[GCC][PATCH][ARM] Add Bfloat16_t scalar type, vector types and machine modes to ARM back-end [2/2]

gcc/ChangeLog:

2020-01-16  Stam Markianos-Wright  <stam.markianos-wright@arm.com>

	* config/arm/arm.c
	(arm_invalid_conversion): New function for target hook.
	(arm_invalid_unary_op): New function for target hook.
	(arm_invalid_binary_op): New function for target hook.

gcc/testsuite/ChangeLog:

2020-01-16  Stam Markianos-Wright  <stam.markianos-wright@arm.com>

	* g++.target/arm/bfloat_cpp_typecheck.C: New test.
	* gcc.target/arm/bfloat16_scalar_typecheck.c: New test.
	* gcc.target/arm/bfloat16_vector_typecheck_1.c: New test.
	* gcc.target/arm/bfloat16_vector_typecheck_2.c: New test.

gcc/ChangeLog

 2020-01-16  Stam Markianos-Wright  <stam.markianos-wright@arm.com>
 
+	* config/arm/arm.c
+	(arm_invalid_conversion): New function for target hook.
+	(arm_invalid_unary_op): New function for target hook.
+	(arm_invalid_binary_op): New function for target hook.
+
+2020-01-16  Stam Markianos-Wright  <stam.markianos-wright@arm.com>
+
 	* config.gcc: Add arm_bf16.h.
 	* config/arm/arm-builtins.c (arm_mangle_builtin_type): Fix comment.
 	(arm_simd_builtin_std_type): Add BFmode.

gcc/config/arm/arm.c

@@ -692,6 +692,15 @@ static const struct attribute_spec arm_attribute_table[] =
 #undef TARGET_MANGLE_TYPE
 #define TARGET_MANGLE_TYPE arm_mangle_type
 
+#undef TARGET_INVALID_CONVERSION
+#define TARGET_INVALID_CONVERSION arm_invalid_conversion
+
+#undef TARGET_INVALID_UNARY_OP
+#define TARGET_INVALID_UNARY_OP arm_invalid_unary_op
+
+#undef TARGET_INVALID_BINARY_OP
+#define TARGET_INVALID_BINARY_OP arm_invalid_binary_op
+
 #undef TARGET_ATOMIC_ASSIGN_EXPAND_FENV
 #define TARGET_ATOMIC_ASSIGN_EXPAND_FENV arm_atomic_assign_expand_fenv
 
@@ -32785,6 +32794,55 @@ arm_coproc_ldc_stc_legitimate_address (rtx op)
   return false;
 }
 
+/* Return the diagnostic message string if conversion from FROMTYPE to
+   TOTYPE is not allowed, NULL otherwise.  */
+
+static const char *
+arm_invalid_conversion (const_tree fromtype, const_tree totype)
+{
+  if (element_mode (fromtype) != element_mode (totype))
+    {
+      /* Do no allow conversions to/from BFmode scalar types.  */
+      if (TYPE_MODE (fromtype) == BFmode)
+	return N_("invalid conversion from type %<bfloat16_t%>");
+      if (TYPE_MODE (totype) == BFmode)
+	return N_("invalid conversion to type %<bfloat16_t%>");
+    }
+
+  /* Conversion allowed.  */
+  return NULL;
+}
+
+/* Return the diagnostic message string if the unary operation OP is
+   not permitted on TYPE, NULL otherwise.  */
+
+static const char *
+arm_invalid_unary_op (int op, const_tree type)
+{
+  /* Reject all single-operand operations on BFmode except for &.  */
+  if (element_mode (type) == BFmode && op != ADDR_EXPR)
+    return N_("operation not permitted on type %<bfloat16_t%>");
+
+  /* Operation allowed.  */
+  return NULL;
+}
+
+/* Return the diagnostic message string if the binary operation OP is
+   not permitted on TYPE1 and TYPE2, NULL otherwise.  */
+
+static const char *
+arm_invalid_binary_op (int op ATTRIBUTE_UNUSED, const_tree type1,
+			   const_tree type2)
+{
+  /* Reject all 2-operand operations on BFmode.  */
+  if (element_mode (type1) == BFmode
+      || element_mode (type2) == BFmode)
+    return N_("operation not permitted on type %<bfloat16_t%>");
+
+  /* Operation allowed.  */
+  return NULL;
+}
+
 /* Implement TARGET_CAN_CHANGE_MODE_CLASS.
 
    In VFPv1, VFP registers could only be accessed in the mode they were

gcc/testsuite/ChangeLog

 2020-01-16  Stam Markianos-Wright  <stam.markianos-wright@arm.com>
 
+	* g++.target/arm/bfloat_cpp_typecheck.C: New test.
+	* gcc.target/arm/bfloat16_scalar_typecheck.c: New test.
+	* gcc.target/arm/bfloat16_vector_typecheck_1.c: New test.
+	* gcc.target/arm/bfloat16_vector_typecheck_2.c: New test.
+
+2020-01-16  Stam Markianos-Wright  <stam.markianos-wright@arm.com>
+
 	* g++.dg/abi/mangle-neon.C: Add BF16 SIMD types.
 	* g++.dg/ext/arm-bf16/bf16-mangle-1.C: New test.
 	* gcc.target/arm/bfloat16_scalar_1_1.c: New test.

gcc/testsuite/g++.target/arm/bfloat_cpp_typecheck.C

+/* { dg-do assemble { target { arm*-*-* } } } */
+/* { dg-require-effective-target arm_v8_2a_bf16_neon_ok } */
+/* { dg-add-options arm_v8_2a_bf16_neon }  */
+/* { dg-additional-options "-O3 --save-temps" } */
+
+#include <arm_neon.h>
+
+void foo (void)
+{
+  bfloat16_t (); /* { dg-bogus {invalid conversion to type 'bfloat16_t'} "" { xfail *-*-* } } */
+  bfloat16_t a = bfloat16_t(); /* { dg-bogus {invalid conversion to type 'bfloat16_t'} "" { xfail *-*-* } } */
+  bfloat16_t (0x1234); /* { dg-error {invalid conversion to type 'bfloat16_t'} } */
+  bfloat16_t (0.1); /* { dg-error {invalid conversion to type 'bfloat16_t'} } */
+}