On Fri, 2022-01-21 at 18:41 -0500, Antoni Boucher wrote:
> Hi.
> Here's the updated patch.
>
Thanks. Review below:
[...snip...]
> diff --git a/gcc/jit/libgccjit.cc b/gcc/jit/libgccjit.cc
> index 4c352e8c93d..6bf1e1ceee0 100644
> --- a/gcc/jit/libgccjit.cc
> +++ b/gcc/jit/libgccjit.cc
> @@ -2405,6 +2405,34 @@ gcc_jit_context_new_cast (gcc_jit_context *ctxt,
> return static_cast <gcc_jit_rvalue *> (ctxt->new_cast (loc, rvalue, type));
> }
>
> +/* Public entrypoint. See description in libgccjit.h.
> +
> + After error-checking, the real work is done by the
> + gcc::jit::recording::context::new_bitcast method in jit-recording.c. */
> +
> +gcc_jit_rvalue *
> +gcc_jit_context_new_bitcast (gcc_jit_context *ctxt,
> + gcc_jit_location *loc,
> + gcc_jit_rvalue *rvalue,
> + gcc_jit_type *type)
> +{
> + RETURN_NULL_IF_FAIL (ctxt, NULL, loc, "NULL context");
> + JIT_LOG_FUNC (ctxt->get_logger ());
> + /* LOC can be NULL. */
> + RETURN_NULL_IF_FAIL (rvalue, ctxt, loc, "NULL rvalue");
> + RETURN_NULL_IF_FAIL (type, ctxt, loc, "NULL type");
> + // TODO: check the sizes.
> + /*RETURN_NULL_IF_FAIL_PRINTF3 (
> + is_valid_cast (rvalue->get_type (), type),
> + ctxt, loc,
> + "cannot cast %s from type: %s to type: %s",
> + rvalue->get_debug_string (),
> + rvalue->get_type ()->get_debug_string (),
> + type->get_debug_string ());*/
I think we agreed that we can't check the sizes at this point, so this
commented-out check would be better replaced with a comment explaining
that we have to defer the check to playback time, when we have the
trees.
> +
> + return static_cast <gcc_jit_rvalue *> (ctxt->new_bitcast (loc, rvalue,
> type));
> +}
> +
> /* Public entrypoint. See description in libgccjit.h.
>
> After error-checking, the real work is done by the
[...snip...]
> diff --git a/gcc/testsuite/jit.dg/test-bitcast.c
> b/gcc/testsuite/jit.dg/test-bitcast.c
> new file mode 100644
> index 00000000000..a092fa117e6
> --- /dev/null
> +++ b/gcc/testsuite/jit.dg/test-bitcast.c
> @@ -0,0 +1,60 @@
> +#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:
> +int
> +my_bitcast (double x)
> +{
> + return bitcast(x, int);
> +}
> + */
> + gcc_jit_type *int_type =
> + gcc_jit_context_get_int_type (ctxt, 4, 1);
> + gcc_jit_type *float_type =
> + gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_FLOAT);
This uses GCC_JIT_TYPE_FLOAT for the param...
> +
> + gcc_jit_param *x =
> + gcc_jit_context_new_param (
> + ctxt,
> + NULL,
> + float_type, "x");
> + gcc_jit_param *params[1] = {x};
> + gcc_jit_function *func =
> + gcc_jit_context_new_function (ctxt,
> + NULL,
> + GCC_JIT_FUNCTION_EXPORTED,
> + int_type,
> + "my_bitcast",
> + 1, params, 0);
[..snip...]
> +
> +void
> +verify_code (gcc_jit_context *ctxt, gcc_jit_result *result)
> +{
> + typedef int (*my_bitcast_fn_type) (double);
...but this uses "double". Presumably these should agree, and have the
same sizeof as the integer type.
> + CHECK_NON_NULL (result);
> + my_bitcast_fn_type my_bitcast =
> + (my_bitcast_fn_type)gcc_jit_result_get_code (result, "my_bitcast");
> + CHECK_NON_NULL (my_bitcast);
> + int val = my_bitcast (-5.1298714);
> + note ("my_bitcast returned: %d", val);
> + CHECK_VALUE (val, 35569201);
Out of curiosity, is there any particular significance for these
values? FWIW I rather like:
http://evanw.github.io/float-toy/
for directly manipulating the bits of floating point numbers.
[...snip...]
> diff --git a/gcc/toplev.cc b/gcc/toplev.cc
> index 534da1462e8..bc4921974eb 100644
> --- a/gcc/toplev.cc
> +++ b/gcc/toplev.cc
> @@ -2368,6 +2368,7 @@ toplev::finalize (void)
> gcse_c_finalize ();
> ipa_cp_c_finalize ();
> ira_costs_c_finalize ();
> + tree_cc_finalize ();
>
> /* save_decoded_options uses opts_obstack, so these must
> be cleaned up together. */
> diff --git a/gcc/tree.cc b/gcc/tree.cc
> index ae159ee20ce..fe9d9083026 100644
> --- a/gcc/tree.cc
> +++ b/gcc/tree.cc
> @@ -6963,6 +6963,15 @@ build_reference_type (tree to_type)
> (HOST_BITS_PER_WIDE_INT > 64 ? HOST_BITS_PER_WIDE_INT : 64)
> static GTY(()) tree nonstandard_integer_type_cache[2 * MAX_INT_CACHED_PREC +
> 2];
>
> +static void
> +clear_nonstandard_integer_type_cache (void)
> +{
> + for (size_t i = 0 ; i < 2 * MAX_INT_CACHED_PREC + 2 ; i++)
> + {
> + nonstandard_integer_type_cache[i] = NULL;
> + }
> +}
> +
> /* Builds a signed or unsigned integer type of precision PRECISION.
> Used for C bitfields whose precision does not match that of
> built-in target types. */
> @@ -14565,6 +14574,12 @@ get_attr_nonstring_decl (tree expr, tree *ref)
> return NULL_TREE;
> }
>
> +void
> +tree_cc_finalize (void)
> +{
> + clear_nonstandard_integer_type_cache ();
> +}
> +
> #if CHECKING_P
>
> namespace selftest {
> diff --git a/gcc/tree.h b/gcc/tree.h
> index 30bc53c2996..bf886fc2472 100644
> --- a/gcc/tree.h
> +++ b/gcc/tree.h
> @@ -5385,6 +5385,7 @@ extern bool real_minus_onep (const_tree);
> extern void init_ttree (void);
> extern void build_common_tree_nodes (bool);
> extern void build_common_builtin_nodes (void);
> +extern void tree_cc_finalize (void);
> extern tree build_nonstandard_integer_type (unsigned HOST_WIDE_INT, int);
> extern tree build_nonstandard_boolean_type (unsigned HOST_WIDE_INT);
> extern tree build_range_type (tree, tree, tree);
Looks OK to me, but am not officially a maintainer of these parts.
LGTM with those nits fixed - for next stage 1, or for trunk now if the
release maintainers are OK with it.
Thanks again for the patch, and sorry about the belated review.
Dave
