Re: [ARM/FDPIC 04/21] [ARM] FDPIC: Add support for FDPIC for arm architecture

2018-06-11 Thread Christophe Lyon 
On 8 June 2018 at 12:31, Kyrill  Tkachov  wrote:
> Hi Christophe,
>
>
> On 25/05/18 09:03, Christophe Lyon wrote:
>>
>> The FDPIC register is hard-coded to r9, as defined in the ABI.
>>
>> We have to disable tailcall optimizations if we don't know if the
>> target function is in the same module. If not, we have to set r9 to
>> the value associated with the target module.
>>
>> When generating a symbol address, we have to take into account whether
>> it is a pointer to data or to a function, because different
>> relocations are needed.
>>
>> 2018-XX-XX  Christophe Lyon  
>> Mickaël Guêné 
>>
>> * config/arm/arm-c.c (__FDPIC__): Define new pre-processor macro
>> in FDPIC mode.
>> * config/arm/arm-protos.h (arm_load_function_descriptor): Declare
>> new function.
>> * config/arm/arm.c (arm_option_override): Define pic register to
>> r9.
>> (arm_function_ok_for_sibcall) Disable sibcall optimization if we
>> have no decl or go through PLT.
>> (arm_load_pic_register): Handle TARGET_FDPIC.
>> (arm_is_segment_info_known): New function.
>> (arm_pic_static_addr): Add support for FDPIC.
>> (arm_load_function_descriptor): New function.
>> (arm_assemble_integer): Add support for FDPIC.
>> * config/arm/arm.h (PIC_OFFSET_TABLE_REG_CALL_CLOBBERED): Define.
>> * config/arm/arm.md (call): Add support for FDPIC.
>> (call_value): Likewise.
>> (*restore_pic_register_after_call): New pattern.
>> (untyped_call): Disable if FDPIC.
>> (untyped_return): Likewise.
>> * config/arm/unspecs.md (UNSPEC_PIC_RESTORE): New.
>>
>> Change-Id: Icee8484772f97ac6f3a9574df4aa4f25a8196786
>>
>> diff --git a/gcc/config/arm/arm-c.c b/gcc/config/arm/arm-c.c
>> index 4471f79..90733cc 100644
>> --- a/gcc/config/arm/arm-c.c
>> +++ b/gcc/config/arm/arm-c.c
>> @@ -202,6 +202,8 @@ arm_cpu_builtins (struct cpp_reader* pfile)
>>builtin_define ("__ARM_EABI__");
>>  }
>>
>> +  def_or_undef_macro (pfile, "__FDPIC__", TARGET_FDPIC);
>> +
>>def_or_undef_macro (pfile, "__ARM_ARCH_EXT_IDIV__", TARGET_IDIV);
>>def_or_undef_macro (pfile, "__ARM_FEATURE_IDIV", TARGET_IDIV);
>>
>> diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
>> index 8537262..edebeb7 100644
>> --- a/gcc/config/arm/arm-protos.h
>> +++ b/gcc/config/arm/arm-protos.h
>> @@ -134,6 +134,7 @@ extern int arm_max_const_double_inline_cost (void);
>>  extern int arm_const_double_inline_cost (rtx);
>>  extern bool arm_const_double_by_parts (rtx);
>>  extern bool arm_const_double_by_immediates (rtx);
>> +extern rtx arm_load_function_descriptor (rtx funcdesc);
>>  extern void arm_emit_call_insn (rtx, rtx, bool);
>>  bool detect_cmse_nonsecure_call (tree);
>>  extern const char *output_call (rtx *);
>> diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
>> index 4a5da7e..56670e3 100644
>> --- a/gcc/config/arm/arm.c
>> +++ b/gcc/config/arm/arm.c
>> @@ -3475,6 +3475,12 @@ arm_option_override (void)
>>if (flag_pic && TARGET_VXWORKS_RTP)
>>  arm_pic_register = 9;
>>
>> +  /* If in FDPIC mode then force arm_pic_register to be r9.  */
>> +  if (TARGET_FDPIC)
>> +{
>> +  arm_pic_register = 9;
>> +}
>> +
>
>
> Leave out the braces.
> Also, I believe you'll want to add option checking for TARGET_FDPIC.
> Your cover letter says that this series supports Armv7. So you should add
> checks in arm_override to error out on unsupported configurations
> appropriately
> (pre-Armv7? TARGET_THUMB1? float-abi configurations?)
>

Indeed, it will be cleaner.

Thanks

> Thanks,
> Kyrill
>
>
>>if (arm_pic_register_string != NULL)
>>  {
>>int pic_register = decode_reg_name (arm_pic_register_string);
>> @@ -7256,6 +7262,21 @@ arm_function_ok_for_sibcall (tree decl, tree exp)
>>if (cfun->machine->sibcall_blocked)
>>  return false;
>>
>> +  if (TARGET_FDPIC)
>> +{
>> +  /* In FDPIC, never tailcall something for which we have no decl:
>> +the target function could be in a different module, requiring
>> +a different r9 value.  */
>> +  if (decl == NULL)
>> +   return false;
>> +
>> +  /* Don't tailcall if we go through the PLT since r9 is then
>> +corrupted and we don't restore it for static function
>> +call.  */
>> +  if (!targetm.binds_local_p (decl))
>> +   return false;
>> +}
>> +
>>/* Never tailcall something if we are generating code for Thumb-1.  */
>>if (TARGET_THUMB1)
>>  return false;
>> @@ -7634,7 +7655,9 @@ arm_load_pic_register (unsigned long saved_regs
>> ATTRIBUTE_UNUSED)
>>  {
>>rtx l1, labelno, pic_tmp, pic_rtx, pic_reg;
>>
>> -  if (crtl->uses_pic_offset_table == 0 || TARGET_SINGLE_PIC_BASE)
>> +  if (crtl->uses_pic_offset_table == 0
>> +  || TARGET_SINGLE_PIC_BASE
>> +  || TARGET_FDPIC)
>>  return;
>>
>>gcc_assert (flag_pic);
>> @@ -7702,28 +7725,167 @@ arm_load_pic_register

Re: [ARM/FDPIC 04/21] [ARM] FDPIC: Add support for FDPIC for arm architecture

2018-06-08 Thread Kyrill Tkachov 

Hi Christophe,

On 25/05/18 09:03, Christophe Lyon wrote:

The FDPIC register is hard-coded to r9, as defined in the ABI.

We have to disable tailcall optimizations if we don't know if the
target function is in the same module. If not, we have to set r9 to
the value associated with the target module.

When generating a symbol address, we have to take into account whether
it is a pointer to data or to a function, because different
relocations are needed.

2018-XX-XX  Christophe Lyon  
Mickaël Guêné 

* config/arm/arm-c.c (__FDPIC__): Define new pre-processor macro
in FDPIC mode.
* config/arm/arm-protos.h (arm_load_function_descriptor): Declare
new function.
* config/arm/arm.c (arm_option_override): Define pic register to
r9.
(arm_function_ok_for_sibcall) Disable sibcall optimization if we
have no decl or go through PLT.
(arm_load_pic_register): Handle TARGET_FDPIC.
(arm_is_segment_info_known): New function.
(arm_pic_static_addr): Add support for FDPIC.
(arm_load_function_descriptor): New function.
(arm_assemble_integer): Add support for FDPIC.
* config/arm/arm.h (PIC_OFFSET_TABLE_REG_CALL_CLOBBERED): Define.
* config/arm/arm.md (call): Add support for FDPIC.
(call_value): Likewise.
(*restore_pic_register_after_call): New pattern.
(untyped_call): Disable if FDPIC.
(untyped_return): Likewise.
* config/arm/unspecs.md (UNSPEC_PIC_RESTORE): New.

Change-Id: Icee8484772f97ac6f3a9574df4aa4f25a8196786

diff --git a/gcc/config/arm/arm-c.c b/gcc/config/arm/arm-c.c
index 4471f79..90733cc 100644
--- a/gcc/config/arm/arm-c.c
+++ b/gcc/config/arm/arm-c.c
@@ -202,6 +202,8 @@ arm_cpu_builtins (struct cpp_reader* pfile)
   builtin_define ("__ARM_EABI__");
 }

+  def_or_undef_macro (pfile, "__FDPIC__", TARGET_FDPIC);
+
   def_or_undef_macro (pfile, "__ARM_ARCH_EXT_IDIV__", TARGET_IDIV);
   def_or_undef_macro (pfile, "__ARM_FEATURE_IDIV", TARGET_IDIV);

diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
index 8537262..edebeb7 100644
--- a/gcc/config/arm/arm-protos.h
+++ b/gcc/config/arm/arm-protos.h
@@ -134,6 +134,7 @@ extern int arm_max_const_double_inline_cost (void);
 extern int arm_const_double_inline_cost (rtx);
 extern bool arm_const_double_by_parts (rtx);
 extern bool arm_const_double_by_immediates (rtx);
+extern rtx arm_load_function_descriptor (rtx funcdesc);
 extern void arm_emit_call_insn (rtx, rtx, bool);
 bool detect_cmse_nonsecure_call (tree);
 extern const char *output_call (rtx *);
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 4a5da7e..56670e3 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -3475,6 +3475,12 @@ arm_option_override (void)
   if (flag_pic && TARGET_VXWORKS_RTP)
 arm_pic_register = 9;

+  /* If in FDPIC mode then force arm_pic_register to be r9.  */
+  if (TARGET_FDPIC)
+{
+  arm_pic_register = 9;
+}
+


Leave out the braces.
Also, I believe you'll want to add option checking for TARGET_FDPIC.
Your cover letter says that this series supports Armv7. So you should add
checks in arm_override to error out on unsupported configurations appropriately
(pre-Armv7? TARGET_THUMB1? float-abi configurations?)

Thanks,
Kyrill


   if (arm_pic_register_string != NULL)
 {
   int pic_register = decode_reg_name (arm_pic_register_string);
@@ -7256,6 +7262,21 @@ arm_function_ok_for_sibcall (tree decl, tree exp)
   if (cfun->machine->sibcall_blocked)
 return false;

+  if (TARGET_FDPIC)
+{
+  /* In FDPIC, never tailcall something for which we have no decl:
+the target function could be in a different module, requiring
+a different r9 value.  */
+  if (decl == NULL)
+   return false;
+
+  /* Don't tailcall if we go through the PLT since r9 is then
+corrupted and we don't restore it for static function
+call.  */
+  if (!targetm.binds_local_p (decl))
+   return false;
+}
+
   /* Never tailcall something if we are generating code for Thumb-1.  */
   if (TARGET_THUMB1)
 return false;
@@ -7634,7 +7655,9 @@ arm_load_pic_register (unsigned long saved_regs 
ATTRIBUTE_UNUSED)
 {
   rtx l1, labelno, pic_tmp, pic_rtx, pic_reg;

-  if (crtl->uses_pic_offset_table == 0 || TARGET_SINGLE_PIC_BASE)
+  if (crtl->uses_pic_offset_table == 0
+  || TARGET_SINGLE_PIC_BASE
+  || TARGET_FDPIC)
 return;

   gcc_assert (flag_pic);
@@ -7702,28 +7725,167 @@ arm_load_pic_register (unsigned long saved_regs 
ATTRIBUTE_UNUSED)
   emit_use (pic_reg);
 }

+/* Try to know if the object will go in text or data segment.  */
+static bool
+arm_is_segment_info_known (rtx orig, bool *is_readonly)
+{
+  bool res = false;
+
+  *is_readonly = false;
+
+  if (GET_CODE (orig) == LABEL_REF)
+{
+  res = true;
+  *is_readonly = true;
+}
+  else if (GET_CODE (orig) == SYMBOL_REF)
+{
+  if

[ARM/FDPIC 04/21] [ARM] FDPIC: Add support for FDPIC for arm architecture

2018-05-25 Thread Christophe Lyon 
The FDPIC register is hard-coded to r9, as defined in the ABI.

We have to disable tailcall optimizations if we don't know if the
target function is in the same module. If not, we have to set r9 to
the value associated with the target module.

When generating a symbol address, we have to take into account whether
it is a pointer to data or to a function, because different
relocations are needed.

2018-XX-XX  Christophe Lyon  
Mickaël Guêné 

* config/arm/arm-c.c (__FDPIC__): Define new pre-processor macro
in FDPIC mode.
* config/arm/arm-protos.h (arm_load_function_descriptor): Declare
new function.
* config/arm/arm.c (arm_option_override): Define pic register to
r9.
(arm_function_ok_for_sibcall) Disable sibcall optimization if we
have no decl or go through PLT.
(arm_load_pic_register): Handle TARGET_FDPIC.
(arm_is_segment_info_known): New function.
(arm_pic_static_addr): Add support for FDPIC.
(arm_load_function_descriptor): New function.
(arm_assemble_integer): Add support for FDPIC.
* config/arm/arm.h (PIC_OFFSET_TABLE_REG_CALL_CLOBBERED): Define.
* config/arm/arm.md (call): Add support for FDPIC.
(call_value): Likewise.
(*restore_pic_register_after_call): New pattern.
(untyped_call): Disable if FDPIC.
(untyped_return): Likewise.
* config/arm/unspecs.md (UNSPEC_PIC_RESTORE): New.

Change-Id: Icee8484772f97ac6f3a9574df4aa4f25a8196786

diff --git a/gcc/config/arm/arm-c.c b/gcc/config/arm/arm-c.c
index 4471f79..90733cc 100644
--- a/gcc/config/arm/arm-c.c
+++ b/gcc/config/arm/arm-c.c
@@ -202,6 +202,8 @@ arm_cpu_builtins (struct cpp_reader* pfile)
   builtin_define ("__ARM_EABI__");
 }
 
+  def_or_undef_macro (pfile, "__FDPIC__", TARGET_FDPIC);
+
   def_or_undef_macro (pfile, "__ARM_ARCH_EXT_IDIV__", TARGET_IDIV);
   def_or_undef_macro (pfile, "__ARM_FEATURE_IDIV", TARGET_IDIV);
 
diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
index 8537262..edebeb7 100644
--- a/gcc/config/arm/arm-protos.h
+++ b/gcc/config/arm/arm-protos.h
@@ -134,6 +134,7 @@ extern int arm_max_const_double_inline_cost (void);
 extern int arm_const_double_inline_cost (rtx);
 extern bool arm_const_double_by_parts (rtx);
 extern bool arm_const_double_by_immediates (rtx);
+extern rtx arm_load_function_descriptor (rtx funcdesc);
 extern void arm_emit_call_insn (rtx, rtx, bool);
 bool detect_cmse_nonsecure_call (tree);
 extern const char *output_call (rtx *);
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 4a5da7e..56670e3 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -3475,6 +3475,12 @@ arm_option_override (void)
   if (flag_pic && TARGET_VXWORKS_RTP)
 arm_pic_register = 9;
 
+  /* If in FDPIC mode then force arm_pic_register to be r9.  */
+  if (TARGET_FDPIC)
+{
+  arm_pic_register = 9;
+}
+
   if (arm_pic_register_string != NULL)
 {
   int pic_register = decode_reg_name (arm_pic_register_string);
@@ -7256,6 +7262,21 @@ arm_function_ok_for_sibcall (tree decl, tree exp)
   if (cfun->machine->sibcall_blocked)
 return false;
 
+  if (TARGET_FDPIC)
+{
+  /* In FDPIC, never tailcall something for which we have no decl:
+the target function could be in a different module, requiring
+a different r9 value.  */
+  if (decl == NULL)
+   return false;
+
+  /* Don't tailcall if we go through the PLT since r9 is then
+corrupted and we don't restore it for static function
+call.  */
+  if (!targetm.binds_local_p (decl))
+   return false;
+}
+
   /* Never tailcall something if we are generating code for Thumb-1.  */
   if (TARGET_THUMB1)
 return false;
@@ -7634,7 +7655,9 @@ arm_load_pic_register (unsigned long saved_regs 
ATTRIBUTE_UNUSED)
 {
   rtx l1, labelno, pic_tmp, pic_rtx, pic_reg;
 
-  if (crtl->uses_pic_offset_table == 0 || TARGET_SINGLE_PIC_BASE)
+  if (crtl->uses_pic_offset_table == 0
+  || TARGET_SINGLE_PIC_BASE
+  || TARGET_FDPIC)
 return;
 
   gcc_assert (flag_pic);
@@ -7702,28 +7725,167 @@ arm_load_pic_register (unsigned long saved_regs 
ATTRIBUTE_UNUSED)
   emit_use (pic_reg);
 }
 
+/* Try to know if the object will go in text or data segment.  */
+static bool
+arm_is_segment_info_known (rtx orig, bool *is_readonly)
+{
+  bool res = false;
+
+  *is_readonly = false;
+
+  if (GET_CODE (orig) == LABEL_REF)
+{
+  res = true;
+  *is_readonly = true;
+}
+  else if (GET_CODE (orig) == SYMBOL_REF)
+{
+  if (CONSTANT_POOL_ADDRESS_P (orig))
+   {
+ res = true;
+ *is_readonly = true;
+   }
+  else if (SYMBOL_REF_LOCAL_P (orig)
+  && !SYMBOL_REF_EXTERNAL_P (orig)
+  && SYMBOL_REF_DECL (orig)
+  && (!DECL_P (SYMBOL_REF_DECL (orig))
+  || !DECL_COMMON (SYMBOL_REF_DECL