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[PATCH] IA64: $fr0==0.0, $fr1==1.0
- From: Pedro Alves <palves at redhat dot com>
- To: gdb-patches at sourceware dot org
- Date: Wed, 28 Mar 2012 15:55:06 +0100
- Subject: [PATCH] IA64: $fr0==0.0, $fr1==1.0
- References: <4F730961.6030003@redhat.com>
> I see that $f0 (always 0.0) and $f1 (always 1.0) could/should be given
> similar treatment:
>
> (gdb) info register $f0 $f1
> f0 *value not available*
> f1 *value not available*
>
(...)
> gcore.exp failures related to these issues.
(because when debugging a live process "info registers" shows 'value
not available', but when debugging a core, "info registers" shows 0.0
for those registers.
(I was lazy and got the raw bytes of 1.0 by using "info float" after
writing 1 to $fp2...)
With yours, and these patches applied, gcore.exp passes cleanly
on ia64-unknown-linux-gnu. Before, we had:
Running ../../../src/gdb/testsuite/gdb.base/gcore.exp ...
FAIL: gdb.base/gcore.exp: corefile restored general registers
FAIL: gdb.base/gcore.exp: corefile restored all registers
No regressions. WDYT?
2012-03-28 Pedro Alves <palves@redhat.com>
* ia64-linux-nat.c (supply_fpregset, ia64_linux_fetch_register):
Always supply $fr0 as 0.0 and $fr1 as 1.0.
---
gdb/ia64-linux-nat.c | 35 ++++++++++++++++++++++++++++++++++-
1 files changed, 34 insertions(+), 1 deletions(-)
diff --git a/gdb/ia64-linux-nat.c b/gdb/ia64-linux-nat.c
index 24bde2d..237f2c7 100644
--- a/gdb/ia64-linux-nat.c
+++ b/gdb/ia64-linux-nat.c
@@ -447,8 +447,20 @@ supply_fpregset (struct regcache *regcache, const fpregset_t *fpregsetp)
{
int regi;
const char *from;
+ const gdb_byte f_zero[16] = { 0 };
+ const gdb_byte f_one[16] =
+ { 0, 0, 0, 0, 0, 0, 0, 0x80, 0xff, 0xff, 0, 0, 0, 0, 0, 0 };
- for (regi = IA64_FR0_REGNUM; regi <= IA64_FR127_REGNUM; regi++)
+ /* Kernel generated cores have fr1==0 instead of 1.0. Older GDBs
+ did the same. So ignore whatever might be recorded in fpregset_t
+ for fr0/fr1 and always supply their expected values. */
+
+ /* fr0 is always read as zero. */
+ regcache_raw_supply (regcache, IA64_FR0_REGNUM, f_zero);
+ /* fr1 is always read as one (1.0). */
+ regcache_raw_supply (regcache, IA64_FR1_REGNUM, f_one);
+
+ for (regi = IA64_FR2_REGNUM; regi <= IA64_FR127_REGNUM; regi++)
{
from = (const char *) &((*fpregsetp)[regi - IA64_FR0_REGNUM]);
regcache_raw_supply (regcache, regi, from);
@@ -690,6 +702,27 @@ ia64_linux_fetch_register (struct regcache *regcache, int regnum)
return;
}
+ /* fr0 cannot be fetched but is always zero. */
+ if (regnum == IA64_FR0_REGNUM)
+ {
+ const gdb_byte f_zero[16] = { 0 };
+
+ gdb_assert (sizeof (f_zero) == register_size (gdbarch, regnum));
+ regcache_raw_supply (regcache, regnum, f_zero);
+ return;
+ }
+
+ /* fr1 cannot be fetched but is always one (1.0). */
+ if (regnum == IA64_FR1_REGNUM)
+ {
+ const gdb_byte f_one[16] =
+ { 0, 0, 0, 0, 0, 0, 0, 0x80, 0xff, 0xff, 0, 0, 0, 0, 0, 0 };
+
+ gdb_assert (sizeof (f_one) == register_size (gdbarch, regnum));
+ regcache_raw_supply (regcache, regnum, f_one);
+ return;
+ }
+
if (ia64_cannot_fetch_register (gdbarch, regnum))
{
regcache_raw_supply (regcache, regnum, NULL);