Fix various bugs in arm_record_exreg_ld_st_insn

This patch fixes various bugs in arm_record_exreg_ld_st_insn, and use
gdb.reverse/insn-reverse.c to test more arm instructions.

 - Set flag SINGLE_REG correctly.  In the arch reference manual,
   SING_REG is true when the bit 8 of instruction is zero.
 - Record the right D registers for instructions changing S registers.
 - Fix the order of length and address in record_buf_mem array.
 - Shift the offset by 2 instead of by 24.

This patch also fixes one internal error,

(gdb) PASS: gdb.reverse/finish-precsave.exp: BP at end of main
continue^M
Continuing.^M
../../binutils-gdb/gdb/utils.c:1072: internal-error: virtual memory exhausted.^M
A problem internal to GDB has been detected,FAIL: gdb.reverse/finish-precsave.exp: run to end of main (GDB internal error)

gdb:

2016-02-26  Yao Qi  <yao.qi@linaro.org>

	* arm-tdep.c (arm_record_exreg_ld_st_insn): Set 'single_reg'
	per bit 8.  Check bit 20 instead of bit 4 for VMOV
	instruction.  Record D registers for instructions changing
	S registers.  Change of the order of length and address
	in record_buf_mem array.

gdb/testsuite:

2016-02-26  Yao Qi  <yao.qi@linaro.org>

	* gdb.reverse/insn-reverse.c [__arm__] (ext_reg_load): New.
	[__arm__] (ext_reg_mov, ext_reg_push_pop): New.
	(testcases): Update.

1 files changed, 43 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.reverse/insn-reverse.c b/gdb/testsuite/gdb.reverse/insn-reverse.c
index 1bfb8b06767..22cd267761d 100644
--- a/gdb/testsuite/gdb.reverse/insn-reverse.c
+++ b/gdb/testsuite/gdb.reverse/insn-reverse.c
@@ -88,6 +88,45 @@ adv_simd_vect_shift (void)
 {
   asm ("fcvtzs s0, s0, #1");
 }
+#elif (defined __arm__)
+static void
+ext_reg_load (void)
+{
+  char in[8];
+
+  asm ("vldr d0, [%0]" : : "r" (in));
+  asm ("vldr s3, [%0]" : : "r" (in));
+
+  asm ("vldm %0, {d3-d4}" : : "r" (in));
+  asm ("vldm %0, {s9-s11}" : : "r" (in));
+}
+
+static void
+ext_reg_mov (void)
+{
+  int i, j;
+  double d;
+
+  i = 1;
+  j = 2;
+
+  asm ("vmov s4, s5, %0, %1" : "=r" (i), "=r" (j): );
+  asm ("vmov s7, s8, %0, %1" : "=r" (i), "=r" (j): );
+  asm ("vmov %0, %1, s10, s11" : : "r" (i), "r" (j));
+  asm ("vmov %0, %1, s1, s2" : : "r" (i), "r" (j));
+
+  asm ("vmov %P2, %0, %1" : "=r" (i), "=r" (j): "w" (d));
+  asm ("vmov %1, %2, %P0" : "=w" (d) : "r" (i), "r" (j));
+}
+
+static void
+ext_reg_push_pop (void)
+{
+  double d;
+
+  asm ("vpush {%P0}" : : "w" (d));
+  asm ("vpop {%P0}" : : "w" (d));
+}
 #endif
 
 typedef void (*testcase_ftype) (void);
@@ -104,6 +143,10 @@ static testcase_ftype testcases[] =
   adv_simd_scalar_index,
   adv_simd_smlal,
   adv_simd_vect_shift,
+#elif (defined __arm__)
+  ext_reg_load,
+  ext_reg_mov,
+  ext_reg_push_pop,
 #endif
 };