Use code cache in aarch64 prologue analyzer

This patch change aarch prologue analyzer using code cache, in order
to improve the performance of remote debugging.

gdb.perf/skip-prologue.exp (measured by wall-time) is improved when
the program is compiled without debug information.

			Original	Patched		Original	Patched
			without dbg	without dbg	with dbg	with dbg

/			11.1635239124	9.99472999573	9.65339517593	9.66648793221
-fstack-protector-all	11.2560930252	9.338118	9.63896489143	9.59474396706

gdb:

2016-12-9  Yao Qi  <yao.qi@linaro.org>

	* aarch64-tdep.c (instruction_reader::read): Call
	read_code_unsigned_integer instead of
	read_memory_unsigned_integer.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index cd5a9eac92c7accbbc02e3264df1c0ebe4c59e49..4b268f58e1292a668cc19a2526b5265216c7bc92 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2016-12-09  Yao Qi  <yao.qi@linaro.org>
+
+       * aarch64-tdep.c (instruction_reader::read): Call
+       read_code_unsigned_integer instead of
+       read_memory_unsigned_integer.
+
 2016-12-09  Yao Qi  <yao.qi@linaro.org>
 
        * arm-tdep.c (skip_prologue_function): Call

diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index 590dcf63144aa091d3f414ecbd11b4f78556f24f..0175630a0b00a29a754e50968b78f566c071d03e 100644 (file)
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -213,7 +213,7 @@ class instruction_reader : public abstract_instruction_reader
  public:
   ULONGEST read (CORE_ADDR memaddr, int len, enum bfd_endian byte_order)
   {
-    return read_memory_unsigned_integer (memaddr, len, byte_order);
+    return read_code_unsigned_integer (memaddr, len, byte_order);
   }
 };