[src/trunk]: src/lib/libc/arch/ns32k/string Go for correctness instead of spe...

[matthias <matthias%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/91f8f08bc731
branches:  trunk
changeset: 473539:91f8f08bc731
user:      matthias <matthias%NetBSD.org@localhost>
date:      Sun Jun 06 20:20:46 1999 +0000

description:
Go for correctness instead of speed as suggested by Ian Dall. This fixes
pr#port-pc532/7710.

diffstat:

 lib/libc/arch/ns32k/string/strcmp.S  |  133 +----------------------------------
 lib/libc/arch/ns32k/string/strncmp.S |   17 +++-
 2 files changed, 18 insertions(+), 132 deletions(-)

diffs (178 lines):

diff -r 98b3d76ce93c -r 91f8f08bc731 lib/libc/arch/ns32k/string/strcmp.S
--- a/lib/libc/arch/ns32k/string/strcmp.S       Sun Jun 06 19:58:31 1999 +0000
+++ b/lib/libc/arch/ns32k/string/strcmp.S       Sun Jun 06 20:20:46 1999 +0000
@@ -1,131 +1,4 @@
-/*     $NetBSD: strcmp.S,v 1.3 1998/04/03 22:58:09 matthias Exp $      */
-
-/* 
- * Written by Randy Hyde, 1993
- * Public domain.
- */
-
-#include <machine/asm.h>
-
-#if defined(LIBC_SCCS)
-       RCSID("$NetBSD: strcmp.S,v 1.3 1998/04/03 22:58:09 matthias Exp $")
-#endif
-
-/*
- * int
- * strcmp (const char *s1, const char *s2)
- *     compare strings s1 and s2.
- */
-
-KENTRY(strcmp, 8)
-       enter   [r3,r4,r5],0
-       movd    B_ARG1,r1
-       movd    B_ARG0,r2
-
-       /*
-        * First begin by seeing if we can doubleword align the
-        * pointers. The following code only aligns the pointer in R1.
-        * If the L.O. two bits of R2 do not match, it's going to run
-        * slower but there is nothing we can do about that. Better to
-        * have at least one of them double word aligned rather than
-        * neither.
-        */
-
-       movqd   3,r3
-       andd    r1,r3
-
-0:     casew   1f(pc)[r3:w]
-1:     .word   5f-0b
-       .word   2f-0b
-       .word   3f-0b
-       .word   4f-0b
-
-       .align  2,0xa2
-2:     cmpb    0(r1),0(r2) ; bne 8f ; cmpqb 0,0(r1) ; beq 9f
-       cmpb    1(r1),1(r2) ; bne 8f ; cmpqb 0,1(r1) ; beq 9f
-       cmpb    2(r1),2(r2) ; bne 8f ; cmpqb 0,2(r1) ; beq 9f
-       addqd   3,r1
-       addqd   3,r2
-       br      5f
-
-       .align  2,0xa2
-3:     cmpb    0(r1),0(r2) ; bne 8f ; cmpqb 0,0(r1) ; beq 9f
-       cmpb    1(r1),1(r2) ; bne 8f ; cmpqb 0,1(r1) ; beq 9f
-       addqd   2,r1
-       addqd   2,r2
-       br      5f
-
-       .align  2,0xa2
-4:     cmpb    0(r1),0(r2) ; bne 8f ; cmpqb 0,0(r1) ; beq 9f
-       addqd   1,r1
-       addqd   1,r2
+/*     $NetBSD: strcmp.S,v 1.4 1999/06/06 20:20:46 matthias Exp $      */
 
-       /*
-        * Okay, when we get down here R1 points at a double word
-        * algined source block of bytes, R2 points at another block of
-        * bytes (typically, though not always double word aligned).
-        * This guy processes four bytes at a time and checks for the
-        * zero terminating byte amongst the bytes in the double word.
-        * This algorithm is de to Dave Rand.
-        *
-        * Sneaky test for zero amongst four bytes:
-        *
-        *       xxyyzztt
-        *      -01010101
-        *      ---------
-        *       aabbccdd
-        *  bic  xxyyzztt
-        *      ---------
-        *       eeffgghh   ee=0x80 if xx=0, ff=0x80 if yy=0, etc. 
-        *
-        *              This whole result will be zero if there
-        *              was no zero byte, it will be non-zero if
-        *              there is a zero byte present.
-        */
-   
-5:     movd    0x01010101,r3           /* Magic number to use */
-       movd    0x80808080,r4           /* Another magic number. */
-       
-       movd    0(r1),r5                /* Get 1st double word. */
-       movd    r5,r0                   /* Save for storage later. */
-       subd    r3,r0                   /* Gets borrow if byte = 0. */
-       bicd    r5,r0                   /* Clear original bits. */
-       andd    r4,r0                   /* See if borrow occurred. */
-       cmpqd   0,r0
-       bne     1f                      /* If this DWORD contained a 0. */
-
-       .align  2,0xa2
-0:     movd    4(r1),r0                /* Get next 4 bytes to process */
-       cmpd    r5,0(r2)                /* Compare prev four bytes. */
-       bne     1f
-       addqd   4,r1
-       addqd   4,r2
-       movd    r0,r5                   /* Save for storage if no zeros. */
-       subd    r3,r0
-       bicd    r5,r0
-       andd    r4,r0
-       cmpqd   0,r0
-       beq     0b
-
-       /*
-        * At this point either the strings are not equal or
-        * they contain a zero byte. Check them.
-        */
-
-1:     cmpb    0(r1),0(r2) ; bne 8f ; cmpqb 0,0(r1) ; beq 9f
-       cmpb    1(r1),1(r2) ; bne 8f ; cmpqb 0,1(r1) ; beq 9f
-       cmpb    2(r1),2(r2) ; bne 8f ; cmpqb 0,2(r1) ; beq 9f
-       cmpb    3(r1),3(r2) ; bne 8f
-
-9:     movqd   0,r0
-       exit    [r3,r4,r5]
-       ret     ARGS
-
-8:     blo     0f                      /* Operands were reversed on cmp. */
-       movqd   -1,r0                   /* It's >, so return one. */
-       exit    [r3,r4,r5]
-       ret     ARGS
-
-0:     movqd   1,r0                    /* It's <, so return -1. */
-       exit    [r3,r4,r5]
-       ret     ARGS
+#define STRCMP
+#include "strncmp.S"
diff -r 98b3d76ce93c -r 91f8f08bc731 lib/libc/arch/ns32k/string/strncmp.S
--- a/lib/libc/arch/ns32k/string/strncmp.S      Sun Jun 06 19:58:31 1999 +0000
+++ b/lib/libc/arch/ns32k/string/strncmp.S      Sun Jun 06 20:20:46 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: strncmp.S,v 1.3 1998/04/03 22:58:10 matthias Exp $     */
+/*     $NetBSD: strncmp.S,v 1.4 1999/06/06 20:20:46 matthias Exp $     */
 
 /* 
  * Written by Matthias Pfaller, 1996
@@ -8,9 +8,21 @@
 #include <machine/asm.h>
 
 #if defined(LIBC_SCCS)
-       RCSID("$NetBSD: strncmp.S,v 1.3 1998/04/03 22:58:10 matthias Exp $")
+       RCSID("$NetBSD: strncmp.S,v 1.4 1999/06/06 20:20:46 matthias Exp $")
+# if defined(STRCMP)
+       RCSID("$Masqueraded: as strcmp $")
+# endif
 #endif
 
+#if defined(STRCMP)
+/*
+ * int
+ * strcmp(const char *s1, const char *s2)
+ */
+KENTRY(strcmp, 8)
+       enter   [r4],0
+       movd    -1,r0
+#else
 /*
  * int
  * strncmp(const char *s1, const char *s2, size_t len)
@@ -20,6 +32,7 @@
        movd    B_ARG2,r0
        cmpqd   0,r0
        beq     1f
+#endif
        movd    B_ARG0,r1
        movd    B_ARG1,r2
        movqd   0,r4