From 8bad25eb56bd16f3482f856a75b1c1ae5cfe1c4f Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Fri, 22 Jan 2021 11:29:17 +0100 Subject: [PATCH] middle-end/98773 - always sign extend CHREC_RIGHT The previous change exposed a miscompile when trying to interpret CHREC_RIGHT correctly which in fact it already was to the extent it is used. The following reverts this part of the change, only retaining the singling out of HOST_WIDE_INT_MIN. 2021-01-22 Richard Biener PR middle-end/98773 * tree-data-ref.c (initalize_matrix_A): Revert previous change, retaining failing on HOST_WIDE_INT_MIN CHREC_RIGHT. * gcc.dg/torture/pr98773.c: New testcase. --- gcc/testsuite/gcc.dg/torture/pr98773.c | 19 +++++++++++++++++++ gcc/tree-data-ref.c | 17 +++-------------- 2 files changed, 22 insertions(+), 14 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr98773.c diff --git a/gcc/testsuite/gcc.dg/torture/pr98773.c b/gcc/testsuite/gcc.dg/torture/pr98773.c new file mode 100644 index 00000000000..026e8efba5c --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr98773.c @@ -0,0 +1,19 @@ +/* { dg-do run } */ + +char a[128]; + +void __attribute__((noipa)) +foo () +{ + for (unsigned i = 27; i >= 5; --i) + a[i] = a[i-5]; +} + +int main() +{ + __builtin_memcpy (a, "Hello World", sizeof ("Hello World")); + foo (); + if (__builtin_memcmp (a + 5, "Hello World", sizeof ("Hello World")) != 0) + __builtin_abort (); + return 0; +} diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c index d19c5eb51e4..124a7bea6a9 100644 --- a/gcc/tree-data-ref.c +++ b/gcc/tree-data-ref.c @@ -3924,21 +3924,10 @@ initialize_matrix_A (lambda_matrix A, tree chrec, unsigned index, int mult) switch (TREE_CODE (chrec)) { case POLYNOMIAL_CHREC: - /* CHREC_RIGHT and its negated value should fit in a lambda_int. - Pointer typed chrecs right are to be interpreted signed. */ HOST_WIDE_INT chrec_right; - if (POINTER_TYPE_P (chrec_type (chrec))) - { - if (!cst_and_fits_in_hwi (CHREC_RIGHT (chrec))) - return chrec_dont_know; - chrec_right = int_cst_value (CHREC_RIGHT (chrec)); - } - else - { - if (!tree_fits_shwi_p (CHREC_RIGHT (chrec))) - return chrec_dont_know; - chrec_right = tree_to_shwi (CHREC_RIGHT (chrec)); - } + if (!cst_and_fits_in_hwi (CHREC_RIGHT (chrec))) + return chrec_dont_know; + chrec_right = int_cst_value (CHREC_RIGHT (chrec)); /* We want to be able to negate without overflow. */ if (chrec_right == HOST_WIDE_INT_MIN) return chrec_dont_know; -- 2.30.2