From: Tom de Vries Date: Wed, 19 Nov 2014 11:08:02 +0000 (+0000) Subject: Fix tail-merge pass for dead type-unsafe code X-Git-Tag: releases/gcc-4.8.4~113 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6e199e84961f272a4b8dd2bc06e24bc1c69d2e2a;p=thirdparty%2Fgcc.git Fix tail-merge pass for dead type-unsafe code 2014-11-19 Tom de Vries Backport from mainline PR tree-optimization/62167 * tree-ssa-tail-merge.c (stmt_local_def): Handle statements with vuse conservatively. (gimple_equal_p): Don't use vn_valueize to compare for lhs equality of assigns. * gcc.dg/pr51879-12.c: Add xfails. * gcc.dg/pr62167-run.c: New test. * gcc.dg/pr62167.c: New test. From-SVN: r217764 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 3bc25c3c2fae..6545ecee992b 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,12 @@ +2014-11-19 Tom de Vries + + Backport from mainline + PR tree-optimization/62167 + * tree-ssa-tail-merge.c (stmt_local_def): Handle statements with vuse + conservatively. + (gimple_equal_p): Don't use vn_valueize to compare for lhs equality of + assigns. + 2014-11-18 Teresa Johnson Backport from mainline and gcc-4_9 branch. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 1de0fd491868..978c74bb9058 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,11 @@ +2014-11-19 Tom de Vries + + Backport from mainline + PR tree-optimization/62167 + * gcc.dg/pr51879-12.c: Add xfails. + * gcc.dg/pr62167-run.c: New test. + * gcc.dg/pr62167.c: New test. + 2014-11-18 Teresa Johnson Backport from mainline and gcc-4_9 branch. diff --git a/gcc/testsuite/gcc.dg/pr51879-12.c b/gcc/testsuite/gcc.dg/pr51879-12.c index 1b25e296fbfb..7490e33f0558 100644 --- a/gcc/testsuite/gcc.dg/pr51879-12.c +++ b/gcc/testsuite/gcc.dg/pr51879-12.c @@ -24,6 +24,6 @@ foo (int y) baz (a); } -/* { dg-final { scan-tree-dump-times "bar \\(" 1 "pre"} } */ -/* { dg-final { scan-tree-dump-times "bar2 \\(" 1 "pre"} } */ +/* { dg-final { scan-tree-dump-times "bar \\(" 1 "pre" { xfail *-*-* } } } */ +/* { dg-final { scan-tree-dump-times "bar2 \\(" 1 "pre" { xfail *-*-* } } } */ /* { dg-final { cleanup-tree-dump "pre" } } */ diff --git a/gcc/testsuite/gcc.dg/pr62167-run.c b/gcc/testsuite/gcc.dg/pr62167-run.c new file mode 100644 index 000000000000..37214a3ecee2 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr62167-run.c @@ -0,0 +1,47 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -ftree-tail-merge" } */ + +struct node +{ + struct node *next; + struct node *prev; +}; + +struct node node; + +struct head +{ + struct node *first; +}; + +struct head heads[5]; + +int k = 2; + +struct head *head = &heads[2]; + +int +main () +{ + struct node *p; + + node.next = (void*)0; + + node.prev = (void *)head; + + head->first = &node; + + struct node *n = head->first; + + struct head *h = &heads[k]; + + heads[2].first = n->next; + + if ((void*)n->prev == (void *)h) + p = h->first; + else + /* Dead tbaa-unsafe load from ((struct node *)&heads[2])->next. */ + p = n->prev->next; + + return !(p == (void*)0); +} diff --git a/gcc/testsuite/gcc.dg/pr62167.c b/gcc/testsuite/gcc.dg/pr62167.c new file mode 100644 index 000000000000..f8c31a0792f2 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr62167.c @@ -0,0 +1,50 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -ftree-tail-merge -fdump-tree-pre" } */ + +struct node +{ + struct node *next; + struct node *prev; +}; + +struct node node; + +struct head +{ + struct node *first; +}; + +struct head heads[5]; + +int k = 2; + +struct head *head = &heads[2]; + +int +main () +{ + struct node *p; + + node.next = (void*)0; + + node.prev = (void *)head; + + head->first = &node; + + struct node *n = head->first; + + struct head *h = &heads[k]; + + heads[2].first = n->next; + + if ((void*)n->prev == (void *)h) + p = h->first; + else + /* Dead tbaa-unsafe load from ((struct node *)&heads[2])->next. */ + p = n->prev->next; + + return !(p == (void*)0); +} + +/* { dg-final { scan-tree-dump-not "Removing basic block" "pre"} } */ +/* { dg-final { cleanup-tree-dump "pre" } } */ diff --git a/gcc/tree-ssa-tail-merge.c b/gcc/tree-ssa-tail-merge.c index 61add6e04459..3f35657e398e 100644 --- a/gcc/tree-ssa-tail-merge.c +++ b/gcc/tree-ssa-tail-merge.c @@ -298,7 +298,8 @@ stmt_local_def (gimple stmt) def_operand_p def_p; if (gimple_has_side_effects (stmt) - || gimple_vdef (stmt) != NULL_TREE) + || gimple_vdef (stmt) != NULL_TREE + || gimple_vuse (stmt) != NULL_TREE) return false; def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_DEF); @@ -1145,7 +1146,8 @@ gimple_equal_p (same_succ same_succ, gimple s1, gimple s2) gimple_assign_rhs1 (s2))); else if (TREE_CODE (lhs1) == SSA_NAME && TREE_CODE (lhs2) == SSA_NAME) - return vn_valueize (lhs1) == vn_valueize (lhs2); + return operand_equal_p (gimple_assign_rhs1 (s1), + gimple_assign_rhs1 (s2), 0); return false; case GIMPLE_COND: