This is the mail archive of the
gdb-patches@sources.redhat.com
mailing list for the GDB project.
ia64 patch to handle predicated insns in prologue
- From: "J. Johnston" <jjohnstn at redhat dot com>
- To: gdb-patches at sources dot redhat dot com
- Date: Tue, 26 Aug 2003 14:30:15 -0400
- Subject: ia64 patch to handle predicated insns in prologue
- Organization: Red Hat Inc.
The accompanying patch handles a bug in backtracing through glibc's sleep.
The compiler generates some predicated insns prior to saving the return register
b0 into a register stack register. The current code stops when it sees a
predicated insn. The change makes the prologue examination stop only if the
function is frameless or we have already seen the return register.
This removes a number of failures in gdb.threads caused when we catch another
thread in sleep and we try and backtrace.
Ok to commit?
-- Jeff J.
2003-08-26 Jeff Johnston <jjohnstn@redhat.com>
* ia64-tdep.c (examine_prologue): Only stop at predicated insns if
we are frameless or the return address register is already known.
Index: ia64-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/ia64-tdep.c,v
retrieving revision 1.94
diff -u -r1.94 ia64-tdep.c
--- ia64-tdep.c 26 Aug 2003 17:33:22 -0000 1.94
+++ ia64-tdep.c 26 Aug 2003 17:46:44 -0000
@@ -1143,11 +1143,18 @@
if (next_pc == 0)
break;
- if ((it == B && ((instr & 0x1e1f800003f) != 0x04000000000))
- || ((instr & 0x3fLL) != 0LL))
+ if (it == B && ((instr & 0x1e1f800003f) != 0x04000000000))
{
- /* Exit loop upon hitting a non-nop branch instruction
- or a predicated instruction. */
+ /* Exit loop upon hitting a non-nop branch instruction. */
+ if (trust_limit)
+ lim_pc = pc;
+ break;
+ }
+ else if (((instr & 0x3fLL) != 0LL) &&
+ (frameless || ret_reg != 0))
+ {
+ /* Exit loop upon hitting a predicated instruction if
+ we already have the return register or if we are frameless. */
if (trust_limit)
lim_pc = pc;
break;