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-rw-r--r--gcc/expr.c79
1 files changed, 64 insertions, 15 deletions
diff --git a/gcc/expr.c b/gcc/expr.c
index b2e25c7..3be412d 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -154,6 +154,7 @@ static int is_aligning_offset (tree, tree);
static rtx expand_increment (tree, int, int);
static void expand_operands (tree, tree, rtx, rtx*, rtx*,
enum expand_modifier);
+static rtx reduce_to_bit_field_precision (rtx, rtx, tree);
static rtx do_store_flag (tree, rtx, enum machine_mode, int);
#ifdef PUSH_ROUNDING
static void emit_single_push_insn (enum machine_mode, rtx, tree);
@@ -6430,9 +6431,26 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
rtx subtarget, original_target;
int ignore;
tree context;
+ bool reduce_bit_field = false;
+#define REDUCE_BIT_FIELD(expr) (reduce_bit_field && !ignore \
+ ? reduce_to_bit_field_precision ((expr), \
+ target, \
+ type) \
+ : (expr))
mode = TYPE_MODE (type);
unsignedp = TYPE_UNSIGNED (type);
+ if (lang_hooks.reduce_bit_field_operations
+ && TREE_CODE (type) == INTEGER_TYPE
+ && GET_MODE_PRECISION (mode) > TYPE_PRECISION (type))
+ {
+ /* An operation in what may be a bit-field type needs the
+ result to be reduced to the precision of the bit-field type,
+ which is narrower than that of the type's mode. */
+ reduce_bit_field = true;
+ if (modifier == EXPAND_STACK_PARM)
+ target = 0;
+ }
/* Use subtarget as the target for operand 0 of a binary operation. */
subtarget = get_subtarget (target);
@@ -7423,10 +7441,11 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
&& GET_CODE (op0) == SUBREG)
SUBREG_PROMOTED_VAR_P (op0) = 0;
- return op0;
+ return REDUCE_BIT_FIELD (op0);
}
op0 = expand_expr (TREE_OPERAND (exp, 0), NULL_RTX, mode, modifier);
+ op0 = REDUCE_BIT_FIELD (op0);
if (GET_MODE (op0) == mode)
return op0;
@@ -7594,7 +7613,7 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
op1 = plus_constant (op1, INTVAL (constant_part));
if (modifier != EXPAND_SUM && modifier != EXPAND_INITIALIZER)
op1 = force_operand (op1, target);
- return op1;
+ return REDUCE_BIT_FIELD (op1);
}
else if (TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST
@@ -7627,7 +7646,7 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
op0 = plus_constant (op0, INTVAL (constant_part));
if (modifier != EXPAND_SUM && modifier != EXPAND_INITIALIZER)
op0 = force_operand (op0, target);
- return op0;
+ return REDUCE_BIT_FIELD (op0);
}
}
@@ -7649,7 +7668,7 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
expand_operands (TREE_OPERAND (exp, 0), TREE_OPERAND (exp, 1),
subtarget, &op0, &op1, modifier);
- return simplify_gen_binary (PLUS, mode, op0, op1);
+ return REDUCE_BIT_FIELD (simplify_gen_binary (PLUS, mode, op0, op1));
case MINUS_EXPR:
/* For initializers, we are allowed to return a MINUS of two
@@ -7667,9 +7686,9 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
/* If the last operand is a CONST_INT, use plus_constant of
the negated constant. Else make the MINUS. */
if (GET_CODE (op1) == CONST_INT)
- return plus_constant (op0, - INTVAL (op1));
+ return REDUCE_BIT_FIELD (plus_constant (op0, - INTVAL (op1)));
else
- return gen_rtx_MINUS (mode, op0, op1);
+ return REDUCE_BIT_FIELD (gen_rtx_MINUS (mode, op0, op1));
}
this_optab = ! unsignedp && flag_trapv
@@ -7691,7 +7710,7 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
if (GET_CODE (op1) == CONST_INT)
{
op1 = negate_rtx (mode, op1);
- return simplify_gen_binary (PLUS, mode, op0, op1);
+ return REDUCE_BIT_FIELD (simplify_gen_binary (PLUS, mode, op0, op1));
}
goto binop2;
@@ -7723,9 +7742,9 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
if (!REG_P (op0))
op0 = copy_to_mode_reg (mode, op0);
- return gen_rtx_MULT (mode, op0,
+ return REDUCE_BIT_FIELD (gen_rtx_MULT (mode, op0,
gen_int_mode (tree_low_cst (exp1, 0),
- TYPE_MODE (TREE_TYPE (exp1))));
+ TYPE_MODE (TREE_TYPE (exp1)))));
}
if (modifier == EXPAND_STACK_PARM)
@@ -7803,13 +7822,13 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
zextend_p);
if (htem != hipart)
emit_move_insn (hipart, htem);
- return temp;
+ return REDUCE_BIT_FIELD (temp);
}
}
}
expand_operands (TREE_OPERAND (exp, 0), TREE_OPERAND (exp, 1),
subtarget, &op0, &op1, 0);
- return expand_mult (mode, op0, op1, target, unsignedp);
+ return REDUCE_BIT_FIELD (expand_mult (mode, op0, op1, target, unsignedp));
case TRUNC_DIV_EXPR:
case FLOOR_DIV_EXPR:
@@ -7885,7 +7904,7 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
? negv_optab : neg_optab, op0, target, 0);
if (temp == 0)
abort ();
- return temp;
+ return REDUCE_BIT_FIELD (temp);
case ABS_EXPR:
op0 = expand_expr (TREE_OPERAND (exp, 0), subtarget, VOIDmode, 0);
@@ -8550,12 +8569,12 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
case PREINCREMENT_EXPR:
case PREDECREMENT_EXPR:
- return expand_increment (exp, 0, ignore);
+ return REDUCE_BIT_FIELD (expand_increment (exp, 0, ignore));
case POSTINCREMENT_EXPR:
case POSTDECREMENT_EXPR:
/* Faster to treat as pre-increment if result is not used. */
- return expand_increment (exp, ! ignore, ignore);
+ return REDUCE_BIT_FIELD (expand_increment (exp, ! ignore, ignore));
case ADDR_EXPR:
if (modifier == EXPAND_STACK_PARM)
@@ -8915,7 +8934,37 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
unsignedp, OPTAB_LIB_WIDEN);
if (temp == 0)
abort ();
- return temp;
+ return REDUCE_BIT_FIELD (temp);
+}
+#undef REDUCE_BIT_FIELD
+
+/* Subroutine of above: reduce EXP to the precision of TYPE (in the
+ signedness of TYPE), possibly returning the result in TARGET. */
+static rtx
+reduce_to_bit_field_precision (rtx exp, rtx target, tree type)
+{
+ HOST_WIDE_INT prec = TYPE_PRECISION (type);
+ if (target && GET_MODE (target) != GET_MODE (exp))
+ target = 0;
+ if (TYPE_UNSIGNED (type))
+ {
+ rtx mask;
+ if (prec < HOST_BITS_PER_WIDE_INT)
+ mask = immed_double_const (((unsigned HOST_WIDE_INT) 1 << prec) - 1, 0,
+ GET_MODE (exp));
+ else
+ mask = immed_double_const ((unsigned HOST_WIDE_INT) -1,
+ ((unsigned HOST_WIDE_INT) 1
+ << (prec - HOST_BITS_PER_WIDE_INT)) - 1,
+ GET_MODE (exp));
+ return expand_and (GET_MODE (exp), exp, mask, target);
+ }
+ else
+ {
+ tree count = build_int_2 (GET_MODE_BITSIZE (GET_MODE (exp)) - prec, 0);
+ exp = expand_shift (LSHIFT_EXPR, GET_MODE (exp), exp, count, target, 0);
+ return expand_shift (RSHIFT_EXPR, GET_MODE (exp), exp, count, target, 0);
+ }
}
/* Subroutine of above: returns 1 if OFFSET corresponds to an offset that
generated by cgit v1.1 at 2025-05-30 23:18:23 +0000