[gcc r12-2384] libgccjit: Handle truncation and extension for casts [PR95498]

[gcc r12-2384] libgccjit: Handle truncation and extension for casts [PR95498]

[Antoni Boucher]

https://gcc.gnu.org/g:5cca4131e4aabf70a18e362620ad65a3cebf227a

commit r12-2384-g5cca4131e4aabf70a18e362620ad65a3cebf227a
Author: Antoni Boucher <bouanto@zoho.com>
Date:   Sun Jul 5 19:07:30 2020 -0400

    libgccjit: Handle truncation and extension for casts [PR95498]
    
    2021-07-18  Antoni Boucher  <bouanto@zoho.com>
    
    gcc/jit/
            PR target/95498
            * jit-playback.c (convert): Add support to handle truncation and
            extension in the convert function.
    
    gcc/testsuite/
            PR target/95498
            * jit.dg/all-non-failing-tests.h: New test.
            * jit.dg/test-cast.c: New test.
    
    Signed-off-by: Antoni Boucher <bouanto@zoho.com>

Diff:
---
 gcc/jit/jit-playback.c                       | 32 +++++++++-----
 gcc/testsuite/jit.dg/all-non-failing-tests.h | 10 +++++
 gcc/testsuite/jit.dg/test-cast.c             | 66 ++++++++++++++++++++++++++++
 3 files changed, 97 insertions(+), 11 deletions(-)

diff --git a/gcc/jit/jit-playback.c b/gcc/jit/jit-playback.c
index c6136301243..79ac525e5df 100644
--- a/gcc/jit/jit-playback.c
+++ b/gcc/jit/jit-playback.c
@@ -62,22 +62,32 @@ along with GCC; see the file COPYING3.  If not see
 
 /* gcc::jit::playback::context::build_cast uses the convert.h API,
    which in turn requires the frontend to provide a "convert"
-   function, apparently as a fallback.
-
-   Hence we provide this dummy one, with the requirement that any casts
-   are handled before reaching this.  */
+   function, apparently as a fallback for casts that can be simplified
+   (truncation, extension). */
 extern tree convert (tree type, tree expr);
 
 tree
 convert (tree dst_type, tree expr)
 {
-  gcc_assert (gcc::jit::active_playback_ctxt);
-  gcc::jit::active_playback_ctxt->add_error (NULL, "unhandled conversion");
-  fprintf (stderr, "input expression:\n");
-  debug_tree (expr);
-  fprintf (stderr, "requested type:\n");
-  debug_tree (dst_type);
-  return error_mark_node;
+  tree t_ret = NULL;
+  t_ret = targetm.convert_to_type (dst_type, expr);
+  if (t_ret)
+      return t_ret;
+  switch (TREE_CODE (dst_type))
+    {
+    case INTEGER_TYPE:
+    case ENUMERAL_TYPE:
+      return fold (convert_to_integer (dst_type, expr));
+
+    default:
+      gcc_assert (gcc::jit::active_playback_ctxt);
+      gcc::jit::active_playback_ctxt->add_error (NULL, "unhandled conversion");
+      fprintf (stderr, "input expression:\n");
+      debug_tree (expr);
+      fprintf (stderr, "requested type:\n");
+      debug_tree (dst_type);
+      return error_mark_node;
+    }
 }
 
 namespace gcc {
diff --git a/gcc/testsuite/jit.dg/all-non-failing-tests.h b/gcc/testsuite/jit.dg/all-non-failing-tests.h
index 4202eb7798b..84ef54a0386 100644
--- a/gcc/testsuite/jit.dg/all-non-failing-tests.h
+++ b/gcc/testsuite/jit.dg/all-non-failing-tests.h
@@ -98,6 +98,13 @@
 #undef create_code
 #undef verify_code
 
+/* test-cast.c */
+#define create_code create_code_cast
+#define verify_code verify_code_cast
+#include "test-cast.c"
+#undef create_code
+#undef verify_code
+
 /* test-compound-assignment.c */
 #define create_code create_code_compound_assignment
 #define verify_code verify_code_compound_assignment
@@ -361,6 +368,9 @@ const struct testcase testcases[] = {
   {"calling_internal_function",
    create_code_calling_internal_function,
    verify_code_calling_internal_function},
+  {"cast",
+   create_code_cast,
+   verify_code_cast},
   {"compound_assignment",
    create_code_compound_assignment,
    verify_code_compound_assignment},
diff --git a/gcc/testsuite/jit.dg/test-cast.c b/gcc/testsuite/jit.dg/test-cast.c
new file mode 100644
index 00000000000..2b1e385ae40
--- /dev/null
+++ b/gcc/testsuite/jit.dg/test-cast.c
@@ -0,0 +1,66 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "libgccjit.h"
+
+#include "harness.h"
+
+void
+create_code (gcc_jit_context *ctxt, void *user_data)
+{
+  /* Let's try to inject the equivalent of:
+char
+my_casts (int x)
+{
+   return (char)(long) x;
+}
+   */
+  gcc_jit_type *int_type =
+    gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_INT);
+  gcc_jit_type *long_type =
+    gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_LONG);
+  gcc_jit_type *return_type =
+    gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_CHAR);
+
+  gcc_jit_param *x =
+    gcc_jit_context_new_param (
+      ctxt,
+      NULL,
+      int_type, "x");
+  gcc_jit_param *params[1] = {x};
+  gcc_jit_function *func =
+    gcc_jit_context_new_function (ctxt,
+				  NULL,
+				  GCC_JIT_FUNCTION_EXPORTED,
+				  return_type,
+				  "my_casts",
+				  1, params, 0);
+
+  gcc_jit_block *initial =
+    gcc_jit_function_new_block (func, "initial");
+
+  gcc_jit_block_end_with_return(initial, NULL,
+    gcc_jit_context_new_cast(ctxt,
+        NULL,
+        gcc_jit_context_new_cast(ctxt,
+            NULL,
+            gcc_jit_param_as_rvalue(x),
+            long_type
+        ),
+        return_type
+    ));
+}
+
+void
+verify_code (gcc_jit_context *ctxt, gcc_jit_result *result)
+{
+  typedef int (*my_casts_fn_type) (int);
+  CHECK_NON_NULL (result);
+  my_casts_fn_type my_casts =
+    (my_casts_fn_type)gcc_jit_result_get_code (result, "my_casts");
+  CHECK_NON_NULL (my_casts);
+  char val = my_casts (10);
+  note ("my_casts returned: %d", val);
+  CHECK_VALUE (val, 10);
+}