[Bug binutils/10288] "objdump -D --target=binary -m arm7tdmi" shows non-ARM7TDMI instructions
--- Additional Comments From cvs-commit at gcc dot gnu dot org 2009-07-20 12:11 --- Subject: Bug 10288 CVSROOT:/cvs/src Module name:src Changes by: ni...@sourceware.org2009-07-20 12:11:18 Modified files: opcodes: ChangeLog arm-dis.c Log message: PR 10288 * arm-dis.c (arm_opcodes): Catch non-zero bits 8-11 in register offset or indexed based addressing mode 3. Patches: http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/opcodes/ChangeLog.diff?cvsroot=src&r1=1.1418&r2=1.1419 http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/opcodes/arm-dis.c.diff?cvsroot=src&r1=1.104&r2=1.105 -- http://sourceware.org/bugzilla/show_bug.cgi?id=10288 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug binutils/10288] "objdump -D --target=binary -m arm7tdmi" shows non-ARM7TDMI instructions
--- Additional Comments From nickc at redhat dot com 2009-07-20 12:16 --- Hi Chris, OK, I have checked in a patch to handle the SBZ field in addressing mode 3. Cheers Nick -- http://sourceware.org/bugzilla/show_bug.cgi?id=10288 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug gold/10419] New: nops[] in binutils/gold/x86_64.cc are not actually x86-64 NOPs
>From binutils-2.19/gold/x86_64.cc:
// Nop sequences of various lengths.
const char nop1[1] = { 0x90 }; // nop
const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax
const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
This table was copied from i386.cc. However, most of these sequences are not
actually NOPs on x86-64! For example, nop3, which actually disassembles to lea
0(%rsi),%esi, has the effect of clearing the high 32 bits of %rsi. This can be
verified with a quick test program:
unsigned long x = 0x12345678ABCDEF00;
printf("x=%lx\n", x);
asm volatile (".byte 0x8d, 0x76, 0x00" : "=S" (x) : "S" (x));
printf("x=%lx\n", x);
Output:
x=12345678abcdef00
x=abcdef00
--
Summary: nops[] in binutils/gold/x86_64.cc are not actually x86-
64 NOPs
Product: binutils
Version: 2.19
Status: NEW
Severity: normal
Priority: P2
Component: gold
AssignedTo: ian at airs dot com
ReportedBy: anders at kaseorg dot com
CC: bug-binutils at gnu dot org
http://sourceware.org/bugzilla/show_bug.cgi?id=10419
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[Bug gas/10420] New: .p2align can generate non-NOPs on x86-64
By default on x86-64, gas uses 0f 1f 00 as a 3-byte NOP for alignment: $ echo 'nop; .p2align 2' > test.s $ as test.s -o test.o $ objdump -d test.o | tail -n2 0: 90 nop 1: 0f 1f 00nopl (%rax) However, with some -mtune options, it can generate 8d 76 00 instead: $ as -mtune=pentium test.s -o test.o $ objdump -d test.o | tail -n2 0: 90 nop 1: 8d 76 00lea0x0(%rsi),%esi This instruction is not actually a NOP on x86-64! It has the effect of clearing the high 32 bits of %rsi (see also bug #10419). This could lead to incorrect code generation, even though -mtune is only supposed to affect optimization decisions and not correctness. -- Summary: .p2align can generate non-NOPs on x86-64 Product: binutils Version: 2.19 Status: NEW Severity: normal Priority: P2 Component: gas AssignedTo: unassigned at sources dot redhat dot com ReportedBy: anders at kaseorg dot com CC: bug-binutils at gnu dot org http://sourceware.org/bugzilla/show_bug.cgi?id=10420 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug gold/10419] nops[] in binutils/gold/x86_64.cc are not actually x86-64 NOPs
--- Additional Comments From hjl dot tools at gmail dot com 2009-07-20 19:21 --- x86-64 should use multi-byte nops. -- http://sourceware.org/bugzilla/show_bug.cgi?id=10419 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug gold/10419] nops[] in binutils/gold/x86_64.cc are not actually x86-64 NOPs
--- Additional Comments From hjl dot tools at gmail dot com 2009-07-20 19:25 --- 0: 0f 1f 00nopl (%rax) 3: 0f 1f 40 00 nopl 0(%rax) -- http://sourceware.org/bugzilla/show_bug.cgi?id=10419 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug gold/10419] nops[] in binutils/gold/x86_64.cc are not actually x86-64 NOPs
--- Additional Comments From cvs-commit at gcc dot gnu dot org 2009-07-21 05:23 --- Subject: Bug 10419 CVSROOT:/cvs/src Module name:src Changes by: i...@sourceware.org 2009-07-21 05:22:55 Modified files: gold : ChangeLog x86_64.cc Log message: PR 10419 * x86_64.cc (Target_x86_64::do_code_fill): Correct nop sequences. Patches: http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gold/ChangeLog.diff?cvsroot=src&r1=1.258&r2=1.259 http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/gold/x86_64.cc.diff?cvsroot=src&r1=1.83&r2=1.84 -- http://sourceware.org/bugzilla/show_bug.cgi?id=10419 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
[Bug gold/10419] nops[] in binutils/gold/x86_64.cc are not actually x86-64 NOPs
--- Additional Comments From ian at airs dot com 2009-07-21 05:26 --- Thanks for noticing this. I committed a patch to fix the problem. -- What|Removed |Added Status|NEW |RESOLVED Resolution||FIXED http://sourceware.org/bugzilla/show_bug.cgi?id=10419 --- You are receiving this mail because: --- You are on the CC list for the bug, or are watching someone who is. ___ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
