Re: [PATCH 2/2][GCC] arm: Declare MVE types internally via pragma

[Richard Earnshaw <Richard.Earnshaw@foss.arm.com>]

On 25/11/2021 09:42, Murray Steele via Gcc-patches wrote:
> Changes from original patch:
> 
> 1. Merged test_redef_* test files into one
> 2. Encapsulated contents of arm-mve-builtins.h in namespace arm_mve (missed
>     in initial patch).
> 3. Added extern declarations for scalar_types and acle_vector types to
>     arm-mve-builtins.h (missed in initial patch).
> 4. Added arm-mve-builtins.(cc|h) to gt_targets for arm-*-*-* (missed in
>     initial patch).
> 5. Added include for gt-arm-mve-builtins.h to arm-mve-builtins.cc (missed in
>     initial patch).
> 6. Removed explicit initialisation of handle_arm_mve_types_p as it is unneeded.
> 
> ---
> 
> This patch moves the implementation of MVE ACLE types from
> arm_mve_types.h to inside GCC via a new pragma, which replaces the prior
> type definitions. This allows for the types to be used internally for
> intrinsic function definitions.
> 
> Bootstrapped and regression tested on arm-none-linux-gnuabihf, and
> regression tested on arm-eabi -- no issues.
> 
> Thanks,
> Murray
> 

Nearly there, but...

Your changelog entry needs some work:

> gcc/ChangeLog:
> 
>          * config.gcc: Add arm-mve-builtins.o to extra_objs for arm-*-*-*
>          targets.

  * config.gcc (arm*-*-*): Add arm-mve-builtins.o to extra_objs.

>          * config/arm/arm-c.c (arm_pragma_arm): Handle new pragma.

  ... Handle "#pragma GCC arm".

>          (arm_register_target_pragmas): Register new pragma.
  ... Register it.

>          * config/arm/arm-protos.h: Add arm_mve namespace and declare
>          arm_handle_mve_types_h.

  ...arm-protos.h (arm_mve::arm_handle_mve_types.h): New prototype.

>          * config/arm/arm_mve_types.h: Replace MVE type definitions with
>          new pragma.
>          * config/arm/t-arm: Add arm-mve-builtins.o target.

.../t-arm (arm-mve-builtins.o): New target rule.

>          * config/arm/arm-mve-builtins.cc: New file.
>          * config/arm/arm-mve-builtins.def: New file.
>          * config/arm/arm-mve-builtins.h: New file.
> 
> gcc/testsuite/ChangeLog:
> 
>          * gcc.target/arm/mve/mve.exp: Add new subdirectories.
>          * gcc.target/arm/mve/general-c/type_redef_1.c: New test.
>          * gcc.target/arm/mve/general/double_pragmas_1.c: New test.
>          * gcc.target/arm/mve/general/nomve_1.c: New test.
> 


diff --git a/gcc/config/arm/arm-mve-builtins.def 
b/gcc/config/arm/arm-mve-builtins.def
new file mode 100644
index 
0000000000000000000000000000000000000000..02a46bec3e4cba6add9bce4021c732e15aa8b012
--- /dev/null
+++ b/gcc/config/arm/arm-mve-builtins.def
@@ -0,0 +1,41 @@

+#ifndef DEF_MVE_TYPE
+#define DEF_MVE_TYPE(A, B)
+#endif

When would this file ever be included when this macro wasn't defined? 
Better to require the caller to define this by using #error if it's missing.

then...

+
+#undef DEF_MVE_TYPE

This isn't needed anymore, because caller should undef it after use.

diff --git a/gcc/config/arm/arm-mve-builtins.cc 
b/gcc/config/arm/arm-mve-builtins.cc
new file mode 100644
index 
0000000000000000000000000000000000000000..99ddc8d49aad39e057c1c0d349c6c02c278553d6
--- /dev/null
+++ b/gcc/config/arm/arm-mve-builtins.cc

...
+}
+
+}
+
+using namespace arm_mve;

Add a comment that this is the end of the earlier namespace declaration.

diff --git a/gcc/config/arm/arm-mve-builtins.h 
b/gcc/config/arm/arm-mve-builtins.h
new file mode 100644
index 
0000000000000000000000000000000000000000..c165ce6997b4560fc87626be4bbaa0e8afcbbfed
--- /dev/null
+++ b/gcc/config/arm/arm-mve-builtins.h
@@ -0,0 +1,41 @@


...
+}
+

Likewise.

R.