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| author | Martin Sebor <msebor@redhat.com> | 2018-08-28 00:25:50 +0000 |
|---|---|---|
| committer | Martin Sebor <msebor@gcc.gnu.org> | 2018-08-27 18:25:50 -0600 |
| commit | d1af2f668fb0fca982183265e1a56e23d4f25fa8 (patch) | |
| tree | dda636af1797625923bd2ed2310ed569091e2033 /gcc | |
| parent | 37223543da6e58eb12b19611b5f20dd5a1fec39e (diff) | |
| download | gcc-d1af2f668fb0fca982183265e1a56e23d4f25fa8.zip gcc-d1af2f668fb0fca982183265e1a56e23d4f25fa8.tar.gz gcc-d1af2f668fb0fca982183265e1a56e23d4f25fa8.tar.bz2 | |
PR tree-optimization/86914 - wrong code with strlen() of poor-man's flexible array member plus offset
gcc/ChangeLog:
PR tree-optimization/86914
* tree-ssa-strlen.c (maybe_set_strlen_range): Avoid MEM_REF.
gcc/testsuite/ChangeLog:
PR tree-optimization/86914
* gcc.dg/strlenopt-57.c: New test.
From-SVN: r263905
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/strlenopt-57.c | 49 | ||||
| -rw-r--r-- | gcc/tree-ssa-strlen.c | 4 |
4 files changed, 62 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2449672..4cbea7a 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2018-08-27 Martin Sebor <msebor@redhat.com> + PR tree-optimization/86914 + * tree-ssa-strlen.c (maybe_set_strlen_range): Avoid MEM_REF. + +2018-08-27 Martin Sebor <msebor@redhat.com> + PR tree-optimization/87112 * builtins.c (expand_builtin_strnlen): Convert c_strlen result to the type of the bound argument. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 92f1540..4b5c153 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,10 @@ 2018-08-27 Martin Sebor <msebor@redhat.com> + PR tree-optimization/86914 + * gcc.dg/strlenopt-57.c: New test. + +2018-08-27 Martin Sebor <msebor@redhat.com> + PR tree-optimization/87112 * gcc.dg/pr87112.c: New test. diff --git a/gcc/testsuite/gcc.dg/strlenopt-57.c b/gcc/testsuite/gcc.dg/strlenopt-57.c new file mode 100644 index 0000000..49dc8cd --- /dev/null +++ b/gcc/testsuite/gcc.dg/strlenopt-57.c @@ -0,0 +1,49 @@ +/* PR tree-optimization/86914 - wrong code with strlen() of poor-man's + flexible array member plus offset + { dg-do compile } + { dg-options "-O2 -Wall -fdump-tree-optimized" } */ + +#include "strlenopt.h" + +struct A0 { char i, a[0]; }; +struct A1 { char i, a[1]; }; +struct A9 { char i, a[9]; }; +struct Ax { char i, a[]; }; + +extern int a[]; + +extern struct A0 a0; +extern struct A1 a1; +extern struct A9 a9; +extern struct Ax ax; + +void test_var_flexarray_cst_off (void) +{ + /* Use arbitrary constants greater than 16 in case GCC ever starts + unrolling strlen() calls with small array arguments. */ + a[0] = 17 < strlen (a0.a + 1); + a[1] = 19 < strlen (a1.a + 1); + a[2] = 23 < strlen (a9.a + 9); + a[3] = 29 < strlen (ax.a + 3); +} + +void test_ptr_flexarray_cst_off (struct A0 *p0, struct A1 *p1, + struct A9 *p9, struct Ax *px) +{ + a[0] = 17 < strlen (p0->a + 1); + a[1] = 19 < strlen (p1->a + 1); + a[2] = 23 < strlen (p9->a + 9); + a[3] = 29 < strlen (px->a + 3); +} + +void test_ptr_flexarray_var_off (struct A0 *p0, struct A1 *p1, + struct A9 *p9, struct Ax *px, + int i) +{ + a[0] = 17 < strlen (p0->a + i); + a[1] = 19 < strlen (p1->a + i); + a[2] = 23 < strlen (p9->a + i); + a[3] = 29 < strlen (px->a + i); +} + +/* { dg-final { scan-tree-dump-times "strlen" 12 "optimized" } } */ diff --git a/gcc/tree-ssa-strlen.c b/gcc/tree-ssa-strlen.c index b90d4a1..84e6152 100644 --- a/gcc/tree-ssa-strlen.c +++ b/gcc/tree-ssa-strlen.c @@ -1160,7 +1160,9 @@ maybe_set_strlen_range (tree lhs, tree src, tree bound) suggests if it's treated as a poor-man's flexible array member. */ src = TREE_OPERAND (src, 0); bool src_is_array = TREE_CODE (TREE_TYPE (src)) == ARRAY_TYPE; - if (src_is_array && !array_at_struct_end_p (src)) + if (src_is_array + && TREE_CODE (src) != MEM_REF + && !array_at_struct_end_p (src)) { tree type = TREE_TYPE (src); if (tree size = TYPE_SIZE_UNIT (type)) |