Displaying 20 results from an estimated 4000 matches similar to: "unusual use of getenv"
2020 Nov 02
4
unusual use of getenv
Oh, right, this stuff. I guess the non-windows solution might've been a
volatile read, for instance? So maybe not so much that the general
machinery isn't needed, but that perhaps MSVC does something interesting
with a volatile read or whatever other solution might've been used.
Hmm, not sure why the whole file was added only when MSVC support was added
- if it is a "static
2020 Nov 10
1
unusual use of getenv
Hi Michael
On Tue Nov 10, 2020 at 1:29 AM GMT, Michael Kruse wrote:
> Am Mo., 2. Nov. 2020 um 14:01 Uhr schrieb David Blaikie
> <dblaikie at gmail.com>:
> > Hmm, not sure why the whole file was added only when MSVC support was added - if it is a "static library object file selection" issue. Wouldn't that have turned up on other platforms before that moment?
>
2020 Jan 15
2
[tablegen] table readability / performance
On Tue Jan 14, 2020 at 8:27 PM, Reid Kleckner wrote:
> I don't think there's any technical reason for the current structure.
Apparently
[this](https://docs.microsoft.com/en-us/cpp/cpp/compiler-limits?view=vs-2019)
is a thing.
This results in the following delight happening on Visual Studio 2015:
> fatal error C1091: compiler limit: string exceeds 65535 bytes in length
So maybe
2020 Jan 14
3
[tablegen] table readability / performance
Hello
I've been looking at the tables generated by
`SequenceToOffsetTable::emit`, and notice that when the generated data
are strings, the data is basically un-grep-able, and very tricky to
read, as they are emitted as an array of comma-separated char-literal:
extern const char HexagonInstrNameData[] = {
/* 0 */ 'G', '_', 'F', 'L', 'O',
2020 Nov 17
10
wasteful cmake defaults
Hi all
I wanted to do a quick build of a clean branch yesterday and noticed
something surprising in the configure log:
> -- No build type selected, default to Debug
It appears that llvm's configuration forces Debug builds if the user
does not specify the build type.
https://github.com/llvm/llvm-project/blob/9218ff50f93085d0a16a974db28ca8f14bc66f64/llvm/CMakeLists.txt#L57-L60
2020 Mar 11
2
DWARF .debug_aranges data objects and address spaces
On Tue Mar 10, 2020 at 7:45 PM, David Blaikie wrote:
> If you only want code addresses, why not use the CU's
> low_pc/high_pc/ranges
> - those are guaranteed to be only code addresses, I think?
>
In the common case, for most targets LLVM supports I think you're right,
but for my case, regrettably, not. Because my target is a Harvard
Architecture, any code address can have the
2020 Mar 12
2
DWARF .debug_aranges data objects and address spaces
On Thu Mar 12, 2020 at 5:37 PM, David Blaikie wrote:
> On Wed, Mar 11, 2020 at 8:09 AM Luke Drummond
> <luke.drummond at codeplay.com>
> wrote:
>
> > On Tue Mar 10, 2020 at 7:45 PM, David Blaikie wrote:
> > > If you only want code addresses, why not use the CU's
> > > low_pc/high_pc/ranges
> > > - those are guaranteed to be only code
2020 Mar 10
2
DWARF .debug_aranges data objects and address spaces
Hello
I've been looking at a debuginfo issue on an out-of-tree target which uses
DWARF aranges.
The problem is that aranges are generated for both data and code objects, and
the debugger gets confused when program addresses overlap data addresses. The
target is a Harvard Architecture CPU, so the appearance of overlapping address
ranges is not in itself a bug as they reside in different
2020 Nov 17
2
wasteful cmake defaults
On Tue Nov 17, 2020 at 6:37 PM GMT, Min-Yih Hsu wrote:
> Just trying to understand: Are you suggesting a way to have a “-O0”
> build without all the debug information?
>
Exactly.
2019 Jul 18
2
Question about TableGen RegisterClass definition
Hi All,
I have a question about TableGen RegisterClass definition.
I need to map different size of MVTs into a register class as below.
def TestReg : RegisterClass<"Test", [v8i32, v4i32], ...>
When I look at TableGen and CodeGen, it looks the types are used as following:
1. MCRegisterClass's RegSize and Alignment
2. SpillSize in TableGen
3. Type constraint for instruction
2017 Jul 26
2
isSSA computation in MIR parser
Hi,
I noticed that a while ago the isSSA flag was removed from MIR, and this
property is now computed. However, the deduction only checks the virtual
registers (whether they are assigned to more than once). Now I have MIR
tests which live after RA, so they only contain physical registers, so
the parser determines they are in SSA form. These tests now fail because
some of our passes can be
2020 Jan 15
2
[tablegen] table readability / performance
On Wed, 15 Jan 2020, Reid Kleckner via llvm-dev wrote:
> On Wed, Jan 15, 2020 at 11:14 AM Luke Drummond <luke.drummond at codeplay.com>
> wrote:
> On Wed Jan 15, 2020 at 6:58 PM, Reid Kleckner wrote:
> > Does the same limitation exist in VS 2017? I think that's our
> support
> > floor
> > these days:
>
2018 Aug 09
2
[DWARF] prologue_end fix not working for VLIW
Hi,
I found that prologue_end markers where badly placed in my test, and
applied https://reviews.llvm.org/D41762 in the hope that it would fix it
(I'm on 4.0.1).
However, this fix doesn't work for VLIW architectures. At this point
we're iterating over bundles, not MachineInstructions, and the
FrameSetup flag is set on MachineInstructions, not bundles.
If bundling happens in the
2020 Mar 12
3
DWARF .debug_aranges data objects and address spaces
I’ve encountered this kind of architecture before, a long time ago (academically). In a flat-address-space machine such as X64, there is still an instruction/data distinction, but usually only down at the level of I-cache versus D-cache (instruction fetch versus data fetch). A Harvard architecture machine exposes that to the programmer, which effectively doubles the available address space.
2017 Jan 27
2
Preserving Call to Intrinsic function
Hello everyone,
Consider we have this following set of code:
int foo() {
int a,b;
a = __builtin_XX(0x11);
b = __builtin_XX(0x11);
return a+b;
}
The problem currently is that LLVM eliminated the second call and copied
the result from the first call into a new set of registers. Is there is a
way to force LLVM to generate two explicit calls to a builtin function. The
builtin takes in an integer
2020 Nov 18
1
wasteful cmake defaults
Yeah, that's one I'd be in favor of fixing, if it's still the case.
On Tue, Nov 17, 2020 at 5:38 PM Sean Silva via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
>
> I'm curious how much of this is due to not using LLD? Last I checked, using ld.bfd instead of LLD (or gold) was one of my major build time issues, and somehow our default configuration would use ld.bfd.
>
2018 Sep 27
2
Ubuntu LLVM packages incompatible with clang built projects?
Hi folks,
Not sure if this is the right mailing list target, but I'm trying out the
new LLVM 7.0 packages found at http://apt.llvm.org by porting over an
existing LLVM 6.0 project of ours to the new version. In doing so, I found
that the executable always segfaulted at the same spot with no explanation:
0x0000000000fefe33 in
2017 Sep 18
1
Resend: assertion in MachineCopyPropagation::isNopCopy
Hi, anyone know anything about copy propagation? Matthias, I see this
was your code originally? Was there some assumptions you made?
I'm hitting an assertion in MachineCopyPropagation::isNopCopy:
if (Src == PreviousSrc) {
assert(Def == PreviousDef);
return true;
}
This code compares two COPY instruction to see whether they are
effectively "the same". The assert assumes
2020 Mar 16
2
DWARF .debug_aranges data objects and address spaces
I'm not across most of this debug info stuff but I'll stomp in here to
confirm that AVR is a Harvard architecture, with separate addressing for
the data and program buses via specialized instructions which will load
from either one, or the other, but never both.
It makes sense that this particular problem would also affect AVR - the
backend does have some issues with debug info
2020 Jan 15
2
[tablegen] table readability / performance
On Wed Jan 15, 2020 at 6:58 PM, Reid Kleckner wrote:
> Does the same limitation exist in VS 2017? I think that's our support
> floor
> these days:
> https://llvm.org/docs/GettingStarted.html#host-c-toolchain-both-compiler-and-standard-library
>
It appears that all releases including the latest 2019 are affected.
>
> One *could* make the tablegen behavior conditional on the