diff options
Diffstat (limited to 'gdb/rs6000-tdep.c')
| -rw-r--r-- | gdb/rs6000-tdep.c | 50 |
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]; |