On Dec 1, 2023, Alexandre Oliva <ol...@adacore.com> wrote:
> Also tested on arm-eabi, but it's *not* enough (or needed) to fix the
> PR, there's another bug lurking there, with a separate patch coming
> up.
Here it is.
----
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.
Regstrapped on x86_64-linux-gnu, tested on arm-eabi with and without the
upthread patch. It fixes the hardcfr fails either way. As for the
ugliness, there's a follow up patch below that attempts to alleviate it
a little (also regstrapped and tested), but I'm not sure we want to go
down that path. WDYT?
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.
---
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 4fc58a0bda9b8..039bb5e997a2c 100644
--- a/gcc/builtins.cc
+++ b/gcc/builtins.cc
@@ -1398,8 +1398,16 @@ 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)
@@ -1409,7 +1417,7 @@ 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;
@@ -1442,6 +1450,8 @@ apply_args_size (void)
}
else
apply_args_mode[regno] = as_a <fixed_size_mode> (VOIDmode);
+
+ set_apply_args_size (size);
}
return size;
}
@@ -1452,7 +1462,7 @@ 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. */
@@ -1484,6 +1494,8 @@ 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 88a26d70cd5a8..1a26fc63a6d10 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;
----
untyped calls: use wrapper class type for implicit plus_one
Instead of get and set macros to apply a delta, use a single macro
that resorts to a temporary wrapper class to apply it.
To be combined (or not) with the previous patch.
---
gcc/builtins.cc | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/gcc/builtins.cc b/gcc/builtins.cc
index 039bb5e997a2c..a60e0a7084513 100644
--- a/gcc/builtins.cc
+++ b/gcc/builtins.cc
@@ -1398,16 +1398,24 @@ 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)
+/* Wrapper that implicitly applies a delta when getting or setting the
+ enclosed value. */
+template <typename T>
+class delta_type
+{
+ T &value; T const delta;
+public:
+ delta_type (T &val, T dlt) : value (val), delta (dlt) {}
+ operator T () const { return value + delta; }
+ T operator = (T val) const { value = val - delta; return val; }
+};
+
+#define saved_apply_args_size \
+ (delta_type<int> (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 saved_apply_result_size \
+ (delta_type<int> (this_target_builtins->x_apply_result_size_plus_one, -1))
#define apply_result_mode \
(this_target_builtins->x_apply_result_mode)
@@ -1417,7 +1425,7 @@ get_memory_rtx (tree exp, tree len)
static int
apply_args_size (void)
{
- int size = get_apply_args_size ();
+ int size = saved_apply_args_size;
int align;
unsigned int regno;
@@ -1451,7 +1459,7 @@ apply_args_size (void)
else
apply_args_mode[regno] = as_a <fixed_size_mode> (VOIDmode);
- set_apply_args_size (size);
+ saved_apply_args_size = size;
}
return size;
}
@@ -1462,7 +1470,7 @@ apply_args_size (void)
static int
apply_result_size (void)
{
- int size = get_apply_result_size ();
+ int size = saved_apply_result_size;
int align, regno;
/* The values computed by this function never change. */
@@ -1495,7 +1503,7 @@ apply_result_size (void)
size = APPLY_RESULT_SIZE;
#endif
- set_apply_result_size (size);
+ saved_apply_result_size = size;
}
return size;
}
--
Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
Free Software Activist GNU Toolchain Engineer
More tolerance and less prejudice are key for inclusion and diversity
Excluding neuro-others for not behaving ""normal"" is *not* inclusive
