For targets that set the "extended" flag in TARGET_C_BITINT_TYPE_INFO,
we assume small _BitInts to be internally extended after arithmetic
operations. In this case, an extra extension during RTL expansion
can be avoided.
gcc/ChangeLog:
* expr.cc (expand_expr_real_1): Do not call
reduce_to_bit_field_precision if the target assume the _BitInt
results to be already extended.
(EXTEND_BITINT): Same.
* expr.h (bitint_extended): Declare the cache variable.
* function.cc (prepare_function_start): Initialize it.
---
gcc/expr.cc | 12 ++++++++++++
gcc/expr.h | 4 ++++
gcc/function.cc | 4 ++++
3 files changed, 20 insertions(+)
diff --git a/gcc/expr.cc b/gcc/expr.cc
index ac4fdfaa218..97d833a33a6 100644
--- a/gcc/expr.cc
+++ b/gcc/expr.cc
@@ -76,6 +76,10 @@ along with GCC; see the file COPYING3. If not see
the same indirect address eventually. */
int cse_not_expected;
+/* Cache of the "extended" flag in the target's _BitInt description
+ for use during expand. */
+int bitint_extended;
+
static bool block_move_libcall_safe_for_call_parm (void);
static bool emit_block_move_via_pattern (rtx, rtx, rtx, unsigned, unsigned,
HOST_WIDE_INT, unsigned HOST_WIDE_INT,
@@ -11280,6 +11284,7 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode
tmode,
when reading from SSA_NAMEs of vars. */
#define EXTEND_BITINT(expr) \
((TREE_CODE (type) == BITINT_TYPE \
+ && !bitint_extended
\
&& reduce_bit_field
\
&& mode != BLKmode \
&& modifier != EXPAND_MEMORY \
@@ -11291,6 +11296,13 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode
tmode,
type = TREE_TYPE (exp);
mode = TYPE_MODE (type);
unsignedp = TYPE_UNSIGNED (type);
+ if (bitint_extended == -1 && TREE_CODE (type) == BITINT_TYPE)
+ {
+ struct bitint_info info;
+ bool ok = targetm.c.bitint_type_info (TYPE_PRECISION (type), &info);
+ gcc_assert (ok);
+ bitint_extended = info.extended;
+ }
treeop0 = treeop1 = treeop2 = NULL_TREE;
if (!VL_EXP_CLASS_P (exp))
diff --git a/gcc/expr.h b/gcc/expr.h
index 53ab625787e..060151df010 100644
--- a/gcc/expr.h
+++ b/gcc/expr.h
@@ -388,4 +388,8 @@ extern void expand_crc_table_based (rtx, rtx, rtx, rtx,
machine_mode);
extern void expand_reversed_crc_table_based (rtx, rtx, rtx, rtx, machine_mode,
void (*) (rtx *));
+/* Cache of the "extended" flag in the target's _BitInt description
+ for use during expand. */
+extern int bitint_extended;
+
#endif /* GCC_EXPR_H */
diff --git a/gcc/function.cc b/gcc/function.cc
index 48167b0c207..502135c6f58 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -4965,6 +4965,10 @@ prepare_function_start (void)
/* Indicate we have no need of a frame pointer yet. */
frame_pointer_needed = 0;
+
+ /* Reset the cache of the "extended" flag in the target's
+ _BitInt info struct. */
+ bitint_extended = -1;
}
void
--
2.46.0
