From: Richard Sandiford Date: Thu, 21 Nov 2019 17:45:36 +0000 (+0000) Subject: Reject versioning for alignment with different masks (PR 92526) X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=557532d1728af193d47867dabbe26bd556fb8586;p=gcc.git Reject versioning for alignment with different masks (PR 92526) Allowing mixed vector sizes broke the assumption in the following assert, since it's now possible for different accesses to require different levels of alignment: /* FORNOW: use the same mask to test all potentially unaligned references in the loop. The vectorizer currently supports a single vector size, see the reference to GET_MODE_NUNITS (TYPE_MODE (vectype)) where the vectorization factor is computed. */ gcc_assert (!LOOP_VINFO_PTR_MASK (loop_vinfo) || LOOP_VINFO_PTR_MASK (loop_vinfo) == mask); I guess we could try to over-align smaller accesses so that all of them are consistent, or try to support multiple alignment masks, but for now the easiest fix seems to be to turn the assert into a bail-out check. 2019-11-21 Richard Sandiford gcc/ PR tree-optimization/92526 * tree-vect-data-refs.c (vect_enhance_data_refs_alignment): Reject versioning for alignment if the accesses do not have a consistent mask, rather than asserting that the masks are consistent. gcc/testsuite/ PR tree-optimization/92526 * gcc.target/aarch64/pr92526.c: New test. From-SVN: r278592 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 859dd7136c7..a4b45808410 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2019-11-21 Richard Sandiford + + PR tree-optimization/92526 + * tree-vect-data-refs.c (vect_enhance_data_refs_alignment): Reject + versioning for alignment if the accesses do not have a consistent + mask, rather than asserting that the masks are consistent. + 2019-11-21 Richard Sandiford PR tree-optimization/92595 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 0250eebb312..1f30ffd9ed3 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2019-11-21 Richard Sandiford + + PR tree-optimization/92526 + * gcc.target/aarch64/pr92526.c: New test. + 2019-11-21 Richard Sandiford PR testsuite/92543 diff --git a/gcc/testsuite/gcc.target/aarch64/pr92526.c b/gcc/testsuite/gcc.target/aarch64/pr92526.c new file mode 100644 index 00000000000..61b347c6a7c --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/pr92526.c @@ -0,0 +1,9 @@ +/* { dg-options "-O3 -mstrict-align" } */ + +void +f (unsigned int *restrict x, unsigned int *restrict y, + unsigned char *restrict z, unsigned int n) +{ + for (unsigned int i = 0; i < n % 4; ++i) + x[i] = x[i] + y[i] + z[i]; +} diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c index 72a70945f08..b876d07f44b 100644 --- a/gcc/tree-vect-data-refs.c +++ b/gcc/tree-vect-data-refs.c @@ -2266,13 +2266,15 @@ vect_enhance_data_refs_alignment (loop_vec_info loop_vinfo) mask must be 15 = 0xf. */ mask = size - 1; - /* FORNOW: use the same mask to test all potentially unaligned - references in the loop. The vectorizer currently supports - a single vector size, see the reference to - GET_MODE_NUNITS (TYPE_MODE (vectype)) where the - vectorization factor is computed. */ - gcc_assert (!LOOP_VINFO_PTR_MASK (loop_vinfo) - || LOOP_VINFO_PTR_MASK (loop_vinfo) == mask); + /* FORNOW: use the same mask to test all potentially unaligned + references in the loop. */ + if (LOOP_VINFO_PTR_MASK (loop_vinfo) + && LOOP_VINFO_PTR_MASK (loop_vinfo) != mask) + { + do_versioning = false; + break; + } + LOOP_VINFO_PTR_MASK (loop_vinfo) = mask; LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo).safe_push (stmt_info); }