* server.h (struct emit_ops): Add compare-goto fields.

[deliverable/binutils-gdb.git] / gdb / gdbserver / tracepoint.c

diff --git a/gdb/gdbserver/tracepoint.c b/gdb/gdbserver/tracepoint.c
index 8cfb7730b64f68bc7cf2366862fadd5dd6659e3a..0a64104072c893a55567ed5527003dca807e8e85 100644 (file)
--- a/gdb/gdbserver/tracepoint.c
+++ b/gdb/gdbserver/tracepoint.c
@@ -483,6 +483,14 @@ static const char *gdb_agent_op_names [gdb_agent_op_last] =
 #undef DEFOP
   };
 
+static const unsigned char gdb_agent_op_sizes [gdb_agent_op_last] =
+  {
+    0
+#define DEFOP(NAME, SIZE, DATA_SIZE, CONSUMED, PRODUCED, VALUE)  , SIZE
+#include "ax.def"
+#undef DEFOP
+  };
+
 struct agent_expr
 {
   int length;
@@ -5663,6 +5671,42 @@ emit_void_call_2 (CORE_ADDR fn, int arg1)
   target_emit_ops ()->emit_void_call_2 (fn, arg1);
 }
 
+static void
+emit_eq_goto (int *offset_p, int *size_p)
+{
+  target_emit_ops ()->emit_eq_goto (offset_p, size_p);
+}
+
+static void
+emit_ne_goto (int *offset_p, int *size_p)
+{
+  target_emit_ops ()->emit_ne_goto (offset_p, size_p);
+}
+
+static void
+emit_lt_goto (int *offset_p, int *size_p)
+{
+  target_emit_ops ()->emit_lt_goto (offset_p, size_p);
+}
+
+static void
+emit_ge_goto (int *offset_p, int *size_p)
+{
+  target_emit_ops ()->emit_ge_goto (offset_p, size_p);
+}
+
+static void
+emit_gt_goto (int *offset_p, int *size_p)
+{
+  target_emit_ops ()->emit_gt_goto (offset_p, size_p);
+}
+
+static void
+emit_le_goto (int *offset_p, int *size_p)
+{
+  target_emit_ops ()->emit_le_goto (offset_p, size_p);
+}
+
 static enum eval_result_type compile_bytecodes (struct agent_expr *aexpr);
 
 static void
@@ -5712,6 +5756,30 @@ compile_tracepoint_condition (struct tracepoint *tpoint,
   *jump_entry += 16;
 }
 
+/* Scan an agent expression for any evidence that the given PC is the
+   target of a jump bytecode in the expression.  */
+
+int
+is_goto_target (struct agent_expr *aexpr, int pc)
+{
+  int i;
+  unsigned char op;
+
+  for (i = 0; i < aexpr->length; i += 1 + gdb_agent_op_sizes[op])
+    {
+      op = aexpr->bytes[i];
+
+      if (op == gdb_agent_op_goto || op == gdb_agent_op_if_goto)
+       {
+         int target = (aexpr->bytes[i + 1] << 8) + aexpr->bytes[i + 2];
+         if (target == pc)
+           return 1;
+       }
+    }
+
+  return 0;
+}
+
 /* Given an agent expression, turn it into native code.  */
 
 static enum eval_result_type
@@ -5719,7 +5787,7 @@ compile_bytecodes (struct agent_expr *aexpr)
 {
   int pc = 0;
   int done = 0;
-  unsigned char op;
+  unsigned char op, next_op;
   int arg;
   /* This is only used to build 64-bit value for constants.  */
   ULONGEST top;
@@ -5831,11 +5899,64 @@ compile_bytecodes (struct agent_expr *aexpr)
          break;
 
        case gdb_agent_op_equal:
-         emit_equal ();
+         next_op = aexpr->bytes[pc];
+         if (next_op == gdb_agent_op_if_goto
+             && !is_goto_target (aexpr, pc)
+             && target_emit_ops ()->emit_eq_goto)
+           {
+             trace_debug ("Combining equal & if_goto");
+             pc += 1;
+             aentry->pc = pc;
+             arg = aexpr->bytes[pc++];
+             arg = (arg << 8) + aexpr->bytes[pc++];
+             aentry->goto_pc = arg;
+             emit_eq_goto (&(aentry->from_offset), &(aentry->from_size));
+           }
+         else if (next_op == gdb_agent_op_log_not
+                  && (aexpr->bytes[pc + 1] == gdb_agent_op_if_goto)
+                  && !is_goto_target (aexpr, pc + 1)
+                  && target_emit_ops ()->emit_ne_goto)
+           {
+             trace_debug ("Combining equal & log_not & if_goto");
+             pc += 2;
+             aentry->pc = pc;
+             arg = aexpr->bytes[pc++];
+             arg = (arg << 8) + aexpr->bytes[pc++];
+             aentry->goto_pc = arg;
+             emit_ne_goto (&(aentry->from_offset), &(aentry->from_size));
+           }
+         else
+           emit_equal ();
          break;
 
        case gdb_agent_op_less_signed:
-         emit_less_signed ();
+         next_op = aexpr->bytes[pc];
+         if (next_op == gdb_agent_op_if_goto
+             && !is_goto_target (aexpr, pc))
+           {
+             trace_debug ("Combining less_signed & if_goto");
+             pc += 1;
+             aentry->pc = pc;
+             arg = aexpr->bytes[pc++];
+             arg = (arg << 8) + aexpr->bytes[pc++];
+             aentry->goto_pc = arg;
+             emit_lt_goto (&(aentry->from_offset), &(aentry->from_size));
+           }
+         else if (next_op == gdb_agent_op_log_not
+                  && !is_goto_target (aexpr, pc)
+                  && (aexpr->bytes[pc + 1] == gdb_agent_op_if_goto)
+                  && !is_goto_target (aexpr, pc + 1))
+           {
+             trace_debug ("Combining less_signed & log_not & if_goto");
+             pc += 2;
+             aentry->pc = pc;
+             arg = aexpr->bytes[pc++];
+             arg = (arg << 8) + aexpr->bytes[pc++];
+             aentry->goto_pc = arg;
+             emit_ge_goto (&(aentry->from_offset), &(aentry->from_size));
+           }
+         else
+           emit_less_signed ();
          break;
 
        case gdb_agent_op_less_unsigned:
@@ -5946,7 +6067,38 @@ compile_bytecodes (struct agent_expr *aexpr)
          break;
 
        case gdb_agent_op_swap:
-         emit_swap ();
+         next_op = aexpr->bytes[pc];
+         /* Detect greater-than comparison sequences.  */
+         if (next_op == gdb_agent_op_less_signed
+             && !is_goto_target (aexpr, pc)
+             && (aexpr->bytes[pc + 1] == gdb_agent_op_if_goto)
+             && !is_goto_target (aexpr, pc + 1))
+           {
+             trace_debug ("Combining swap & less_signed & if_goto");
+             pc += 2;
+             aentry->pc = pc;
+             arg = aexpr->bytes[pc++];
+             arg = (arg << 8) + aexpr->bytes[pc++];
+             aentry->goto_pc = arg;
+             emit_gt_goto (&(aentry->from_offset), &(aentry->from_size));
+           }
+         else if (next_op == gdb_agent_op_less_signed
+                  && !is_goto_target (aexpr, pc)
+                  && (aexpr->bytes[pc + 1] == gdb_agent_op_log_not)
+                  && !is_goto_target (aexpr, pc + 1)
+                  && (aexpr->bytes[pc + 2] == gdb_agent_op_if_goto)
+                  && !is_goto_target (aexpr, pc + 2))
+           {
+             trace_debug ("Combining swap & less_signed & log_not & if_goto");
+             pc += 3;
+             aentry->pc = pc;
+             arg = aexpr->bytes[pc++];
+             arg = (arg << 8) + aexpr->bytes[pc++];
+             aentry->goto_pc = arg;
+             emit_le_goto (&(aentry->from_offset), &(aentry->from_size));
+           }
+         else
+           emit_swap ();
          break;
 
        case gdb_agent_op_getv: