* arm-tdep.c (arm_scan_prologue): Don't require "mov ip, sp"

to be the first instruction in the prologue.  Also, revise
	the way the frame offset is computed for frameless functions.
This commit is contained in:
Kevin Buettner 2001-12-20 21:56:56 +00:00
parent f079148d61
commit d4473757f1
2 changed files with 79 additions and 69 deletions

View File

@ -8,6 +8,10 @@
is no longer needed now that the frame info is being properly
initialized.
* arm-tdep.c (arm_scan_prologue): Don't require "mov ip, sp"
to be the first instruction in the prologue. Also, revise
the way the frame offset is computed for frameless functions.
2001-12-20 Michael Snyder <msnyder@redhat.com>
* maint.c (maintenance_info_sections): Pass string argument to

View File

@ -812,98 +812,104 @@ arm_scan_prologue (struct frame_info *fi)
traceback.
In the APCS, the prologue should start with "mov ip, sp" so
if we don't see this as the first insn, we will stop. */
if we don't see this as the first insn, we will stop. [Note:
This doesn't seem to be true any longer, so it's now an optional
part of the prologue. - Kevin Buettner, 2001-11-20] */
sp_offset = fp_offset = 0;
if (read_memory_unsigned_integer (prologue_start, 4)
== 0xe1a0c00d) /* mov ip, sp */
current_pc = prologue_start + 4;
else
current_pc = prologue_start;
for (; current_pc < prologue_end; current_pc += 4)
{
for (current_pc = prologue_start + 4; current_pc < prologue_end;
current_pc += 4)
unsigned int insn = read_memory_unsigned_integer (current_pc, 4);
if ((insn & 0xffff0000) == 0xe92d0000)
/* stmfd sp!, {..., fp, ip, lr, pc}
or
stmfd sp!, {a1, a2, a3, a4} */
{
unsigned int insn = read_memory_unsigned_integer (current_pc, 4);
int mask = insn & 0xffff;
if ((insn & 0xffff0000) == 0xe92d0000)
/* stmfd sp!, {..., fp, ip, lr, pc}
or
stmfd sp!, {a1, a2, a3, a4} */
{
int mask = insn & 0xffff;
/* Calculate offsets of saved registers. */
for (regno = PC_REGNUM; regno >= 0; regno--)
if (mask & (1 << regno))
{
sp_offset -= 4;
fi->fsr.regs[regno] = sp_offset;
}
}
else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */
{
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
imm = (imm >> rot) | (imm << (32 - rot));
fp_offset = -imm;
fi->framereg = FP_REGNUM;
}
else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */
{
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
imm = (imm >> rot) | (imm << (32 - rot));
sp_offset -= imm;
}
else if ((insn & 0xffff7fff) == 0xed6d0103) /* stfe f?, [sp, -#c]! */
{
sp_offset -= 12;
regno = F0_REGNUM + ((insn >> 12) & 0x07);
fi->fsr.regs[regno] = sp_offset;
}
else if ((insn & 0xffbf0fff) == 0xec2d0200) /* sfmfd f0, 4, [sp!] */
{
int n_saved_fp_regs;
unsigned int fp_start_reg, fp_bound_reg;
/* Calculate offsets of saved registers. */
for (regno = PC_REGNUM; regno >= 0; regno--)
if (mask & (1 << regno))
{
sp_offset -= 4;
fi->fsr.regs[regno] = sp_offset;
}
}
else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */
if ((insn & 0x800) == 0x800) /* N0 is set */
{
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
imm = (imm >> rot) | (imm << (32 - rot));
fp_offset = -imm;
fi->framereg = FP_REGNUM;
if ((insn & 0x40000) == 0x40000) /* N1 is set */
n_saved_fp_regs = 3;
else
n_saved_fp_regs = 1;
}
else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */
else
{
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
imm = (imm >> rot) | (imm << (32 - rot));
sp_offset -= imm;
if ((insn & 0x40000) == 0x40000) /* N1 is set */
n_saved_fp_regs = 2;
else
n_saved_fp_regs = 4;
}
else if ((insn & 0xffff7fff) == 0xed6d0103) /* stfe f?, [sp, -#c]! */
fp_start_reg = F0_REGNUM + ((insn >> 12) & 0x7);
fp_bound_reg = fp_start_reg + n_saved_fp_regs;
for (; fp_start_reg < fp_bound_reg; fp_start_reg++)
{
sp_offset -= 12;
regno = F0_REGNUM + ((insn >> 12) & 0x07);
fi->fsr.regs[regno] = sp_offset;
fi->fsr.regs[fp_start_reg++] = sp_offset;
}
else if ((insn & 0xffbf0fff) == 0xec2d0200) /* sfmfd f0, 4, [sp!] */
{
int n_saved_fp_regs;
unsigned int fp_start_reg, fp_bound_reg;
if ((insn & 0x800) == 0x800) /* N0 is set */
{
if ((insn & 0x40000) == 0x40000) /* N1 is set */
n_saved_fp_regs = 3;
else
n_saved_fp_regs = 1;
}
else
{
if ((insn & 0x40000) == 0x40000) /* N1 is set */
n_saved_fp_regs = 2;
else
n_saved_fp_regs = 4;
}
fp_start_reg = F0_REGNUM + ((insn >> 12) & 0x7);
fp_bound_reg = fp_start_reg + n_saved_fp_regs;
for (; fp_start_reg < fp_bound_reg; fp_start_reg++)
{
sp_offset -= 12;
fi->fsr.regs[fp_start_reg++] = sp_offset;
}
}
else if ((insn & 0xf0000000) != 0xe0000000)
break; /* Condition not true, exit early */
else if ((insn & 0xfe200000) == 0xe8200000) /* ldm? */
break; /* Don't scan past a block load */
else
/* The optimizer might shove anything into the prologue,
so we just skip what we don't recognize. */
continue;
}
else if ((insn & 0xf0000000) != 0xe0000000)
break; /* Condition not true, exit early */
else if ((insn & 0xfe200000) == 0xe8200000) /* ldm? */
break; /* Don't scan past a block load */
else
/* The optimizer might shove anything into the prologue,
so we just skip what we don't recognize. */
continue;
}
/* The frame size is just the negative of the offset (from the original SP)
of the last thing thing we pushed on the stack. The frame offset is
[new FP] - [new SP]. */
fi->framesize = -sp_offset;
fi->frameoffset = fp_offset - sp_offset;
if (fi->framereg == FP_REGNUM)
fi->frameoffset = fp_offset - sp_offset;
else
fi->frameoffset = 0;
save_prologue_cache (fi);
}