Adding upstream version 5.1.upstream/5.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 63 insertions, 0 deletions

diff --git a/lib/malloc/x386-alloca.s b/lib/malloc/x386-alloca.s
new file mode 100644
index 0000000..112d33c
--- /dev/null
+++ b/lib/malloc/x386-alloca.s
@@ -0,0 +1,63 @@
+;; alloca386.s 1.2
+;; GNU-compatible stack allocation function for Xenix/386.
+;; Written by Chip Salzenberg at ComDev.
+;; Last modified 90/01/11
+;;> Is your alloca clearly better than the one in i386-alloca.s?  I haven't
+;;> looked at either.
+;;
+;;They're different because Xenix/386 has a different assembler.  SCO
+;;Xenix has the Microsoft C compiler and the Microsoft macro assembler,
+;;called "masm".  MASM's assembler syntax is quite different from AT&T's
+;;in all sorts of ways.  Xenix people can't use the AT&T version.
+;;-- 
+;;Chip Salzenberg at ComDev/TCT     <chip@tct.uucp>, <uunet!ateng!tct!chip>
+
+	TITLE   $alloca386
+
+	.386
+DGROUP	GROUP	CONST, _BSS, _DATA
+_DATA	SEGMENT  DWORD USE32 PUBLIC 'DATA'
+_DATA      ENDS
+_BSS	SEGMENT  DWORD USE32 PUBLIC 'BSS'
+_BSS      ENDS
+CONST	SEGMENT  DWORD USE32 PUBLIC 'CONST'
+CONST      ENDS
+_TEXT	SEGMENT  DWORD USE32 PUBLIC 'CODE'
+	ASSUME   CS: _TEXT, DS: DGROUP, SS: DGROUP, ES: DGROUP
+
+	PUBLIC  _alloca
+_alloca PROC NEAR
+
+; Get argument.
+	pop     edx             ; edx -> return address
+	pop     eax             ; eax = amount to allocate
+
+; Validate allocation amount.
+	add     eax,3
+	and     eax,not 3
+	cmp     eax,0
+	jg      aa_size_ok
+	mov     eax,4
+aa_size_ok:
+
+; Allocate stack space.
+	mov     ecx,esp         ; ecx -> old stack pointer
+	sub     esp,eax         ; perform allocation
+	mov     eax,esp         ; eax -> new stack pointer
+
+; Copy the three saved register variables from old stack top to new stack top.
+; They may not be there.  So we waste twelve bytes.  Big fat hairy deal.
+	push    DWORD PTR 8[ecx]
+	push    DWORD PTR 4[ecx]
+	push    DWORD PTR 0[ecx]
+
+; Push something so the caller can pop it off.
+	push    eax
+
+; Return to caller.
+	jmp     edx
+
+_alloca ENDP
+
+_TEXT   ENDS
+	END