From 33a002b0ab6f8827631cc50eddaa2b2d4aa1bd35 Mon Sep 17 00:00:00 2001 From: Kyrylo Tkachov Date: Thu, 24 Nov 2016 15:22:34 +0000 Subject: [PATCH] [TER] PR target/48863 : Don't replace expressions across local register variable definitions PR target/48863 PR inline-asm/70184 * tree-ssa-ter.c (temp_expr_table): Add reg_vars_cnt field. (new_temp_expr_table): Initialise reg_vars_cnt. (free_temp_expr_table): Release reg_vars_cnt. (process_replaceable): Add reg_vars_cnt argument, set reg_vars_cnt field of TAB. (find_replaceable_in_bb): Use the above to record register variable write occurrences and cancel replacement across them. * gcc.target/arm/pr48863.c: New test. From-SVN: r242840 --- gcc/ChangeLog | 12 ++++++++++++ gcc/testsuite/ChangeLog | 6 ++++++ gcc/testsuite/gcc.target/arm/pr48863.c | 35 ++++++++++++++++++++++++++++++++++ gcc/tree-ssa-ter.c | 25 ++++++++++++++++++++---- 4 files changed, 74 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/gcc.target/arm/pr48863.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 4e83a48..a6641c1 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,15 @@ +2016-11-24 Kyrylo Tkachov + + PR target/48863 + PR inline-asm/70184 + * tree-ssa-ter.c (temp_expr_table): Add reg_vars_cnt field. + (new_temp_expr_table): Initialise reg_vars_cnt. + (free_temp_expr_table): Release reg_vars_cnt. + (process_replaceable): Add reg_vars_cnt argument, set reg_vars_cnt + field of TAB. + (find_replaceable_in_bb): Use the above to record register variable + write occurrences and cancel replacement across them. + 2016-11-24 Eric Botcazou PR rtl-optimization/78437 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index fa0c0e2..96c5957 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2016-11-24 Kyrylo Tkachov + + PR target/48863 + PR inline-asm/70184 + * gcc.target/arm/pr48863.c: New test. + 2016-11-24 Martin Liska * gcc.dg/builtin-unreachable-6.c: Update test to not to scan diff --git a/gcc/testsuite/gcc.target/arm/pr48863.c b/gcc/testsuite/gcc.target/arm/pr48863.c new file mode 100644 index 0000000..33bc7a4 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pr48863.c @@ -0,0 +1,35 @@ +/* PR target/48863. */ +/* { dg-do run } */ +/* { dg-options "-O2" } */ + +/* Check that Temporary Expression Replacement does not move a + libcall-producing expression across a statement initialising a local + register variable. */ + +static inline int +dosvc (int fd, unsigned long high, unsigned low) +{ + register int r0 asm("r0") = fd; + register int r2 asm("r2") = high; + register int r3 asm("r3") = low; + + asm volatile("" : "=r"(r0) : "0"(r0), "r"(r2), "r"(r3)); + return r0; +} + +struct s +{ + int fd; + long long length; +} s = { 2, 0 }, *p = &s; + +int +main (void) +{ + unsigned low = p->length & 0xffffffff; + unsigned high = p->length / 23; + + if (dosvc (p->fd, high, low) != 2) + __builtin_abort (); + return 0; +} diff --git a/gcc/tree-ssa-ter.c b/gcc/tree-ssa-ter.c index c7d8b7e..af5d91c 100644 --- a/gcc/tree-ssa-ter.c +++ b/gcc/tree-ssa-ter.c @@ -169,6 +169,8 @@ struct temp_expr_table bitmap new_replaceable_dependencies; /* Holding place for pending dep's. */ int *num_in_part; /* # of ssa_names in a partition. */ int *call_cnt; /* Call count at definition. */ + int *reg_vars_cnt; /* Number of register variable + definitions encountered. */ }; /* Used to indicate a dependency on VDEFs. */ @@ -211,6 +213,7 @@ new_temp_expr_table (var_map map) t->num_in_part[p]++; } t->call_cnt = XCNEWVEC (int, num_ssa_names + 1); + t->reg_vars_cnt = XCNEWVEC (int, num_ssa_names + 1); return t; } @@ -243,6 +246,7 @@ free_temp_expr_table (temp_expr_table *t) free (t->partition_dependencies); free (t->num_in_part); free (t->call_cnt); + free (t->reg_vars_cnt); if (t->replaceable_expressions) ret = t->replaceable_expressions; @@ -435,7 +439,8 @@ ter_is_replaceable_p (gimple *stmt) /* Create an expression entry for a replaceable expression. */ static void -process_replaceable (temp_expr_table *tab, gimple *stmt, int call_cnt) +process_replaceable (temp_expr_table *tab, gimple *stmt, int call_cnt, + int reg_vars_cnt) { tree var, def, basevar; int version; @@ -477,6 +482,7 @@ process_replaceable (temp_expr_table *tab, gimple *stmt, int call_cnt) } tab->call_cnt[version] = call_cnt; + tab->reg_vars_cnt[version] = reg_vars_cnt; } @@ -573,6 +579,7 @@ find_replaceable_in_bb (temp_expr_table *tab, basic_block bb) ssa_op_iter iter; bool stmt_replaceable; int cur_call_cnt = 0; + int cur_reg_vars_cnt = 0; for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) { @@ -649,11 +656,14 @@ find_replaceable_in_bb (temp_expr_table *tab, basic_block bb) /* Mark expression as replaceable unless stmt is volatile, or the def variable has the same root variable as something in the substitution list, or the def and use span a call such that - we'll expand lifetimes across a call. */ + we'll expand lifetimes across a call. We also don't want to + replace across these expressions that may call libcalls that + clobber the register involved. See PR 70184. */ if (gimple_has_volatile_ops (stmt) || same_root_var || (tab->call_cnt[ver] != cur_call_cnt && SINGLE_SSA_USE_OPERAND (SSA_NAME_DEF_STMT (use), SSA_OP_USE) - == NULL_USE_OPERAND_P)) + == NULL_USE_OPERAND_P) + || tab->reg_vars_cnt[ver] != cur_reg_vars_cnt) finished_with_expr (tab, ver, true); else mark_replaceable (tab, use, stmt_replaceable); @@ -676,9 +686,16 @@ find_replaceable_in_bb (temp_expr_table *tab, basic_block bb) && DECL_BUILT_IN (fndecl))) cur_call_cnt++; + /* Increment counter if this statement sets a local + register variable. */ + if (gimple_assign_single_p (stmt) + && (TREE_CODE (gimple_assign_lhs (stmt)) == VAR_DECL + && DECL_HARD_REGISTER (gimple_assign_lhs (stmt)))) + cur_reg_vars_cnt++; + /* Now see if we are creating a new expression or not. */ if (stmt_replaceable) - process_replaceable (tab, stmt, cur_call_cnt); + process_replaceable (tab, stmt, cur_call_cnt, cur_reg_vars_cnt); /* Free any unused dependency lists. */ bitmap_clear (tab->new_replaceable_dependencies); -- 2.7.4