */
+
+	je L(2)			/* yes => return */
+
+	incl %eax		/* increment pointer */
+	xorl $2, %edx
+
+	jz L(1)
+
+L(0):	cmpb %dh, (%eax)	/* is byte NUL? */
+	je L(2)			/* yes => return */
+
+	incl %eax		/* increment pointer */
+	xorl %edx, %edx		/* We need %edx == 0 for later */
+
+      /* We exit the loop if adding MAGIC_BITS to LONGWORD fails to
+	 change any of the hole bits of LONGWORD.
+
+	 1) Is this safe?  Will it catch all the zero bytes?
+	 Suppose there is a byte with all zeros.  Any carry bits
+	 propagating from its left will fall into the hole at its
+	 least significant bit and stop.  Since there will be no
+	 carry from its most significant bit, the LSB of the
+	 byte to the left will be unchanged, and the zero will be
+	 detected.
+
+	 2) Is this worthwhile?  Will it ignore everything except
+	 zero bytes?  Suppose every byte of LONGWORD has a bit set
+	 somewhere.  There will be a carry into bit 8.	If bit 8
+	 is set, this will carry into bit 16.  If bit 8 is clear,
+	 one of bits 9-15 must be set, so there will be a carry
+	 into bit 16.  Similarly, there will be a carry into bit
+	 24.  If one of bits 24-31 is set, there will be a carry
+	 into bit 32 (=carry flag), so all of the hole bits will
+	 be changed.
+
+	 Note: %edx == 0 in any case here.  */
+
+L(1):
+	movl (%eax), %ecx	/* get word (= 4 bytes) in question */
+	addl $4, %eax		/* adjust pointer for *next* word */
+
+	subl %ecx, %edx		/* first step to negate word */
+	addl $magic, %ecx	/* add magic word */
+
+	decl %edx		/* complete negation of word */
+	jnc L(3)		/* previous addl caused overflow? */
+
+	xorl %ecx, %edx		/* (word+magic)^word */
+
+	andl $~magic, %edx	/* any of the carry flags set? */
+
+	jne L(3)		/* yes => determine byte */
+
+
+	movl (%eax), %ecx	/* get word (= 4 bytes) in question */
+	addl $4, %eax		/* adjust pointer for *next* word */
+
+	subl %ecx, %edx		/* first step to negate word */
+	addl $magic, %ecx	/* add magic word */
+
+	decl %edx		/* complete negation of word */
+	jnc L(3)		/* previous addl caused overflow? */
+
+	xorl %ecx, %edx		/* (word+magic)^word */
+
+	andl $~magic, %edx	/* any of the carry flags set? */
+
+	jne L(3)		/* yes => determine byte */
+
+
+	movl (%eax), %ecx	/* get word (= 4 bytes) in question */
+	addl $4, %eax		/* adjust pointer for *next* word */
+
+	subl %ecx, %edx		/* first step to negate word */
+	addl $magic, %ecx	/* add magic word */
+
+	decl %edx		/* complete negation of word */
+	jnc L(3)		/* previous addl caused overflow? */
+
+	xorl %ecx, %edx		/* (word+magic)^word */
+
+	andl $~magic, %edx	/* any of the carry flags set? */
+
+	jne L(3)		/* yes => determine byte */
+
+
+	movl (%eax), %ecx	/* get word (= 4 bytes) in question */
+	addl $4, %eax		/* adjust pointer for *next* word */
+
+	subl %ecx, %edx		/* first step to negate word */
+	addl $magic, %ecx	/* add magic word */
+
+	decl %edx		/* complete negation of word */
+	jnc L(3)		/* previous addl caused overflow? */
+
+	xorl %ecx, %edx		/* (word+magic)^word */
+
+	andl $~magic, %edx	/* any of the carry flags set? */
+
+	je L(1)			/* no => start loop again */
+
+
+L(3):	subl $4, %eax		/* correct too early pointer increment */
+	subl $magic, %ecx
+
+	cmpb $0, %cl		/* lowest byte NUL? */
+	jz L(2)			/* yes => return */
+
+	inc %eax		/* increment pointer */
+	testb %ch, %ch		/* second byte NUL? */
+
+	jz L(2)			/* yes => return */
+
+	shrl $16, %ecx		/* make upper bytes accessible */
+	incl %eax		/* increment pointer */
+
+	cmpb $0, %cl		/* is third byte NUL? */
+	jz L(2)			/* yes => return */
+
+	incl %eax		/* increment pointer */
+
+L(2):	CHECK_BOUNDS_HIGH (%eax, STR(%esp), jb)
+	subl STR(%esp), %eax	/* now compute the length as difference
+				   between start and terminating NUL
+				   character */
+	LEAVE
+	ret
+END (BP_SYM (strlen))

src/system/libroot/posix/string/Jamfile

@@ -25,7 +25,6 @@ MergeObject posix_string.o :
 	strerror.c
 	strlcat.c
 	strlcpy.c
-	strlen.c
 	strncat.c
 	strncmp.c
 	strncpy.c

src/system/libroot/posix/string/strlen.c

@@ -1,20 +0,0 @@
-/* 
-** Copyright 2001, Travis Geiselbrecht. All rights reserved.
-** Distributed under the terms of the NewOS License.
-*/
-
-#include <sys/types.h>
-#include <string.h>
-
-
-size_t
-strlen(char const *s)
-{
-	size_t i = 0;
-
-	while (s[i]) {
-		i += 1;
-	}
-
-	return i;
-}