procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

GCN, nvptx: Allow for "hosted" libstdc++ build

Browse source 
We need '-fno-exceptions', '-fno-rtti', disable generation of PCH files, and
for nvptx twiddle some more knobs.

	PR target/92713
	PR target/101544
	libstdc++-v3/
	* config/cpu/nvptx/cpu_defines.h: New.
	* config/cpu/nvptx/t-nvptx: Likewise.
	* configure.host: Handle GCN, nvptx.
This commit is contained in:
Thomas Schwinge 2025-02-20 16:31:50 +01:00
parent 62dc2d24f1
commit 1268924a2e
3 changed files with 80 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

36
libstdc++-v3/config/cpu/nvptx/cpu_defines.h Normal file
View file

@ -0,0 +1,36 @@
// Specific definitions for nvptx platforms -*- C++ -*-
// Copyright (C) 2025 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file bits/cpu_defines.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{iosfwd}
*/
#ifndef _GLIBCXX_CPU_DEFINES
#define _GLIBCXX_CPU_DEFINES 1
// No support for referencing weak symbols without a definition.
#define _GLIBCXX_USE_WEAK_REF 0
#endif

7
libstdc++-v3/config/cpu/nvptx/t-nvptx Normal file
View file

@ -0,0 +1,7 @@
# Per-file flags, see '../../../configure.host', "inject per-file flags".
# 'ptxas'/CUDA Driver rejects objects with a lot of global constant data:
# ptxas error : File uses too much global constant data ([...])
# Cut short the assembly-time check; defer to actual use of the object file.
AM_MAKEFLAGS += CXXFLAGS-src/c++17/floating_to_chars.lo=-Wa,--no-verify
AM_MAKEFLAGS += CXXFLAGS-src/c++20/tzdb.lo=-Wa,--no-verify

37
libstdc++-v3/configure.host
View file

@ -150,6 +150,9 @@ case "${host_cpu}" in
arm*)
cpu_defines_dir=cpu/arm
;;
nvptx)
cpu_defines_dir=cpu/nvptx
;;
powerpc* | rs6000)
cpu_defines_dir=cpu/powerpc
;;
@ -367,6 +370,16 @@ case "${host}" in
arm*-*-freebsd*)
port_specific_symbol_files="\$(srcdir)/../config/os/gnu-linux/arm-eabi-extra.ver"
;;
nvptx-*-none)
# For 'make all-target-libstdc++-v3', we need to inject per-file flags:
OPTIMIZE_CXXFLAGS="${OPTIMIZE_CXXFLAGS} \$(CXXFLAGS-\$(subdir)/\$@)"
# ..., see:
tmake_file="$tmake_file cpu/nvptx/t-nvptx"
# For 'make all-target-libstdc++-v3', re 'alloca'/VLA usage:
EXTRA_CFLAGS="${EXTRA_CFLAGS} -mfake-ptx-alloca"
OPTIMIZE_CXXFLAGS="${OPTIMIZE_CXXFLAGS} -mfake-ptx-alloca"
;;
powerpc*-*-darwin*)
port_specific_symbol_files="\$(srcdir)/../config/os/bsd/darwin/ppc-extra.ver"
;;
@ -383,3 +396,27 @@ case "${host}" in
abi_baseline_subdir_switch=--print-multi-os-directory
;;
esac
# Dumb down libstdc++ for certain configurations.
# THIS TABLE IS SORTED. KEEP IT THAT WAY.
case "${host}" in
amdgcn-*-amdhsa \
| nvptx-*-none )
# For 'make all-target-libstdc++-v3' and 'make check-target-libstdc++-v3',
# exception handling is not supported: in case that exception handling
# constructs survive compiler optimizations, the back ends error out:
# sorry, unimplemented: exception handling not supported
EXTRA_CXX_FLAGS="${EXTRA_CXX_FLAGS} -fno-exceptions"
# For 'make all-target-libstdc++-v3' and 'make check-target-libstdc++-v3',
# RTTI is not supported.
EXTRA_CXX_FLAGS="${EXTRA_CXX_FLAGS} -fno-rtti"
# Cannot '#include' all newlib header files without explosion, for example:
# error: 'jmp_buf' was not declared in this scope
# Just disable generation of PCH files here, instead of attempting to care
# for such special cases in some more complex way.
enable_libstdcxx_pch=no
;;
esac