[gcc r14-5618] arm: [MVE intrinsics] Add support for void and load/store pointers as argument types.

[Christophe Lyon <clyon@gcc.gnu.org>]

https://gcc.gnu.org/g:524c892e642e87da853d2a9d0314dd6c220f59de

commit r14-5618-g524c892e642e87da853d2a9d0314dd6c220f59de
Author: Christophe Lyon <christophe.lyon@linaro.org>
Date:   Wed Nov 15 08:03:51 2023 +0000

    arm: [MVE intrinsics] Add support for void and load/store pointers as argument types.
    
    This patch adds support for '_', 'al' and 'as' for void, load pointer
    and store pointer argument/return value types in intrinsic signatures.
    
    It also adds a mew memory_scalar_type() helper to function_instance,
    which is used by 'al' and 'as'.
    
    2023-11-16  Christophe Lyon  <christophe.lyon@linaro.org>
    
            gcc/
            * config/arm/arm-mve-builtins-shapes.cc (build_const_pointer):
            New.
            (parse_type): Add support for '_', 'al' and 'as'.
            * config/arm/arm-mve-builtins.h (function_instance): Add
            memory_scalar_type.
            (function_base): Likewise.

Diff:
---
 gcc/config/arm/arm-mve-builtins-shapes.cc | 25 +++++++++++++++++++++++++
 gcc/config/arm/arm-mve-builtins.h         | 17 +++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/gcc/config/arm/arm-mve-builtins-shapes.cc b/gcc/config/arm/arm-mve-builtins-shapes.cc
index 23eb9d0e69b..ce87ebcef30 100644
--- a/gcc/config/arm/arm-mve-builtins-shapes.cc
+++ b/gcc/config/arm/arm-mve-builtins-shapes.cc
@@ -39,6 +39,13 @@
 
 namespace arm_mve {
 
+/* Return a representation of "const T *".  */
+static tree
+build_const_pointer (tree t)
+{
+  return build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
+}
+
 /* If INSTANCE has a predicate, add it to the list of argument types
    in ARGUMENT_TYPES.  RETURN_TYPE is the type returned by the
    function.  */
@@ -140,6 +147,9 @@ parse_element_type (const function_instance &instance, const char *&format)
 /* Read and return a type from FORMAT for function INSTANCE.  Advance
    FORMAT beyond the type string.  The format is:
 
+   _       - void
+   al      - array pointer for loads
+   as      - array pointer for stores
    p       - predicates with type mve_pred16_t
    s<elt>  - a scalar type with the given element suffix
    t<elt>  - a vector or tuple type with given element suffix [*1]
@@ -156,6 +166,21 @@ parse_type (const function_instance &instance, const char *&format)
 {
   int ch = *format++;
 
+
+  if (ch == '_')
+    return void_type_node;
+
+  if (ch == 'a')
+    {
+      ch = *format++;
+      if (ch == 'l')
+	return build_const_pointer (instance.memory_scalar_type ());
+      if (ch == 's') {
+	return build_pointer_type (instance.memory_scalar_type ());
+      }
+      gcc_unreachable ();
+    }
+
   if (ch == 'p')
     return get_mve_pred16_t ();
 
diff --git a/gcc/config/arm/arm-mve-builtins.h b/gcc/config/arm/arm-mve-builtins.h
index 37b8223dfb2..4fd230fe4c7 100644
--- a/gcc/config/arm/arm-mve-builtins.h
+++ b/gcc/config/arm/arm-mve-builtins.h
@@ -277,6 +277,7 @@ public:
   bool could_trap_p () const;
 
   unsigned int vectors_per_tuple () const;
+  tree memory_scalar_type () const;
 
   const mode_suffix_info &mode_suffix () const;
 
@@ -519,6 +520,14 @@ public:
      of vectors in the tuples, otherwise return 1.  */
   virtual unsigned int vectors_per_tuple () const { return 1; }
 
+  /* If the function addresses memory, return the type of a single
+     scalar memory element.  */
+  virtual tree
+  memory_scalar_type (const function_instance &) const
+  {
+    gcc_unreachable ();
+  }
+
   /* Try to fold the given gimple call.  Return the new gimple statement
      on success, otherwise return null.  */
   virtual gimple *fold (gimple_folder &) const { return NULL; }
@@ -644,6 +653,14 @@ function_instance::vectors_per_tuple () const
   return base->vectors_per_tuple ();
 }
 
+/* If the function addresses memory, return the type of a single
+   scalar memory element.  */
+inline tree
+function_instance::memory_scalar_type () const
+{
+  return base->memory_scalar_type (*this);
+}
+
 /* Return information about the function's mode suffix.  */
 inline const mode_suffix_info &
 function_instance::mode_suffix () const