Hi! 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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