Update.

	* sysdeps/ia64/strncpy.S: Complete rewrite.
	Contributed by Jakub Jelinek <jakub@redhat.com>.

1 files changed, 186 insertions, 63 deletions

diff --git a/sysdeps/ia64/strncpy.S b/sysdeps/ia64/strncpy.S
index 051fefa..a6e0e7b 100644
--- a/sysdeps/ia64/strncpy.S
+++ b/sysdeps/ia64/strncpy.S
@@ -1,7 +1,8 @@
 /* Optimized version of the standard strncpy() function.
    This file is part of the GNU C Library.
    Copyright (C) 2000, 2001 Free Software Foundation, Inc.
-   Contributed by Dan Pop <Dan.Pop@cern.ch>.
+   Contributed by Dan Pop <Dan.Pop@cern.ch>
+	      and Jakub Jelinek <jakub@redhat.com>.
 
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
@@ -21,80 +22,202 @@
 /* Return: dest
 
    Inputs:
-        in0:    dest
-        in1:    src
-        in2:    char count
+	in0:    dest
+	in1:    src
+	in2:	len
 
-   If n >= 24, do a memcpy(dest, src, min(strnlen(src, n)+1, n)), followed by a
-   memset(dest + strlen(src, n), 0, n - strlen(src, n) - 1) if necessary.
-
-   Otherwise, copy characters one by one and fill with nulls if necessary.  */
+   In this form, it assumes little endian mode.
+ */
 
 #include <sysdep.h>
 #undef ret
 
-#define saved_b0	loc0
-#define saved_pfs	loc1
-#define saved_pr	loc2
-#define saved_lc	loc3
-#define tmp		loc4
-#define len		loc5
+#define saved_lc	r15
+#define saved_pr	r16
+#define thresh		r17
+#define dest		r18
+#define dest2		r19
+#define src		r20
+#define len		r21
+#define asrc		r22
+#define tmp		r23
+#define pos		r24
+#define w0		r25
+#define w1		r26
+#define c		r27
+#define sh2		r28
+#define	sh1		r29
+#define loopcnt		r30
+#define	value		r31
 
-#define dest		in0
-#define src		in1
-#define n		in2
+ENTRY(strncpy)
+	.prologue
+	alloc 	r2 = ar.pfs, 3, 0, 29, 32
 
-#define rc		ret0
+#define MEMLAT 2
+	.rotr	r[MEMLAT + 2]
+	.rotp	p[MEMLAT + 1]
 
-ENTRY(strncpy)
-	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(3)
-	alloc 	saved_pfs = ar.pfs, 3, 6, 3, 0
-	mov	saved_b0 = b0
+	mov	ret0 = in0		// return value = dest
 	.save pr, saved_pr
-	mov	saved_pr = pr
+	mov	saved_pr = pr           // save the predicate registers
 	.save ar.lc, saved_lc
-	mov	saved_lc = ar.lc
+	mov 	saved_lc = ar.lc	// save the loop counter
 	.body
-	cmp.gtu	p6, p0 = 24, n
-(p6)	br.cond.spnt .cpyfew
-	mov	out0 = src
-	mov	out1 = n
-	mov     tmp = gp
-	br.call.sptk.many b0 = strnlen# ;; 	// rc = strnlen(src, n);
-	add	len = 1, rc			// include the null in len
-        mov	gp = tmp
-	mov	out0 = dest ;;
-	cmp.ltu	p4, p5 = len, n
-	mov	out1 = src ;;
-(p4)	mov	out2 = len
-(p5)	mov	out2 = n
-	br.call.sptk.many b0 = memcpy# ;;	// memcpy(dest, src, min(len, n));
-	mov     gp = tmp
-(p4)	add	out0 = dest, len
-(p4)	mov	out1 = r0
-(p4)	sub	out2 = n, len
-(p4)	br.call.sptk.many b0 = memset# ;;	// fill the rest with nulls
-(p4)	mov	gp = tmp
-	mov	rc = dest
-	mov	b0 = saved_b0
-	mov	ar.pfs = saved_pfs
-	mov	pr = saved_pr, -1
-	br.ret.sptk.many b0
-.cpyfew:
-	mov	rc = dest
-	cmp.eq	p6, p0 = n, r0		
-	adds	n = -1, n
-(p6)	br.cond.spnt .restore_and_exit ;;	// do nothing if n == 0
-	mov	ar.lc = n
-	cmp.eq	p6, p0 = r0, r0	;;		// set p6
-.loop:
-(p6)	ld1	tmp = [src],1 
+	cmp.geu p6, p5 = 24, in2
+(p6)	br.cond.spnt .short_len
+	sub	tmp = r0, in0 ;;	// tmp = -dest
+	mov	len = in2		// len
+	mov 	dest = in0		// dest
+	mov 	src = in1		// src
+	and	tmp = 7, tmp ;;		// loopcnt = -dest % 8
+	cmp.eq	p6, p7 = tmp, r0
+	adds	loopcnt = -1, tmp	// --loopcnt
+(p6)	br.cond.sptk .dest_aligned ;;
+	sub	len = len, tmp		// len -= -dest % 8
+	mov	ar.lc = loopcnt
+.l1:					// copy -dest % 8 bytes
+(p5)	ld1	c = [src], 1		// c = *src++
+	;;
+	st1	[dest] = c, 1		// *dest++ = c
+	cmp.ne	p5, p7 = c, r0
+	br.cloop.dptk .l1 ;;
+(p7)	br.cond.dpnt	.found0_align
+
+.dest_aligned:				// p7 should be cleared here
+	shr.u	c = len, 3		// c = len / 8
+	and	sh1 = 7, src 		// sh1 = src % 8
+	and	asrc = -8, src ;;	// asrc = src & -OPSIZ  -- align src
+	adds	c = (MEMLAT-1), c	// c = (len / 8) + MEMLAT - 1
+	sub	thresh = 8, sh1
+	mov	pr.rot = 1 << 16	// set rotating predicates
+	shl	sh1 = sh1, 3 ;;		// sh1 = 8 * (src % 8)
+	mov	ar.lc = c		// "infinite" loop
+	sub	sh2 = 64, sh1		// sh2 = 64 - sh1
+	cmp.eq  p6, p0 = sh1, r0 	// is the src aligned?
+(p6)    br.cond.sptk .src_aligned
+	adds	c = -(MEMLAT-1), c ;;	// c = (len / 8)
+	ld8	r[1] = [asrc],8
+	mov	ar.lc = c ;;
+
+	.align	32
+.l2:
+(p6)	st8	[dest] = value, 8	// store val to dest
+	ld8.s	r[0] = [asrc], 8
+	shr.u	value = r[1], sh1 ;; 	// value = w0 >> sh1
+	czx1.r	pos = value ;;		// do we have an "early" zero
+	cmp.lt	p7, p0 = pos, thresh	// in w0 >> sh1?
+	adds	len = -8, len		// len -= 8
+(p7)	br.cond.dpnt .nonalign_found0
+	chk.s	r[0], .recovery2	// it is safe to do that only
+.back2:					// after the previous test
+	shl	tmp = r[0], sh2  	// tmp = w1 << sh2
 	;;
-	st1	[dest] = tmp, 1
-(p6)	cmp.ne	p6, p0 = tmp, r0	// clear p6 after encountering the
-	br.cloop.dptk .loop ;;		// null character in src
+	or	value = value, tmp ;;	// value |= tmp
+	czx1.r	pos = value ;;
+	cmp.ne	p7, p6 = 8, pos
+(p7)	br.cond.dpnt .nonalign_found0
+	br.ctop.dptk    .l2 ;;
+	adds	len = 8, len
+	br.cond.sptk	.not_found0 ;;
+.nonalign_found0:
+	cmp.gtu	p6, p0 = -8, len
+(p6)	br.cond.dptk .found0
+	adds	len = 8, len
+	br.cond.sptk	.not_found0 ;;
+
+	.align	32
+.src_aligned:
+.l3:
+(p[0])		ld8.s	r[0] = [src], 8
+(p[MEMLAT])	chk.s	r[MEMLAT], .recovery3
+.back3:
+(p[MEMLAT])	mov	value = r[MEMLAT]
+(p[MEMLAT])	czx1.r	pos = r[MEMLAT] ;;
+(p[MEMLAT])	cmp.ne	p7, p0 = 8, pos
+(p[MEMLAT])	adds	len = -8, len	// len -= 8
+(p7)		br.cond.dpnt .found0
+(p[MEMLAT])	st8	[dest] = r[MEMLAT], 8
+		br.ctop.dptk .l3 ;;
+
+	chk.s	r[MEMLAT-1], .recovery4
+.back4:
+	mov	value = r[MEMLAT-1]
+
+.not_found0:
+	cmp.eq	p5, p6 = len, r0
+	adds	len = -1, len
+(p5)	br.cond.dptk	.restore_and_exit ;;
+	mov	ar.lc = len
+.l4:
+(p6)	extr.u	c = value, 0, 8		// c = value & 0xff
+(p6)	shr.u	value = value, 8 ;;
+	st1	[dest] = c, 1
+	cmp.ne	p6, p0 = c, r0
+	br.cloop.dptk	.l4
+	br.cond.sptk	.restore_and_exit
+
+.found0_align:
+	mov	pos = 0
+	adds	len = -8, len
+	mov	value = 0 ;;
+.found0:
+	shl	tmp = pos, 3
+	shr.u	loopcnt = len, 4	// loopcnt = len / 16
+	mov	c = -1 ;;
+	cmp.eq	p6, p0 = loopcnt, r0
+	adds	loopcnt = -1, loopcnt
+	shl	c = c, tmp ;;
+	and	len = 0xf, len
+	andcm	value = value, c
+	mov	ar.lc = loopcnt ;;
+	cmp.le	p7, p0 = 8, len
+	adds	dest2 = 16, dest
+	st8	[dest] = value, 8
+	and	len = 0x7, len
+(p6)	br.cond.dpnt	.l6 ;;
+.l5:
+	st8	[dest] = r0, 16
+	st8	[dest2] = r0, 16
+	br.cloop.dptk	.l5 ;;
+.l6:
+(p7)	st8	[dest] = r0, 8
+	cmp.eq	p5, p0 = len, r0
+	adds	len = -1, len
+(p5)	br.cond.dptk .restore_and_exit ;;
+	mov	ar.lc = len ;;
+.l7:
+	st1	[dest] = r0, 1
+	br.cloop.dptk	.l7 ;;
 .restore_and_exit:
-	mov	ar.lc = saved_lc
-	mov	ar.pfs = saved_pfs
+	mov 	ar.lc = saved_lc	// restore the loop counter
+	mov	pr = saved_pr, -1	// restore the predicate registers
+	br.ret.sptk.many b0
+
+.short_len:
+	cmp.eq	p5, p0 = in2, r0
+	adds	loopcnt = -1, in2
+(p5)	br.cond.spnt .restore_and_exit ;;
+	mov	ar.lc = loopcnt		// p6 should be set when we get here
+.l8:
+(p6)	ld1	c = [in1], 1		// c = *src++
+	;;
+	st1	[in0] = c, 1		// *dest++ = c
+(p6)	cmp.ne	p6, p0 = c, r0
+	br.cloop.dptk .l8
+	mov 	ar.lc = saved_lc	// restore the loop counter
+	mov	pr = saved_pr, -1	// restore the predicate registers
 	br.ret.sptk.many b0
+.recovery2:
+	add	tmp = -8, asrc ;;
+	ld8	r[0] = [tmp]
+	br.cond.sptk .back2
+.recovery3:
+	add	tmp = -(MEMLAT + 1) * 8, src ;;
+	ld8	r[MEMLAT] = [tmp]
+	br.cond.sptk .back3
+.recovery4:
+	add	tmp = -(MEMLAT + 1) * 8, src ;;
+	ld8	r[MEMLAT] = [tmp]
+	br.cond.sptk .back4
 END(strncpy)