[PATCH] arm, aarch64, csky: Fix C++ ICEs with _Float16 and __fp16 [PR107080]

[Jakub Jelinek]

On Fri, Sep 30, 2022 at 06:38:39PM +0100, Richard Sandiford wrote:
> OK for the aarch64 part, thanks.  But could you add some scan-assemblers
> to the test to check for the mangled names?  I assume they should be:

Ok, about to commit the aarch64 part, will await review of the rest
afterwards.
> 
> _Z3fooIDF16_DF16_EiT_T0_
> _Z3fooIDF16_DhEiT_T0_
> 
> (which is what clang produces).

Indeed, that is what we now get.  Added.

2022-09-30  Jakub Jelinek  <jakub@redhat.com>

	PR c++/107080
	* config/arm/arm.cc (arm_mangle_type): Mangle just __fp16 as Dh
	and _Float16 as DF16_.
	* config/aarch64/aarch64.cc (aarch64_mangle_type): Likewise.
	* config/csky/csky.cc (csky_init_builtins): Fix a comment typo.
	(csky_mangle_type): Mangle __fp16 as Dh and _Float16 as DF16_
	rather than mangling __fp16 as __fp16.

	* g++.target/arm/pr107080.C: New test.
	* g++.target/aarch64/pr107080.C: New test.

--- gcc/config/arm/arm.cc.jj	2022-09-29 18:11:28.746750048 +0200
+++ gcc/config/arm/arm.cc	2022-09-30 19:01:48.774286551 +0200
@@ -30359,6 +30359,8 @@ arm_mangle_type (const_tree type)
   /* Half-precision floating point types.  */
   if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
     {
+      if (TYPE_MAIN_VARIANT (type) == float16_type_node)
+	return NULL;
       if (TYPE_MODE (type) == BFmode)
 	return "u6__bf16";
       else
--- gcc/config/aarch64/aarch64.cc.jj	2022-09-29 18:11:34.806667210 +0200
+++ gcc/config/aarch64/aarch64.cc	2022-09-30 19:02:02.079108171 +0200
@@ -20664,6 +20664,8 @@ aarch64_mangle_type (const_tree type)
   /* Half-precision floating point types.  */
   if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
     {
+      if (TYPE_MAIN_VARIANT (type) == float16_type_node)
+	return NULL;
       if (TYPE_MODE (type) == BFmode)
 	return "u6__bf16";
       else
--- gcc/config/csky/csky.cc.jj	2022-09-08 13:01:19.239779562 +0200
+++ gcc/config/csky/csky.cc	2022-09-30 19:06:09.126794587 +0200
@@ -7300,7 +7300,7 @@ csky_init_cumulative_args (CUMULATIVE_AR
 void
 csky_init_builtins (void)
 {
-  /* Inint fp16.  */
+  /* Init fp16.  */
   static tree csky_floatHF_type_node = make_node (REAL_TYPE);
   TYPE_PRECISION (csky_floatHF_type_node) = GET_MODE_PRECISION (HFmode);
   layout_type (csky_floatHF_type_node);
@@ -7313,10 +7313,10 @@ csky_init_builtins (void)
 static const char *
 csky_mangle_type (const_tree type)
 {
-  if (TYPE_NAME (type) && TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
-      && DECL_NAME (TYPE_NAME (type))
-      && !strcmp (IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))), "__fp16"))
-    return "__fp16";
+  if (TREE_CODE (type) == REAL_TYPE
+      && TYPE_PRECISION (type) == 16
+      && TYPE_MAIN_VARIANT (type) != float16_type_node)
+    return "Dh";
 
   /* Use the default mangling.  */
   return NULL;
--- gcc/testsuite/g++.target/arm/pr107080.C.jj	2022-09-30 18:56:08.885797047 +0200
+++ gcc/testsuite/g++.target/arm/pr107080.C	2022-09-30 18:58:07.812221153 +0200
@@ -0,0 +1,19 @@
+// PR c++/107080
+// { dg-do compile }
+// { dg-options "-mfp16-format=ieee" }
+
+template <typename T, typename T1> 
+int
+foo (T x, T1 y)
+{
+  return 3;
+}
+
+int
+main ()
+{
+  return (foo (0.0f16, 0.0f16) + foo (0.0f16, (__fp16) 0.0)) != 6;
+}
+
+// { dg-final { scan-assembler "_Z3fooIDF16_DF16_EiT_T0_" } }
+// { dg-final { scan-assembler "_Z3fooIDF16_DhEiT_T0_" } }
--- gcc/testsuite/g++.target/aarch64/pr107080.C.jj	2022-09-30 18:56:08.885797047 +0200
+++ gcc/testsuite/g++.target/aarch64/pr107080.C	2022-09-30 19:45:08.657342253 +0200
@@ -0,0 +1,19 @@
+// PR c++/107080
+// { dg-do compile }
+// { dg-options "" }
+
+template <typename T, typename T1> 
+int
+foo (T x, T1 y)
+{
+  return 3;
+}
+
+int
+main ()
+{
+  return (foo (0.0f16, 0.0f16) + foo (0.0f16, (__fp16) 0.0)) != 6;
+}
+
+// { dg-final { scan-assembler "_Z3fooIDF16_DF16_EiT_T0_" } }
+// { dg-final { scan-assembler "_Z3fooIDF16_DhEiT_T0_" } }

	Jakub