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authorUlrich Weigand <uweigand@de.ibm.com>2007-05-10 20:29:03 +0000
committerUlrich Weigand <uweigand@de.ibm.com>2007-05-10 20:29:03 +0000
commit6c5588bf4e0d1a155ea1911a81911ac8fdd4c73d (patch)
treef9b0037153bf321865a8804ca2a8d78de5dbc3cc /gdb/rs6000-tdep.c
parentb6a94d310a846a6af67a45a49d867e00a95f6fda (diff)
downloadgdb-6c5588bf4e0d1a155ea1911a81911ac8fdd4c73d.tar.gz
2007-05-10 Luis Machado <luisgpm@br.ibm.com>
* rs6000-tdep.c: (deal_with_atomic_sequence) Stores branch instruction's opcode in the "opcode" variable and declares new variable "closing_insn".
Diffstat (limited to 'gdb/rs6000-tdep.c')
-rw-r--r--gdb/rs6000-tdep.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
index 96b28ec14d9..e9f8a86c4fb 100644
--- a/gdb/rs6000-tdep.c
+++ b/gdb/rs6000-tdep.c
@@ -729,12 +729,13 @@ deal_with_atomic_sequence (struct regcache *regcache)
CORE_ADDR breaks[2] = {-1, -1};
CORE_ADDR loc = pc;
CORE_ADDR branch_bp; /* Breakpoint at branch instruction's destination. */
+ CORE_ADDR closing_insn; /* Instruction that closes the atomic sequence. */
int insn = read_memory_integer (loc, PPC_INSN_SIZE);
int insn_count;
int index;
int last_breakpoint = 0; /* Defaults to 0 (no breakpoints placed). */
const int atomic_sequence_length = 16; /* Instruction sequence length. */
- const int opcode = BC_INSTRUCTION; /* Branch instruction's OPcode. */
+ int opcode; /* Branch instruction's OPcode. */
int bc_insn_count = 0; /* Conditional branch instruction count. */
/* Assume all atomic sequences start with a lwarx/ldarx instruction. */
@@ -758,6 +759,7 @@ deal_with_atomic_sequence (struct regcache *regcache)
return 0; /* More than one conditional branch found, fallback
to the standard single-step code. */
+ opcode = insn >> 26;
branch_bp = branch_dest (opcode, insn, pc, breaks[0]);
if (branch_bp != -1)
@@ -778,14 +780,19 @@ deal_with_atomic_sequence (struct regcache *regcache)
&& (insn & STWCX_MASK) != STDCX_INSTRUCTION)
return 0;
+ closing_insn = loc;
loc += PPC_INSN_SIZE;
insn = read_memory_integer (loc, PPC_INSN_SIZE);
/* Insert a breakpoint right after the end of the atomic sequence. */
breaks[0] = loc;
- /* Check for duplicated breakpoints. */
- if (last_breakpoint && (breaks[1] == breaks[0]))
+ /* Check for duplicated breakpoints. Check also for a breakpoint
+ placed (branch instruction's destination) at the stwcx/stdcx
+ instruction, this resets the reservation and take us back to the
+ lwarx/ldarx instruction at the beginning of the atomic sequence. */
+ if (last_breakpoint && ((breaks[1] == breaks[0])
+ || (breaks[1] == closing_insn)))
last_breakpoint = 0;
/* Effectively inserts the breakpoints. */