[11/16] aarch64: Generalise _m rules for SVE intrinsics

Message ID mptcz9rnpe9.fsf@arm.com
State New
Headers
Series aarch64: Add support for SME |

Commit Message

Richard Sandiford Nov. 13, 2022, 10:02 a.m. UTC
  In SVE there was a simple rule that unary merging (_m) intrinsics
had a separate initial argument to specify the values of inactive
lanes, whereas other merging functions took inactive lanes from
the first operand to the operation.

That rule began to break down in SVE2, and it continues to do
so in SME.  This patch therefore adds a virtual function to
specify whether the separate initial argument is present or not.
The old rule is still the default.

gcc/
	* config/aarch64/aarch64-sve-builtins.h
	(function_shape::has_merge_argument_p): New member function.
	* config/aarch64/aarch64-sve-builtins.cc:
	(function_resolver::check_gp_argument): Use it.
	(function_expander::get_fallback_value): Likewise.
	* config/aarch64/aarch64-sve-builtins-shapes.cc
	(apply_predication): Likewise.
	(unary_convert_narrowt_def::has_merge_argument_p): New function.
---
 gcc/config/aarch64/aarch64-sve-builtins-shapes.cc | 10 ++++++++--
 gcc/config/aarch64/aarch64-sve-builtins.cc        |  4 ++--
 gcc/config/aarch64/aarch64-sve-builtins.h         | 13 +++++++++++++
 3 files changed, 23 insertions(+), 4 deletions(-)
  

Patch

diff --git a/gcc/config/aarch64/aarch64-sve-builtins-shapes.cc b/gcc/config/aarch64/aarch64-sve-builtins-shapes.cc
index 8e26bd8a60f..5b47dff0b41 100644
--- a/gcc/config/aarch64/aarch64-sve-builtins-shapes.cc
+++ b/gcc/config/aarch64/aarch64-sve-builtins-shapes.cc
@@ -66,8 +66,8 @@  apply_predication (const function_instance &instance, tree return_type,
 	 the same type as the result.  For unary_convert_narrowt it also
 	 provides the "bottom" half of active elements, and is present
 	 for all types of predication.  */
-      if ((argument_types.length () == 2 && instance.pred == PRED_m)
-	  || instance.shape == shapes::unary_convert_narrowt)
+      auto nargs = argument_types.length () - 1;
+      if (instance.shape->has_merge_argument_p (instance, nargs))
 	argument_types.quick_insert (0, return_type);
     }
 }
@@ -3238,6 +3238,12 @@  SHAPE (unary_convert)
    predicate.  */
 struct unary_convert_narrowt_def : public overloaded_base<1>
 {
+  bool
+  has_merge_argument_p (const function_instance &, unsigned int) const override
+  {
+    return true;
+  }
+
   void
   build (function_builder &b, const function_group_info &group) const override
   {
diff --git a/gcc/config/aarch64/aarch64-sve-builtins.cc b/gcc/config/aarch64/aarch64-sve-builtins.cc
index cb3eb76dd77..450a8d958a8 100644
--- a/gcc/config/aarch64/aarch64-sve-builtins.cc
+++ b/gcc/config/aarch64/aarch64-sve-builtins.cc
@@ -2152,7 +2152,7 @@  function_resolver::check_gp_argument (unsigned int nops,
   if (pred != PRED_none)
     {
       /* Unary merge operations should use resolve_unary instead.  */
-      gcc_assert (nops != 1 || pred != PRED_m);
+      gcc_assert (!shape->has_merge_argument_p (*this, nops));
       nargs = nops + 1;
       if (!check_num_arguments (nargs)
 	  || !require_vector_type (i, VECTOR_TYPE_svbool_t))
@@ -2790,7 +2790,7 @@  function_expander::get_fallback_value (machine_mode mode, unsigned int nops,
 
   gcc_assert (pred == PRED_m || pred == PRED_x);
   if (merge_argno == DEFAULT_MERGE_ARGNO)
-    merge_argno = nops == 1 && pred == PRED_m ? 0 : 1;
+    merge_argno = shape->has_merge_argument_p (*this, nops) ? 0 : 1;
 
   if (merge_argno == 0)
     return args[argno++];
diff --git a/gcc/config/aarch64/aarch64-sve-builtins.h b/gcc/config/aarch64/aarch64-sve-builtins.h
index 0d130b871d0..623b9e3a07b 100644
--- a/gcc/config/aarch64/aarch64-sve-builtins.h
+++ b/gcc/config/aarch64/aarch64-sve-builtins.h
@@ -636,6 +636,9 @@  public:
 class function_shape
 {
 public:
+  virtual bool has_merge_argument_p (const function_instance &,
+				     unsigned int) const;
+
   virtual bool explicit_type_suffix_p (unsigned int) const = 0;
 
   /* Define all functions associated with the given group.  */
@@ -877,6 +880,16 @@  function_base::call_properties (const function_instance &instance) const
   return flags;
 }
 
+/* Return true if INSTANCE (which has NARGS arguments) has an initial
+   vector argument whose only purpose is to specify the values of
+   inactive lanes.  */
+inline bool
+function_shape::has_merge_argument_p (const function_instance &instance,
+				      unsigned int nargs) const
+{
+  return nargs == 1 && instance.pred == PRED_m;
+}
+
 }
 
 #endif