powerpc: POWER7 optimizations ibm/2.8/master

    Add optimizations for classification functions (32-bit and 64-bit) and
    string functions (32-bit and 64-bit).

    powerpc: Re-work the Implies structure

    This patch tries to organize the implies files for ppc, since there are
    a number of processors and most of them are compatible with each other
    (backwards compatible).

    Having in mind that we start the search for processor-specific files in
    the sysdeps/unix/sysv/linux tree
    (sysdeps/unix/sysv/linux/powerpc/powerpc[32|64]/[processor]/fpu to be
    exact), we would like to grab any linux-specific code from that tree
    prior to going through the other tree (sysdeps/powerpc/...).

    For that, i removed the Implies files that were originally inside the
    fpu directories and placed then in the non-fpu directories (still inside
    the unix/sysv/linux tree). If no processor-specific/linux-specific files
    could be found, we "imply" the other tree's (sysdeps/powerpc/...) fpu
    directory for that specific processor AND also the non-fpu directory for
    that same tree.

    If, again, no processor-specific code is found, we read another Implies
    file that will point to the most compatible processor that we should
    grab code from, and so on, until we reach the power4 processor.

    So, in summary, the Implies files will live inside these directories
    now:

    * sysdeps/unix/sysv/linux/powerpc/powerpc[32|64]/[processor]
    * sysdeps/powerpc/powerpc[32|64]/[processor]

    Practical example of the order we will use to pick power6-specific code
    with the new structure.

    sysdeps/unix/sysv/linux/powerpc/powerpc[32|64]/power6/fpu ->
    sysdeps/unix/sysv/linux/powerpc/powerpc[32|64]/power6 ->
    sysdeps/powerpc/powerpc[32|64]/power6/fpu ->
    sysdeps/powerpc/powerpc[32|64]/power6 ->
    sysdeps/powerpc/powerpc[32|64]/power5+/fpu ->
    sysdeps/powerpc/powerpc[32|64]/power5+ ->
    sysdeps/powerpc/powerpc[32|64]/power5/fpu ->
    sysdeps/powerpc/powerpc[32|64]/power5 ->
    sysdeps/powerpc/powerpc[32|64]/power4/fpu ->
    sysdeps/powerpc/powerpc[32|64]/power4 (from here, it'll go to the
    generic path as usual)

1 files changed, 177 insertions, 0 deletions

diff --git a/sysdeps/powerpc/powerpc32/power7/strncmp.S b/sysdeps/powerpc/powerpc32/power7/strncmp.S
new file mode 100644
index 0000000000..ba72d0a029
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/power7/strncmp.S
@@ -0,0 +1,177 @@
+/* Optimized strcmp implementation for POWER7/PowerPC32.
+   Copyright (C) 2010 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., 51 Franklin Street, Fifth Floor, Boston MA
+   02110-1301 USA.  */
+
+#include <sysdep.h>
+#include <bp-sym.h>
+#include <bp-asm.h>
+
+/* See strlen.s for comments on how the end-of-string testing works.  */
+
+/* int [r3] strncmp (const char *s1 [r3],
+		     const char *s2 [r4],
+		     size_t size [r5])  */
+
+EALIGN (BP_SYM(strncmp),4,0)
+
+#define rTMP	r0
+#define rRTN	r3
+#define rSTR1	r3	/* first string arg */
+#define rSTR2	r4	/* second string arg */
+#define rN	r5	/* max string length */
+/* Note:  The Bounded pointer support in this code is broken.  This code
+   was inherited from PPC32 and and that support was never completed.
+   Current PPC gcc does not support -fbounds-check or -fbounded-pointers.  */
+#define rWORD1	r6	/* current word in s1 */
+#define rWORD2	r7	/* current word in s2 */
+#define rWORD3	r10
+#define rWORD4	r11
+#define rFEFE	r8	/* constant 0xfefefeff (-0x01010101) */
+#define r7F7F	r9	/* constant 0x7f7f7f7f */
+#define rNEG	r10	/* ~(word in s1 | 0x7f7f7f7f) */
+#define rBITDIF	r11	/* bits that differ in s1 & s2 words */
+
+	dcbt	0,rSTR1
+	or	rTMP,rSTR2,rSTR1
+	lis	r7F7F,0x7f7f
+	dcbt	0,rSTR2
+	clrlwi.	rTMP,rTMP,30
+	cmplwi	cr1,rN,0
+	lis	rFEFE,-0x101
+	bne	L(unaligned)
+/* We are word alligned so set up for two loops.  first a word
+   loop, then fall into the byte loop if any residual.  */
+	srwi.	rTMP,rN,2
+	clrlwi	rN,rN,30
+	addi	rFEFE,rFEFE,-0x101
+	addi	r7F7F,r7F7F,0x7f7f
+	cmplwi	cr1,rN,0
+	beq	L(unaligned)
+
+	mtctr	rTMP
+	lwz	rWORD1,0(rSTR1)
+	lwz	rWORD2,0(rSTR2)
+	b	L(g1)
+
+L(g0):
+	lwzu	rWORD1,4(rSTR1)
+	bne	cr1,L(different)
+	lwzu	rWORD2,4(rSTR2)
+L(g1):	add	rTMP,rFEFE,rWORD1
+	nor	rNEG,r7F7F,rWORD1
+	bdz	L(tail)
+	and.	rTMP,rTMP,rNEG
+	cmpw	cr1,rWORD1,rWORD2
+	beq	L(g0)
+
+/* OK. We've hit the end of the string. We need to be careful that
+   we don't compare two strings as different because of gunk beyond
+   the end of the strings...  */
+
+L(endstring):
+	and	rTMP,r7F7F,rWORD1
+	beq	cr1,L(equal)
+	add	rTMP,rTMP,r7F7F
+	xor.	rBITDIF,rWORD1,rWORD2
+
+	andc	rNEG,rNEG,rTMP
+	blt	L(highbit)
+	cntlzw	rBITDIF,rBITDIF
+	cntlzw	rNEG,rNEG
+	addi	rNEG,rNEG,7
+	cmpw	cr1,rNEG,rBITDIF
+	sub	rRTN,rWORD1,rWORD2
+	blt	cr1,L(equal)
+	srawi	rRTN,rRTN,31
+	ori	rRTN,rRTN,1
+	blr
+L(equal):
+	li	rRTN,0
+	blr
+
+L(different):
+	lwzu	rWORD1,-4(rSTR1)
+	xor.	rBITDIF,rWORD1,rWORD2
+	sub	rRTN,rWORD1,rWORD2
+	blt	L(highbit)
+	srawi	rRTN,rRTN,31
+	ori	rRTN,rRTN,1
+	blr
+L(highbit):
+	srwi	rWORD2,rWORD2,24
+	srwi	rWORD1,rWORD1,24
+	sub	rRTN,rWORD1,rWORD2
+	blr
+
+
+/* Oh well. In this case, we just do a byte-by-byte comparison.  */
+	.align	4
+L(tail):
+	and.	rTMP,rTMP,rNEG
+	cmpw	cr1,rWORD1,rWORD2
+	bne	L(endstring)
+	addi	rSTR1,rSTR1,4
+	bne	cr1,L(different)
+	addi	rSTR2,rSTR2,4
+	cmplwi	cr1,rN,0
+L(unaligned):
+	mtctr	rN
+	ble	cr1,L(ux)
+L(uz):
+	lbz	rWORD1,0(rSTR1)
+	lbz	rWORD2,0(rSTR2)
+	.align	4
+L(u1):
+	cmpwi	cr1,rWORD1,0
+	bdz	L(u4)
+	cmpw	rWORD1,rWORD2
+	beq	cr1,L(u4)
+	lbzu	rWORD3,1(rSTR1)
+	lbzu	rWORD4,1(rSTR2)
+	bne	L(u4)
+	cmpwi	cr1,rWORD3,0
+	bdz	L(u3)
+	cmpw	rWORD3,rWORD4
+	beq	cr1,L(u3)
+	lbzu	rWORD1,1(rSTR1)
+	lbzu	rWORD2,1(rSTR2)
+	bne	L(u3)
+	cmpwi	cr1,rWORD1,0
+	bdz	L(u4)
+	cmpw	rWORD1,rWORD2
+	beq	cr1,L(u4)
+	lbzu	rWORD3,1(rSTR1)
+	lbzu	rWORD4,1(rSTR2)
+	bne	L(u4)
+	cmpwi	cr1,rWORD3,0
+	bdz	L(u3)
+	cmpw	rWORD3,rWORD4
+	beq	cr1,L(u3)
+	lbzu	rWORD1,1(rSTR1)
+	lbzu	rWORD2,1(rSTR2)
+	beq	L(u1)
+
+L(u3):  sub	rRTN,rWORD3,rWORD4
+	blr
+L(u4):	sub	rRTN,rWORD1,rWORD2
+	blr
+L(ux):
+	li	rRTN,0
+	blr
+END (BP_SYM (strncmp))
+libc_hidden_builtin_def (strncmp)