[nvptx] Ignore c++ exceptions

Message ID 20180802153052.ycw3rxjj3kwy5pqa@delia
State New
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  • [nvptx] Ignore c++ exceptions
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Commit Message

Tom de Vries Aug. 2, 2018, 3:30 p.m.
Hi,

The nvptx port can't support exceptions using sjlj, because ptx does not
support sjlj.  However, default_except_unwind_info still returns UI_SJLJ, even
even if we configure with --disable-sjlj-exceptions, because UI_SJLJ is the
fallback option.

The reason default_except_unwind_info doesn't return UI_DWARF2 is because
DWARF2_UNWIND_INFO is not defined in defaults.h, because
INCOMING_RETURN_ADDR_RTX is not defined, because there's no ptx equivalent.

Testcase libgomp.c++/for-15.C currently doesn't compile unless fno-exceptions
is added because:
- it tries to generate sjlj exception handling code, and
- it tries to generate exception tables using label-addressed .byte sequence.
  Ptx doesn't support generating random data at a label, nor being able to
  load/write data relative to a label.

This patch fixes the first problem by using UI_TARGET for nvptx.

The second problem is worked around by generating all .byte sequences commented
out.  It would be better to have a narrower workaround, and define
TARGET_ASM_BYTE_OP to "error: .byte unsupported " or some such.

This patch does not enable exceptions for nvptx, it merely allows c++ programs
to run correctly if they do no use exception handling.

Build on x86_64 with nvptx accelerator and reg-tested libgomp.

OK for trunk?

Thanks,
- Tom

[nvptx] Ignore c++ exceptions

2018-08-02  Tom de Vries  <tdevries@suse.de>

	PR target/86660
	* common/config/nvptx/nvptx-common.c (nvptx_except_unwind_info): New
	function.  Return UI_TARGET unconditionally.
	(TARGET_EXCEPT_UNWIND_INFO): Redefine to nvptx_except_unwind_info.
	* config/nvptx/nvptx.c (TARGET_ASM_BYTE_OP): Emit commented out '.byte'.

	* testsuite/libgomp.oacc-c++/routine-1-auto.C: Remove -fno-exceptions.
	* testsuite/libgomp.oacc-c++/routine-1-template-auto.C: Same.
	* testsuite/libgomp.oacc-c++/routine-1-template-trailing-return-type.C:
	Same.
	* testsuite/libgomp.oacc-c++/routine-1-template.C: Same.
	* testsuite/libgomp.oacc-c++/routine-1-trailing-return-type.C: Same.
	* testsuite/libgomp.oacc-c-c++-common/routine-1.c: Same.

---
 gcc/common/config/nvptx/nvptx-common.c                           | 9 +++++++++
 gcc/config/nvptx/nvptx.c                                         | 3 +++
 libgomp/testsuite/libgomp.oacc-c++/routine-1-auto.C              | 2 --
 libgomp/testsuite/libgomp.oacc-c++/routine-1-template-auto.C     | 2 --
 .../libgomp.oacc-c++/routine-1-template-trailing-return-type.C   | 2 --
 libgomp/testsuite/libgomp.oacc-c++/routine-1-template.C          | 2 --
 .../testsuite/libgomp.oacc-c++/routine-1-trailing-return-type.C  | 2 --
 libgomp/testsuite/libgomp.oacc-c-c++-common/routine-1.c          | 2 --
 8 files changed, 12 insertions(+), 12 deletions(-)

Comments

Jakub Jelinek Aug. 2, 2018, 3:39 p.m. | #1
On Thu, Aug 02, 2018 at 05:30:53PM +0200, Tom de Vries wrote:
> The nvptx port can't support exceptions using sjlj, because ptx does not

> support sjlj.  However, default_except_unwind_info still returns UI_SJLJ, even

> even if we configure with --disable-sjlj-exceptions, because UI_SJLJ is the

> fallback option.

> 

> The reason default_except_unwind_info doesn't return UI_DWARF2 is because

> DWARF2_UNWIND_INFO is not defined in defaults.h, because

> INCOMING_RETURN_ADDR_RTX is not defined, because there's no ptx equivalent.

> 

> Testcase libgomp.c++/for-15.C currently doesn't compile unless fno-exceptions

> is added because:

> - it tries to generate sjlj exception handling code, and

> - it tries to generate exception tables using label-addressed .byte sequence.

>   Ptx doesn't support generating random data at a label, nor being able to

>   load/write data relative to a label.

> 

> This patch fixes the first problem by using UI_TARGET for nvptx.

> 

> The second problem is worked around by generating all .byte sequences commented

> out.  It would be better to have a narrower workaround, and define

> TARGET_ASM_BYTE_OP to "error: .byte unsupported " or some such.


Hopefully this part is temporary and there is some way to figure this out
later.

> This patch does not enable exceptions for nvptx, it merely allows c++ programs

> to run correctly if they do no use exception handling.

> 

> Build on x86_64 with nvptx accelerator and reg-tested libgomp.

> 

> OK for trunk?


You are the nvptx maintainer, so you can approve the changes yourself.
The libgomp changes are ok.

> [nvptx] Ignore c++ exceptions

> 

> 2018-08-02  Tom de Vries  <tdevries@suse.de>

> 

> 	PR target/86660

> 	* common/config/nvptx/nvptx-common.c (nvptx_except_unwind_info): New

> 	function.  Return UI_TARGET unconditionally.

> 	(TARGET_EXCEPT_UNWIND_INFO): Redefine to nvptx_except_unwind_info.

> 	* config/nvptx/nvptx.c (TARGET_ASM_BYTE_OP): Emit commented out '.byte'.

> 

> 	* testsuite/libgomp.oacc-c++/routine-1-auto.C: Remove -fno-exceptions.

> 	* testsuite/libgomp.oacc-c++/routine-1-template-auto.C: Same.

> 	* testsuite/libgomp.oacc-c++/routine-1-template-trailing-return-type.C:

> 	Same.

> 	* testsuite/libgomp.oacc-c++/routine-1-template.C: Same.

> 	* testsuite/libgomp.oacc-c++/routine-1-trailing-return-type.C: Same.

> 	* testsuite/libgomp.oacc-c-c++-common/routine-1.c: Same.


	Jakub
Tom de Vries Aug. 2, 2018, 4:10 p.m. | #2
On 08/02/2018 05:39 PM, Jakub Jelinek wrote:
> On Thu, Aug 02, 2018 at 05:30:53PM +0200, Tom de Vries wrote:

>> The nvptx port can't support exceptions using sjlj, because ptx does not

>> support sjlj.  However, default_except_unwind_info still returns UI_SJLJ, even

>> even if we configure with --disable-sjlj-exceptions, because UI_SJLJ is the

>> fallback option.

>>

>> The reason default_except_unwind_info doesn't return UI_DWARF2 is because

>> DWARF2_UNWIND_INFO is not defined in defaults.h, because

>> INCOMING_RETURN_ADDR_RTX is not defined, because there's no ptx equivalent.

>>

>> Testcase libgomp.c++/for-15.C currently doesn't compile unless fno-exceptions

>> is added because:

>> - it tries to generate sjlj exception handling code, and

>> - it tries to generate exception tables using label-addressed .byte sequence.

>>   Ptx doesn't support generating random data at a label, nor being able to

>>   load/write data relative to a label.

>>

>> This patch fixes the first problem by using UI_TARGET for nvptx.

>>

>> The second problem is worked around by generating all .byte sequences commented

>> out.  It would be better to have a narrower workaround, and define

>> TARGET_ASM_BYTE_OP to "error: .byte unsupported " or some such.

> 

> Hopefully this part is temporary and there is some way to figure this out

> later.

> 


I except that for UI_NONE we don't want to write out exception tables,
so that's something we can fix, and then we can return UI_NONE in
nvptx_except_unwind_info.

>> This patch does not enable exceptions for nvptx, it merely allows c++ programs

>> to run correctly if they do no use exception handling.

>>

>> Build on x86_64 with nvptx accelerator and reg-tested libgomp.

>>

>> OK for trunk?

> 

> You are the nvptx maintainer, so you can approve the changes yourself.


Right, sorry, force of habit, I meant: 'any comments?'

> The libgomp changes are ok.


Committed.

Thanks,
- Tom

> 

>> [nvptx] Ignore c++ exceptions

>>

>> 2018-08-02  Tom de Vries  <tdevries@suse.de>

>>

>> 	PR target/86660

>> 	* common/config/nvptx/nvptx-common.c (nvptx_except_unwind_info): New

>> 	function.  Return UI_TARGET unconditionally.

>> 	(TARGET_EXCEPT_UNWIND_INFO): Redefine to nvptx_except_unwind_info.

>> 	* config/nvptx/nvptx.c (TARGET_ASM_BYTE_OP): Emit commented out '.byte'.

>>

>> 	* testsuite/libgomp.oacc-c++/routine-1-auto.C: Remove -fno-exceptions.

>> 	* testsuite/libgomp.oacc-c++/routine-1-template-auto.C: Same.

>> 	* testsuite/libgomp.oacc-c++/routine-1-template-trailing-return-type.C:

>> 	Same.

>> 	* testsuite/libgomp.oacc-c++/routine-1-template.C: Same.

>> 	* testsuite/libgomp.oacc-c++/routine-1-trailing-return-type.C: Same.

>> 	* testsuite/libgomp.oacc-c-c++-common/routine-1.c: Same.

> 

> 	Jakub

>

Patch

diff --git a/gcc/common/config/nvptx/nvptx-common.c b/gcc/common/config/nvptx/nvptx-common.c
index 27a4f4675d0..f31e0696281 100644
--- a/gcc/common/config/nvptx/nvptx-common.c
+++ b/gcc/common/config/nvptx/nvptx-common.c
@@ -30,10 +30,19 @@  along with GCC; see the file COPYING3.  If not see
 #include "opts.h"
 #include "flags.h"
 
+enum unwind_info_type
+nvptx_except_unwind_info (struct gcc_options *opts ATTRIBUTE_UNUSED)
+{
+  return UI_TARGET;
+}
+
 #undef TARGET_HAVE_NAMED_SECTIONS
 #define TARGET_HAVE_NAMED_SECTIONS false
 
 #undef TARGET_DEFAULT_TARGET_FLAGS
 #define TARGET_DEFAULT_TARGET_FLAGS MASK_ABI64
 
+#undef TARGET_EXCEPT_UNWIND_INFO
+#define TARGET_EXCEPT_UNWIND_INFO nvptx_except_unwind_info
+
 struct gcc_targetm_common targetm_common = TARGETM_COMMON_INITIALIZER;
diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
index c1946e75f42..b804f5611fb 100644
--- a/gcc/config/nvptx/nvptx.c
+++ b/gcc/config/nvptx/nvptx.c
@@ -6048,6 +6048,9 @@  nvptx_can_change_mode_class (machine_mode, machine_mode, reg_class_t)
 #undef TARGET_CAN_CHANGE_MODE_CLASS
 #define TARGET_CAN_CHANGE_MODE_CLASS nvptx_can_change_mode_class
 
+#undef TARGET_ASM_BYTE_OP
+#define TARGET_ASM_BYTE_OP "// .byte "
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 #include "gt-nvptx.h"
diff --git a/libgomp/testsuite/libgomp.oacc-c++/routine-1-auto.C b/libgomp/testsuite/libgomp.oacc-c++/routine-1-auto.C
index f4b54e55fa7..771a2734306 100644
--- a/libgomp/testsuite/libgomp.oacc-c++/routine-1-auto.C
+++ b/libgomp/testsuite/libgomp.oacc-c++/routine-1-auto.C
@@ -1,7 +1,5 @@ 
 // Routine with "auto" return type.
 
-// { dg-additional-options "-fno-exceptions" }
-
 #define TEMPLATE
 #define TYPE int
 #define RETURN_1 auto
diff --git a/libgomp/testsuite/libgomp.oacc-c++/routine-1-template-auto.C b/libgomp/testsuite/libgomp.oacc-c++/routine-1-template-auto.C
index 444f1f32a76..17bdaa0c1c1 100644
--- a/libgomp/testsuite/libgomp.oacc-c++/routine-1-template-auto.C
+++ b/libgomp/testsuite/libgomp.oacc-c++/routine-1-template-auto.C
@@ -1,7 +1,5 @@ 
 // Templated routine with "auto" return type.
 
-// { dg-additional-options "-fno-exceptions" }
-
 #define TEMPLATE template<typename TYPE>
 #define RETURN_1 auto
 #define RETURN_2
diff --git a/libgomp/testsuite/libgomp.oacc-c++/routine-1-template-trailing-return-type.C b/libgomp/testsuite/libgomp.oacc-c++/routine-1-template-trailing-return-type.C
index bfe2787d931..99faa865041 100644
--- a/libgomp/testsuite/libgomp.oacc-c++/routine-1-template-trailing-return-type.C
+++ b/libgomp/testsuite/libgomp.oacc-c++/routine-1-template-trailing-return-type.C
@@ -1,7 +1,5 @@ 
 // Templated routine using trailing return type syntax.
 
-// { dg-additional-options "-fno-exceptions" }
-
 #define TEMPLATE template<typename TYPE>
 #define RETURN_1 auto
 #define RETURN_2 -> TYPE
diff --git a/libgomp/testsuite/libgomp.oacc-c++/routine-1-template.C b/libgomp/testsuite/libgomp.oacc-c++/routine-1-template.C
index a7e0323d44f..89defb196b1 100644
--- a/libgomp/testsuite/libgomp.oacc-c++/routine-1-template.C
+++ b/libgomp/testsuite/libgomp.oacc-c++/routine-1-template.C
@@ -1,7 +1,5 @@ 
 // Templated routine.
 
-// { dg-additional-options "-fno-exceptions" }
-
 #define TEMPLATE template<typename TYPE>
 #define RETURN_1 TYPE
 #define RETURN_2
diff --git a/libgomp/testsuite/libgomp.oacc-c++/routine-1-trailing-return-type.C b/libgomp/testsuite/libgomp.oacc-c++/routine-1-trailing-return-type.C
index 3074ba47c2a..767e0ce4666 100644
--- a/libgomp/testsuite/libgomp.oacc-c++/routine-1-trailing-return-type.C
+++ b/libgomp/testsuite/libgomp.oacc-c++/routine-1-trailing-return-type.C
@@ -1,7 +1,5 @@ 
 // Routine using trailing return type syntax.
 
-// { dg-additional-options "-fno-exceptions" }
-
 #define TEMPLATE
 #define TYPE int
 #define RETURN_1 auto
diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/routine-1.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/routine-1.c
index 2a36b3b1fac..0f70e264240 100644
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/routine-1.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/routine-1.c
@@ -1,5 +1,3 @@ 
-// { dg-additional-options "-fno-exceptions" }
-
 // Defaults, if not "#include"d from ../libgomp.oacc-c++/routine-1-*.C.
 #ifndef TEMPLATE
 # define TEMPLATE