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| author | Richard Biener <rguenther@suse.de> | 2021-01-20 08:48:34 +0100 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2021-01-20 09:38:22 +0100 |
| commit | 34599780d0de72faf5719ea08d11a061722b9d19 (patch) | |
| tree | 7d7bed343ddc84aed63c12baad330f9d792b4171 /gcc | |
| parent | 7ab1abf3b82a3bcfff9b7bc596166fef6a0d83ab (diff) | |
| download | gcc-34599780d0de72faf5719ea08d11a061722b9d19.zip gcc-34599780d0de72faf5719ea08d11a061722b9d19.tar.gz gcc-34599780d0de72faf5719ea08d11a061722b9d19.tar.bz2 | |
tree-optimization/98758 - fix integer arithmetic in data-ref analysis
This fixes some int arithmetic issues and a bogus truncation.
2021-01-20 Richard Biener <rguenther@suse.de>
PR tree-optimization/98758
* tree-data-ref.c (int_divides_p): Use lambda_int arguments.
(lambda_matrix_right_hermite): Avoid undefinedness with
signed integer abs and multiplication.
(analyze_subscript_affine_affine): Use lambda_int.
* gcc.dg/torture/pr98758.c: New testcase.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr98758.c | 13 | ||||
| -rw-r--r-- | gcc/tree-data-ref.c | 12 |
2 files changed, 19 insertions, 6 deletions
diff --git a/gcc/testsuite/gcc.dg/torture/pr98758.c b/gcc/testsuite/gcc.dg/torture/pr98758.c new file mode 100644 index 0000000..7b9fdb2 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr98758.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ + +long *a, *b; +long c; +void d(void) +{ + b = a; + while (c) { + *a = (__INTPTR_TYPE__)(a += (long)1 << (sizeof(long) * 8 - 10)); + c = b[0]; + b = a; + } +} diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c index 65fe6d5..9d07b41 100644 --- a/gcc/tree-data-ref.c +++ b/gcc/tree-data-ref.c @@ -143,7 +143,7 @@ tree_fold_divides_p (const_tree a, const_tree b) /* Returns true iff A divides B. */ static inline bool -int_divides_p (int a, int b) +int_divides_p (lambda_int a, lambda_int b) { return ((b % a) == 0); } @@ -4280,10 +4280,10 @@ lambda_matrix_right_hermite (lambda_matrix A, int m, int n, a = S[i-1][j]; b = S[i][j]; - sigma = (a * b < 0) ? -1: 1; - a = abs_hwi (a); - b = abs_hwi (b); - factor = sigma * (a / b); + sigma = ((a < 0) ^ (b < 0)) ? -1: 1; + unsigned HOST_WIDE_INT abs_a = absu_hwi (a); + unsigned HOST_WIDE_INT abs_b = absu_hwi (b); + factor = sigma * (lambda_int)(abs_a / abs_b); lambda_matrix_row_add (S, n, i, i-1, -factor); std::swap (S[i], S[i-1]); @@ -4309,7 +4309,7 @@ analyze_subscript_affine_affine (tree chrec_a, tree *last_conflicts) { unsigned nb_vars_a, nb_vars_b, dim; - HOST_WIDE_INT gamma, gcd_alpha_beta; + lambda_int gamma, gcd_alpha_beta; lambda_matrix A, U, S; struct obstack scratch_obstack; |