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+ #++
+ #
+ # Copyright (c) 1993 by
+ # Digital Equipment Corporation, Maynard, MA
+ #
+ # This software is furnished under a license and may be used and copied
+ # only in accordance with the terms of such license and with the
+ # inclusion of the above copyright notice. This software or any other
+ # copies thereof may not be provided or otherwise made available to any
+ # other person. No title to and ownership of the software is hereby
+ # transferred.
+ #
+ # The information in this software is subject to change without notice
+ # and should not be construed as a commitment by Digital Equipment
+ # Corporation.
+ #
+ # Digital assumes no responsibility for the use or reliability of its
+ # software on equipment which is not supplied by Digital.
+ #
+
+ # Facility:
+ #
+ # GEM/OTS - GEM compiler system support library
+ #
+ # Abstract:
+ #
+ # OTS character string support, Alpha version
+ #
+ # Authors:
+ #
+ # Bill Noyce
+ #
+ #
+ # long ots_strcmp_eqls(char *str1, long strlen, char *str2);
+ # compares two strings of the same length.
+ # returns r0=1 if str1=str2, r0=0 otherwise.
+
+ # long ots_strcmp_eql(char *str1, long str1len, char *str2, long str2len);
+ # compares two strings of different lengths, without padding.
+ # returns r0=1 if str1=str2, r0=0 otherwise.
+ #
+ # Special conventions: No stack space, r16-r21 and r27-r28 ONLY,
+ # no linkage pointer required.
+ # (Warning: The auto-loader potentially takes some regs across
+ # the call if this is being used in a shared lib. environment.)
+ #
+ # Modification history:
+ #
+ # 005 27 Aug 1991 WBN Initial version, replacing BLISS -004
+ #
+ # 006 19 May 1992 KDG Changes for common VMS/OSF sources
+ #
+ # 007 22 Sep 1992 KDG Add case-sensitive name
+ #
+ # 008 26 Jan 1993 KDG Add underscore
+ #--
+
+#include "ots_defs.hs"
+
+ # r16 --> A
+ # r17 = len
+ # r18 --> B
+ # returns r0=1 if equal, r0=0 if not equal
+ # destroys r16-r21, r27-r28
+
+ #.align octa
+ .globl _OtsStringCompareEqlSameLen
+ .ent _OtsStringCompareEqlSameLen
+_OtsStringCompareEqlSameLen:
+ .set noat
+ .set noreorder
+ .frame sp,0,r26
+ subq r17, 8, r19 # More than 8 bytes to compare?
+ beq r17, equal # Done if empty strings
+
+join: ldq_u r20, (r16) # Get first QW containing part of A
+ addq r18, r17, r27 # Point to end of B
+
+ ldq_u r21, (r18) # Get first QW containing part of B
+ bgt r19, big # Skip if more than 8 bytes
+
+ ldq_u r27, -1(r27) # Get last QW containing part of B
+ addq r16, r17, r28 # Point to end of A
+
+ extql r20, r16, r20 # Get first part of A
+
+ ldq_u r28, -1(r28) # Get last QW containing part of A
+
+ extql r21, r18, r21 # Get first part of B
+
+ extqh r27, r18, r27 # Get last part of B
+
+ extqh r28, r16, r28 # Get last part of A
+
+ or r21, r27, r27 # Combine B
+
+ or r20, r28, r28 # Combine A
+
+ xor r28, r27, r0 # Are they different?
+
+ extqh r0, r19, r0 # Discard differences after length
+
+ nop
+
+ cmpeq r0, 0, r0 # Return 1 or 0 as xor=0 or not
+ ret r31, (r26)
+
+equal: mov 1, r0 # Return true
+ ret r31, (r26)
+
+ # r16 --> A
+ # r17 = A_len
+ # r18 --> B
+ # r19 = B_len
+ # returns r0=1 if equal, r0=0 if not equal
+ # destroys r16-r21, r27-r28
+ #
+ nop #.align octa
+ nop
+
+ .globl _OtsStringCompareEql
+ .aent _OtsStringCompareEql
+_OtsStringCompareEql:
+ .frame sp,0,r26
+ cmpeq r17, r19, r0 # Are lengths equal?
+ beq r17, done # If one is zero, no compares needed
+
+ subq r17, 8, r19 # More than 8 bytes to compare?
+ blbs r0, join # Only compare if lengths equal
+
+done: ret r31, (r26) # Return result of length comparison
+
+ #.odd
+big: and r16, 7, r0 # A alignment, or amount not compared
+
+ subq r18, r0, r18 # Back up B pointer that much
+
+ and r18, 7, r17 # Is B now aligned?
+
+ addq r19, r0, r19 # (Len-8+align) is amount left to do
+ ldq_u r27, 8(r18) # Get next QW of B
+
+ subq r19, 16, r19 # More than 2 QW's left?
+ bne r17, unalign # Skip if B alignment doesn't match
+
+ xor r20, r21, r0 # Compare first (partial) QW
+ ldq_u r28, 8(r16) # Get next QW of A
+
+ mskqh r0, r16, r0 # Discard junk preceding strings
+ ble r19, bottom # Skip if two quadwords or less to go
+
+ # stall
+
+loop: ldq_u r20, 16(r16) # Get yet another QW of A
+ bne r0, not_eq # Done if difference in prior compare
+
+ xor r28, r27, r0 # Compare prior QW's
+ ldq r21, 16(r18) # Get yet another QW of B
+
+ subq r19, 16, r19 # Decrement length
+ bne r0, not_eq # Done if difference in this compare
+
+ ldq r27, 24(r18) # Get next QW of B
+ addq r18, 16, r18 # Increment pointer
+
+ ldq_u r28, 24(r16) # Get next QW of A
+ addq r16, 16, r16 # Increment pointer
+
+ xor r20, r21, r0 # Compare QW's loaded at top of loop
+ bgt r19, loop # Repeat until two or less QWs left
+
+bottom: addq r19, 8, r19 # More than 1 QW left?
+ bne r0, not_eq # Done if difference in prior compare
+
+ xor r28, r27, r0 # Compare QW's just loaded
+ ble r19, last # Skip if this is last compare
+
+ ldq_u r28, 16(r16) # Get last QW of A
+ bne r0, not_eq # Done if difference in this compare
+
+ ldq r27, 16(r18) # Get last QW of B
+
+ #2 stalls
+
+ xor r28, r27, r0 # Compare last QW's
+
+last: extqh r0, r19, r0 # Discard diffs after length
+
+ nop
+
+ cmpeq r0, 0, r0 # Return 1 or 0 as xor=0 or not
+ ret r31, (r26)
+
+ #.align quad
+unalign:
+ extql r21, r18, r21 # Get first part of B
+
+ extqh r27, r18, r0 # Get second part of B
+
+ #stall
+
+ or r0, r21, r21 # Combine pieces of B
+
+ xor r20, r21, r0 # Compare with A
+
+ mskqh r0, r16, r0 # Trim junk preceding strings
+ blt r19, bott_u # Skip if fewer than 16 bytes left
+
+loop_u: ldq_u r21, 16(r18) # Get more B
+ subq r19, 16, r19 # Decrement length
+
+ extql r27, r18, r17 # Get piece of B from prior QW
+ bne r0, not_eq # Done if r1.ne.r2
+
+ ldq_u r27, 24(r18) # Get still more B
+ addq r18, 16, r18 # Increment B pointer
+
+ ldq_u r28, 8(r16) # Get more A
+ extqh r21, r18, r0 # Get piece of B from first QW in loop
+
+ ldq_u r20, 16(r16) # Get still more A
+ extql r21, r18, r21 # Get second piece of B from there
+
+ or r17, r0, r17 # Combine pieces for first B
+
+ xor r28, r17, r0 # Compare with first A
+
+ extqh r27, r18, r17 # Start building second B
+ bne r0, not_eq # Done if r28.ne.r17
+
+ addq r16, 16, r16 # Increment A pointer
+
+ or r17, r21, r21 # Combine pieces for second B
+
+ xor r20, r21, r0 # Compare with second A
+ bge r19, loop_u # Repeat if at least 16 more bytes
+
+bott_u: and r19, 8, r17 # At least 8 more bytes?
+ bne r0, not_eq # Done if r1.ne.r2
+
+ and r19, 7, r19 # How many odd bytes?
+ beq r17, last_u # Skip if not a whole QW
+
+ extql r27, r18, r17 # Get a piece of B
+ ldq_u r27, 16(r18) # Load another QW of B
+
+ addq r18, 8, r18 # Increment B pointer
+ ldq_u r28, 8(r16) # Load another QW of A
+
+ addq r16, 8, r16 # Increment A pointer
+
+ extqh r27, r18, r0 # Get a piece of new B QW
+
+ #stall
+
+ or r17, r0, r17 # Combine pieces
+
+ xor r28, r17, r0 # Compare with A
+
+ nop
+ bne r0, not_eq # Done if r28.ne.r17
+
+last_u: addq r18, r19, r17 # Point to end of B
+ beq r19, eql_u # Return true if no more bytes
+
+ ldq_u r28, 8(r16) # Get last QW of A
+
+ ldq_u r20, 7(r17) # Get QW containing end of B
+
+ extql r27, r18, r27 # Get piece of prior B QW
+
+ #stall
+
+ extqh r20, r18, r0 # Get a piece of last B QW
+
+ #stall
+
+ or r27, r0, r27 # Combine
+
+ xor r28, r27, r0 # Compare with A
+
+ mskql r0, r19, r0 # Discard diffs after strings
+
+ nop
+
+eql_u: cmpeq r0, 0, r0 # Return 1 or 0 as xor=0 or not
+ ret r31, (r26)
+
+
+not_eq: clr r0 # Return false
+ ret r31, (r26)
+
+ .set at
+ .set reorder
+ .end _OtsStringCompareEqlSameLen