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[src/trunk]: src/sys/lib/libkern/arch/m68k Restrict usage of m68k assembler v...
details: https://anonhg.NetBSD.org/src/rev/bd8b810a0321
branches: trunk
changeset: 1009383:bd8b810a0321
user: rin <rin%NetBSD.org@localhost>
date: Wed Apr 22 11:58:26 2020 +0000
description:
Restrict usage of m68k assembler versions of {,u}divsi3 and {,u}divsi3 to
kernel and bootloader for 68010.
They requires a special calling convention to udivsi3, and cannot to be
mixed up in normal routines provided by libgcc or compiler_rt. Although,
there's no problem for using in a controlled situation, i.e., kernel and
standalone programs.
Note that this does not affect m68k ports other than sun2, since codes
generated by gcc do not call these routines.
Assembler files are moved from common/lib/libc/arch/m68k/gen to
sys/lib/libkern/arch/m68k in order not to be compiled in libc.
Revert hack introduced to lib/libc/compiler_rt/Makefile.inc rev 1.37:
http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/compiler_rt/Makefile.inc#rev1.37
Proposed on port-sun2@ with no response...
(Again, this does not affect m68k ports other than sun2.)
http://mail-index.netbsd.org/port-sun2/2020/03/10/msg000102.html
diffstat:
sys/lib/libkern/arch/m68k/divsi3.S | 71 +++++++++++++++++++
sys/lib/libkern/arch/m68k/modsi3.S | 77 +++++++++++++++++++++
sys/lib/libkern/arch/m68k/udivsi3.S | 130 ++++++++++++++++++++++++++++++++++++
sys/lib/libkern/arch/m68k/umodsi3.S | 68 ++++++++++++++++++
4 files changed, 346 insertions(+), 0 deletions(-)
diffs (truncated from 362 to 300 lines):
diff -r f9f9fab944f7 -r bd8b810a0321 sys/lib/libkern/arch/m68k/divsi3.S
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/lib/libkern/arch/m68k/divsi3.S Wed Apr 22 11:58:26 2020 +0000
@@ -0,0 +1,71 @@
+/* $NetBSD: divsi3.S,v 1.3 2020/04/22 11:58:26 rin Exp $ */
+
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * the Systems Programming Group of the University of Utah Computer
+ * Science Department.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <machine/asm.h>
+
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+ RCSID("from: @(#)divsi3.s 5.1 (Berkeley) 6/7/90")
+#else
+ RCSID("$NetBSD: divsi3.S,v 1.3 2020/04/22 11:58:26 rin Exp $")
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+/* int / int */
+#ifndef __mc68010__
+#error
+ENTRY(__divsi3)
+ movel 4(%sp),%d0
+ divsl 8(%sp),%d0
+ rts
+END(__divsi3)
+#else
+ENTRY(__divsi3)
+| NB: this requires that __udivsi3 preserve %a0:
+ movel 4(%sp), %d1 | load the dividend
+ bpl 1f
+ negl 4(%sp) | store abs(dividend)
+1: movel 8(%sp), %d0 | load the divisor
+ bpl 2f
+ negl 8(%sp) | store abs(divisor)
+2: eorl %d1, %d0
+ bpl 3f | branch if sgn(divisor) == sgn(dividend)
+ movel (%sp)+, %a0 | pop return address
+ pea (.Lret,%pc) | push our return address
+3: jmp _C_LABEL(__udivsi3)
+.Lret: negl %d0 | negate quotient
+ jmp (%a0)
+END(__divsi3)
+#endif /* __mc68010__ */
diff -r f9f9fab944f7 -r bd8b810a0321 sys/lib/libkern/arch/m68k/modsi3.S
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/lib/libkern/arch/m68k/modsi3.S Wed Apr 22 11:58:26 2020 +0000
@@ -0,0 +1,77 @@
+/* $NetBSD: modsi3.S,v 1.3 2020/04/22 11:58:26 rin Exp $ */
+
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * the Systems Programming Group of the University of Utah Computer
+ * Science Department.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <machine/asm.h>
+
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+ RCSID("from: @(#)modsi3.s 5.1 (Berkeley) 6/7/90")
+#else
+ RCSID("$NetBSD: modsi3.S,v 1.3 2020/04/22 11:58:26 rin Exp $")
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+/* int % int */
+#ifndef __mc68010__
+#error
+ENTRY(__modsi3)
+ movel 4(%sp),%d1
+#ifdef __mcoldfire__
+ remsl 8(%sp),%d0:%d1
+ divsl 8(%sp),%d1
+#else
+ divsll 8(%sp),%d0:%d1
+#endif
+ rts
+END(__modsi3)
+#else
+ENTRY(__modsi3)
+| NB: this requires that __udivsi3 preserve %a0 and return
+| the modulus in %d1:
+ movel (%sp)+, %a0 | pop return address
+ movel 4(%sp), %d1 | load the divisor
+ bpl 1f
+ negl 4(%sp) | store abs(divisor)
+1: movel (%sp), %d0 | load the dividend
+ pea (.Lret,%pc) | push our return address
+ bpl 2f
+ negl 4(%sp) | store abs(dividend)
+ subql #2, (%sp) | adjust return address
+2: jmp _C_LABEL(__udivsi3)
+ negl %d1 | negate modulus
+.Lret: movl %d1, %d0 | move modulus into %d0
+ jmp (%a0)
+END(__modsi3)
+#endif /* __mc68010__ */
diff -r f9f9fab944f7 -r bd8b810a0321 sys/lib/libkern/arch/m68k/udivsi3.S
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/lib/libkern/arch/m68k/udivsi3.S Wed Apr 22 11:58:26 2020 +0000
@@ -0,0 +1,130 @@
+/* $NetBSD: udivsi3.S,v 1.5 2020/04/22 11:58:26 rin Exp $ */
+
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * the Systems Programming Group of the University of Utah Computer
+ * Science Department.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <machine/asm.h>
+
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+ RCSID("from: @(#)udivsi3.s 5.1 (Berkeley) 6/7/90")
+#else
+ RCSID("$NetBSD: udivsi3.S,v 1.5 2020/04/22 11:58:26 rin Exp $")
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+/* unsigned / unsigned */
+#ifndef __mc68010__
+#error
+ENTRY(__udivsi3)
+ movel 4(%sp),%d0
+ divul 8(%sp),%d0
+ rts
+END(__udivsi3)
+#else
+ENTRY(__udivsi3)
+ movel %d2, -(%sp) | save %d2
+ movel 12(%sp), %d0 | load divisor
+ movel 8(%sp), %d1 | load dividend
+
+| first, we divide the divisor and dividend by two until
+| the divisor fits into 16 bits:
+1: cmpil #0x10000, %d0
+ bcs 2f
+ lsrl #1, %d0
+ lsrl #1, %d1
+ bra 1b
+2:
+
+| now we can do the divide. to avoid overflow, we have to
+| do the divide in two parts, high and low, and add the
+| results together:
+ movew %d1, %d2 | save low(dividend)
+ clrw %d1
+ swap %d1 | %d1 = dividend >> 16
+ divuw %d0, %d1 | do the high divide
+ moveal %d1, %a1 | save high divide result
+ movew %d2, %d1 | concat(remainder, low(dividend))
+ divuw %d0, %d1 | do the low divide
+ movel %a1, %d0 | recover high divide result
+ swap %d0
+ clrw %d0 | %d0 = finished high divide result
+ andil #0xffff, %d1 | %d1 = finished low divide result
+ addl %d1, %d0 | %d0 = quotient guess
+
+| the quotient we have so far is only a guess. the divide we
+| did above was really the divide of some dividendB by some
+| divisorB, where the following hold:
+|
+| (dividend - divisor) <= dividendB <= dividend
+| (divisor / 2) < divisorB <= divisor
+|
+| so our guess quotient cannot be less than our real desired
+| quotient. however, it might be one too big.
+|
+| to adjust this quotient, we multiply it by the original
+| divisor and subtract the result from the original dividend.
+| if the result is nonnegative, our guessed quotient was
+| correct, and the subtraction result is our remainder.
+| if the result is negative, our guessed quotient was one
+| too big, and the subtraction result plus the original
+| divisor is our remainder.
+|
+| as in mulsi3, we have to do the multiply in stages to avoid
+| overflow:
+
+ movel 12(%sp), %d2 | load divisor
+ swap %d2
+ movel %d0, %d1
+ muluw %d2, %d1 | high(divisor) * low(guess)
+ moveal %d1, %a1 | save high(divisor) * low(guess)
+ swap %d2
+ movel %d0, %d1
+ swap %d1
+ muluw %d2, %d1 | low(divisor) * high(guess)
+ addl %a1, %d1
+ swap %d1
+ clrw %d1 | %d1 = finished high multiply result
+ moveal %d2, %a1 | save original divisor
+ muluw %d0, %d2 | low(guess) * low(divisor)
+ addl %d1, %d2 | %d2 = guess * divisor
+
+ movel 8(%sp), %d1 | load original dividend
+ subl %d2, %d1 | subtract
+ bcc 3f
+ subql #1, %d0 | adjust quotient
+ addl %a1, %d1 | adjust remainder
+3: movel (%sp)+, %d2 | restore %d2
+ rts
+END(__udivsi3)
+#endif /* __mc68010__ */
diff -r f9f9fab944f7 -r bd8b810a0321 sys/lib/libkern/arch/m68k/umodsi3.S
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/lib/libkern/arch/m68k/umodsi3.S Wed Apr 22 11:58:26 2020 +0000
@@ -0,0 +1,68 @@
+/* $NetBSD: umodsi3.S,v 1.3 2020/04/22 11:58:26 rin Exp $ */
+
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
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