Make aarch64_decode_adrp handle both ADR and ADRP instructions

We will need to decode both ADR and ADRP instructions in GDBserver.
This patch makes common code handle both cases, even if GDB only needs
to decode the ADRP instruction.

gdb/ChangeLog:

	* aarch64-tdep.c (aarch64_analyze_prologue): New is_adrp
	variable.  Call aarch64_decode_adr instead of
	aarch64_decode_adrp.
	* arch/aarch64-insn.h (aarch64_decode_adrp): Delete.
	(aarch64_decode_adr): New function declaration.
	* arch/aarch64-insn.c (aarch64_decode_adrp): Delete.
	(aarch64_decode_adr): New function, factored out from
	aarch64_decode_adrp to decode both adr and adrp instructions.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7d8feeb0ce5644d44ed33f8659d795c8fbade7d9..935daf17c681780257d622da705f5500502e7fa0 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,14 @@
+2015-09-21  Pierre Langlois  <pierre.langlois@arm.com>
+
+       * aarch64-tdep.c (aarch64_analyze_prologue): New is_adrp
+       variable.  Call aarch64_decode_adr instead of
+       aarch64_decode_adrp.
+       * arch/aarch64-insn.h (aarch64_decode_adrp): Delete.
+       (aarch64_decode_adr): New function declaration.
+       * arch/aarch64-insn.c (aarch64_decode_adrp): Delete.
+       (aarch64_decode_adr): New function, factored out from
+       aarch64_decode_adrp to decode both adr and adrp instructions.
+
 2015-09-21  Pierre Langlois  <pierre.langlois@arm.com>
 
        * Makefile.in (ALL_64_TARGET_OBS): Add aarch64-insn.o.

diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index 92e24047bb4874b2c052db14f154a0afae052dee..da61e546db9d54ccec386ff3dbf9d6cdd5b90ec9 100644 (file)
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -551,13 +551,15 @@ aarch64_analyze_prologue (struct gdbarch *gdbarch,
       int is_cbnz;
       int is_tbnz;
       unsigned bit;
+      int is_adrp;
       int32_t offset;
 
       insn = read_memory_unsigned_integer (start, 4, byte_order_for_code);
 
       if (aarch64_decode_add_sub_imm (start, insn, &rd, &rn, &imm))
        regs[rd] = pv_add_constant (regs[rn], imm);
-      else if (aarch64_decode_adrp (start, insn, &rd))
+      else if (aarch64_decode_adr (start, insn, &is_adrp, &rd, &offset)
+              && is_adrp)
        regs[rd] = pv_unknown ();
       else if (aarch64_decode_b (start, insn, &is_link, &offset))
        {

diff --git a/gdb/arch/aarch64-insn.c b/gdb/arch/aarch64-insn.c
index 3a289a26da811b7c0fdf385db3ad2883e69ec801..13d0013d6e971b728191c29a1a0668f89e5dc855 100644 (file)
--- a/gdb/arch/aarch64-insn.c
+++ b/gdb/arch/aarch64-insn.c
@@ -55,25 +55,44 @@ decode_masked_match (uint32_t insn, uint32_t mask, uint32_t pattern)
   return (insn & mask) == pattern;
 }
 
-/* Decode an opcode if it represents an ADRP instruction.
+/* Decode an opcode if it represents an ADR or ADRP instruction.
 
    ADDR specifies the address of the opcode.
    INSN specifies the opcode to test.
+   IS_ADRP receives the 'op' field from the decoded instruction.
    RD receives the 'rd' field from the decoded instruction.
+   OFFSET receives the 'immhi:immlo' field from the decoded instruction.
 
    Return 1 if the opcodes matches and is decoded, otherwise 0.  */
 
 int
-aarch64_decode_adrp (CORE_ADDR addr, uint32_t insn, unsigned *rd)
+aarch64_decode_adr (CORE_ADDR addr, uint32_t insn, int *is_adrp,
+                   unsigned *rd, int32_t *offset)
 {
-  if (decode_masked_match (insn, 0x9f000000, 0x90000000))
+  /* adr  0ii1 0000 iiii iiii iiii iiii iiir rrrr */
+  /* adrp 1ii1 0000 iiii iiii iiii iiii iiir rrrr */
+  if (decode_masked_match (insn, 0x1f000000, 0x10000000))
     {
+      uint32_t immlo = (insn >> 29) & 0x3;
+      int32_t immhi = extract_signed_bitfield (insn, 19, 5) << 2;
+
+      *is_adrp = (insn >> 31) & 0x1;
       *rd = (insn >> 0) & 0x1f;
 
+      if (*is_adrp)
+       {
+         /* The ADRP instruction has an offset with a -/+ 4GB range,
+            encoded as (immhi:immlo * 4096).  */
+         *offset = (immhi | immlo) * 4096;
+       }
+      else
+       *offset = (immhi | immlo);
+
       if (aarch64_debug)
        {
-         debug_printf ("decode: 0x%s 0x%x adrp x%u, #?\n",
-                       core_addr_to_string_nz (addr), insn, *rd);
+         debug_printf ("decode: 0x%s 0x%x %s x%u, #?\n",
+                       core_addr_to_string_nz (addr), insn,
+                       *is_adrp ?  "adrp" : "adr", *rd);
        }
       return 1;
     }

diff --git a/gdb/arch/aarch64-insn.h b/gdb/arch/aarch64-insn.h
index 7775a34e829990efbc334d11b15d20a9b039cf01..2facb44aea8445331d97b075f5b31b8bab589f1d 100644 (file)
--- a/gdb/arch/aarch64-insn.h
+++ b/gdb/arch/aarch64-insn.h
@@ -21,7 +21,8 @@
 
 extern int aarch64_debug;
 
-int aarch64_decode_adrp (CORE_ADDR addr, uint32_t insn, unsigned *rd);
+int aarch64_decode_adr (CORE_ADDR addr, uint32_t insn, int *is_adrp,
+                       unsigned *rd, int32_t *offset);
 
 int aarch64_decode_b (CORE_ADDR addr, uint32_t insn, int *is_bl,
                      int32_t *offset);