From 664540008bf3784a9b9995da0a1696d02c5ffea5 Mon Sep 17 00:00:00 2001 From: Kugan Vivekanandarajah Date: Wed, 21 Sep 2016 03:28:24 +0000 Subject: [PATCH] Incorrect arithmetic optimization involving bitfield arguments gcc/ChangeLog: 2016-09-21 Kugan Vivekanandarajah PR tree-optimization/72835 * tree-ssa-reassoc.c (make_new_ssa_for_def): New. (make_new_ssa_for_all_defs): Likewise. (zero_one_operation): Replace all SSA_NAMEs defined in the chain. gcc/testsuite/ChangeLog: 2016-09-21 Kugan Vivekanandarajah PR tree-optimization/72835 * gcc.dg/tree-ssa/pr72835.c: New test. From-SVN: r240299 --- gcc/ChangeLog | 7 +++ gcc/testsuite/ChangeLog | 5 ++ gcc/testsuite/gcc.dg/tree-ssa/pr72835.c | 37 ++++++++++++ gcc/tree-ssa-reassoc.c | 80 ++++++++++++++++++++++--- 4 files changed, 121 insertions(+), 8 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr72835.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8ccafc548a0..faa7fb2d8d1 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2016-09-21 Kugan Vivekanandarajah + + PR tree-optimization/72835 + * tree-ssa-reassoc.c (make_new_ssa_for_def): New. + (make_new_ssa_for_all_defs): Likewise. + (zero_one_operation): Replace all SSA_NAMEs defined in the chain. + 2016-09-20 Martin Sebor PR middle-end/49905 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 6d26e43fcef..e05a76e4c18 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-09-21 Kugan Vivekanandarajah + + PR tree-optimization/72835 + * gcc.dg/tree-ssa/pr72835.c: New test. + 2016-09-20 Martin Sebor PR middle-end/49905 diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr72835.c b/gcc/testsuite/gcc.dg/tree-ssa/pr72835.c new file mode 100644 index 00000000000..468e0f02fcb --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr72835.c @@ -0,0 +1,37 @@ +/* PR tree-optimization/72835. */ +/* { dg-do run } */ +/* { dg-options "-O2" } */ +/* { dg-require-effective-target int32plus } */ + +struct struct_1 { + unsigned int m1 : 6 ; + unsigned int m2 : 24 ; + unsigned int m3 : 6 ; +}; + +unsigned short var_32 = 0x2d10; + +struct struct_1 s1; + +void init () +{ + s1.m1 = 4; + s1.m2 = 0x7ca4b8; + s1.m3 = 24; +} + +void foo () +{ + unsigned int c + = ((unsigned int) s1.m2) * (-((unsigned int) s1.m3)) + + (var_32) * (-((unsigned int) (s1.m1))); + if (c != 4098873984) + __builtin_abort (); +} + +int main () +{ + init (); + foo (); + return 0; +} diff --git a/gcc/tree-ssa-reassoc.c b/gcc/tree-ssa-reassoc.c index 7fd7550ab33..8fc76e4fb6f 100644 --- a/gcc/tree-ssa-reassoc.c +++ b/gcc/tree-ssa-reassoc.c @@ -1148,6 +1148,52 @@ decrement_power (gimple *stmt) } } +/* Replace SSA defined by STMT and replace all its uses with new + SSA. Also return the new SSA. */ + +static tree +make_new_ssa_for_def (gimple *stmt) +{ + gimple *use_stmt; + use_operand_p use; + imm_use_iterator iter; + tree new_lhs; + tree lhs = gimple_assign_lhs (stmt); + + new_lhs = make_ssa_name (TREE_TYPE (lhs)); + gimple_set_lhs (stmt, new_lhs); + + /* Also need to update GIMPLE_DEBUGs. */ + FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) + { + FOR_EACH_IMM_USE_ON_STMT (use, iter) + SET_USE (use, new_lhs); + update_stmt (use_stmt); + } + return new_lhs; +} + +/* Replace all SSAs defined in STMTS_TO_FIX and replace its + uses with new SSAs. Also do this for the stmt that defines DEF + if *DEF is not OP. */ + +static void +make_new_ssa_for_all_defs (tree *def, tree op, + vec &stmts_to_fix) +{ + unsigned i; + gimple *stmt; + + if (*def != op + && TREE_CODE (*def) == SSA_NAME + && (stmt = SSA_NAME_DEF_STMT (*def)) + && gimple_code (stmt) != GIMPLE_NOP) + *def = make_new_ssa_for_def (stmt); + + FOR_EACH_VEC_ELT (stmts_to_fix, i, stmt) + make_new_ssa_for_def (stmt); +} + /* Find the single immediate use of STMT's LHS, and replace it with OP. Remove STMT. If STMT's LHS is the same as *DEF, replace *DEF with OP as well. */ @@ -1186,6 +1232,9 @@ static void zero_one_operation (tree *def, enum tree_code opcode, tree op) { gimple *stmt = SSA_NAME_DEF_STMT (*def); + /* PR72835 - Record the stmt chain that has to be updated such that + we dont use the same LHS when the values computed are different. */ + auto_vec stmts_to_fix; do { @@ -1196,23 +1245,29 @@ zero_one_operation (tree *def, enum tree_code opcode, tree op) if (stmt_is_power_of_op (stmt, op)) { if (decrement_power (stmt) == 1) - propagate_op_to_single_use (op, stmt, def); - return; + { + if (stmts_to_fix.length () > 0) + stmts_to_fix.pop (); + propagate_op_to_single_use (op, stmt, def); + } + break; } else if (gimple_assign_rhs_code (stmt) == NEGATE_EXPR) { if (gimple_assign_rhs1 (stmt) == op) { tree cst = build_minus_one_cst (TREE_TYPE (op)); + if (stmts_to_fix.length () > 0) + stmts_to_fix.pop (); propagate_op_to_single_use (cst, stmt, def); - return; + break; } else if (integer_minus_onep (op) || real_minus_onep (op)) { gimple_assign_set_rhs_code (stmt, TREE_CODE (gimple_assign_rhs1 (stmt))); - return; + break; } } } @@ -1228,8 +1283,10 @@ zero_one_operation (tree *def, enum tree_code opcode, tree op) { if (name == op) name = gimple_assign_rhs2 (stmt); + if (stmts_to_fix.length () > 0) + stmts_to_fix.pop (); propagate_op_to_single_use (name, stmt, def); - return; + break; } /* We might have a multiply of two __builtin_pow* calls, and @@ -1245,7 +1302,9 @@ zero_one_operation (tree *def, enum tree_code opcode, tree op) { if (decrement_power (stmt2) == 1) propagate_op_to_single_use (op, stmt2, def); - return; + else + stmts_to_fix.safe_push (stmt2); + break; } else if (is_gimple_assign (stmt2) && gimple_assign_rhs_code (stmt2) == NEGATE_EXPR) @@ -1254,14 +1313,15 @@ zero_one_operation (tree *def, enum tree_code opcode, tree op) { tree cst = build_minus_one_cst (TREE_TYPE (op)); propagate_op_to_single_use (cst, stmt2, def); - return; + break; } else if (integer_minus_onep (op) || real_minus_onep (op)) { + stmts_to_fix.safe_push (stmt2); gimple_assign_set_rhs_code (stmt2, TREE_CODE (gimple_assign_rhs1 (stmt2))); - return; + break; } } } @@ -1270,8 +1330,12 @@ zero_one_operation (tree *def, enum tree_code opcode, tree op) gcc_assert (name != op && TREE_CODE (name) == SSA_NAME); stmt = SSA_NAME_DEF_STMT (name); + stmts_to_fix.safe_push (stmt); } while (1); + + if (stmts_to_fix.length () > 0) + make_new_ssa_for_all_defs (def, op, stmts_to_fix); } /* Returns true if statement S1 dominates statement S2. Like -- 2.30.2