From: Jakub Jelinek <jakub@redhat.com>
To: Richard Biener <rguenther@suse.de>
Cc: gcc-patches@gcc.gnu.org
Subject: [PATCH] Disallow pointer operands for |, ^ and partly & [PR106878]
Date: Wed, 14 Sep 2022 09:43:11 +0200 [thread overview]
Message-ID: <YyGGD/5HXAXh13N0@tucnak> (raw)
Hi!
My change to match.pd (that added the two simplifications this patch
touches) results in more |/^/& assignments with pointer arguments,
but since r12-1608 we reject pointer operands for BIT_NOT_EXPR.
Disallowing them for BIT_NOT_EXPR and allowing for BIT_{IOR,XOR,AND}_EXPR
leads to a match.pd maintainance nightmare (see one of the patches in the
PR), so either we want to allow pointer operand on BIT_NOT_EXPR (but then
we run into issues e.g. with the ranger which expects it can emulate
BIT_NOT_EXPR ~X as - 1 - X which doesn't work for pointers which don't
support MINUS_EXPR), or the following patch disallows pointer arguments
for all of BIT_{IOR,XOR,AND}_EXPR with the exception of BIT_AND_EXPR
with INTEGER_CST last operand (for simpler pointer realignment).
I had to tweak one reassoc optimization and the two match.pd
simplifications.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
P.S.: I know it would be better for the verifiers to have positive
set of types it wants to allow for each operation, but I have no idea
what exactly we use there right now.
2022-09-14 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/106878
* tree-cfg.cc (verify_gimple_assign_binary): Disallow pointer,
reference or OFFSET_TYPE BIT_IOR_EXPR, BIT_XOR_EXPR or, unless
the second argument is INTEGER_CST, BIT_AND_EXPR.
* match.pd ((type) X op CST -> (type) (X op ((type-x) CST)),
(type) (((type2) X) op Y) -> (X op (type) Y)): Punt for
POINTER_TYPE_P or OFFSET_TYPE.
* tree-ssa-reassoc.cc (optimize_range_tests_cmp_bitwise): For
pointers cast them to pointer sized integers first.
* gcc.c-torture/compile/pr106878.c: New test.
--- gcc/tree-cfg.cc.jj 2022-09-08 20:22:07.788184491 +0200
+++ gcc/tree-cfg.cc 2022-09-13 09:28:53.563243962 +0200
@@ -4167,6 +4167,8 @@ verify_gimple_assign_binary (gassign *st
case ROUND_MOD_EXPR:
case RDIV_EXPR:
case EXACT_DIV_EXPR:
+ case BIT_IOR_EXPR:
+ case BIT_XOR_EXPR:
/* Disallow pointer and offset types for many of the binary gimple. */
if (POINTER_TYPE_P (lhs_type)
|| TREE_CODE (lhs_type) == OFFSET_TYPE)
@@ -4182,9 +4184,23 @@ verify_gimple_assign_binary (gassign *st
case MIN_EXPR:
case MAX_EXPR:
- case BIT_IOR_EXPR:
- case BIT_XOR_EXPR:
+ /* Continue with generic binary expression handling. */
+ break;
+
case BIT_AND_EXPR:
+ if (POINTER_TYPE_P (lhs_type)
+ && TREE_CODE (rhs2) == INTEGER_CST)
+ break;
+ /* Disallow pointer and offset types for many of the binary gimple. */
+ if (POINTER_TYPE_P (lhs_type)
+ || TREE_CODE (lhs_type) == OFFSET_TYPE)
+ {
+ error ("invalid types for %qs", code_name);
+ debug_generic_expr (lhs_type);
+ debug_generic_expr (rhs1_type);
+ debug_generic_expr (rhs2_type);
+ return true;
+ }
/* Continue with generic binary expression handling. */
break;
--- gcc/match.pd.jj 2022-09-08 20:22:00.836276502 +0200
+++ gcc/match.pd 2022-09-13 10:21:04.567853941 +0200
@@ -1763,6 +1763,8 @@ (define_operator_list SYNC_FETCH_AND_AND
&& (int_fits_type_p (@1, TREE_TYPE (@0))
|| tree_nop_conversion_p (TREE_TYPE (@0), type)))
|| types_match (@0, @1))
+ && !POINTER_TYPE_P (TREE_TYPE (@0))
+ && TREE_CODE (TREE_TYPE (@0)) != OFFSET_TYPE
/* ??? This transform conflicts with fold-const.cc doing
Convert (T)(x & c) into (T)x & (T)c, if c is an integer
constants (if x has signed type, the sign bit cannot be set
@@ -1799,7 +1801,9 @@ (define_operator_list SYNC_FETCH_AND_AND
(if (GIMPLE
&& TREE_CODE (@1) != INTEGER_CST
&& tree_nop_conversion_p (type, TREE_TYPE (@2))
- && types_match (type, @0))
+ && types_match (type, @0)
+ && !POINTER_TYPE_P (TREE_TYPE (@0))
+ && TREE_CODE (TREE_TYPE (@0)) != OFFSET_TYPE)
(bitop @0 (convert @1)))))
(for bitop (bit_and bit_ior)
--- gcc/tree-ssa-reassoc.cc.jj 2022-06-28 13:03:31.292684917 +0200
+++ gcc/tree-ssa-reassoc.cc 2022-09-13 10:18:27.466085947 +0200
@@ -3608,10 +3608,14 @@ optimize_range_tests_cmp_bitwise (enum t
tree type2 = NULL_TREE;
bool strict_overflow_p = false;
candidates.truncate (0);
+ if (POINTER_TYPE_P (type1))
+ type1 = pointer_sized_int_node;
for (j = i; j; j = chains[j - 1])
{
tree type = TREE_TYPE (ranges[j - 1].exp);
strict_overflow_p |= ranges[j - 1].strict_overflow_p;
+ if (POINTER_TYPE_P (type))
+ type = pointer_sized_int_node;
if ((b % 4) == 3)
{
/* For the signed < 0 cases, the types should be
@@ -3642,6 +3646,8 @@ optimize_range_tests_cmp_bitwise (enum t
tree type = TREE_TYPE (ranges[j - 1].exp);
if (j == k)
continue;
+ if (POINTER_TYPE_P (type))
+ type = pointer_sized_int_node;
if ((b % 4) == 3)
{
if (!useless_type_conversion_p (type1, type))
@@ -3671,7 +3677,7 @@ optimize_range_tests_cmp_bitwise (enum t
op = r->exp;
continue;
}
- if (id == l)
+ if (id == l || POINTER_TYPE_P (TREE_TYPE (op)))
{
code = (b % 4) == 3 ? BIT_NOT_EXPR : NOP_EXPR;
g = gimple_build_assign (make_ssa_name (type1), code, op);
@@ -3695,6 +3701,14 @@ optimize_range_tests_cmp_bitwise (enum t
gimple_seq_add_stmt_without_update (&seq, g);
op = gimple_assign_lhs (g);
}
+ type1 = TREE_TYPE (ranges[k - 1].exp);
+ if (POINTER_TYPE_P (type1))
+ {
+ gimple *g
+ = gimple_build_assign (make_ssa_name (type1), NOP_EXPR, op);
+ gimple_seq_add_stmt_without_update (&seq, g);
+ op = gimple_assign_lhs (g);
+ }
candidates.pop ();
if (update_range_test (&ranges[k - 1], NULL, candidates.address (),
candidates.length (), opcode, ops, op,
--- gcc/testsuite/gcc.c-torture/compile/pr106878.c.jj 2022-09-13 10:21:04.567853941 +0200
+++ gcc/testsuite/gcc.c-torture/compile/pr106878.c 2022-09-13 10:21:04.567853941 +0200
@@ -0,0 +1,15 @@
+/* PR tree-optimization/106878 */
+
+typedef __INTPTR_TYPE__ intptr_t;
+typedef __UINTPTR_TYPE__ uintptr_t;
+int a;
+
+int
+foo (const int *c)
+{
+ uintptr_t d = ((intptr_t) c | (intptr_t) &a) & 65535 << 16;
+ intptr_t e = (intptr_t) c;
+ if (d != (e & 65535 << 16))
+ return 1;
+ return 0;
+}
Jakub
next reply other threads:[~2022-09-14 7:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-14 7:43 Jakub Jelinek [this message]
2022-09-14 7:58 ` Richard Biener
2022-09-14 8:47 ` Jakub Jelinek
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