From 7405dc3753cde327b396793e219268e7b378b39e Mon Sep 17 00:00:00 2001
From: Nick Clifton <nickc@redhat.com>
Date: Tue, 22 Aug 2000 19:37:02 +0000
Subject: [PATCH] Before performing any restorative additions...
Before performing any restorative additions, test for bottom bits of IP being
set, rather than relying upon the RORs not matching.
From-SVN: r35888
---
gcc/ChangeLog | 7 ++++
gcc/config/arm/lib1funcs.asm | 74 ++++++++++++++++++++++++------------
2 files changed, 56 insertions(+), 25 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ce6bf5a9422b..5f56c85783e4 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2000-08-22 Nick Clifton <nickc@redhat.com>
+
+ * config/arm/lib1funcs.asm (__umodsi3): Before performing any
+ restorative additions, test for bottom bits of IP being set,
+ rather than relying upon the RORs not matching.
+ (__modsi3): Ditto.
+
2000-08-22 David Edelsohn <edelsohn@gnu.org>
* aix.h (ASM_DECLARE_FUNCTION_NAME): Call named_section() or
diff --git a/gcc/config/arm/lib1funcs.asm b/gcc/config/arm/lib1funcs.asm
index e0cc2f5d241c..619a4802e495 100644
--- a/gcc/config/arm/lib1funcs.asm
+++ b/gcc/config/arm/lib1funcs.asm
@@ -1,7 +1,7 @@
@ libgcc1 routines for ARM cpu.
@ Division routines, written by Richard Earnshaw, (rearnsha@armltd.co.uk)
-/* Copyright (C) 1995, 1996, 1998, 1999, 2000 Free Software Foundation, Inc.
+/* Copyright 1995, 1996, 1998, 1999, 2000 Free Software Foundation, Inc.
This file is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
@@ -238,7 +238,7 @@ Lgot_result:
mov r0, result
pop { work }
RET
-
+
#else /* ARM version. */
cmp divisor, #0
@@ -294,7 +294,7 @@ Lgot_result:
#endif /* ARM version */
- FUNC_END udivsi3
+ FUNC_END udivsi3
#endif /* L_udivsi3 */
/* ------------------------------------------------------------------------ */
@@ -400,16 +400,24 @@ Over6:
@ Any subtractions that we should not have done will be recorded in
@ the top three bits of "overdone". Exactly which were not needed
@ are governed by the position of the bit, stored in ip.
- @ If we terminated early, because dividend became zero,
- @ then none of the below will match, since the bit in ip will not be
- @ in the bottom nibble.
-
mov work, #0xe
lsl work, #28
and overdone, work
bne Over7
pop { work }
RET @ No fixups needed
+
+ @ If we terminated early, because dividend became zero, then the
+ @ bit in ip will not be in the bottom nibble, and we should not
+ @ perform the additions below. We must test for this though
+ @ (rather relying upon the TSTs to prevent the additions) since
+ @ the bit in ip could be in the top two bits which might then match
+ @ with one of the smaller RORs.
+ mov curbit, ip
+ mov work, #0x7
+ tst curbit, work
+ beq Over10
+
Over7:
mov curbit, ip
mov work, #3
@@ -490,10 +498,14 @@ Loop3:
@ Any subtractions that we should not have done will be recorded in
@ the top three bits of "overdone". Exactly which were not needed
@ are governed by the position of the bit, stored in ip.
- @ If we terminated early, because dividend became zero,
- @ then none of the below will match, since the bit in ip will not be
- @ in the bottom nibble.
ands overdone, overdone, #0xe0000000
+ @ If we terminated early, because dividend became zero, then the
+ @ bit in ip will not be in the bottom nibble, and we should not
+ @ perform the additions below. We must test for this though
+ @ (rather relying upon the TSTs to prevent the additions) since
+ @ the bit in ip could be in the top two bits which might then match
+ @ with one of the smaller RORs.
+ tstNE ip, #0x7
RETc(eq) @ No fixups needed
tst overdone, ip, ror #3
addne dividend, dividend, divisor, lsr #3
@@ -503,7 +515,7 @@ Loop3:
addne dividend, dividend, divisor, lsr #1
RET
-#endif /* arm version */
+#endif /* ARM version. */
FUNC_END umodsi3
@@ -797,14 +809,22 @@ Over7:
@ Any subtractions that we should not have done will be recorded in
@ the top three bits of "overdone". Exactly which were not needed
@ are governed by the position of the bit, stored in ip.
- @ If we terminated early, because dividend became zero,
- @ then none of the below will match, since the bit in ip will not be
- @ in the bottom nibble.
mov work, #0xe
lsl work, #28
and overdone, work
beq Lgot_result
+ @ If we terminated early, because dividend became zero, then the
+ @ bit in ip will not be in the bottom nibble, and we should not
+ @ perform the additions below. We must test for this though
+ @ (rather relying upon the TSTs to prevent the additions) since
+ @ the bit in ip could be in the top two bits which might then match
+ @ with one of the smaller RORs.
+ mov curbit, ip
+ mov work, #0x7
+ tst curbit, work
+ beq Lgot_result
+
mov curbit, ip
mov work, #3
ror curbit, work
@@ -836,7 +856,7 @@ Lgot_result:
Over10:
pop { work }
RET
-
+
#else /* ARM version. */
mov curbit, #1
@@ -896,10 +916,14 @@ Loop3:
@ Any subtractions that we should not have done will be recorded in
@ the top three bits of "overdone". Exactly which were not needed
@ are governed by the position of the bit, stored in ip.
- @ If we terminated early, because dividend became zero,
- @ then none of the below will match, since the bit in ip will not be
- @ in the bottom nibble.
ands overdone, overdone, #0xe0000000
+ @ If we terminated early, because dividend became zero, then the
+ @ bit in ip will not be in the bottom nibble, and we should not
+ @ perform the additions below. We must test for this though
+ @ (rather relying upon the TSTs to prevent the additions) since
+ @ the bit in ip could be in the top two bits which might then match
+ @ with one of the smaller RORs.
+ tstNE ip, #0x7
beq Lgot_result
tst overdone, ip, ror #3
addne dividend, dividend, divisor, lsr #3
@@ -912,7 +936,7 @@ Lgot_result:
cmp ip, #0
rsbmi dividend, dividend, #0
RET
-
+
#endif /* ARM version */
FUNC_END modsi3
@@ -921,9 +945,9 @@ Lgot_result:
/* ------------------------------------------------------------------------ */
#ifdef L_dvmd_tls
- FUNC_START div0
+ FUNC_START div0
- RET
+ RET
SIZE (__div0)
@@ -936,7 +960,7 @@ Lgot_result:
#define SIGFPE 8 @ cant use <asm/signal.h> as it
@ contains too much C rubbish
- FUNC_START div0
+ FUNC_START div0
stmfd sp!, {r1, lr}
swi __NR_getpid
@@ -950,7 +974,7 @@ Lgot_result:
#else
ldmfd sp!, {r1, pc}RETCOND
#endif
-
+
SIZE (__div0)
#endif /* L_dvmd_lnx */
@@ -973,7 +997,7 @@ Lgot_result:
.text
.align 0
.force_thumb
-
+
.macro call_via register
THUMB_FUNC_START _call_via_\register
@@ -1005,7 +1029,7 @@ Lgot_result:
is the arm v3 architecture. (This is one of the multilib
options). */
#if defined L_interwork_call_via_rX && ! defined __ARM_ARCH_3__
-
+
/* These labels & instructions are used by the Arm/Thumb interworking code,
when the target address is in an unknown instruction set. The address
of function to be called is loaded into a register and then one of these
--
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