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-rw-r--r--libc/string/frv/memcpy.S124
1 files changed, 124 insertions, 0 deletions
diff --git a/libc/string/frv/memcpy.S b/libc/string/frv/memcpy.S
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+/* memcpy.S: optimised assembly memcpy
+ *
+ * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+ .text
+ .p2align 4
+
+###############################################################################
+#
+# void *memcpy(void *to, const char *from, size_t count)
+#
+# - NOTE: must not use any stack. exception detection performs function return
+# to caller's fixup routine, aborting the remainder of the copy
+#
+###############################################################################
+ .globl memcpy
+ .type memcpy,@function
+memcpy:
+ or.p gr8,gr9,gr4
+ orcc gr10,gr0,gr0,icc3
+ or.p gr10,gr4,gr4
+ beqlr icc3,#0
+
+ # optimise based on best common alignment for to, from & count
+ andicc.p gr4,#0x1f,gr0,icc0
+ setlos #8,gr11
+ andicc.p gr4,#0x0f,gr0,icc1
+ beq icc0,#0,memcpy_32
+ andicc.p gr4,#0x07,gr0,icc0
+ beq icc1,#0,memcpy_16
+ andicc.p gr4,#0x03,gr0,icc1
+ beq icc0,#0,memcpy_8
+ andicc.p gr4,#0x01,gr0,icc0
+ beq icc1,#0,memcpy_4
+ setlos.p #1,gr11
+ beq icc0,#0,memcpy_2
+
+ # do byte by byte copy
+ sub.p gr8,gr11,gr3
+ sub gr9,gr11,gr9
+0: ldubu.p @(gr9,gr11),gr4
+ subicc gr10,#1,gr10,icc0
+ stbu.p gr4,@(gr3,gr11)
+ bne icc0,#2,0b
+ bralr
+
+ # do halfword by halfword copy
+memcpy_2:
+ setlos #2,gr11
+ sub.p gr8,gr11,gr3
+ sub gr9,gr11,gr9
+0: lduhu.p @(gr9,gr11),gr4
+ subicc gr10,#2,gr10,icc0
+ sthu.p gr4,@(gr3,gr11)
+ bne icc0,#2,0b
+ bralr
+
+ # do word by word copy
+memcpy_4:
+ setlos #4,gr11
+ sub.p gr8,gr11,gr3
+ sub gr9,gr11,gr9
+0: ldu.p @(gr9,gr11),gr4
+ subicc gr10,#4,gr10,icc0
+ stu.p gr4,@(gr3,gr11)
+ bne icc0,#2,0b
+ bralr
+
+ # do double-word by double-word copy
+memcpy_8:
+ sub.p gr8,gr11,gr3
+ sub gr9,gr11,gr9
+0: lddu.p @(gr9,gr11),gr4
+ subicc gr10,#8,gr10,icc0
+ stdu.p gr4,@(gr3,gr11)
+ bne icc0,#2,0b
+ bralr
+
+ # do quad-word by quad-word copy
+memcpy_16:
+ sub.p gr8,gr11,gr3
+ sub gr9,gr11,gr9
+0: lddu @(gr9,gr11),gr4
+ lddu.p @(gr9,gr11),gr6
+ subicc gr10,#16,gr10,icc0
+ stdu gr4,@(gr3,gr11)
+ stdu.p gr6,@(gr3,gr11)
+ bne icc0,#2,0b
+ bralr
+
+ # do eight-word by eight-word copy
+memcpy_32:
+ sub.p gr8,gr11,gr3
+ sub gr9,gr11,gr9
+0: lddu @(gr9,gr11),gr4
+ lddu @(gr9,gr11),gr6
+ lddu @(gr9,gr11),gr12
+ lddu.p @(gr9,gr11),gr14
+ subicc gr10,#32,gr10,icc0
+ stdu gr4,@(gr3,gr11)
+ stdu gr6,@(gr3,gr11)
+ stdu gr12,@(gr3,gr11)
+ stdu.p gr14,@(gr3,gr11)
+ bne icc0,#2,0b
+ bralr
+
+ .size memcpy, .-memcpy