From 5961d779d0f20b61363091ac7849d457cc80275d Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Tue, 4 Feb 2014 09:34:58 +0000 Subject: [PATCH] re PR tree-optimization/60012 (Vectorizer generates unnecessary loop versioning for alias) 2014-02-04 Richard Biener PR tree-optimization/60012 * tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Apply TBAA disambiguation to all DDRs. * gcc.dg/vect/pr60012.c: New testcase. From-SVN: r207455 --- gcc/ChangeLog | 6 ++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/vect/pr60012.c | 21 +++++++++++++++++++++ gcc/tree-vect-data-refs.c | 12 ++++++++++++ 4 files changed, 44 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/vect/pr60012.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index cd8acae396d..93a502f399f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2014-02-04 Richard Biener + + PR tree-optimization/60012 + * tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Apply + TBAA disambiguation to all DDRs. + 2014-02-04 Rainer Orth PR target/59788 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 3c7682fad50..f630cd974d1 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2014-02-04 Richard Biener + + PR tree-optimization/60012 + * gcc.dg/vect/pr60012.c: New testcase. + 2014-02-04 Rainer Orth PR target/59788 diff --git a/gcc/testsuite/gcc.dg/vect/pr60012.c b/gcc/testsuite/gcc.dg/vect/pr60012.c new file mode 100644 index 00000000000..2f737998434 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/pr60012.c @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-additional-options "--param vect-max-version-for-alias-checks=0" } */ + +typedef struct +{ + short real; + short imag; +} complex16_t; + +void +libvector_AccSquareNorm_ref (unsigned long long *acc, + const complex16_t *x, unsigned len) +{ + unsigned i; + for (i = 0; i < len; i++) + acc[i] += ((unsigned long long)((int)x[i].real * x[i].real)) + + ((unsigned long long)((int)x[i].imag * x[i].imag)); +} + +/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */ +/* { dg-final { cleanup-tree-dump "vect" } } */ diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c index c3e8f372b83..d018add0a96 100644 --- a/gcc/tree-vect-data-refs.c +++ b/gcc/tree-vect-data-refs.c @@ -235,6 +235,18 @@ vect_analyze_data_ref_dependence (struct data_dependence_relation *ddr, || (DR_IS_READ (dra) && DR_IS_READ (drb))) return false; + /* Even if we have an anti-dependence then, as the vectorized loop covers at + least two scalar iterations, there is always also a true dependence. + As the vectorizer does not re-order loads and stores we can ignore + the anti-dependence if TBAA can disambiguate both DRs similar to the + case with known negative distance anti-dependences (positive + distance anti-dependences would violate TBAA constraints). */ + if (((DR_IS_READ (dra) && DR_IS_WRITE (drb)) + || (DR_IS_WRITE (dra) && DR_IS_READ (drb))) + && !alias_sets_conflict_p (get_alias_set (DR_REF (dra)), + get_alias_set (DR_REF (drb)))) + return false; + /* Unknown data dependence. */ if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) { -- 2.30.2