From da76b2532f85d0e928862303b1fc92fa2a5a6138 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Tue, 24 Oct 2017 13:51:45 +0000 Subject: [PATCH] re PR tree-optimization/82697 (Wrong optimization with aliasing and "if") 2017-10-24 Richard Biener PR tree-optimization/82697 * tree-ssa-phiopt.c (cond_store_replacement): Use alias-set zero for conditional load and unconditional store. * gcc.dg/torture/pr82697.c: New testcase. From-SVN: r254047 --- gcc/ChangeLog | 6 ++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/torture/pr82697.c | 23 +++++++++++++++++++++++ gcc/tree-ssa-phiopt.c | 17 ++++++++++++++++- 4 files changed, 50 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr82697.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index ce02caa6d24..63bb64fafeb 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2017-10-24 Richard Biener + + PR tree-optimization/82697 + * tree-ssa-phiopt.c (cond_store_replacement): Use alias-set + zero for conditional load and unconditional store. + 2017-10-24 H.J. Lu * doc/install.texi: Document bootstrap-cet. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index a8a4a119886..18794e49c64 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-10-24 Richard Biener + + PR tree-optimization/82697 + * gcc.dg/torture/pr82697.c: New testcase. + 2017-10-24 Mukesh Kapoor Paolo Carlini diff --git a/gcc/testsuite/gcc.dg/torture/pr82697.c b/gcc/testsuite/gcc.dg/torture/pr82697.c new file mode 100644 index 00000000000..57da8a264b9 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr82697.c @@ -0,0 +1,23 @@ +/* { dg-do run } */ + +__attribute__((noinline,noclone)) +void test(int *pi, long *pl, int f) +{ + *pl = 0; + + *pi = 1; + + if (f) + *pl = 2; +} + +int main() +{ + void *p = __builtin_malloc(sizeof (long)); + + test(p, p, 0); + + if (*(int *)p != 1) + __builtin_abort (); + return 0; +} diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c index d0570c3fa9c..6e0e18689da 100644 --- a/gcc/tree-ssa-phiopt.c +++ b/gcc/tree-ssa-phiopt.c @@ -1912,9 +1912,24 @@ cond_store_replacement (basic_block middle_bb, basic_block join_bb, gsi_remove (&gsi, true); release_defs (assign); + /* Make both store and load use alias-set zero as we have to + deal with the case of the store being a conditional change + of the dynamic type. */ + lhs = unshare_expr (lhs); + tree *basep = &lhs; + while (handled_component_p (*basep)) + basep = &TREE_OPERAND (*basep, 0); + if (TREE_CODE (*basep) == MEM_REF + || TREE_CODE (*basep) == TARGET_MEM_REF) + TREE_OPERAND (*basep, 1) + = fold_convert (ptr_type_node, TREE_OPERAND (*basep, 1)); + else + *basep = build2 (MEM_REF, TREE_TYPE (*basep), + build_fold_addr_expr (*basep), + build_zero_cst (ptr_type_node)); + /* 2) Insert a load from the memory of the store to the temporary on the edge which did not contain the store. */ - lhs = unshare_expr (lhs); name = make_temp_ssa_name (TREE_TYPE (lhs), NULL, "cstore"); new_stmt = gimple_build_assign (name, lhs); gimple_set_location (new_stmt, locus); -- 2.30.2