| Message ID | CA+=Sn1nEo5FF4zAYD_ojNuDJ9v2Qh=RAw-XQ0B9W=F8S8EpKxg@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Jun 29, 2017 at 10:12 PM, Andrew Pinski <pinskia@gmail.com> wrote: > Hi, > As described in the bug, tree-if-conv is calling update_stmt on an > old stmt which might have been removed from the IR already > (transforming of an assignment to a call in this case). This fixes > the problem by calling update_stmt on the new statement that fold_stmt > might have created. > > OK? Bootstrapped and tested on aarch64-linux-gnu with no regressions. update_stmt is not necessary when fold_stmt doesn't return true as gsi_insert_before already updates the stmt. Thus ok with moving update_stmt under the conditional. Thanks, Richard. > Thanks, > Andrew Pinski > ChangeLog: > * tree-if-conv.c (predicate_scalar_phi): Update new_stmt if fold_stmt > returned true. > > testsuite/ChangeLog: > * gcc.dg/torture/pr81245.c: New testcase.
Index: testsuite/gcc.dg/torture/pr81245.c =================================================================== --- testsuite/gcc.dg/torture/pr81245.c (nonexistent) +++ testsuite/gcc.dg/torture/pr81245.c (working copy) @@ -0,0 +1,16 @@ +/* { dg-options "-ffast-math" } */ +/* { dg-do compile } */ +/* This test used to crash the vectorizer as the ifconvert pass + used to convert the if to copysign but called update_stmt on + the old statement after calling fold_stmt. */ +double sg[18]; +void f(void) +{ + for (int i = 0 ;i < 18;i++) + { + if (sg[i] < 0.0) + sg[i] = -1.0; + else + sg[i] = 1.0; + } +} Index: tree-if-conv.c =================================================================== --- tree-if-conv.c (revision 249769) +++ tree-if-conv.c (working copy) @@ -1853,7 +1853,8 @@ new_stmt = gimple_build_assign (res, rhs); gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT); gimple_stmt_iterator new_gsi = gsi_for_stmt (new_stmt); - fold_stmt (&new_gsi, ifcvt_follow_ssa_use_edges); + if (fold_stmt (&new_gsi, ifcvt_follow_ssa_use_edges)) + new_stmt = gsi_stmt (new_gsi); update_stmt (new_stmt); if (dump_file && (dump_flags & TDF_DETAILS))