On 1/25/18 3:56 PM, Peter Bergner wrote:
> Ok, I'll move the table to driver-rs6000.c and I'll resubmit.
Ok, here is a separate translation table like you wanted. I still use the
RS6000_CPU table to hold entire list of canonical cpu names, the new
translation table in driver-rs6000.c only contains cpus whose AT_PLATFORM
names do not match their GCC canonical names. I also added the pa6t to
970 translation you mentioned in the bugzilla. If you want me to drop
that, that's easy enough to do.
I realize I also failed to mention in the first submission, that I have
added caching of the elf_plaform() result, so we don't have to mount and
scan /proc/self/auxv multiple times.
Is this better? I did the same unit testing by forcing unknown names
and names that need translation and I've verified it works. Bootstrap
and regtesting is still running though.
Peter
PR target/56010
PR target/83743
* config/rs6000/driver-rs6000.c: #include "diagnostic.h".
(rs6000_supported_cpu_names): New static variable.
(linux_cpu_translation_table): Likewise.
(elf_platform) <cpu>: Define new static variable and use it.
Translate kernel AT_PLATFORM name to canonical name if needed.
Error if platform name is unknown.
Index: gcc/config/rs6000/driver-rs6000.c
===================================================================
--- gcc/config/rs6000/driver-rs6000.c (revision 256364)
+++ gcc/config/rs6000/driver-rs6000.c (working copy)
@@ -23,6 +23,7 @@
#include "system.h"
#include "coretypes.h"
#include "tm.h"
+#include "diagnostic.h"
#include <stdlib.h>
#ifdef _AIX
@@ -38,6 +39,44 @@
# include <sys/sysctl.h>
#endif
+#ifdef __linux__
+/* Canonical GCC cpu name table. */
+static const char *rs6000_supported_cpu_names[] =
+{
+#define RS6000_CPU(NAME, CPU, FLAGS) NAME,
+#include "rs6000-cpus.def"
+#undef RS6000_CPU
+};
+
+/* This table holds a list of cpus where their Linux AT_PLATFORM name differs
+ from their GCC canonical name. The first column in a row contains the GCC
+ canonical cpu name and the other columns in that row contain AT_PLATFORM
+ names that should be mapped to the canonical name. */
+
+static const char *linux_cpu_translation_table[][4] = {
+ { "403", "ppc403", NULL },
+ { "405", "ppc405", NULL },
+ { "440", "ppc440", "ppc440gp", NULL },
+ { "476", "ppc470", NULL },
+ { "601", "ppc601", NULL },
+ { "603", "ppc603", NULL },
+ { "604", "ppc604", NULL },
+ { "7400", "ppc7400", NULL },
+ { "7450", "ppc7450", NULL },
+ { "750", "ppc750", NULL },
+ { "823", "ppc823", NULL },
+ { "8540", "ppc8540", NULL },
+ { "8548", "ppc8548", NULL },
+ { "970", "ppc970", "pa6t", NULL },
+ { "cell", "ppc-cell-be", NULL },
+ { "e500mc", "ppce500mc", NULL },
+ { "e5500", "ppce5500", NULL },
+ { "e6500", "ppce6500", NULL },
+ { "power7", "power7+", NULL },
+ { NULL } /* End of table sentinel. */
+};
+#endif
+
const char *host_detect_local_cpu (int argc, const char **argv);
#if GCC_VERSION >= 0
@@ -158,15 +197,19 @@
#ifdef __linux__
-/* Returns AT_PLATFORM if present, otherwise generic PowerPC. */
+/* Returns the canonical AT_PLATFORM if present, otherwise NULL. */
static const char *
elf_platform (void)
{
- int fd;
+ static const char *cpu = NULL;
- fd = open ("/proc/self/auxv", O_RDONLY);
+ /* Use the cached AT_PLATFORM cpu name if we've already determined it. */
+ if (cpu != NULL)
+ return cpu;
+ int fd = open ("/proc/self/auxv", O_RDONLY);
+
if (fd != -1)
{
char buf[1024];
@@ -179,15 +222,60 @@
if (n > 0)
{
for (av = (ElfW(auxv_t) *) buf; av->a_type != AT_NULL; ++av)
- switch (av->a_type)
+ if (av->a_type == AT_PLATFORM)
{
- case AT_PLATFORM:
- return (const char *) av->a_un.a_val;
-
- default:
+ cpu = (const char *) av->a_un.a_val;
break;
}
}
+
+ /* Verify that CPU is either a valid -mcpu=<cpu> option name, or is a
+ valid alternative name. If it is a valid alternative name, then use
+ the canonical name. */
+ if (cpu != NULL)
+ {
+ size_t i, j, len = 0;
+ char *s, *p;
+
+ /* Check if AT_PLATFORM is a GCC canonical cpu name. */
+ for (i = 0; i < ARRAY_SIZE (rs6000_supported_cpu_names); i++)
+ {
+ if (!strcmp (cpu, rs6000_supported_cpu_names[i]))
+ return cpu;
+ len += strlen (rs6000_supported_cpu_names[i]) + 1;
+ }
+
+ /* Check if AT_PLATFORM can be translated to a canonical cpu name. */
+ for (i = 0; linux_cpu_translation_table[i][0] != NULL; i++)
+ {
+ const char *canonical = linux_cpu_translation_table[i][0];
+ for (j = 1; linux_cpu_translation_table[i][j] != NULL; j++)
+ if (!strcmp (cpu, linux_cpu_translation_table[i][j]))
+ {
+ cpu = canonical;
+ return cpu;
+ }
+ }
+
+ /* The kernel returned an AT_PLATFORM name we do not support. */
+ s = XALLOCAVEC (char, len);
+ p = s;
+ for (i = 0; i < ARRAY_SIZE (rs6000_supported_cpu_names); i++)
+ {
+ size_t arglen = strlen (rs6000_supported_cpu_names[i]);
+ memcpy (p, rs6000_supported_cpu_names[i], arglen);
+ p[arglen] = ' ';
+ p += arglen + 1;
+ }
+ p[-1] = 0;
+
+ fatal_error (
+ input_location,
+ "Unsupported cpu name returned from kernel for -mcpu=native: %s\n"
+ "Please use an explicit cpu name. Valid cpu names are: %s",
+ cpu, s);
+ }
+
}
return NULL;
}
