/* Target-dependent code for the ALPHA architecture, for GDB, the GNU Debugger.
Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
- 2003, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+ 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011
+ Free Software Foundation, Inc.
This file is part of GDB.
#include "alpha-tdep.h"
+/* Instruction decoding. The notations for registers, immediates and
+ opcodes are the same as the one used in Compaq's Alpha architecture
+ handbook. */
+
+#define INSN_OPCODE(insn) ((insn & 0xfc000000) >> 26)
+
+/* Memory instruction format */
+#define MEM_RA(insn) ((insn & 0x03e00000) >> 21)
+#define MEM_RB(insn) ((insn & 0x001f0000) >> 16)
+#define MEM_DISP(insn) \
+ (((insn & 0x8000) == 0) ? (insn & 0xffff) : -((-insn) & 0xffff))
+
+static const int lda_opcode = 0x08;
+static const int stq_opcode = 0x2d;
+
+/* Branch instruction format */
+#define BR_RA(insn) MEM_RA(insn)
+
+static const int bne_opcode = 0x3d;
+
+/* Operate instruction format */
+#define OPR_FUNCTION(insn) ((insn & 0xfe0) >> 5)
+#define OPR_HAS_IMMEDIATE(insn) ((insn & 0x1000) == 0x1000)
+#define OPR_RA(insn) MEM_RA(insn)
+#define OPR_RC(insn) ((insn & 0x1f))
+#define OPR_LIT(insn) ((insn & 0x1fe000) >> 13)
+
+static const int subq_opcode = 0x10;
+static const int subq_function = 0x29;
+
\f
/* Return the name of the REGNO register.
An empty name corresponds to a register number that used to
- be used for a virtual register. That virtual register has
+ be used for a virtual register. That virtual register has
been removed, but the index is still reserved to maintain
compatibility with existing remote alpha targets. */
register is a floating point register and memory format is float, as the
register format must be double or memory format is an integer with 4
bytes or less, as the representation of integers in floating point
- registers is different. */
+ registers is different. */
static int
-alpha_convert_register_p (struct gdbarch *gdbarch, int regno, struct type *type)
+alpha_convert_register_p (struct gdbarch *gdbarch, int regno,
+ struct type *type)
{
return (regno >= ALPHA_FP0_REGNUM && regno < ALPHA_FP0_REGNUM + 31
&& TYPE_LENGTH (type) != 8);
}
-static void
+static int
alpha_register_to_value (struct frame_info *frame, int regnum,
- struct type *valtype, gdb_byte *out)
+ struct type *valtype, gdb_byte *out,
+ int *optimizedp, int *unavailablep)
{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
gdb_byte in[MAX_REGISTER_SIZE];
- frame_register_read (frame, regnum, in);
- switch (TYPE_LENGTH (valtype))
+ /* Convert to TYPE. */
+ if (!get_frame_register_bytes (frame, regnum, 0,
+ register_size (gdbarch, regnum),
+ in, optimizedp, unavailablep))
+ return 0;
+
+ if (TYPE_LENGTH (valtype) == 4)
{
- case 4:
- alpha_sts (get_frame_arch (frame), out, in);
- break;
- default:
- error (_("Cannot retrieve value from floating point register"));
+ alpha_sts (gdbarch, out, in);
+ *optimizedp = *unavailablep = 0;
+ return 1;
}
+
+ error (_("Cannot retrieve value from floating point register"));
}
static void
int accumulate_size = struct_return ? 8 : 0;
struct alpha_arg
{
- gdb_byte *contents;
+ const gdb_byte *contents;
int len;
int offset;
};
m_arg->len = TYPE_LENGTH (arg_type);
m_arg->offset = accumulate_size;
accumulate_size = (accumulate_size + m_arg->len + 7) & ~7;
- m_arg->contents = value_contents_writeable (arg);
+ m_arg->contents = value_contents (arg);
}
/* Determine required argument register loads, loading an argument register
/* `Push' arguments on the stack. */
for (i = nargs; m_arg--, --i >= 0;)
{
- gdb_byte *contents = m_arg->contents;
+ const gdb_byte *contents = m_arg->contents;
int offset = m_arg->offset;
int len = m_arg->len;
break;
default:
- internal_error (__FILE__, __LINE__, _("unknown floating point width"));
+ internal_error (__FILE__, __LINE__,
+ _("unknown floating point width"));
}
break;
break;
default:
- internal_error (__FILE__, __LINE__, _("unknown floating point width"));
+ internal_error (__FILE__, __LINE__,
+ _("unknown floating point width"));
}
break;
error (_("Cannot set a 128-bit long double return value."));
default:
- internal_error (__FILE__, __LINE__, _("unknown floating point width"));
+ internal_error (__FILE__, __LINE__,
+ _("unknown floating point width"));
}
break;
error (_("Cannot set a 128-bit long double return value."));
default:
- internal_error (__FILE__, __LINE__, _("unknown floating point width"));
+ internal_error (__FILE__, __LINE__,
+ _("unknown floating point width"));
}
break;
/* Can't determine prologue from the symbol table, need to examine
instructions. */
- /* Skip the typical prologue instructions. These are the stack adjustment
+ /* Skip the typical prologue instructions. These are the stack adjustment
instruction and the instructions that save registers on the stack
or in the gcc frame. */
for (offset = 0; offset < 100; offset += ALPHA_INSN_SIZE)
static const struct frame_unwind alpha_sigtramp_frame_unwind = {
SIGTRAMP_FRAME,
+ default_frame_unwind_stop_reason,
alpha_sigtramp_frame_this_id,
alpha_sigtramp_frame_prev_register,
NULL,
/* It's not clear to me why we reach this point when stopping quietly,
but with this test, at least we don't print out warnings for every
child forked (eg, on decstation). 22apr93 rich@cygnus.com. */
- if (inf->stop_soon == NO_STOP_QUIETLY)
+ if (inf->control.stop_soon == NO_STOP_QUIETLY)
{
static int blurb_printed = 0;
int return_reg;
};
+/* If a probing loop sequence starts at PC, simulate it and compute
+ FRAME_SIZE and PC after its execution. Otherwise, return with PC and
+ FRAME_SIZE unchanged. */
+
+static void
+alpha_heuristic_analyze_probing_loop (struct gdbarch *gdbarch, CORE_ADDR *pc,
+ int *frame_size)
+{
+ CORE_ADDR cur_pc = *pc;
+ int cur_frame_size = *frame_size;
+ int nb_of_iterations, reg_index, reg_probe;
+ unsigned int insn;
+
+ /* The following pattern is recognized as a probing loop:
+
+ lda REG_INDEX,NB_OF_ITERATIONS
+ lda REG_PROBE,<immediate>(sp)
+
+ LOOP_START:
+ stq zero,<immediate>(REG_PROBE)
+ subq REG_INDEX,0x1,REG_INDEX
+ lda REG_PROBE,<immediate>(REG_PROBE)
+ bne REG_INDEX, LOOP_START
+
+ lda sp,<immediate>(REG_PROBE)
+
+ If anything different is found, the function returns without
+ changing PC and FRAME_SIZE. Otherwise, PC will point immediately
+ after this sequence, and FRAME_SIZE will be updated. */
+
+ /* lda REG_INDEX,NB_OF_ITERATIONS */
+
+ insn = alpha_read_insn (gdbarch, cur_pc);
+ if (INSN_OPCODE (insn) != lda_opcode)
+ return;
+ reg_index = MEM_RA (insn);
+ nb_of_iterations = MEM_DISP (insn);
+
+ /* lda REG_PROBE,<immediate>(sp) */
+
+ cur_pc += ALPHA_INSN_SIZE;
+ insn = alpha_read_insn (gdbarch, cur_pc);
+ if (INSN_OPCODE (insn) != lda_opcode
+ || MEM_RB (insn) != ALPHA_SP_REGNUM)
+ return;
+ reg_probe = MEM_RA (insn);
+ cur_frame_size -= MEM_DISP (insn);
+
+ /* stq zero,<immediate>(REG_PROBE) */
+
+ cur_pc += ALPHA_INSN_SIZE;
+ insn = alpha_read_insn (gdbarch, cur_pc);
+ if (INSN_OPCODE (insn) != stq_opcode
+ || MEM_RA (insn) != 0x1f
+ || MEM_RB (insn) != reg_probe)
+ return;
+
+ /* subq REG_INDEX,0x1,REG_INDEX */
+
+ cur_pc += ALPHA_INSN_SIZE;
+ insn = alpha_read_insn (gdbarch, cur_pc);
+ if (INSN_OPCODE (insn) != subq_opcode
+ || !OPR_HAS_IMMEDIATE (insn)
+ || OPR_FUNCTION (insn) != subq_function
+ || OPR_LIT(insn) != 1
+ || OPR_RA (insn) != reg_index
+ || OPR_RC (insn) != reg_index)
+ return;
+
+ /* lda REG_PROBE,<immediate>(REG_PROBE) */
+
+ cur_pc += ALPHA_INSN_SIZE;
+ insn = alpha_read_insn (gdbarch, cur_pc);
+ if (INSN_OPCODE (insn) != lda_opcode
+ || MEM_RA (insn) != reg_probe
+ || MEM_RB (insn) != reg_probe)
+ return;
+ cur_frame_size -= MEM_DISP (insn) * nb_of_iterations;
+
+ /* bne REG_INDEX, LOOP_START */
+
+ cur_pc += ALPHA_INSN_SIZE;
+ insn = alpha_read_insn (gdbarch, cur_pc);
+ if (INSN_OPCODE (insn) != bne_opcode
+ || MEM_RA (insn) != reg_index)
+ return;
+
+ /* lda sp,<immediate>(REG_PROBE) */
+
+ cur_pc += ALPHA_INSN_SIZE;
+ insn = alpha_read_insn (gdbarch, cur_pc);
+ if (INSN_OPCODE (insn) != lda_opcode
+ || MEM_RA (insn) != ALPHA_SP_REGNUM
+ || MEM_RB (insn) != reg_probe)
+ return;
+ cur_frame_size -= MEM_DISP (insn);
+
+ *pc = cur_pc;
+ *frame_size = cur_frame_size;
+}
+
static struct alpha_heuristic_unwind_cache *
alpha_heuristic_frame_unwind_cache (struct frame_info *this_frame,
void **this_prologue_cache,
if (word & 0x8000)
{
/* Consider only the first stack allocation instruction
- to contain the static size of the frame. */
+ to contain the static size of the frame. */
if (frame_size == 0)
frame_size = (-word) & 0xffff;
}
So we recognize only a few registers (t7, t9, ra) within
the procedure prologue as valid return address registers.
If we encounter a return instruction, we extract the
- the return address register from it.
+ return address register from it.
FIXME: Rewriting GDB to access the procedure descriptors,
- e.g. via the minimal symbol table, might obviate this hack. */
+ e.g. via the minimal symbol table, might obviate this
+ hack. */
if (return_reg == -1
&& cur_pc < (start_pc + 80)
&& (reg == ALPHA_T7_REGNUM
frame_reg = ALPHA_GCC_FP_REGNUM;
else if (word == 0x47fe040f) /* bis zero,sp,fp */
frame_reg = ALPHA_GCC_FP_REGNUM;
+
+ alpha_heuristic_analyze_probing_loop (gdbarch, &cur_pc, &frame_size);
}
/* If we haven't found a valid return address register yet, keep
static const struct frame_unwind alpha_heuristic_frame_unwind = {
NORMAL_FRAME,
+ default_frame_unwind_stop_reason,
alpha_heuristic_frame_this_id,
alpha_heuristic_frame_prev_register,
NULL,
insn = alpha_read_insn (gdbarch, pc);
- /* Opcode is top 6 bits. */
+ /* Opcode is top 6 bits. */
op = (insn >> 26) & 0x3f;
if (op == 0x1a)
tdep->sc_regs_offset = 4 * 8;
tdep->sc_fpregs_offset = tdep->sc_regs_offset + 32 * 8 + 8;
- tdep->jb_pc = -1; /* longjmp support not enabled by default */
+ tdep->jb_pc = -1; /* longjmp support not enabled by default. */
tdep->return_in_memory = alpha_return_in_memory_always;
program for the start of a function. This command sets the distance of the\n\
search. The only need to set it is when debugging a stripped executable."),
reinit_frame_cache_sfunc,
- NULL, /* FIXME: i18n: The distance searched for the start of a function is \"%d\". */
+ NULL, /* FIXME: i18n: The distance searched for
+ the start of a function is \"%d\". */
&setlist, &showlist);
}
projects / deliverable / binutils-gdb.git / blobdiff