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-rw-r--r--arch/sparc/lib/strlen.S83
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/sparc/lib/strlen.S b/arch/sparc/lib/strlen.S
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+/* SPDX-License-Identifier: GPL-2.0 */
+/* strlen.S: Sparc optimized strlen code
+ * Hand optimized from GNU libc's strlen
+ * Copyright (C) 1991,1996 Free Software Foundation
+ * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 1996, 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
+ */
+
+#include <linux/export.h>
+#include <linux/linkage.h>
+#include <asm/asm.h>
+
+#define LO_MAGIC 0x01010101
+#define HI_MAGIC 0x80808080
+
+ .text
+ENTRY(strlen)
+ mov %o0, %o1
+ andcc %o0, 3, %g0
+ BRANCH32(be, pt, 9f)
+ sethi %hi(HI_MAGIC), %o4
+ ldub [%o0], %o5
+ BRANCH_REG_ZERO(pn, %o5, 11f)
+ add %o0, 1, %o0
+ andcc %o0, 3, %g0
+ BRANCH32(be, pn, 4f)
+ or %o4, %lo(HI_MAGIC), %o3
+ ldub [%o0], %o5
+ BRANCH_REG_ZERO(pn, %o5, 12f)
+ add %o0, 1, %o0
+ andcc %o0, 3, %g0
+ BRANCH32(be, pt, 5f)
+ sethi %hi(LO_MAGIC), %o4
+ ldub [%o0], %o5
+ BRANCH_REG_ZERO(pn, %o5, 13f)
+ add %o0, 1, %o0
+ BRANCH32(ba, pt, 8f)
+ or %o4, %lo(LO_MAGIC), %o2
+9:
+ or %o4, %lo(HI_MAGIC), %o3
+4:
+ sethi %hi(LO_MAGIC), %o4
+5:
+ or %o4, %lo(LO_MAGIC), %o2
+8:
+ ld [%o0], %o5
+2:
+ sub %o5, %o2, %o4
+ andcc %o4, %o3, %g0
+ BRANCH32(be, pt, 8b)
+ add %o0, 4, %o0
+
+ /* Check every byte. */
+ srl %o5, 24, %g7
+ andcc %g7, 0xff, %g0
+ BRANCH32(be, pn, 1f)
+ add %o0, -4, %o4
+ srl %o5, 16, %g7
+ andcc %g7, 0xff, %g0
+ BRANCH32(be, pn, 1f)
+ add %o4, 1, %o4
+ srl %o5, 8, %g7
+ andcc %g7, 0xff, %g0
+ BRANCH32(be, pn, 1f)
+ add %o4, 1, %o4
+ andcc %o5, 0xff, %g0
+ BRANCH32_ANNUL(bne, pt, 2b)
+ ld [%o0], %o5
+ add %o4, 1, %o4
+1:
+ retl
+ sub %o4, %o1, %o0
+11:
+ retl
+ mov 0, %o0
+12:
+ retl
+ mov 1, %o0
+13:
+ retl
+ mov 2, %o0
+ENDPROC(strlen)
+EXPORT_SYMBOL(strlen)