Displaying 20 results from an estimated 14000 matches similar to: "[RFC] DebugInfo: A different way of specifying variable locations post-isel"
2020 Feb 25
2
[RFC] DebugInfo: A different way of specifying variable locations post-isel
Hi Vedant, thanks for the detailed response,
On Tue, Feb 25, 2020 at 7:23 AM Vedant Kumar <vedant_kumar at apple.com> wrote:
> > Finally, being forced to always specify both the machine location and
> > the program location at the same time (in a single DBG_VALUE)
> > introduces un-necessary burdens. In MachineSink, when we sink between
> > blocks an instruction that
2020 Nov 11
1
[RFC] A value-tracking LiveDebugValues implementation
Hi Xiang,
On Wed, Nov 11, 2020 at 1:59 AM Zhang, Xiang1 <xiang1.zhang at intel.com> wrote:
> Jeremy wrote:
> > ... The value %0 is live up to and including the ADD64ri but not past it, meaning LLVM today will drop the DBG_VALUE ...
>
> Just a little puzzle about the " drop the DBG_VALUE ", maybe I didn't get your key point,
>
2020 Jun 18
4
[RFC] A value-tracking LiveDebugValues implementation
Hi debuginfo-cabal,
tl;dr: Let's please consider using a new implementation of LiveDebugValues
that produces richer information, might be slightly faster, but mostly will
support the instruction referencing and value tracking paradigm from my RFC [0]
rather than the location tracking that LiveDebugValues does today.
In that RFC, the main motivator is to treat variable locations a bit more
2020 Nov 06
2
[DebugInfo] A value-tracking variable location update
Hi debug-info folks,
Time for another update on the variable location "instruction referencing"
implementation I've been doing, see this RFC [0, 1] for background. It's now at
the point where I'd call it "done" (as far as software ever is), and so it's a
good time to look at what results it produces. And here are the
scores-on-the-doors using llvm-locstats, on
2016 May 12
2
[LLVMdev] Improving the quality of debug locations / DbgValueHistoryCalculator
> On May 12, 2016, at 11:00 AM, Francois Pichet <pichet2000 at gmail.com> wrote:
>
> Here is a specific case that make the debugging experiences degraded on my target:
> This is a loop simplified CFG:
>
> BB#0:
> %R5<def> = OR_rr %R0, %R49 // this is %R5 only def.
> DBG_VALUE %R5, %noreg, !"argc", <!18>; line no:4
> Successors
2016 May 11
3
[LLVMdev] Improving the quality of debug locations / DbgValueHistoryCalculator
The most obvious place where it is lacking at the moment is that it only supports DBG_VALUEs in registers. Adding support for constant values, memory locations, and fp constants would be a big win!
thanks,
Adrian
> On May 11, 2016, at 2:52 PM, Francois Pichet <pichet2000 at gmail.com> wrote:
>
> In retrospect I totally agree with you. I am looking at LiveDebugValue again to see
2020 Nov 06
0
[DebugInfo] A value-tracking variable location update
Awesome to read how it's coming along - I'm mostly aside from the
debug location work, but had just one or two clarifying questions
On Fri, Nov 6, 2020 at 10:27 AM Jeremy Morse
<jeremy.morse.llvm at gmail.com> wrote:
>
> Hi debug-info folks,
>
> Time for another update on the variable location "instruction referencing"
> implementation I've been doing,
2011 Oct 11
1
[LLVMdev] Expected behavior of eliminateFrameIndex() on dbg_value machine instructions
On 10/10/11 19:19, Jakob Stoklund Olesen wrote:
> On Oct 10, 2011, at 10:26 AM, Richard Osborne wrote:
>> I'm investigating a bug associated with debug information that manifests
>> itself in the XCore backend (PR11105). I'd like to understand what the
>> expected behavior of eliminateFrameIndex() is when it is called on a
>> dbg_value machine instruction.
>
2011 Oct 10
0
[LLVMdev] Expected behavior of eliminateFrameIndex() on dbg_value machine instructions
On Oct 10, 2011, at 10:26 AM, Richard Osborne wrote:
> I'm investigating a bug associated with debug information that manifests
> itself in the XCore backend (PR11105). I'd like to understand what the
> expected behavior of eliminateFrameIndex() is when it is called on a
> dbg_value machine instruction.
That is up to the target.
The TII::emitFrameIndexDebugValue() hook is
2011 Oct 10
2
[LLVMdev] Expected behavior of eliminateFrameIndex() on dbg_value machine instructions
I'm investigating a bug associated with debug information that manifests
itself in the XCore backend (PR11105). I'd like to understand what the
expected behavior of eliminateFrameIndex() is when it is called on a
dbg_value machine instruction.
Currently the XCore target replaces the frame index with the frame
register and sets the next operand to the byte offset from the frame
2020 Jun 22
2
[RFC] A value-tracking LiveDebugValues implementation
Hi Adrian,
> quite a lot of work
Large amounts of credit should go to llvm-reduce, which was fundamental to
getting any of this done,
> I've skimmed your implementation and it looks nice and well-documented.
The thing that worries me is the over-complicated lattices -- I didn't
anticipate the problem, and there's a risk that it's more complex than it
needs to be. As it
2018 May 08
0
DEBUG INFO: improve handling of DBG_VALUEs and DebugLocs in CodeGen
> On May 7, 2018, at 11:29 PM, Jonas Paulsson via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>
> Hi, (Resent with proper subject line)
>
> I recently found myself in trouble because the crash I had disappeared
> with -g, so I could not debug the program. This happened because the
> optimizer did not remember to consider DBG_VALUEs
2018 May 08
3
DEBUG INFO: improve handling of DBG_VALUEs and DebugLocs in CodeGen
Hi, (Resent with proper subject line)
I recently found myself in trouble because the crash I had disappeared
with -g, so I could not debug the program. This happened because the
optimizer did not remember to consider DBG_VALUEs instruction so it
changed its behavior, and the bug went hiding.
I then started discussing this onhttps://reviews.llvm.org/D45878, and
2020 Oct 07
2
[Debuginfo] Changing llvm.dbg.value and DBG_VALUE to support multiple location operands
> I don't see how this is a meaningful distinction in LLVM IR. In LLVM IR we only have SSA values. An SSA value could be an alloca, or a gep into an alloca, or spilled onto the stack at the MIR level, in which case the dbg.value should get lowered into a memory location (if it isn't explicitly a DW_OP_stack_value).
I think the distinction is still important; even at the IR level, if we
2016 Jul 29
3
IR @llvm.dbg.value entries for variables when a phi node has been created
I have been investigating missing variables / incorrect variable values when debugging code compiled at -O1 (and above) and believe that I have tracked the issue down to the interaction of the generation of IR @llvm.dbg.value entries and phi nodes. I would welcome someone who is more familiar with the generation of debug information to help me determine if what I think is going wrong is correct
2020 Sep 01
2
[RFC] [DebugInfo] Using DW_OP_entry_value within LLVM IR
Hi David,
Thanks for your comments!
I just want to add that I think it would neat if the entry values could map into
multi-location dbg.values and DBG_VALUEs that are being proposed on this list.
For example, if we have:
int local = param1 + param2 + 123;
I think it would be good if we would be able to to represent the four different
permutations of the values of the parameters being
2015 Jun 23
4
[LLVMdev] Improving the quality of debug locations / DbgValueHistoryCalculator
Here is a proposal for improving DbgValueHistoryCalculator and the
overall quality of debug locations.
Focus: This is about lowering the DBG_VALUE machine instructions to
DWARF location lists.
Non-focus: This is not about (typical -O0) variables that permanently
reside at a frame index and are described with dbg.declare intrinsics
in the IR. These variables are stored in the MMI side-table and
2017 Sep 06
4
RFC: Introduce DW_OP_LLVM_memory to describe variables in memory with dbg.value
On Wed, Sep 6, 2017 at 10:01 AM, David Blaikie <dblaikie at gmail.com> wrote:
> On Tue, Sep 5, 2017 at 1:00 PM Reid Kleckner via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> LLVM SSA values obviously do not have an address that we can take and
>> they don’t live in registers, so neither the default memory location model
>> nor DW_OP_regN make sense
2020 Sep 01
4
[RFC] [DebugInfo] Using DW_OP_entry_value within LLVM IR
Hi all,
The debug entry values feature introduces new DWARF symbols (tags, attributes, operations) on caller (call site) as well as on callee side; and the intention is to improve debugging user experience by using the functionality (especially in “optimized” code by turning “<optimized_out>” values into real values). The call site information includes info about call itself (described with
2017 Sep 07
2
RFC: Introduce DW_OP_LLVM_memory to describe variables in memory with dbg.value
On Wed, Sep 6, 2017 at 5:01 PM, David Blaikie <dblaikie at gmail.com> wrote:
> On Wed, Sep 6, 2017 at 2:01 PM Reid Kleckner <rnk at google.com> wrote:
>
>> On Wed, Sep 6, 2017 at 10:01 AM, David Blaikie <dblaikie at gmail.com>
>> wrote:
>>
>>> I guess you described this already, but talking it through for
>>> myself/maybe others will