tree.cc: Add tree_builtin_call_types_compatible_p [PR105150]

And here is the follow-up patch that does the argument checking
on GENERIC.  It ensures TYPE_MAIN_VARIANT == TYPE_MAIN_VARIANT
compatibility on the arguments, except for pointer arguments
where both builtin's prototype and actual arguments have to be
pointers and satisfy tree_nop_conversion_p, and for promoted
char/short arguments where argument need to have integral
signed type tree_nop_conversion_p compatible with integer_type_node.

2022-04-07  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/105150
	* tree.cc (tree_builtin_call_types_compatible_p): New function.
	(get_call_combined_fn): Use it.

	* gcc.dg/pr105150.c: New test.

2 files changed, 64 insertions, 1 deletions

diff --git a/gcc/testsuite/gcc.dg/pr105150.c b/gcc/testsuite/gcc.dg/pr105150.c
new file mode 100644
index 0000000..900460c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr105150.c
@@ -0,0 +1,8 @@
+/* PR tree-optimization/105150 */
+/* { dg-options "-w -Ofast" } */
+
+#define A(name) __typeof (__builtin_##name (0)) name (); \
+  float name##1 () { return !name (1); } \
+  double name##2 () { return name (1.0L); }
+#define B(name) A(name) A(name##l)
+B (sqrt)
diff --git a/gcc/tree.cc b/gcc/tree.cc
index ec200e9..8f83ea1 100644
--- a/gcc/tree.cc
+++ b/gcc/tree.cc
@@ -8406,6 +8406,59 @@ get_callee_fndecl (const_tree call)
   return NULL_TREE;
 }
 
+/* Return true when STMTs arguments and return value match those of FNDECL,
+   a decl of a builtin function.  */
+
+static bool
+tree_builtin_call_types_compatible_p (const_tree call, tree fndecl)
+{
+  gcc_checking_assert (DECL_BUILT_IN_CLASS (fndecl) != NOT_BUILT_IN);
+
+  if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
+    if (tree decl = builtin_decl_explicit (DECL_FUNCTION_CODE (fndecl)))
+      fndecl = decl;
+
+  if (TYPE_MAIN_VARIANT (TREE_TYPE (call))
+      != TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (fndecl))))
+    return false;
+
+  tree targs = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
+  unsigned nargs = call_expr_nargs (call);
+  for (unsigned i = 0; i < nargs; ++i, targs = TREE_CHAIN (targs))
+    {
+      /* Variadic args follow.  */
+      if (!targs)
+	return true;
+      tree arg = CALL_EXPR_ARG (call, i);
+      tree type = TREE_VALUE (targs);
+      if (TYPE_MAIN_VARIANT (type) != TYPE_MAIN_VARIANT (TREE_TYPE (arg)))
+	{
+	  /* For pointer arguments be more forgiving, e.g. due to
+	     FILE * vs. fileptr_type_node, or say char * vs. const char *
+	     differences etc.  */
+	  if (POINTER_TYPE_P (type)
+	      && POINTER_TYPE_P (TREE_TYPE (arg))
+	      && tree_nop_conversion_p (type, TREE_TYPE (arg)))
+	    continue;
+	  /* char/short integral arguments are promoted to int
+	     by several frontends if targetm.calls.promote_prototypes
+	     is true.  Allow such promotion too.  */
+	  if (INTEGRAL_TYPE_P (type)
+	      && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)
+	      && INTEGRAL_TYPE_P (TREE_TYPE (arg))
+	      && !TYPE_UNSIGNED (TREE_TYPE (arg))
+	      && targetm.calls.promote_prototypes (TREE_TYPE (fndecl))
+	      && tree_nop_conversion_p (integer_type_node,
+					TREE_TYPE (arg)))
+	    continue;
+	  return false;
+	}
+    }
+  if (targs && !VOID_TYPE_P (TREE_VALUE (targs)))
+    return false;
+  return true;
+}
+
 /* If CALL_EXPR CALL calls a normal built-in function or an internal function,
    return the associated function code, otherwise return CFN_LAST.  */
 
@@ -8419,7 +8472,9 @@ get_call_combined_fn (const_tree call)
     return as_combined_fn (CALL_EXPR_IFN (call));
 
   tree fndecl = get_callee_fndecl (call);
-  if (fndecl && fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
+  if (fndecl
+      && fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)
+      && tree_builtin_call_types_compatible_p (call, fndecl))
     return as_combined_fn (DECL_FUNCTION_CODE (fndecl));
 
   return CFN_LAST;