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Diffstat (limited to 'gdb/rs6000-tdep.c')
-rw-r--r--gdb/rs6000-tdep.c50
1 files changed, 43 insertions, 7 deletions
diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
index f1d9799..d48ea9e 100644
--- a/gdb/rs6000-tdep.c
+++ b/gdb/rs6000-tdep.c
@@ -129,17 +129,20 @@ struct rs6000_framedata
by which we decrement sp to allocate
the frame */
int saved_gpr; /* smallest # of saved gpr */
+ unsigned int gpr_mask; /* Each bit is an individual saved GPR. */
int saved_fpr; /* smallest # of saved fpr */
int saved_vr; /* smallest # of saved vr */
int saved_ev; /* smallest # of saved ev */
int alloca_reg; /* alloca register number (frame ptr) */
char frameless; /* true if frameless functions. */
char nosavedpc; /* true if pc not saved. */
+ char used_bl; /* true if link register clobbered */
int gpr_offset; /* offset of saved gprs from prev sp */
int fpr_offset; /* offset of saved fprs from prev sp */
int vr_offset; /* offset of saved vrs from prev sp */
int ev_offset; /* offset of saved evs from prev sp */
int lr_offset; /* offset of saved lr */
+ int lr_register; /* register of saved lr, if trustworthy */
int cr_offset; /* offset of saved cr */
int vrsave_offset; /* offset of saved vrsave register */
};
@@ -870,6 +873,7 @@ insn_changes_sp_or_jumps (unsigned long insn)
static int
rs6000_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
bfd_byte insn_buf[PPC_INSN_SIZE];
CORE_ADDR scan_pc, func_start, func_end, epilogue_start, epilogue_end;
unsigned long insn;
@@ -897,6 +901,17 @@ rs6000_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
insn = extract_unsigned_integer (insn_buf, PPC_INSN_SIZE);
if (insn == 0x4e800020)
break;
+ /* Assume a bctr is a tail call unless it points strictly within
+ this function. */
+ if (insn == 0x4e800420)
+ {
+ CORE_ADDR ctr = get_frame_register_unsigned (curfrm,
+ tdep->ppc_ctr_regnum);
+ if (ctr > func_start && ctr < func_end)
+ return 0;
+ else
+ break;
+ }
if (insn_changes_sp_or_jumps (insn))
return 0;
}
@@ -1316,6 +1331,7 @@ skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
fdata->alloca_reg = -1;
fdata->frameless = 1;
fdata->nosavedpc = 1;
+ fdata->lr_register = -1;
for (;; pc += 4)
{
@@ -1357,7 +1373,7 @@ skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
remember just the first one, but skip over additional
ones. */
if (lr_reg == -1)
- lr_reg = (op & 0x03e00000);
+ lr_reg = (op & 0x03e00000) >> 21;
if (lr_reg == 0)
r0_contains_arg = 0;
continue;
@@ -1388,6 +1404,10 @@ skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
{
reg = GET_SRC_REG (op);
+ if ((op & 0xfc1f0000) == 0xbc010000)
+ fdata->gpr_mask |= ~((1U << reg) - 1);
+ else
+ fdata->gpr_mask |= 1U << reg;
if (fdata->saved_gpr == -1 || fdata->saved_gpr > reg)
{
fdata->saved_gpr = reg;
@@ -1479,6 +1499,7 @@ skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
else if (op == 0x48000005)
{ /* bl .+4 used in
-mrelocatable */
+ fdata->used_bl = 1;
continue;
}
@@ -1503,7 +1524,10 @@ skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
/* If the return address has already been saved, we can skip
calls to blrl (for PIC). */
if (lr_reg != -1 && bl_to_blrl_insn_p (pc, op))
- continue;
+ {
+ fdata->used_bl = 1;
+ continue;
+ }
/* Don't skip over the subroutine call if it is not within
the first three instructions of the prologue and either
@@ -1529,8 +1553,9 @@ skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
if (op == 0x4def7b82 || op == 0) /* crorc 15, 15, 15 */
break; /* don't skip over
this branch */
- continue;
+ fdata->used_bl = 1;
+ continue;
}
/* update stack pointer */
else if ((op & 0xfc1f0000) == 0x94010000)
@@ -1791,11 +1816,15 @@ skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
else
{
+ unsigned int all_mask = ~((1U << fdata->saved_gpr) - 1);
+
/* Not a recognized prologue instruction.
Handle optimizer code motions into the prologue by continuing
the search if we have no valid frame yet or if the return
- address is not yet saved in the frame. */
- if (fdata->frameless == 0 && fdata->nosavedpc == 0)
+ address is not yet saved in the frame. Also skip instructions
+ if some of the GPRs expected to be saved are not yet saved. */
+ if (fdata->frameless == 0 && fdata->nosavedpc == 0
+ && (fdata->gpr_mask & all_mask) == all_mask)
break;
if (op == 0x4e800020 /* blr */
@@ -1848,6 +1877,9 @@ skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, CORE_ADDR lim_pc,
}
#endif /* 0 */
+ if (pc == lim_pc && lr_reg >= 0)
+ fdata->lr_register = lr_reg;
+
fdata->offset = -fdata->offset;
return last_prologue_pc;
}
@@ -2892,7 +2924,8 @@ rs6000_frame_cache (struct frame_info *this_frame, void **this_cache)
}
/* if != -1, fdata.saved_gpr is the smallest number of saved_gpr.
- All gpr's from saved_gpr to gpr31 are saved. */
+ All gpr's from saved_gpr to gpr31 are saved (except during the
+ prologue). */
if (fdata.saved_gpr >= 0)
{
@@ -2900,7 +2933,8 @@ rs6000_frame_cache (struct frame_info *this_frame, void **this_cache)
CORE_ADDR gpr_addr = cache->base + fdata.gpr_offset;
for (i = fdata.saved_gpr; i < ppc_num_gprs; i++)
{
- cache->saved_regs[tdep->ppc_gp0_regnum + i].addr = gpr_addr;
+ if (fdata.gpr_mask & (1U << i))
+ cache->saved_regs[tdep->ppc_gp0_regnum + i].addr = gpr_addr;
gpr_addr += wordsize;
}
}
@@ -2947,6 +2981,8 @@ rs6000_frame_cache (struct frame_info *this_frame, void **this_cache)
holds the LR. */
if (fdata.lr_offset != 0)
cache->saved_regs[tdep->ppc_lr_regnum].addr = cache->base + fdata.lr_offset;
+ else if (fdata.lr_register != -1)
+ cache->saved_regs[tdep->ppc_lr_regnum].realreg = fdata.lr_register;
/* The PC is found in the link register. */
cache->saved_regs[gdbarch_pc_regnum (gdbarch)] =
cache->saved_regs[tdep->ppc_lr_regnum];