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| author | Richard Biener <rguenther@suse.de> | 2017-06-13 07:07:08 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2017-06-13 07:07:08 +0000 |
| commit | 4f2c198d7675168416b8c994467d2941bfa5a309 (patch) | |
| tree | b55bb2ec58b8a6522fbeaa63b5db22e702c496a2 | |
| parent | cd34e54306bfb2ef53fbb2405de435e375337ef9 (diff) | |
| download | gcc-4f2c198d7675168416b8c994467d2941bfa5a309.tar.gz | |
re PR sanitizer/81065 (UBSAN: false positive as a result of distribution involving different types)
2017-06-13 Richard Biener <rguenther@suse.de>
PR middle-end/81065
* fold-const.c (extract_muldiv_1): Remove bogus distribution
case of C * (x * C2 + C3).
(fold_addr_of_array_ref_difference): Properly fold index difference.
* c-c++-common/ubsan/pr81065.c: New testcase.
From-SVN: r249144
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/fold-const.c | 7 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/c-c++-common/ubsan/pr81065.c | 13 |
4 files changed, 26 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9be291e3d2a..f0b9f6b8f34 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2017-06-13 Richard Biener <rguenther@suse.de> + + PR middle-end/81065 + * fold-const.c (extract_muldiv_1): Remove bogus distribution + case of C * (x * C2 + C3). + (fold_addr_of_array_ref_difference): Properly fold index difference. + 2017-06-12 David S. Miller <davem@davemloft.net> PR target/80968 diff --git a/gcc/fold-const.c b/gcc/fold-const.c index f3975c7391f..a6dd274f3d2 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -6241,11 +6241,6 @@ extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type, if (TYPE_UNSIGNED (ctype) && ctype != type) break; - /* If we were able to eliminate our operation from the first side, - apply our operation to the second side and reform the PLUS. */ - if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR)) - return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1); - /* The last case is if we are a multiply. In that case, we can apply the distributive law to commute the multiply and addition if the multiplication of the constants doesn't overflow @@ -8908,7 +8903,7 @@ fold_addr_of_array_ref_difference (location_t loc, tree type, tree op0 = fold_convert_loc (loc, type, TREE_OPERAND (aref0, 1)); tree op1 = fold_convert_loc (loc, type, TREE_OPERAND (aref1, 1)); tree esz = fold_convert_loc (loc, type, array_ref_element_size (aref0)); - tree diff = build2 (MINUS_EXPR, type, op0, op1); + tree diff = fold_build2_loc (loc, MINUS_EXPR, type, op0, op1); return fold_build2_loc (loc, PLUS_EXPR, type, base_offset, fold_build2_loc (loc, MULT_EXPR, type, diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index fc941afae3f..5e9d5ffaef2 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-06-13 Richard Biener <rguenther@suse.de> + + PR middle-end/81065 + * c-c++-common/ubsan/pr81065.c: New testcase. + 2017-06-12 Ian Lance Taylor <iant@golang.org> * gcc.dg/tree-prof/split-1.c: Require split_stack, don't require diff --git a/gcc/testsuite/c-c++-common/ubsan/pr81065.c b/gcc/testsuite/c-c++-common/ubsan/pr81065.c new file mode 100644 index 00000000000..1b342273f95 --- /dev/null +++ b/gcc/testsuite/c-c++-common/ubsan/pr81065.c @@ -0,0 +1,13 @@ +/* { dg-do run } */ +/* { dg-options "-fsanitize=undefined -fsanitize-undefined-trap-on-error" } */ + +unsigned char x = 154; +int foo() { + // 8575 * (254408 - 9057) = 8575 * 245351 = 2103884825 = 0x7d66bc19 + return 8575 * (1652 * x - 9057); +} + +int main() { + foo(); + return 0; +} |