aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJakub Jelinek <jakub@redhat.com>2017-12-06 20:22:06 +0100
committerJakub Jelinek <jakub@gcc.gnu.org>2017-12-06 20:22:06 +0100
commitd7f44d4d00640240af8731911eed207eca5ac4d0 (patch)
treeb4e1816175ba649a8f594b1c017f750ae055d13a
parent9c1caf50e16b50903364709d774244928c719b35 (diff)
downloadgcc-d7f44d4d00640240af8731911eed207eca5ac4d0.zip
gcc-d7f44d4d00640240af8731911eed207eca5ac4d0.tar.gz
gcc-d7f44d4d00640240af8731911eed207eca5ac4d0.tar.bz2
re PR sanitizer/81281 (UBSAN: false positive, dropped promotion to long type.)
PR sanitizer/81281 * match.pd ((T)(P + A) - (T)P -> (T) A): Split into separate simplify for plus with :c added, and pointer_plus without that. ((T)P - (T)(P + A) -> -(T) A): Likewise. If type is integral with undefined overflow and the conversion is not widening, perform negation in utype and only convert to type afterwards. ((T)(P + A) - (T)(P + B) -> (T)A - (T)B): Split into separate simplify for plus with :c added, and pointer_plus without that. If type is integral with undefined overflow and the conversion is not widening, perform minus in utype and only convert to type afterwards. Move the last pointer_diff_expr simplify into the two outermost ifs. * gcc.c-torture/execute/pr81281.c: New test. * gcc.dg/pr81281-1.c: New test. * gcc.dg/pr81281-2.c: New test. * g++.dg/ubsan/pr81281.C: New test. * g++.dg/ubsan/pr81281-aux.cc: New test. From-SVN: r255449
-rw-r--r--gcc/ChangeLog15
-rw-r--r--gcc/match.pd100
-rw-r--r--gcc/testsuite/ChangeLog9
-rw-r--r--gcc/testsuite/g++.dg/ubsan/pr81281-aux.cc3
-rw-r--r--gcc/testsuite/g++.dg/ubsan/pr81281.C26
-rw-r--r--gcc/testsuite/gcc.c-torture/execute/pr81281.c33
-rw-r--r--gcc/testsuite/gcc.dg/pr81281-1.c150
-rw-r--r--gcc/testsuite/gcc.dg/pr81281-2.c80
8 files changed, 382 insertions, 34 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index de037da6..9cfc382 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2017-12-06 Jakub Jelinek <jakub@redhat.com>
+
+ PR sanitizer/81281
+ * match.pd ((T)(P + A) - (T)P -> (T) A): Split into separate
+ simplify for plus with :c added, and pointer_plus without that.
+ ((T)P - (T)(P + A) -> -(T) A): Likewise. If type is integral
+ with undefined overflow and the conversion is not widening,
+ perform negation in utype and only convert to type afterwards.
+ ((T)(P + A) - (T)(P + B) -> (T)A - (T)B): Split into separate
+ simplify for plus with :c added, and pointer_plus without that.
+ If type is integral with undefined overflow and the conversion is
+ not widening, perform minus in utype and only convert to type
+ afterwards. Move the last pointer_diff_expr simplify into the
+ two outermost ifs.
+
2017-12-06 Martin Sebor <msebor@redhat.com>
PR tree-optimization/82646
diff --git a/gcc/match.pd b/gcc/match.pd
index 53f8b86..0a4ff6b 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1783,28 +1783,32 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(bit_not @0))
/* (T)(P + A) - (T)P -> (T) A */
- (for add (plus pointer_plus)
- (simplify
- (minus (convert (add @@0 @1))
- (convert @0))
- (if (element_precision (type) <= element_precision (TREE_TYPE (@1))
- /* For integer types, if A has a smaller type
- than T the result depends on the possible
- overflow in P + A.
- E.g. T=size_t, A=(unsigned)429497295, P>0.
- However, if an overflow in P + A would cause
- undefined behavior, we can assume that there
- is no overflow. */
- || (INTEGRAL_TYPE_P (TREE_TYPE (@0))
- && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
- /* For pointer types, if the conversion of A to the
- final type requires a sign- or zero-extension,
- then we have to punt - it is not defined which
- one is correct. */
- || (POINTER_TYPE_P (TREE_TYPE (@0))
- && TREE_CODE (@1) == INTEGER_CST
- && tree_int_cst_sign_bit (@1) == 0))
- (convert @1))))
+ (simplify
+ (minus (convert (plus:c @0 @1))
+ (convert @0))
+ (if (element_precision (type) <= element_precision (TREE_TYPE (@1))
+ /* For integer types, if A has a smaller type
+ than T the result depends on the possible
+ overflow in P + A.
+ E.g. T=size_t, A=(unsigned)429497295, P>0.
+ However, if an overflow in P + A would cause
+ undefined behavior, we can assume that there
+ is no overflow. */
+ || (INTEGRAL_TYPE_P (TREE_TYPE (@0))
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))))
+ (convert @1)))
+ (simplify
+ (minus (convert (pointer_plus @@0 @1))
+ (convert @0))
+ (if (element_precision (type) <= element_precision (TREE_TYPE (@1))
+ /* For pointer types, if the conversion of A to the
+ final type requires a sign- or zero-extension,
+ then we have to punt - it is not defined which
+ one is correct. */
+ || (POINTER_TYPE_P (TREE_TYPE (@0))
+ && TREE_CODE (@1) == INTEGER_CST
+ && tree_int_cst_sign_bit (@1) == 0))
+ (convert @1)))
(simplify
(pointer_diff (pointer_plus @@0 @1) @0)
/* The second argument of pointer_plus must be interpreted as signed, and
@@ -1813,10 +1817,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(convert (convert:stype @1))))
/* (T)P - (T)(P + A) -> -(T) A */
- (for add (plus pointer_plus)
- (simplify
- (minus (convert @0)
- (convert (add @@0 @1)))
+ (simplify
+ (minus (convert @0)
+ (convert (plus:c @0 @1)))
+ (if (INTEGRAL_TYPE_P (type)
+ && TYPE_OVERFLOW_UNDEFINED (type)
+ && element_precision (type) <= element_precision (TREE_TYPE (@1)))
+ (with { tree utype = unsigned_type_for (type); }
+ (convert (negate (convert:utype @1))))
(if (element_precision (type) <= element_precision (TREE_TYPE (@1))
/* For integer types, if A has a smaller type
than T the result depends on the possible
@@ -1826,7 +1834,17 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
undefined behavior, we can assume that there
is no overflow. */
|| (INTEGRAL_TYPE_P (TREE_TYPE (@0))
- && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))))
+ (negate (convert @1)))))
+ (simplify
+ (minus (convert @0)
+ (convert (pointer_plus @@0 @1)))
+ (if (INTEGRAL_TYPE_P (type)
+ && TYPE_OVERFLOW_UNDEFINED (type)
+ && element_precision (type) <= element_precision (TREE_TYPE (@1)))
+ (with { tree utype = unsigned_type_for (type); }
+ (convert (negate (convert:utype @1))))
+ (if (element_precision (type) <= element_precision (TREE_TYPE (@1))
/* For pointer types, if the conversion of A to the
final type requires a sign- or zero-extension,
then we have to punt - it is not defined which
@@ -1843,10 +1861,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(negate (convert (convert:stype @1)))))
/* (T)(P + A) - (T)(P + B) -> (T)A - (T)B */
- (for add (plus pointer_plus)
- (simplify
- (minus (convert (add @@0 @1))
- (convert (add @0 @2)))
+ (simplify
+ (minus (convert (plus:c @0 @1))
+ (convert (plus:c @0 @2)))
+ (if (INTEGRAL_TYPE_P (type)
+ && TYPE_OVERFLOW_UNDEFINED (type)
+ && element_precision (type) <= element_precision (TREE_TYPE (@1)))
+ (with { tree utype = unsigned_type_for (type); }
+ (convert (minus (convert:utype @1) (convert:utype @2))))
(if (element_precision (type) <= element_precision (TREE_TYPE (@1))
/* For integer types, if A has a smaller type
than T the result depends on the possible
@@ -1856,7 +1878,17 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
undefined behavior, we can assume that there
is no overflow. */
|| (INTEGRAL_TYPE_P (TREE_TYPE (@0))
- && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))))
+ (minus (convert @1) (convert @2)))))
+ (simplify
+ (minus (convert (pointer_plus @@0 @1))
+ (convert (pointer_plus @0 @2)))
+ (if (INTEGRAL_TYPE_P (type)
+ && TYPE_OVERFLOW_UNDEFINED (type)
+ && element_precision (type) <= element_precision (TREE_TYPE (@1)))
+ (with { tree utype = unsigned_type_for (type); }
+ (convert (minus (convert:utype @1) (convert:utype @2))))
+ (if (element_precision (type) <= element_precision (TREE_TYPE (@1))
/* For pointer types, if the conversion of A to the
final type requires a sign- or zero-extension,
then we have to punt - it is not defined which
@@ -1866,13 +1898,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
&& tree_int_cst_sign_bit (@1) == 0
&& TREE_CODE (@2) == INTEGER_CST
&& tree_int_cst_sign_bit (@2) == 0))
- (minus (convert @1) (convert @2)))))))
+ (minus (convert @1) (convert @2)))))
(simplify
(pointer_diff (pointer_plus @@0 @1) (pointer_plus @0 @2))
/* The second argument of pointer_plus must be interpreted as signed, and
thus sign-extended if necessary. */
(with { tree stype = signed_type_for (TREE_TYPE (@1)); }
- (minus (convert (convert:stype @1)) (convert (convert:stype @2)))))
+ (minus (convert (convert:stype @1)) (convert (convert:stype @2)))))))
/* Simplifications of MIN_EXPR, MAX_EXPR, fmin() and fmax(). */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a42348f..782e04d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,12 @@
+2017-12-06 Jakub Jelinek <jakub@redhat.com>
+
+ PR sanitizer/81281
+ * gcc.c-torture/execute/pr81281.c: New test.
+ * gcc.dg/pr81281-1.c: New test.
+ * gcc.dg/pr81281-2.c: New test.
+ * g++.dg/ubsan/pr81281.C: New test.
+ * g++.dg/ubsan/pr81281-aux.cc: New test.
+
2017-12-06 Martin Sebor <msebor@redhat.com>
PR tree-optimization/82646
diff --git a/gcc/testsuite/g++.dg/ubsan/pr81281-aux.cc b/gcc/testsuite/g++.dg/ubsan/pr81281-aux.cc
new file mode 100644
index 0000000..4a34a61
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ubsan/pr81281-aux.cc
@@ -0,0 +1,3 @@
+extern const int ci = 1716607962;
+int i = -943738830;
+long long ll = -43165919987465092LL;
diff --git a/gcc/testsuite/g++.dg/ubsan/pr81281.C b/gcc/testsuite/g++.dg/ubsan/pr81281.C
new file mode 100644
index 0000000..a812924
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ubsan/pr81281.C
@@ -0,0 +1,26 @@
+// PR sanitizer/81281
+// { dg-do run }
+// { dg-options "-fsanitize=undefined -fno-sanitize-recover=undefined" }
+// { dg-additional-sources "pr81281-aux.cc" }
+
+extern const int ci;
+extern int i;
+extern long long ll;
+
+int
+foo ()
+{
+ int a = (int) (-2024172551 - i - (ci - ll))
+ - ((int) (-2024172551 - i - (ci - ll))
+ - (int) (-2024172551 - (long long)ci));
+ return a;
+}
+
+int
+main ()
+{
+ if (__SIZEOF_INT__ * __CHAR_BIT__ == 32
+ && __SIZEOF_LONG_LONG__ * __CHAR_BIT__ == 64)
+ foo ();
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr81281.c b/gcc/testsuite/gcc.c-torture/execute/pr81281.c
new file mode 100644
index 0000000..5d8908f
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr81281.c
@@ -0,0 +1,33 @@
+/* PR sanitizer/81281 */
+
+void
+foo (unsigned p, unsigned a, unsigned b)
+{
+ unsigned q = p + 7;
+ if (a - (1U + __INT_MAX__) >= 2)
+ __builtin_unreachable ();
+ int d = p + b;
+ int c = p + a;
+ if (c - d != __INT_MAX__)
+ __builtin_abort ();
+}
+
+void
+bar (unsigned p, unsigned a)
+{
+ unsigned q = p + 7;
+ if (a - (1U + __INT_MAX__) >= 2)
+ __builtin_unreachable ();
+ int c = p;
+ int d = p + a;
+ if (c - d != -__INT_MAX__ - 1)
+ __builtin_abort ();
+}
+
+int
+main ()
+{
+ foo (-1U, 1U + __INT_MAX__, 1U);
+ bar (-1U, 1U + __INT_MAX__);
+ return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/pr81281-1.c b/gcc/testsuite/gcc.dg/pr81281-1.c
new file mode 100644
index 0000000..5fec25d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr81281-1.c
@@ -0,0 +1,150 @@
+/* PR sanitizer/81281 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump-not "p_\[0-9]*\\(D\\)" "optimized" } } */
+
+long long
+f1 (int p, int a, int b)
+{
+ int c = p + 1;
+ int d = a + 2;
+ int e = b + 3;
+ long long f = p + a;
+ long long g = p + b;
+ return f - g;
+}
+
+long long
+f2 (int p, int a, int b)
+{
+ int c = a + 1;
+ int d = p + 2;
+ int e = b + 3;
+ long long f = p + a;
+ long long g = p + b;
+ return f - g;
+}
+
+long long
+f3 (int p, int a, int b)
+{
+ int c = b + 1;
+ int d = p + 2;
+ int e = a + 3;
+ long long f = p + a;
+ long long g = p + b;
+ return f - g;
+}
+
+signed char
+f4 (int p, int a, int b)
+{
+ int c = p + 1;
+ int d = a + 2;
+ int e = b + 3;
+ signed char f = p + a;
+ signed char g = p + b;
+ return f - g;
+}
+
+signed char
+f5 (int p, int a, int b)
+{
+ int c = a + 1;
+ int d = p + 2;
+ int e = b + 3;
+ signed char f = p + a;
+ signed char g = p + b;
+ return f - g;
+}
+
+signed char
+f6 (int p, int a, int b)
+{
+ int c = b + 1;
+ int d = p + 2;
+ int e = a + 3;
+ signed char f = p + a;
+ signed char g = p + b;
+ return f - g;
+}
+
+long long
+f7 (int p, int a)
+{
+ int c = p + 1;
+ int d = a + 2;
+ long long f = p + a;
+ long long g = p;
+ return f - g;
+}
+
+long long
+f8 (int p, int a)
+{
+ int c = a + 1;
+ int d = p + 2;
+ long long f = p + a;
+ long long g = p;
+ return f - g;
+}
+
+signed char
+f9 (int p, int a)
+{
+ int c = p + 1;
+ int d = a + 2;
+ signed char f = p + a;
+ signed char g = p;
+ return f - g;
+}
+
+signed char
+f10 (int p, int a)
+{
+ int c = a + 1;
+ int d = p + 2;
+ signed char f = p + a;
+ signed char g = p;
+ return f - g;
+}
+
+long long
+f11 (int p, int a)
+{
+ int c = p + 1;
+ int d = a + 2;
+ long long f = p;
+ long long g = p + a;
+ return f - g;
+}
+
+long long
+f12 (int p, int a)
+{
+ int c = a + 1;
+ int d = p + 2;
+ long long f = p;
+ long long g = p + a;
+ return f - g;
+}
+
+signed char
+f13 (int p, int a)
+{
+ int c = p + 1;
+ int d = a + 2;
+ signed char f = p;
+ signed char g = p + a;
+ return f - g;
+}
+
+signed char
+f14 (int p, int a)
+{
+ int c = a + 1;
+ int d = p + 2;
+ signed char f = p;
+ signed char g = p + a;
+ return f - g;
+}
diff --git a/gcc/testsuite/gcc.dg/pr81281-2.c b/gcc/testsuite/gcc.dg/pr81281-2.c
new file mode 100644
index 0000000..ba2c648
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr81281-2.c
@@ -0,0 +1,80 @@
+/* PR sanitizer/81281 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump-not "p_\[0-9]*\\(D\\)" "optimized" } } */
+
+typedef __SIZE_TYPE__ size_t;
+typedef __INTPTR_TYPE__ T;
+
+T
+f1 (char *p, size_t a, size_t b)
+{
+ char *c = p + 1;
+ size_t d = a + 2;
+ size_t e = b + 3;
+ T f = (T) (p + a);
+ T g = (T) (p + b);
+ return f - g;
+}
+
+T
+f2 (char *p, size_t a, size_t b)
+{
+ size_t c = a + 1;
+ char *d = p + 2;
+ size_t e = b + 3;
+ T f = (T) (p + a);
+ T g = (T) (p + b);
+ return f - g;
+}
+
+T
+f3 (char *p, size_t a, size_t b)
+{
+ size_t c = b + 1;
+ char *d = p + 2;
+ size_t e = a + 3;
+ T f = (T) (p + a);
+ T g = (T) (p + b);
+ return f - g;
+}
+
+T
+f4 (char *p, size_t a)
+{
+ char *c = p + 1;
+ size_t d = a + 2;
+ T f = (T) (p + a);
+ T g = (T) p;
+ return f - g;
+}
+
+T
+f5 (char *p, size_t a)
+{
+ size_t c = a + 1;
+ char *d = p + 2;
+ T f = (T) (p + a);
+ T g = (T) p;
+ return f - g;
+}
+
+T
+f6 (char *p, size_t a)
+{
+ char *c = p + 1;
+ size_t d = a + 2;
+ T f = (T) p;
+ T g = (T) (p + a);
+ return f - g;
+}
+
+T
+f7 (char *p, size_t a)
+{
+ size_t c = a + 1;
+ char *d = p + 2;
+ T f = (T) p;
+ T g = (T) (p + a);
+ return f - g;
+}