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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/frv/lib/memcpy.S
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/frv/lib/memcpy.S')
-rw-r--r--arch/frv/lib/memcpy.S135
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/frv/lib/memcpy.S b/arch/frv/lib/memcpy.S
new file mode 100644
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+++ b/arch/frv/lib/memcpy.S
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+/* memcpy.S: optimised assembly memcpy
+ *
+ * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+
+ .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,__memcpy_end
+ .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,#0x0f,gr0,icc0
+ setlos #8,gr11
+ andicc.p gr4,#0x07,gr0,icc1
+ beq icc0,#0,memcpy_16
+ andicc.p gr4,#0x03,gr0,icc0
+ beq icc1,#0,memcpy_8
+ andicc.p gr4,#0x01,gr0,icc1
+ beq icc0,#0,memcpy_4
+ setlos.p #1,gr11
+ beq icc1,#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
+__memcpy_end:
+
+ .size memcpy, __memcpy_end-memcpy
+
+###############################################################################
+#
+# copy to/from userspace
+# - return the number of bytes that could not be copied (0 on complete success)
+#
+# long __memcpy_user(void *dst, const void *src, size_t count)
+#
+###############################################################################
+ .globl __memcpy_user, __memcpy_user_error_lr, __memcpy_user_error_handler
+ .type __memcpy_user,@function
+__memcpy_user:
+ movsg lr,gr7
+ subi.p sp,#8,sp
+ add gr8,gr10,gr6 ; calculate expected end address
+ stdi gr6,@(sp,#0)
+
+ # abuse memcpy to do the dirty work
+ call memcpy
+__memcpy_user_error_lr:
+ ldi.p @(sp,#4),gr7
+ setlos #0,gr8
+ jmpl.p @(gr7,gr0)
+ addi sp,#8,sp
+
+ # deal any exception generated by memcpy
+ # GR8 - memcpy's current dest address
+ # GR11 - memset's step value (index register for store insns)
+__memcpy_user_error_handler:
+ lddi.p @(sp,#0),gr4 ; load GR4 with dst+count, GR5 with ret addr
+ add gr11,gr3,gr7
+ sub.p gr4,gr7,gr8
+
+ addi sp,#8,sp
+ jmpl @(gr5,gr0)
+
+ .size __memcpy_user, .-__memcpy_user