Changeset 40788 in vbox for trunk/src/VBox/Runtime/common/string

Timestamp:

Apr 6, 2012 12:52:33 PM (13 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

77296

Message:

IPRT:strncpy implementation for the no-crt mode.

File:

• trunk/src/VBox/Runtime/common/string/strncpy.asm (copied) (copied from trunk/src/VBox/Runtime/common/string/strcpy.asm ) (4 diffs)

trunk/src/VBox/Runtime/common/string/strncpy.asm

@@ -1 +1 @@
 ; $Id$
 ;; @file
-; IPRT - No-CRT strcpy - AMD64 & X86.
+; IPRT - No-CRT strncpy - AMD64 & X86.
 ;
 
 ;
-; Copyright (C) 2006-2007 Oracle Corporation
+; Copyright (C) 2006-2012 Oracle Corporation
 ;
 ; This file is part of VirtualBox Open Source Edition (OSE), as
@@ -32 +32 @@
 ; @param    pszDst   gcc: rdi  msc: rcx  x86:[esp+4]
 ; @param    pszSrc   gcc: rsi  msc: rdx  x86:[esp+8]
+; @param    cbMax    gcc: rdx  msc: r8   x86:[esp+12]
 RT_NOCRT_BEGINPROC strcpy
         ; input
@@ -38 +39 @@
   %define pszDst rcx
   %define pszSrc rdx
+  %define cbMax  r8
  %else
   %define pszDst rdi
   %define pszSrc rsi
+  %define cbMax  rdx
  %endif
-        mov     r8, pszDst
+        mov     r9, pszDst
 %else
         mov     ecx, [esp + 4]
         mov     edx, [esp + 8]
+        push    ebx
+        mov     ebx, [esp + 12 + 4]
   %define pszDst ecx
   %define pszSrc edx
+  %define cbMax  ebx
         push    pszDst
 %endif
 
         ;
-        ; The loop.
+        ; The rolled out loop.
         ;
 .next:
+        cmp     cbMax, 4
+        jb      .simple_intro
+
         mov     al, [pszSrc]
         mov     [pszDst], al
@@ -77 +86 @@
         add     pszDst, 4
         add     pszSrc, 4
+        sub     cbMax,  4
         jmp     .next
+
+        ;
+        ; Char by char.
+        ;
+.simple_intro:
+        test    cbMax, cbMax
+        jz      .done
+
+.simple_next:
+        mov     al, [pszSrc]
+        mov     [pszDst], al
+        test    al, al
+        jz      .done
+
+        dec     cbMax
+        jz      .done
+
+        inc     pszSrc
+        inc     pszDst
+        jmp     .simple_next
 
 .done:
 %ifdef RT_ARCH_AMD64
-        mov     rax, r8
+        mov     rax, r9
 %else
+        pop     ebx
         pop     eax
 %endif