summaryrefslogtreecommitdiff
path: root/libc/string/arc/arcv2/memset.S
diff options
context:
space:
mode:
Diffstat (limited to 'libc/string/arc/arcv2/memset.S')
-rw-r--r--libc/string/arc/arcv2/memset.S85
1 files changed, 85 insertions, 0 deletions
diff --git a/libc/string/arc/arcv2/memset.S b/libc/string/arc/arcv2/memset.S
new file mode 100644
index 000000000..d076ad1cd
--- /dev/null
+++ b/libc/string/arc/arcv2/memset.S
@@ -0,0 +1,85 @@
+
+/*
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
+ *
+ * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ */
+
+#include <features.h>
+#include <sysdep.h>
+
+#ifdef DONT_USE_PREALLOC
+#define PREWRITE(A,B) prefetchw [(A),(B)]
+#else
+#define PREWRITE(A,B) prealloc [(A),(B)]
+#endif
+
+ENTRY(memset)
+ prefetchw [r0] ; Prefetch the write location
+ mov.f 0, r2
+;;; if size is zero
+ jz.d [blink]
+ mov r3, r0 ; don't clobber ret val
+
+;;; if length < 8
+ brls.d.nt r2, 8, .Lsmallchunk
+ mov.f lp_count,r2
+
+ and.f r4, r0, 0x03
+ rsub lp_count, r4, 4
+ lpnz @.Laligndestination
+ ;; LOOP BEGIN
+ stb.ab r1, [r3,1]
+ sub r2, r2, 1
+.Laligndestination:
+
+;;; Destination is aligned
+ and r1, r1, 0xFF
+ asl r4, r1, 8
+ or r4, r4, r1
+ asl r5, r4, 16
+ or r5, r5, r4
+ mov r4, r5
+
+ sub3 lp_count, r2, 8
+ cmp r2, 64
+ bmsk.hi r2, r2, 5
+ mov.ls lp_count, 0
+ add3.hi r2, r2, 8
+
+;;; Convert len to Dwords, unfold x8
+ lsr.f lp_count, lp_count, 6
+ lpnz @.Lset64bytes
+ ;; LOOP START
+ PREWRITE(r3, 64) ;Prefetch the next write location
+ std.ab r4, [r3, 8]
+ std.ab r4, [r3, 8]
+ std.ab r4, [r3, 8]
+ std.ab r4, [r3, 8]
+ std.ab r4, [r3, 8]
+ std.ab r4, [r3, 8]
+ std.ab r4, [r3, 8]
+ std.ab r4, [r3, 8]
+.Lset64bytes:
+
+ lsr.f lp_count, r2, 5 ;Last remaining max 124 bytes
+ lpnz .Lset32bytes
+ ;; LOOP START
+ prefetchw [r3, 32] ;Prefetch the next write location
+ std.ab r4, [r3, 8]
+ std.ab r4, [r3, 8]
+ std.ab r4, [r3, 8]
+ std.ab r4, [r3, 8]
+.Lset32bytes:
+
+ and.f lp_count, r2, 0x1F ;Last remaining 31 bytes
+.Lsmallchunk:
+ lpnz .Lcopy3bytes
+ ;; LOOP START
+ stb.ab r1, [r3, 1]
+.Lcopy3bytes:
+
+ j [blink]
+
+END(memset)
+libc_hidden_def(memset)