paweld/fpc
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/fpc/source.git synced 2025-12-16 03:30:34 +01:00
Code Issues Packages Projects Releases Wiki Activity

* use r7 instead of r11 as frame pointer on Darwin/iOS, and make sure r7

Browse Source 
always points to the previous r7 on the stack (with the saved return
    address coming right after it) so that the debugger and crashreporter
    can use it for backtraces as specified in the ABI
   o changed NR_FRAME_POINTER_REG and RS_FRAME_POINTER_REG from a symbolic
     into a typed constant, and added a new method to tprocinfo that can
     be used to initialze it (so it can be inited to r7/r11 depending on
     the target platform)
  * allow using r9 on Darwin, it was only used by the system on iOS up to
    2.x, which we no longer support
  * prefer using r9 and r12 before r4..r11 on Darwin, because they are
    volatile and hence do not have to be saved

git-svn-id: trunk@20661 -
This commit is contained in:
Jonas Maebe 2012-03-29 20:54:33 +00:00
parent 6ba8dc7146
commit bba4b02eb2
6 changed files with 183 additions and 51 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

172
compiler/arm/cgcpu.pas
View File

@ -209,17 +209,18 @@ unit cgcpu;
procedure tarmcgarm.init_register_allocators;
begin
inherited init_register_allocators;
{ currently, we save R14 always, so we can use it }
{ currently, we always save R14, so we can use it }
if (target_info.system<>system_arm_darwin) then
rg[R_INTREGISTER]:=trgintcpu.create(R_INTREGISTER,R_SUBWHOLE,
[RS_R0,RS_R1,RS_R2,RS_R3,RS_R4,RS_R5,RS_R6,RS_R7,RS_R8,
RS_R9,RS_R10,RS_R12,RS_R14],first_int_imreg,[])
[RS_R0,RS_R1,RS_R2,RS_R3,RS_R12,RS_R4,RS_R5,RS_R6,RS_R7,RS_R8,
RS_R9,RS_R10,RS_R14],first_int_imreg,[])
else
{ r9 is not (always) available on Darwin according to the llvm code
generator. }
{ r7 is not available on Darwin, it's used as frame pointer (always,
for backtrace support -- also in gcc/clang -> R11 can be used).
r9 is volatile }
rg[R_INTREGISTER]:=trgintcpu.create(R_INTREGISTER,R_SUBWHOLE,
[RS_R0,RS_R1,RS_R2,RS_R3,RS_R4,RS_R5,RS_R6,RS_R7,RS_R8,
RS_R10,RS_R12,RS_R14],first_int_imreg,[]);
[RS_R0,RS_R1,RS_R2,RS_R3,RS_R9,RS_R12,RS_R4,RS_R5,RS_R6,RS_R8,
RS_R10,RS_R11,RS_R14],first_int_imreg,[]);
rg[R_FPUREGISTER]:=trgcpu.create(R_FPUREGISTER,R_SUBNONE,
[RS_F0,RS_F1,RS_F2,RS_F3,RS_F4,RS_F5,RS_F6,RS_F7],first_fpu_imreg,[]);
{ The register allocator currently cannot deal with multiple
@ -1410,7 +1411,8 @@ unit cgcpu;
firstfloatreg,lastfloatreg,
r : byte;
mmregs,
regs : tcpuregisterset;
regs, saveregs : tcpuregisterset;
r7offset,
stackmisalignment : pint;
postfix: toppostfix;
begin
@ -1446,41 +1448,91 @@ unit cgcpu;
end;
a_reg_alloc(list,NR_STACK_POINTER_REG);
if current_procinfo.framepointer<>NR_STACK_POINTER_REG then
begin
a_reg_alloc(list,NR_FRAME_POINTER_REG);
a_reg_alloc(list,NR_R12);
list.concat(taicpu.op_reg_reg(A_MOV,NR_R12,NR_STACK_POINTER_REG));
end;
a_reg_alloc(list,NR_FRAME_POINTER_REG);
{ save int registers }
reference_reset(ref,4);
ref.index:=NR_STACK_POINTER_REG;
ref.addressmode:=AM_PREINDEXED;
regs:=rg[R_INTREGISTER].used_in_proc-paramanager.get_volatile_registers_int(pocall_stdcall);
{ the (old) ARM APCS requires saving both the stack pointer (to
crawl the stack) and the PC (to identify the function this
stack frame belongs to) -> also save R12 (= copy of R13 on entry)
and R15 -- still needs updating for EABI and Darwin, they don't
need that }
if current_procinfo.framepointer<>NR_STACK_POINTER_REG then
regs:=regs+[RS_FRAME_POINTER_REG,RS_R12,RS_R14,RS_R15]
else
if (regs<>[]) or (pi_do_call in current_procinfo.flags) then
include(regs,RS_R14);
if regs<>[] then
begin
for r:=RS_R0 to RS_R15 do
if (r in regs) then
inc(stackmisalignment,4);
list.concat(setoppostfix(taicpu.op_ref_regset(A_STM,ref,R_INTREGISTER,R_SUBWHOLE,regs),PF_FD));
end;
if current_procinfo.framepointer<>NR_STACK_POINTER_REG then
if not(target_info.system in systems_darwin) then
begin
{ the framepointer now points to the saved R15, so the saved
framepointer is at R11-12 (for get_caller_frame) }
list.concat(taicpu.op_reg_reg_const(A_SUB,NR_FRAME_POINTER_REG,NR_R12,4));
a_reg_dealloc(list,NR_R12);
a_reg_alloc(list,NR_STACK_POINTER_REG);
if current_procinfo.framepointer<>NR_STACK_POINTER_REG then
begin
a_reg_alloc(list,NR_R12);
list.concat(taicpu.op_reg_reg(A_MOV,NR_R12,NR_STACK_POINTER_REG));
end;
{ the (old) ARM APCS requires saving both the stack pointer (to
crawl the stack) and the PC (to identify the function this
stack frame belongs to) -> also save R12 (= copy of R13 on entry)
and R15 -- still needs updating for EABI and Darwin, they don't
need that }
if current_procinfo.framepointer<>NR_STACK_POINTER_REG then
regs:=regs+[RS_FRAME_POINTER_REG,RS_R12,RS_R14,RS_R15]
else
if (regs<>[]) or (pi_do_call in current_procinfo.flags) then
include(regs,RS_R14);
if regs<>[] then
begin
for r:=RS_R0 to RS_R15 do
if r in regs then
inc(stackmisalignment,4);
list.concat(setoppostfix(taicpu.op_ref_regset(A_STM,ref,R_INTREGISTER,R_SUBWHOLE,regs),PF_FD));
end;
if current_procinfo.framepointer<>NR_STACK_POINTER_REG then
begin
{ the framepointer now points to the saved R15, so the saved
framepointer is at R11-12 (for get_caller_frame) }
list.concat(taicpu.op_reg_reg_const(A_SUB,NR_FRAME_POINTER_REG,NR_R12,4));
a_reg_dealloc(list,NR_R12);
end;
end
else
begin
{ always save r14 if we use r7 as the framepointer, because
the parameter offsets are hardcoded in advance and always
assume that r14 sits on the stack right behind the saved r7
}
if current_procinfo.framepointer=NR_FRAME_POINTER_REG then
include(regs,RS_FRAME_POINTER_REG);
if (regs<>[]) or (pi_do_call in current_procinfo.flags) then
include(regs,RS_R14);
if regs<>[] then
begin
{ on Darwin, you first have to save [r4-r7,lr], and then
[r8,r10,r11] and make r7 point to the previously saved
r7 so that you can perform a stack crawl based on it
([r7] is previous stack frame, [r7+4] is return address
}
include(regs,RS_FRAME_POINTER_REG);
saveregs:=regs-[RS_R8,RS_R10,RS_R11];
r7offset:=0;
for r:=RS_R0 to RS_R15 do
if r in saveregs then
begin
inc(stackmisalignment,4);
if r<RS_FRAME_POINTER_REG then
inc(r7offset,4);
end;
{ save the registers }
list.concat(setoppostfix(taicpu.op_ref_regset(A_STM,ref,R_INTREGISTER,R_SUBWHOLE,saveregs),PF_FD));
{ make r7 point to the saved r7 (regardless of whether this
frame uses the framepointer, for backtrace purposes) }
if r7offset<>0 then
list.concat(taicpu.op_reg_reg_const(A_ADD,NR_FRAME_POINTER_REG,NR_R13,r7offset))
else
list.concat(taicpu.op_reg_reg(A_MOV,NR_R7,NR_R13));
{ now save the rest (if any) }
saveregs:=regs-saveregs;
if saveregs<>[] then
begin
for r:=RS_R8 to RS_R11 do
if r in saveregs then
inc(stackmisalignment,4);
list.concat(setoppostfix(taicpu.op_ref_regset(A_STM,ref,R_INTREGISTER,R_SUBWHOLE,saveregs),PF_FD));
end;
end;
end;
stackmisalignment:=stackmisalignment mod current_settings.alignment.localalignmax;
@ -1564,6 +1616,7 @@ unit cgcpu;
r,
shift : byte;
mmregs,
saveregs,
regs : tcpuregisterset;
stackmisalignment: pint;
mmpostfix: toppostfix;
@ -1649,22 +1702,47 @@ unit cgcpu;
end;
regs:=rg[R_INTREGISTER].used_in_proc-paramanager.get_volatile_registers_int(pocall_stdcall) ;
if (pi_do_call in current_procinfo.flags) or (regs<>[]) then
if (pi_do_call in current_procinfo.flags) or
(regs<>[]) or
((target_info.system in systems_darwin) and
(current_procinfo.framepointer<>NR_STACK_POINTER_REG)) then
begin
exclude(regs,RS_R14);
include(regs,RS_R15);
if (target_info.system in systems_darwin) then
include(regs,RS_FRAME_POINTER_REG);
end;
{ restore saved stack pointer to SP (R13) and saved lr to PC (R15).
The saved PC came after that but is discarded, since we restore
the stack pointer }
if (current_procinfo.framepointer<>NR_STACK_POINTER_REG) then
regs:=regs+[RS_FRAME_POINTER_REG,RS_R13,RS_R15];
if not(target_info.system in systems_darwin) then
begin
{ restore saved stack pointer to SP (R13) and saved lr to PC (R15).
The saved PC came after that but is discarded, since we restore
the stack pointer }
if (current_procinfo.framepointer<>NR_STACK_POINTER_REG) then
regs:=regs+[RS_FRAME_POINTER_REG,RS_R13,RS_R15];
end
else
begin
{ restore R8-R11 already if necessary (they've been stored
before the others) }
saveregs:=regs*[RS_R8,RS_R10,RS_R11];
if saveregs<>[] then
begin
reference_reset(ref,4);
ref.index:=NR_STACK_POINTER_REG;
ref.addressmode:=AM_PREINDEXED;
for r:=RS_R8 to RS_R11 do
if r in saveregs then
inc(stackmisalignment,4);
regs:=regs-saveregs;
end;
end;
for r:=RS_R0 to RS_R15 do
if (r in regs) then
if r in regs then
inc(stackmisalignment,4);
stackmisalignment:=stackmisalignment mod current_settings.alignment.localalignmax;
if (current_procinfo.framepointer=NR_STACK_POINTER_REG) then
if (current_procinfo.framepointer=NR_STACK_POINTER_REG) or
(target_info.system in systems_darwin) then
begin
LocalSize:=current_procinfo.calc_stackframe_size;
if (LocalSize<>0) or
@ -1686,6 +1764,10 @@ unit cgcpu;
end;
end;
if (target_info.system in systems_darwin) and
(saveregs<>[]) then
list.concat(setoppostfix(taicpu.op_ref_regset(A_LDM,ref,R_INTREGISTER,R_SUBWHOLE,saveregs),PF_FD));
if regs=[] then
begin
if (current_settings.cputype<cpu_armv6) then

6
compiler/arm/cpubase.pas
View File

@ -269,9 +269,9 @@ unit cpubase;
{ Stack pointer register }
NR_STACK_POINTER_REG = NR_R13;
RS_STACK_POINTER_REG = RS_R13;
{ Frame pointer register }
RS_FRAME_POINTER_REG = RS_R11;
NR_FRAME_POINTER_REG = NR_R11;
{ Frame pointer register (initialized in tarmprocinfo.init_framepointer) }
RS_FRAME_POINTER_REG: tsuperregister = RS_NO;
NR_FRAME_POINTER_REG: tregister = NR_NO;
{ Register for addressing absolute data in a position independant way,
such as in PIC code. The exact meaning is ABI specific. For
further information look at GCC source : PIC_OFFSET_TABLE_REGNUM

11
compiler/arm/cpupara.pas
View File

@ -487,7 +487,16 @@ unit cpupara;
if paraloc^.loc=LOC_REFERENCE then
begin
paraloc^.reference.index:=NR_FRAME_POINTER_REG;
inc(paraloc^.reference.offset,4);
{ on non-Darwin, the framepointer contains the value
of the stack pointer on entry. On Darwin, the
framepointer points to the previously saved
framepointer (which is followed only by the saved
return address -> framepointer + 4 = stack pointer
on entry }
if not(target_info.system in systems_darwin) then
inc(paraloc^.reference.offset,4)
else
inc(paraloc^.reference.offset,8);
end;
end;
dec(paralen,tcgsize2size[paraloc^.size]);

22
compiler/arm/cpupi.pas
View File

@ -38,6 +38,7 @@ unit cpupi;
// procedure after_pass1;override;
procedure set_first_temp_offset;override;
function calc_stackframe_size:longint;override;
procedure init_framepointer; override;
end;
@ -70,8 +71,10 @@ unit cpupi;
register (= last register in list above) -> + 4 }
tg.setfirsttemp(-28-16+4)
else
{ on Darwin r9 is not usable -> one less register to save }
tg.setfirsttemp(-24-16+4)
{ on Darwin first r4-r7,r14 are saved, then r7 is adjusted to
point to the saved r7, and next r8,r10,r11 gets saved -> -24
(r4-r6 and r8,r10,r11) }
tg.setfirsttemp(-24)
end
else
tg.setfirsttemp(maxpushedparasize);
@ -124,6 +127,21 @@ unit cpupi;
end;
procedure tarmprocinfo.init_framepointer;
begin
if not(target_info.system in systems_darwin) then
begin
RS_FRAME_POINTER_REG:=RS_R11;
NR_FRAME_POINTER_REG:=NR_R11;
end
else
begin
RS_FRAME_POINTER_REG:=RS_R7;
NR_FRAME_POINTER_REG:=NR_R7;
end;
end;
begin
cprocinfo:=tarmprocinfo;
end.

11
compiler/procinfo.pas
View File

@ -140,6 +140,9 @@ unit procinfo;
{ Allocate got register }
procedure allocate_got_register(list: TAsmList);virtual;
{ get frame pointer }
procedure init_framepointer; virtual;
{ Destroy the entire procinfo tree, starting from the outermost parent }
procedure destroy_tree;
@ -182,6 +185,7 @@ implementation
procdef:=nil;
para_stack_size:=0;
flags:=[];
init_framepointer;
framepointer:=NR_FRAME_POINTER_REG;
maxpushedparasize:=0;
{ asmlists }
@ -289,4 +293,11 @@ implementation
end;
procedure tprocinfo.init_framepointer;
begin
{ most targets use a constant, but some have a typed constant that must
be initialized }
end;
end.

12
rtl/arm/arm.inc
View File

@ -101,7 +101,11 @@ end;
{$define FPC_SYSTEM_HAS_GET_FRAME}
function get_frame:pointer;assembler;nostackframe;
asm
{$ifndef darwin}
mov r0,r11
{$else}
mov r0,r7
{$endif}
end;
{$ENDIF not INTERNAL_BACKTRACE}
@ -109,7 +113,11 @@ end;
function get_caller_addr(framebp:pointer):pointer;assembler;nostackframe;
asm
cmp r0,#0
{$ifndef darwin}
ldrne r0,[r0,#-4]
{$else}
ldrne r0,[r0,#4]
{$endif}
end;
@ -117,7 +125,11 @@ end;
function get_caller_frame(framebp:pointer):pointer;assembler;nostackframe;
asm
cmp r0,#0
{$ifndef darwin}
ldrne r0,[r0,#-12]
{$else}
ldrne r0,[r0]
{$endif}
end;