Message ID | 11d635d0-9798-5344-934b-969cb01974ba@codesourcery.com |
---|---|
State | New |
Headers | show |
Series | install.texi: Bump newlib version for nvptx + gcn | expand |
On Sat, 21 Jan 2023, Tobias Burnus wrote: > A new newlib version has been realized yesterday: newlib-4.3.0 (yearly > snapshot) : > Comments? Suggestions? – If there are none, I intent to commit the patch > as obvious. Is it maybe a little tough to bump the minimal requirement to something only released yesterday? Or is this not an issue looking at the use cases? (Genuine question. Maybe nothing to worry at all.) And, this predates your patch, in one instance we refer to Newlib (upper case9, in the other to newlib (lower case). Would it make sense to converge to one? Not an objection to the patch - you are the expert - just two (naive) questions. Gerald
Hi Gerald, On 21.01.23 12:58, Gerald Pfeifer wrote: > Is it maybe a little tough to bump the minimal requirement to something > only released yesterday? Or is this not an issue looking at the use cases? > (Genuine question. Maybe nothing to worry at all.) On the technical side, the newer newlib version is not yet required. But it looks as if it soon makes a lot of sense to have it: For the AMGCN stack builtins, they currently expand to the same registers and offset calculations as hard-coded in newlib (older version or if the builtin is not available). – If the stack allocation is changed to non-threadprivate, this will change the location. With the builtins, just recompiling newlib (+libgomp) will work (API preserved but not ABI). [Andrew to provide the stack patch; then me for the 2-line patch to enable OpenMP's reverse offload.] (Hen-egg problem in terms of compilation as newlib is compiled by GCC. Probably only detectable by running it on the offload device and checking whether it fails - not practical for a cross-compiler build.) For AMDGCN's vectorization functions: Those can lead to a significant performance advantage. I know that newlib only used some builtins if they are available. I think AMDGCN will emit code using the new libm functions, which in turn newlib only generates if GCC supports certain new builtins. (hen-egg problem, if my assumptions are correct.) [I think Kwok will provide this patch - he did implement the funcs in newlib.] nvptx: Thomas' patch for libgfortran(*) effectively requires the newer newlib - albeit one could imaging that there could be a configure check. [(*) "nvptx, libgfortran: Switch out of "minimal" mode", approved but awaiting approval of another patch)] Thus: As nvptx/amdgcn is (mostly) about offloading code, newlib is compiled usually alongside GCC (e.g. in SUSE, Debian/Ubuntu, ...); additionally, there is static linking such that mixing old vs. new libraries is less likely. Hence, requiring the newest version of newlib together with the newest compiler shouldn't be a problem in my opinion. And the if documented now, it cannot be forgotten by the time the pending patches get committed... ;-) > And, this predates your patch, in one instance we refer to Newlib (upper > case9, in the other to newlib (lower case). Would it make sense to > converge to one? Maybe, but the question is what to use? The project's webpage has on the first page: "patch submissions to Newlib" and "automate the testing of newlib". As uppercase, we have: gcc/d/implement-d.texi:@code{CRuntime_Newlib} is set when Newlib is the default C library. gcc/doc/install.texi:Use Newlib (4.3.0 or newer). gcc/doc/invoke.texi:This option requires Newlib Nano IO, so GCC must be configured with gcc/doc/invoke.texi:Newlib. gcc/doc/invoke.texi:Specify the PRU MCU variant to use. Check Newlib for the exact list of gcc/doc/sourcebuild.texi:Target supports Newlib. gcc/doc/sourcebuild.texi:the code size of Newlib formatted I/O functions. gcc/po/gcc.pot:"Newlib Nano IO." (Add a missing "Requires " to complete the sentence.) and as lowercase: gcc/doc/install.texi:Specifies that @samp{newlib} is gcc/doc/install.texi:@samp{newlib}. gcc/doc/install.texi:RTEMS configurations, which currently use newlib. The option is denotes a configure argument.) gcc/doc/invoke.texi:newlib board library linking. The default is @code{or1ksim}. gcc/doc/invoke.texi:select linker and preprocessor options for use with newlib. gcc/doc/sourcebuild.texi:@item newlib (Side remark: While some @sample{newlib} in install.texi refer to a value to a configure argument, in the quote above it refers to the library itself.) gcc/po/gcc.pot:msgid "Configure the newlib board specific runtime. The default is or1ksim." gcc/po/gcc.pot:"This used to select linker and preprocessor options for use with newlib." libstdc++-v3/doc/xml/manual/configure.xml: vintage (2.3 and newer), 'gnu' is automatically selected. On newlib-based libstdc++-v3/doc/xml/manual/configure.xml: systems (<code>'--with_newlib=yes'</code>) and OpenBSD, 'newlib' is libstdc++-v3/doc/xml/manual/evolution.xml:<para>A new clocale model for newlib is available.</para> Thoughts? Thanks for the comments! Tobias ----------------- Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
On Sat, 21 Jan 2023, Tobias Burnus wrote: > On the technical side, the newer newlib version is not yet required. But > it looks as if it soon makes a lot of sense to have it: : > As nvptx/amdgcn is (mostly) about offloading code, newlib is compiled > usually alongside GCC (e.g. in SUSE, Debian/Ubuntu, ...); additionally, > there is static linking such that mixing old vs. new libraries is less > likely. Hence, requiring the newest version of newlib together with the > newest compiler shouldn't be a problem in my opinion. That sounds like a convincing argument. >> And, this predates your patch, in one instance we refer to Newlib >> (upper case9, in the other to newlib (lower case). Would it make >> sense to converge to one? > Maybe, but the question is what to use? The project's webpage has on the > first page: "patch submissions to Newlib" and "automate the testing of > newlib". I also dug into the newlib web page and other sources and - while my personal preference slightly leans towards Newlib - believe newlib is more established overall. For the web pages, it's clearer than for our *.texi ones you dug into: ~/src/wwwdocs/htdocs> grep -r newlib . | wc -l 15 ~/src/wwwdocs/htdocs> grep -r Newlib . | wc -l 3 > Thoughts? Let's go for newlib (lowercase) I'd say; if you agree I can take care of wwwdocs Cheers, Gerald
On 22.01.23 02:45, Gerald Pfeifer wrote: >> Maybe, but the question is what to use? The project's webpage has on the >> first page: "patch submissions to Newlib" and "automate the testing of >> newlib". > I also dug into the newlib web page and other sources and - while my > personal preference slightly leans towards Newlib - believe newlib is > more established overall. > > For the web pages, it's clearer than for our *.texi ones you dug into: > > ~/src/wwwdocs/htdocs> grep -r newlib . | wc -l > 15 > ~/src/wwwdocs/htdocs> grep -r Newlib . | wc -l > 3 You need to be careful with those counts as there is not only 'the [nN]ewlib library' but also flags/configure arguments etc: gcc/doc/install.texi:@item --with-newlib gcc/doc/install.texi-@item --with-nds32-lib=@var{library} gcc/doc/install.texi:Currently, the valid @var{library} is @samp{newlib} or @samp{mculib}. gcc/doc/install.texi:to nvptx-newlib's @file{newlib} directory to the directory containing gcc/doc/install.texi:@option{--enable-newlib-io-long-long} options when configuring. gcc/doc/invoke.texi:@samp{--enable-newlib-nano-formatted-io}. gcc/doc/invoke.texi:@item -mnewlib gcc/doc/invoke.texi:@opindex mnewlib (and a few more). In the libstdc++-v3/doc/xml/, there are two 'newlib' and one 'Newlib' (plus a bunch of newlib as filename/argument/config option). Still, I concur that 'newlib' is still used a bit more often than 'Newlib'. * * * In any case, I concur that it would be nice to unify .texi/.xml and diagnostic output (twice in config/or1k/elf.opt) - and likewise the wwwdocs pages. (That elf.opt file has twice 'newlib' and once 'Newlib'.) -> adds this to the to-do list. Tobias ----------------- Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
install.texi: Bump newlib version for nvptx + gcn Before, newlib 3.2 was required for amdgcn and 3.1 for nvptx. Now recommended is 4.3.0 which was just released on 2023-01-20. While currently the old versions would work fine, upcoming GCC changes depend on a newer newlib. Thus, the minimal version is bumped instead of just recommending the new version. For GCN, the bump is in preparation for permitting non-threadlocal stack variables and vectorized math functions - both scheduled for GCC 13 and added to newlib in 4.3.0. For nvptx, this includes an emulated clock (commit 6bb96d13a), a calloc fix (5fca4e0f1) and changes to permit libgfortran to be compiled with I/O support instead of only in minimal mode. (Patch approved for GCC 13 but pending on a nvtpx patch.) gcc/ChangeLog: * doc/install.texi (amdgcn, nvptx): Require newlib 4.3.0. diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi index ccc8d15fd08..b1861a6a437 100644 --- a/gcc/doc/install.texi +++ b/gcc/doc/install.texi @@ -3855,7 +3855,7 @@ Instead of GNU Binutils, you will need to install LLVM 13.0.1, or later, and cop @file{bin/llvm-ar} to both @file{bin/amdgcn-amdhsa-ar} and @file{bin/amdgcn-amdhsa-ranlib}. -Use Newlib (3.2.0, or newer). +Use Newlib (4.3.0 or newer). To run the binaries, install the HSA Runtime from the @uref{https://rocm.github.io,,ROCm Platform}, and use @@ -4672,7 +4672,7 @@ Instead of GNU binutils, you will need to install Tell GCC where to find it: @option{--with-build-time-tools=[install-nvptx-tools]/nvptx-none/bin}. -You will need newlib 3.1.0 or later. It can be +You will need newlib 4.3.0 or later. It can be automatically built together with GCC@. For this, add a symbolic link to nvptx-newlib's @file{newlib} directory to the directory containing the GCC sources.