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authorRichard Biener <rguenther@suse.de>2021-01-20 08:48:34 +0100
committerRichard Biener <rguenther@suse.de>2021-01-20 09:38:22 +0100
commit34599780d0de72faf5719ea08d11a061722b9d19 (patch)
tree7d7bed343ddc84aed63c12baad330f9d792b4171 /gcc/tree-data-ref.c
parent7ab1abf3b82a3bcfff9b7bc596166fef6a0d83ab (diff)
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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/tree-data-ref.c')
-rw-r--r--gcc/tree-data-ref.c12
1 files changed, 6 insertions, 6 deletions
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;