Changeset 194 in vbox for trunk/src/VBox/Runtime/string/memchr.asm

Timestamp:

Jan 19, 2007 9:56:57 PM (18 years ago)

Author:

vboxsync

Message:

memchr.

File:

• trunk/src/VBox/Runtime/string/memchr.asm (copied) (copied from trunk/src/VBox/Runtime/string/memset.asm ) (2 diffs)

trunk/src/VBox/Runtime/string/memchr.asm

@@ -1 +1 @@
 ; $Id$
 ;; @file
-; InnoTek Portable Runtime - No-CRT memset - AMD64 & X86.
+; InnoTek Portable Runtime - No-CRT memchr - AMD64 & X86.
 ;
 
@@ -23 +23 @@
 
 ;;
-; @param    pvDst   gcc: rdi  msc: ecx  x86:[esp+4]
+; @param    pv      gcc: rdi  msc: ecx  x86:[esp+4]
 ; @param    ch      gcc: esi  msc: edx  x86:[esp+8]
 ; @param    cb      gcc: rdx  msc: r8   x86:[esp+0ch]
-BEGINPROC RT_NOCRT(memset)
+BEGINPROC RT_NOCRT(memchr)
         cld
 %ifdef __AMD64__
  %ifdef ASM_CALL64_MSC
-        int3
-  %error "Port me"
+        or      r8, r8
+        jz      .not_found_early
+
+        mov     r9, rdi                 ; save rdi
+        mov     eax, edx
+        mov     rdi, rcx
+        mov     rcx, r8
  %else
-        movzx   eax, sil
-        cmp     rdx, 32
-        jb      .dobytes
+        mov     rcx, rdx
+        jrcxz   .not_found_early
 
-        ; eax = (al << 24) | (al << 16) | (al << 8) | al;
-        ; rdx = (eax << 32) | eax
-        movzx   esi, sil
-        mov     rax, qword 0101010101010101h
-        imul    rax, rsi
-
-        ; todo: alignment.
-
-        mov     rcx, rdx
-        shr     rcx, 3
-        rep stosq
-
-        and     rdx, 7
-.dobytes:
-        mov     rcx, rdx
-        rep stosb
+        mov     eax, esi
  %endif
 
 %else
-        push    edi
+        mov     ecx, [esp + 0ch]
+        jecxz   .not_found_early
+        mov     edx, edi                ; save edi
+        mov     eax, [esp + 8]
+        mov     edi, [esp + 4]
+%endif
 
-        mov     ecx, [esp + 0ch + 4]
-        movzx   eax, byte [esp + 08h + 4]
-        mov     edi, [esp + 04h + 4]
-        cmp     ecx, 12
-        jb      .dobytes
+        ; do the search
+        repne   scasb
+        jne     .not_found
 
-        ; eax = (al << 24) | (al << 16) | (al << 8) | al;
-        mov     ah, al
-        mov     edx, eax
-        shr     edx, 16
-        or      eax, edx
-
-        mov     edx, ecx
-        shr     ecx, 2
-        rep stosd
-
-        and     edx, 3
-        mov     ecx, edx
-.dobytes:
-        rep stosb
-
-        pop     edi
+        ; found it
+        lea     xAX, [xDI - 1]
+%ifdef ASM_CALL64_MSC
+        mov     rdi, r9
+%endif
+%ifdef __X86__
+        mov     edi, edx
 %endif
         ret
-ENDPROC RT_NOCRT(memset)
 
+.not_found:
+%ifdef ASM_CALL64_MSC
+        mov     rdi, r9
+%endif
+%ifdef __X86__
+        mov     edi, edx
+%endif
+.not_found_early:
+        xor     eax, eax
+        ret
+ENDPROC RT_NOCRT(memchr)
+