Hi Linaro Toolchain Group,
I am going through the binutils code base specific to arm & aarch64. Please
give some insight on below questions.
1. In the struct bfd_arch_info {...} (in bfd/bfd-in2.h) there are two
fields 'enum bfd_architecture arch' and 'unsigned long mach'.
I went trough the binutils porting guide (by MR.Swami.Reddy(a)nsc.com) which
says 'arch' is for architecture & 'mach' is for machine value.
At present in the bfd/bfd-in2.h :- arch = bfd_arch_aarch64 and mach =
bfd_mach_aarch64 or bfd_mach_aarch64_ilp32.
But what these fields really means ? What is the difference between 'arch'
and 'mach'?
Lets say instruction set architecture is ARMv8 (also known as aarch64 for
64 bit- if I am not wrong). Then we have specific implementation of this
like cortex53, cortex57, Cavium ThunderX etc. With respect to this what
will be the value of arch = ? and mach = ?
2. In the include/opcode/arm.h the 'arm_feature_set' is defined as a
structure where as in include/opcode/aarch64.h 'aarch64_feature_set' is
defined as unsigned long. Is there any specific reason for this? Why
structure definition was not followed in aarch64 ?
typedef struct
{
unsigned long core;
unsigned long coproc;
} arm_feature_set;
typedef unsigned long aarch64_feature_set;
3. Also I see that in the case of arm, 'mach' values are derived from cpu
extension value specified in that 'arm_feature_set' structure.
For example.
if (ARM_CPU_HAS_FEATURE (cpu_variant, arm_cext_iwmmxt2))
mach = bfd_mach_arm_iWMMXt2;
Whereas in aarch64 mach is derived based on API type (64 or 32). Any
reason for this ?
mach = ilp32_p ? bfd_mach_aarch64_ilp32 : bfd_mach_aarch64;
Thanks in advance.
--
with regards,
Virendra Kumar Pathak
== Progress ==
TCWG-775 NEON error messages (2/10)
. wrote new patch for Aarch64
. tried to test it, but GCC testsuite stopped working on my laptop
(random failures with "test for errors, tests randomly being marked
UNSUPPORTED)
Bank Holiday [2/10]
Bug #1599 [1/10]
. reproduced bug on Linaro GCC 4.9
, bisected both the cause and the trunk fix
Misc [5/10]
. attempted to diagnose GCC testsuite problems. Seems to be related to
kernel version somehow.
. Erratum workaround stuff (bug 1550, bug 1596)
== Plans ==
Find working kernel for laptop
Cleanup/submit patch for TCWG-775
Create JIRA cards following vectorization study (TCWG-735)
Bank holiday on Monday. [2/10]
# Issue #
No. Ubuntu is successfully installed on my chromebook.
# Progress #
* Linaro GDB [4/10]
** TCWG-517, GDB AAarch64 record/replay. Done.
Patches are committed upstream. Fix one build failure caused
these patches.
** TCWG-805, aarch64 native debugging multi-arch support.
*** Switch to PTRACE_GETREGSET and PTRACE_SETREGSET. Patches are posted
upstreams.
*** Get ubuntun 14.02 running on chrombook successfully.
** Give my input on GDB kernel awareness too.
* FSF GDB [3/10]
** PR 18392, review the fix and understand the code about tail call
unwinding.
** Approve and commit some tiny patches.
* Misc [1/10]
** Prepare for incoming France travel.
** Book flight and hotel for GNU Tools Cauldron.
Next week:
* TCWG-805, aarch64 native debugging multi-arch support.
--
Yao
== Progress ==
* Bank Holiday (2/10)
* Maintenance (CARD-1833 6/10)
- Finished all FIXMEs in LLVM and Clang
- Working on ASM warnings
* Background (2/10)
- Code review, meetings, discussions, etc.
- Updated arm-bots.html to account for build num, commit range
== Plan ==
* Continue working on ASM warnings
* Move a few left-overs in ARMAsmParser to use ARMTargetParser
If time allows...
* Check the ADD -> SUB change in the assembler
* Try to get the test-suite running on a CMake buildbot
Background
* Check the progress of some Android bugs
* 1 day off
* Neon intrinsics tests (4/10)
- submitted last set for review
* Misc (4/10)
- meetings, conf-calls, emails, ...
- checks for our new GCC mirror
== Next ==
* Neon intrinsics tests: work on vget_lane test.
* linaro-gcc-5.1-2015.06 release:
- start working on backports
* TCWG-619 (2/10)
- "branch out of range" error disappears by disabling sibling call optimization
- using gold results in internal error at arm.cc:4192
- using ld.bfd results in tons of same errors message during LINK
chrome - "thumb2 branch out of range"
- building with "-dp" option shows the error comes for function calls,
generated from pattern call_value_symbol.
* PR49551 (2/10)
- Bootstrapped on x86, tested on x86 and arm.
- added test-case.
* Misc (6/10)
- Exams
== Next Week ==
- Submit patch to PR49551 upstream
- Continue investigating "branch out of range" error.
- Rebase and submit cfgloop.h flattening patch upstream.
== Progress ==
* Upstream GCC (8/10)
- vector cost (TCWG-779)
- benchmarking complete and analysed
- Committed after full testing (bootstrap and regression testing)
- Started working on widening pass based on review comments (TCWG-555)
- Completed re-factoring with the new ideas
- ran into many ICEs with the patch and making progress
* Misc (2/10)
- Looked at http://ctuning.org/wiki/index.php?title=CTools:MilepostGCC
again
- gcc-patches, gcc-bugs list
- Meetings
== Plan ==
- Continue with gcc stage1 activities
== Progress ==
* Releases (CARD-1431 1/10)
- Final ARM/AArch64 3.6.1
* Automation Framework (CARD-1378 1/10)
- More meetings with Lab about infrastructure
* Maintenance (CARD-1833 5/10)
- Working on FIXMEs to TargetParser
* Buildbots (CARD-1823 1/10)
- Bisecting self-hosting failure on thumbv7a
* Background (2/10)
- Code review, meetings, discussions, etc.
- More stride vectorizer reviews (D9368)
- Setting up boards for developers
== Plan ==
* Finish the parser FIXMEs, get on with ASM warnings
* Check some Android bugs and see if I can reduce their numbers
* Probably a bit more infrastructure discussions
# Issues #
* Don't have arm board to run native gdb testsuite (my pandaboard is
too slow to run native tests). Get a chromebook, but takes a lot
of time installing ubuntu on it. Network still doesn't work, don't
know how much time are still needed to fix networking issues.
# Progress #
* Linaro GDB
** TCWG-517, GDB AAarch64 record/replay. [3/10]
These bits are finally posted upstream. The review looks good.
** TCWG-805, aarch64 native debugging multi-arch support. [4/10]
*** Switch to PTRACE_GETREGSET and PTRACE_SETREGSET. Patches are done,
but takes much time to set up GDB native testing env, as linaro
tcwglab is still unreachable.
Install ubuntun 14.02 on chrombook. Done, but network driver
doesn't work.
** Give my input on GDB kernel awareness.
** Tweak pandaboard for native gdb testing. Done.
** AArch64 debugging on different ELs, a meeting is scheduled
in the sprint but I ask more details before that meeting.
* FSF GDB [1/10]
** Review a patch about arm abi detection for ELFOSABI_GNU. Approve it.
** Review a patch about compile feature in GDB.
* Misc [2/10]
** Go to London for France Visa application on Monday and get visa on
Thu.
# Plan #
* TCWG-517, GDB AAarch64 record/replay.
Address review comments and push them in.
* TCWG-805, aarch64 native debugging multi-arch support.
Set up chromebook and test my patches on it.
--
Yao
