| Message ID | 001b01d7954d$32192c90$964b85b0$@nextmovesoftware.com |
|---|---|
| State | New |
| Headers | show |
| Series | nvptx: Add a __PTX_ISA__ predefined macro based on target ISA. | expand |
On 8/20/21 12:54 AM, Roger Sayle wrote: > > This patch adds a __PTX_ISA__ predefined macro to the nvptx backend that > allows code to check the compute model being targeted by the compiler. Hi Roger, The naming __PTX_ISA__ is consistent with the naming of -misa=sm_30/sm_35. The -misa=sm_30/sm_35 naming was very unfortunate given that the ptx format actually defines an ISA version which gcc now accepts using -mptx=3.1/6.3. We really should have had something like: - -march=sm_30/sm_35 - -mptx-isa=3.1/6.3 but I suppose it's too late to change that now. Having said that, the __PTX_ISA__ name very much suggests that it's the ptx ISA version, which, as explained above, it's not. Sigh. We could go for __PTX_ARCH__ instead, but it would be very counterintuitive to have -misa=sm_30/sm_35 set this. So I propose __PTX_SM__ instead. [ I also considered __PTX_ISA_SM__ but if we ever decide to change the name of the switch then that doesn't make sense anymore. ] > This is equivalent to the __CUDA_ARCH__ macro defined by CUDA's nvcc > compiler, but to avoid causing problems for source code that checks > for that compiler, this macro uses GCC's nomenclature; it's easy > enough for users to "#define __CUDA_ARCH__ __PTX_ISA__", but I'm > also happy to modify this patch to define __CUDA_ARCH__ if that's > the preference of the nvptx backend maintainers. > I agree with this approach. The definition of the __CUDA_ARCH__ macro in the cuda documentation is nvcc-specific, so let's not define it. > What might have been a four line patch is actually a little more > complicated, as this patch takes the opportunity to upgrade the > nvptx backend to use the now preferred nvptx-c.c idiom. > Ack. You could split it up, but not strictly necessary. > This patch has been tested with a cross-compiler from > x86_64-pc-linux-gnu to nvptx-none, and tested with > "make -k check" with no new failures. This feature is > useful for implementing clock() on nvptx in newlib. > I see, thanks for working on that. > Ok for mainline? OK with name of predefined macro updated to __PTX_SM__ . Thanks, - Tom > 2021-08-19 Roger Sayle <roger@nextmovesoftware.com> > > gcc/ChangeLog > * config.gcc (nvptx-*-*): Define {c,c++}_target_objs. > * config/nvptx/nvptx-protos.h (nvptx_cpu_cpp_builtins): Prototype. > * config/nvptx/nvptx.h (TARGET_CPU_CPP_BUILTINS): Implement with > a call to the new nvptx_cpu_cpp_builtins function in nvptx-c.c. > * config/nvptx/t-nvptx (nvptx-c.o): New rule. > * config/nvptx/nvptx-c.c: New source file. > (nvptx_cpu_cpp_builtins): Move implementation here. > > Roger > -- > Roger Sayle > NextMove Software > Cambridge, UK >
diff --git a/gcc/config.gcc b/gcc/config.gcc index 93e2b32..cbad989 100644 --- a/gcc/config.gcc +++ b/gcc/config.gcc @@ -468,6 +468,8 @@ nios2-*-*) ;; nvptx-*-*) cpu_type=nvptx + c_target_objs="nvptx-c.o" + cxx_target_objs="nvptx-c.o" ;; or1k*-*-*) cpu_type=or1k diff --git a/gcc/config/nvptx/nvptx-protos.h b/gcc/config/nvptx/nvptx-protos.h index b7e6ae2..b29ddc9 100644 --- a/gcc/config/nvptx/nvptx-protos.h +++ b/gcc/config/nvptx/nvptx-protos.h @@ -40,6 +40,7 @@ extern void nvptx_output_aligned_decl (FILE *file, const char *name, extern void nvptx_function_end (FILE *); extern void nvptx_output_skip (FILE *, unsigned HOST_WIDE_INT); extern void nvptx_output_ascii (FILE *, const char *, unsigned HOST_WIDE_INT); +extern void nvptx_cpu_cpp_builtins (void); extern void nvptx_register_pragmas (void); extern unsigned int nvptx_data_alignment (const_tree, unsigned int); diff --git a/gcc/config/nvptx/nvptx.h b/gcc/config/nvptx/nvptx.h index fdaacdd..d367174 100644 --- a/gcc/config/nvptx/nvptx.h +++ b/gcc/config/nvptx/nvptx.h @@ -34,17 +34,7 @@ nvptx-as. */ #define ASM_SPEC "%{misa=*:-m %*; :-m sm_35}" -#define TARGET_CPU_CPP_BUILTINS() \ - do \ - { \ - builtin_assert ("machine=nvptx"); \ - builtin_assert ("cpu=nvptx"); \ - builtin_define ("__nvptx__"); \ - if (TARGET_SOFT_STACK) \ - builtin_define ("__nvptx_softstack__"); \ - if (TARGET_UNIFORM_SIMT) \ - builtin_define ("__nvptx_unisimt__"); \ - } while (0) +#define TARGET_CPU_CPP_BUILTINS() nvptx_cpu_cpp_builtins () /* Avoid the default in ../../gcc.c, which adds "-pthread", which is not supported for nvptx. */ diff --git a/gcc/config/nvptx/t-nvptx b/gcc/config/nvptx/t-nvptx index 6c1010d..d33bacd 100644 --- a/gcc/config/nvptx/t-nvptx +++ b/gcc/config/nvptx/t-nvptx @@ -1,3 +1,7 @@ +nvptx-c.o: $(srcdir)/config/nvptx/nvptx-c.c + $(COMPILE) $< + $(POSTCOMPILE) + CFLAGS-mkoffload.o += $(DRIVER_DEFINES) \ -DGCC_INSTALL_NAME=\"$(GCC_INSTALL_NAME)\" mkoffload.o: $(srcdir)/config/nvptx/mkoffload.c diff --git a/gcc/config/nvptx/nvptx-c.c b/gcc/config/nvptx/nvptx-c.c new file mode 100644 index 0000000..5a7a0ef --- /dev/null +++ b/gcc/config/nvptx/nvptx-c.c @@ -0,0 +1,47 @@ +/* Subroutines for the C front end on the NVPTX architecture. + * Copyright (C) 2021 Free Software Foundation, Inc. + * + * This file is part of GCC. + * + * GCC 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. + * + * GCC 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. + * + * You should have received a copy of the GNU General Public License + * along with GCC; see the file COPYING3. If not see + * <http://www.gnu.org/licenses/>. */ + +#define IN_TARGET_CODE 1 + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "target.h" +#include "c-family/c-common.h" +#include "memmodel.h" +#include "tm_p.h" +#include "c-family/c-pragma.h" + +/* Function to tell the preprocessor about the defines for the target. */ +void +nvptx_cpu_cpp_builtins (void) +{ + cpp_assert (parse_in, "machine=nvptx"); + cpp_assert (parse_in, "cpu=nvptx"); + cpp_define (parse_in, "__nvptx__"); + if (TARGET_SOFT_STACK) + cpp_define (parse_in, "__nvptx_softstack__"); + if (TARGET_UNIFORM_SIMT) + cpp_define (parse_in,"__nvptx_unisimt__"); + if (TARGET_SM35) + cpp_define (parse_in, "__PTX_ISA__=350"); + else + cpp_define (parse_in,"__PTX_ISA__=300"); +} +
This patch adds a __PTX_ISA__ predefined macro to the nvptx backend that allows code to check the compute model being targeted by the compiler. This is equivalent to the __CUDA_ARCH__ macro defined by CUDA's nvcc compiler, but to avoid causing problems for source code that checks for that compiler, this macro uses GCC's nomenclature; it's easy enough for users to "#define __CUDA_ARCH__ __PTX_ISA__", but I'm also happy to modify this patch to define __CUDA_ARCH__ if that's the preference of the nvptx backend maintainers. What might have been a four line patch is actually a little more complicated, as this patch takes the opportunity to upgrade the nvptx backend to use the now preferred nvptx-c.c idiom. This patch has been tested with a cross-compiler from x86_64-pc-linux-gnu to nvptx-none, and tested with "make -k check" with no new failures. This feature is useful for implementing clock() on nvptx in newlib. Ok for mainline? 2021-08-19 Roger Sayle <roger@nextmovesoftware.com> gcc/ChangeLog * config.gcc (nvptx-*-*): Define {c,c++}_target_objs. * config/nvptx/nvptx-protos.h (nvptx_cpu_cpp_builtins): Prototype. * config/nvptx/nvptx.h (TARGET_CPU_CPP_BUILTINS): Implement with a call to the new nvptx_cpu_cpp_builtins function in nvptx-c.c. * config/nvptx/t-nvptx (nvptx-c.o): New rule. * config/nvptx/nvptx-c.c: New source file. (nvptx_cpu_cpp_builtins): Move implementation here. Roger -- Roger Sayle NextMove Software Cambridge, UK