[gcc(refs/users/aoliva/heads/testme)] untyped calls: enable target switching [PR112334]

[Alexandre Oliva]

https://gcc.gnu.org/g:7e7a437d1a272c99d4a8d18ed8e24a16444be6e3

commit 7e7a437d1a272c99d4a8d18ed8e24a16444be6e3
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Fri Dec 1 09:44:07 2023 -0300

    untyped calls: enable target switching [PR112334]
    
    The computation of apply_args_size and apply_result_size is saved in a
    static variable, so that the corresponding _mode arrays are
    initialized only once.  That is not compatible with switchable
    targets, and ARM's arm_set_current_function, by saving and restoring
    target globals, exercises this problem with a testcase such as that in
    the PR, in which more than one function in the translation unit calls
    __builtin_apply or __builtin_return, respectively.
    
    This patch moves the _size statics into the target_builtins array,
    with a bit of ugliness over _plus_one so that zero initialization of
    the struct does the right thing.
    
    
    for  gcc/ChangeLog
    
            PR target/112334
            * builtins.h (target_builtins): Add fields for apply_args_size
            and apply_result_size.
            * builtins.cc (apply_args_size, apply_result_size): Cache
            results in fields rather than in static variables.
            (get_apply_args_size, set_apply_args_size): New.
            (get_apply_result_size, set_apply_result_size): New.

Diff:
---
 gcc/builtins.cc | 16 ++++++++++++++--
 gcc/builtins.h  |  7 +++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/gcc/builtins.cc b/gcc/builtins.cc
index afa9be51443..d2884bd60af 100644
--- a/gcc/builtins.cc
+++ b/gcc/builtins.cc
@@ -1403,8 +1403,16 @@ get_memory_rtx (tree exp, tree len)
 
 /* Built-in functions to perform an untyped call and return.  */
 
+#define set_apply_args_size(x) \
+  (this_target_builtins->x_apply_args_size_plus_one = 1 + (x))
+#define get_apply_args_size() \
+  (this_target_builtins->x_apply_args_size_plus_one - 1)
 #define apply_args_mode \
   (this_target_builtins->x_apply_args_mode)
+#define set_apply_result_size(x) \
+  (this_target_builtins->x_apply_result_size_plus_one = 1 + (x))
+#define get_apply_result_size() \
+  (this_target_builtins->x_apply_result_size_plus_one - 1)
 #define apply_result_mode \
   (this_target_builtins->x_apply_result_mode)
 
@@ -1414,7 +1422,7 @@ get_memory_rtx (tree exp, tree len)
 static int
 apply_args_size (void)
 {
-  static int size = -1;
+  int size = get_apply_args_size ();
   int align;
   unsigned int regno;
 
@@ -1447,6 +1455,8 @@ apply_args_size (void)
 	  }
 	else
 	  apply_args_mode[regno] = as_a <fixed_size_mode> (VOIDmode);
+
+      set_apply_args_size (size);
     }
   return size;
 }
@@ -1457,7 +1467,7 @@ apply_args_size (void)
 static int
 apply_result_size (void)
 {
-  static int size = -1;
+  int size = get_apply_result_size ();
   int align, regno;
 
   /* The values computed by this function never change.  */
@@ -1489,6 +1499,8 @@ apply_result_size (void)
 #ifdef APPLY_RESULT_SIZE
       size = APPLY_RESULT_SIZE;
 #endif
+
+      set_apply_result_size (size);
     }
   return size;
 }
diff --git a/gcc/builtins.h b/gcc/builtins.h
index 88a26d70cd5..1a26fc63a6d 100644
--- a/gcc/builtins.h
+++ b/gcc/builtins.h
@@ -37,6 +37,13 @@ struct target_builtins {
      register windows, this gives only the outbound registers.
      INCOMING_REGNO gives the corresponding inbound register.  */
   fixed_size_mode_pod x_apply_result_mode[FIRST_PSEUDO_REGISTER];
+
+  /* Nonzero iff the arrays above have been initialized.  The _plus_one suffix
+     is for zero initialization to make it an unreasonable size, used to signal
+     that the size and the corresponding mode array has not been
+     initialized.  */
+  int x_apply_args_size_plus_one;
+  int x_apply_result_size_plus_one;
 };
 
 extern struct target_builtins default_target_builtins;