Hi! Ping.
On Thu, 19 Feb 2015 09:39:52 +0100, I wrote:
> On Wed, 18 Feb 2015 18:04:21 +0100, I wrote:
> > On Mon, 13 Oct 2014 14:33:11 +0400, Ilya Verbin <iver...@gmail.com> wrote:
> > > On 13 Oct 12:19, Jakub Jelinek wrote:
> > > > On Sat, Oct 11, 2014 at 06:49:00PM +0400, Ilya Verbin wrote:
> > > > > 2. -foffload-abi=[lp64|ilp32]
> > > > > This option is supposed to tell mkoffload (and offload compiler)
> > > > > which ABI is
> > > > > used in streamed GIMPLE. This option is desirable, because host and
> > > > > offload
> > > > > compilers must have the same ABI. The option is generated by the
> > > > > host compiler
> > > > > automatically, it should not be specified by user.
> > > >
> > > > But I'd like to understand why is this one needed.
> > > > Why should the compilers care? Aggregates layout and alignment of
> > > > integral/floating types must match between host and offload compilers,
> > > > sure,
> > > > but isn't that something streamed already in the LTO bytecode?
> > > > Or is LTO streamer not streaming some types like long_type_node?
> > > > I'd expect if host and offload compiler disagree on long type size that
> > > > you'd just use a different integral type with the same size as long on
> > > > the
> > > > host.
> > > > Different sized pointers are of course a bigger problem, but can't you
> > > > just
> > > > error out on that during reading of the LTO, or even handle it (just use
> > > > some integral type for when is the pointer stored in memory, and just
> > > > convert to pointer after reads from memory, and convert back before
> > > > storing
> > > > to memory). Erroring out during LTO streaming in sounds just fine to me
> > > > though.
> > >
> > > Actually this option was developed by Bernd, so I think PTX team is going
> > > to use
> > > it somehow. In MIC's case we're planning just to check in mkoffload that
> > > host
> > > and target compiler's ABI are the same. Without this check we will crash
> > > in LTO
> > > streamer with ICE, so I'd like to issue an error message, rather than
> > > crashing.
> >
> > In gcc/config/i386/intelmic-mkoffload.c, this option is now parsed to
> > initialize the target_ilp32 variable, which will then be used
> > (target_ilp32 ? "-m32" : "-m64") when invoking different tools.
> >
> > In nvptx, we've been using the following approach:
> >
> > --- gcc/config/nvptx/nvptx.h
> > +++ gcc/config/nvptx/nvptx.h
> > @@ -54,24 +54,28 @@
> >
> > /* Type Layout. */
> >
> > +#define TARGET_64BIT \
> > + (flag_offload_abi == OFFLOAD_ABI_UNSET ? TARGET_ABI64 \
> > + : flag_offload_abi == OFFLOAD_ABI_LP64 ? true : false)
> > +
> > #define DEFAULT_SIGNED_CHAR 1
> >
> > #define SHORT_TYPE_SIZE 16
> > #define INT_TYPE_SIZE 32
> > -#define LONG_TYPE_SIZE (TARGET_ABI64 ? 64 : 32)
> > +#define LONG_TYPE_SIZE (TARGET_64BIT ? 64 : 32)
> > #define LONG_LONG_TYPE_SIZE 64
> > #define FLOAT_TYPE_SIZE 32
> > #define DOUBLE_TYPE_SIZE 64
> > #define LONG_DOUBLE_TYPE_SIZE 64
> >
> > #undef SIZE_TYPE
> > -#define SIZE_TYPE (TARGET_ABI64 ? "long unsigned int" : "unsigned int")
> > +#define SIZE_TYPE (TARGET_64BIT ? "long unsigned int" : "unsigned int")
> > #undef PTRDIFF_TYPE
> > -#define PTRDIFF_TYPE (TARGET_ABI64 ? "long int" : "int")
> > +#define PTRDIFF_TYPE (TARGET_64BIT ? "long int" : "int")
> >
> > -#define POINTER_SIZE (TARGET_ABI64 ? 64 : 32)
> > +#define POINTER_SIZE (TARGET_64BIT ? 64 : 32)
> >
> > -#define Pmode (TARGET_ABI64 ? DImode : SImode)
> > +#define Pmode (TARGET_64BIT ? DImode : SImode)
> >
> > /* Registers. Since ptx is a virtual target, we just define a few
> > hard registers for special purposes and leave pseudos unallocated. */
> >
> > Should we settle on one of the two, that is, either pass -m[...] from
> > mkoffload, or handle flag_offload_abi in the respective backend? I think
> > I prefer the intelmic-mkoffload.c approach; this seems cleaner to me:
> > mkoffload "configures" the offloading compiler. (Also, the flag 32-bit
> > vs. 64-bit flag may in fact be needed for tools other than the offloading
> > compiler).
>
> Well, "for instance", when in -m32 mode, we also need to use it in
> gcc/config/nvptx/mkoffload.c:compile_native -- otherwise, later on, the
> linker will not be happy with the request to link a 64-bit object file
> with 32-bit object files...
>
> > Bernd, is there any specific reason for the approach you had
> > chosen?
>
> OK to do the following instead? (Coding style/code copied from
> gcc/config/i386/intelmic-mkoffload.c for consistency.)
>
> --- gcc/config/nvptx/mkoffload.c
> +++ gcc/config/nvptx/mkoffload.c
> @@ -126,6 +126,9 @@ static id_map *var_ids, **vars_tail = &var_ids;
> static const char *ptx_name;
> static const char *ptx_cfile_name;
>
> +/* Shows if we should compile binaries for i386 instead of x86-64. */
> +bool target_ilp32 = false;
> +
> /* Delete tempfiles. */
>
> /* Unlink a temporary file unless requested otherwise. */
> @@ -883,6 +886,7 @@ compile_native (const char *infile, const char *outfile,
> const char *compiler)
> struct obstack argv_obstack;
> obstack_init (&argv_obstack);
> obstack_ptr_grow (&argv_obstack, compiler);
> + obstack_ptr_grow (&argv_obstack, target_ilp32 ? "-m32" : "-m64");
> obstack_ptr_grow (&argv_obstack, infile);
> obstack_ptr_grow (&argv_obstack, "-c");
> obstack_ptr_grow (&argv_obstack, "-o");
> @@ -960,10 +964,23 @@ main (int argc, char **argv)
> passed with @file. Expand them into argv before processing. */
> expandargv (&argc, &argv);
>
> + /* Find out whether we should compile binaries for i386 or x86-64. */
> + for (int i = argc - 1; i > 0; i--)
> + if (strncmp (argv[i], "-foffload-abi=", sizeof ("-foffload-abi=") - 1)
> == 0)
> + {
> + if (strstr (argv[i], "ilp32"))
> + target_ilp32 = true;
> + else if (!strstr (argv[i], "lp64"))
> + fatal_error (input_location,
> + "unrecognizable argument of option -foffload-abi");
> + break;
> + }
> +
> struct obstack argv_obstack;
> obstack_init (&argv_obstack);
> obstack_ptr_grow (&argv_obstack, driver);
> obstack_ptr_grow (&argv_obstack, "-xlto");
> + obstack_ptr_grow (&argv_obstack, target_ilp32 ? "-m32" : "-m64");
> obstack_ptr_grow (&argv_obstack, "-S");
>
> for (int ix = 1; ix != argc; ix++)
> diff --git gcc/config/nvptx/nvptx.h gcc/config/nvptx/nvptx.h
> index 15460b7..e74d16f 100644
> --- gcc/config/nvptx/nvptx.h
> +++ gcc/config/nvptx/nvptx.h
> @@ -58,28 +58,24 @@
>
> /* Type Layout. */
>
> -#define TARGET_64BIT \
> - (flag_offload_abi == OFFLOAD_ABI_UNSET ? TARGET_ABI64 \
> - : flag_offload_abi == OFFLOAD_ABI_LP64 ? true : false)
> -
> #define DEFAULT_SIGNED_CHAR 1
>
> #define SHORT_TYPE_SIZE 16
> #define INT_TYPE_SIZE 32
> -#define LONG_TYPE_SIZE (TARGET_64BIT ? 64 : 32)
> +#define LONG_TYPE_SIZE (TARGET_ABI64 ? 64 : 32)
> #define LONG_LONG_TYPE_SIZE 64
> #define FLOAT_TYPE_SIZE 32
> #define DOUBLE_TYPE_SIZE 64
> #define LONG_DOUBLE_TYPE_SIZE 64
>
> #undef SIZE_TYPE
> -#define SIZE_TYPE (TARGET_64BIT ? "long unsigned int" : "unsigned int")
> +#define SIZE_TYPE (TARGET_ABI64 ? "long unsigned int" : "unsigned int")
> #undef PTRDIFF_TYPE
> -#define PTRDIFF_TYPE (TARGET_64BIT ? "long int" : "int")
> +#define PTRDIFF_TYPE (TARGET_ABI64 ? "long int" : "int")
>
> -#define POINTER_SIZE (TARGET_64BIT ? 64 : 32)
> +#define POINTER_SIZE (TARGET_ABI64 ? 64 : 32)
>
> -#define Pmode (TARGET_64BIT ? DImode : SImode)
> +#define Pmode (TARGET_ABI64 ? DImode : SImode)
>
> /* Registers. Since ptx is a virtual target, we just define a few
> hard registers for special purposes and leave pseudos unallocated. */
Grüße,
Thomas
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