From: Bill Schmidt Date: Tue, 5 Sep 2017 21:52:01 +0000 (+0000) Subject: backport: re PR tree-optimization/81503 (Wrong code at -O2) X-Git-Tag: releases/gcc-5.5.0~78 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e834fadf024565cff573a470b35eb8ff517ccb99;p=thirdparty%2Fgcc.git backport: re PR tree-optimization/81503 (Wrong code at -O2) [gcc] 2017-09-05 Bill Schmidt Backport from mainline 2017-08-29 Bill Schmidt Jakub Jelinek Richard Biener PR tree-optimization/81503 * gimple-ssa-strength-reduction.c (replace_mult_candidate): Ensure folded constant fits in the target type; reorder tests for clarity. [gcc/testsuite] 2017-09-05 Bill Schmidt Backport from mainline 2017-08-29 Bill Schmidt Jakub Jelinek Richard Biener PR tree-optimization/81503 * gcc.c-torture/execute/pr81503.c: New file. From-SVN: r251745 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index f1dcf48b372e..06aeb5bb3d5f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,14 @@ +2017-09-05 Bill Schmidt + + Backport from mainline + 2017-08-29 Bill Schmidt + Jakub Jelinek + Richard Biener + + PR tree-optimization/81503 + * gimple-ssa-strength-reduction.c (replace_mult_candidate): Ensure + folded constant fits in the target type; reorder tests for clarity. + 2017-08-22 Peter Bergner Backport from mainline diff --git a/gcc/gimple-ssa-strength-reduction.c b/gcc/gimple-ssa-strength-reduction.c index 8f7c56d6085a..63f1e6b1fd77 100644 --- a/gcc/gimple-ssa-strength-reduction.c +++ b/gcc/gimple-ssa-strength-reduction.c @@ -2041,92 +2041,92 @@ replace_mult_candidate (slsr_cand_t c, tree basis_name, widest_int bump) tree target_type = TREE_TYPE (gimple_assign_lhs (c->cand_stmt)); enum tree_code cand_code = gimple_assign_rhs_code (c->cand_stmt); - /* It is highly unlikely, but possible, that the resulting - bump doesn't fit in a HWI. Abandon the replacement - in this case. This does not affect siblings or dependents - of C. Restriction to signed HWI is conservative for unsigned - types but allows for safe negation without twisted logic. */ - if (wi::fits_shwi_p (bump) - && bump.to_shwi () != HOST_WIDE_INT_MIN - /* It is not useful to replace casts, copies, negates, or adds of - an SSA name and a constant. */ - && cand_code != MODIFY_EXPR - && !CONVERT_EXPR_CODE_P (cand_code) - && cand_code != PLUS_EXPR - && cand_code != POINTER_PLUS_EXPR - && cand_code != MINUS_EXPR - && cand_code != NEGATE_EXPR) - { - enum tree_code code = PLUS_EXPR; - tree bump_tree; - gimple stmt_to_print = NULL; + /* It is not useful to replace casts, copies, negates, or adds of + an SSA name and a constant. */ + if (cand_code == MODIFY_EXPR + || CONVERT_EXPR_CODE_P (cand_code) + || cand_code == PLUS_EXPR + || cand_code == POINTER_PLUS_EXPR + || cand_code == MINUS_EXPR + || cand_code == NEGATE_EXPR) + return; - /* If the basis name and the candidate's LHS have incompatible - types, introduce a cast. */ - if (!useless_type_conversion_p (target_type, TREE_TYPE (basis_name))) - basis_name = introduce_cast_before_cand (c, target_type, basis_name); - if (wi::neg_p (bump)) - { - code = MINUS_EXPR; - bump = -bump; - } + enum tree_code code = PLUS_EXPR; + tree bump_tree; + gimple stmt_to_print = NULL; - bump_tree = wide_int_to_tree (target_type, bump); + /* If the basis name and the candidate's LHS have incompatible + types, introduce a cast. */ + if (!useless_type_conversion_p (target_type, TREE_TYPE (basis_name))) + basis_name = introduce_cast_before_cand (c, target_type, basis_name); + if (wi::neg_p (bump)) + { + code = MINUS_EXPR; + bump = -bump; + } - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fputs ("Replacing: ", dump_file); - print_gimple_stmt (dump_file, c->cand_stmt, 0, 0); - } + /* It is possible that the resulting bump doesn't fit in target_type. + Abandon the replacement in this case. This does not affect + siblings or dependents of C. */ + if (bump != wi::ext (bump, TYPE_PRECISION (target_type), + TYPE_SIGN (target_type))) + return; + + bump_tree = wide_int_to_tree (target_type, bump); - if (bump == 0) + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fputs ("Replacing: ", dump_file); + print_gimple_stmt (dump_file, c->cand_stmt, 0, 0); + } + + if (bump == 0) + { + tree lhs = gimple_assign_lhs (c->cand_stmt); + gassign *copy_stmt = gimple_build_assign (lhs, basis_name); + gimple_stmt_iterator gsi = gsi_for_stmt (c->cand_stmt); + gimple_set_location (copy_stmt, gimple_location (c->cand_stmt)); + gsi_replace (&gsi, copy_stmt, false); + c->cand_stmt = copy_stmt; + if (dump_file && (dump_flags & TDF_DETAILS)) + stmt_to_print = copy_stmt; + } + else + { + tree rhs1, rhs2; + if (cand_code != NEGATE_EXPR) { + rhs1 = gimple_assign_rhs1 (c->cand_stmt); + rhs2 = gimple_assign_rhs2 (c->cand_stmt); + } + if (cand_code != NEGATE_EXPR + && ((operand_equal_p (rhs1, basis_name, 0) + && operand_equal_p (rhs2, bump_tree, 0)) + || (operand_equal_p (rhs1, bump_tree, 0) + && operand_equal_p (rhs2, basis_name, 0)))) { - tree lhs = gimple_assign_lhs (c->cand_stmt); - gassign *copy_stmt = gimple_build_assign (lhs, basis_name); - gimple_stmt_iterator gsi = gsi_for_stmt (c->cand_stmt); - gimple_set_location (copy_stmt, gimple_location (c->cand_stmt)); - gsi_replace (&gsi, copy_stmt, false); - c->cand_stmt = copy_stmt; if (dump_file && (dump_flags & TDF_DETAILS)) - stmt_to_print = copy_stmt; + { + fputs ("(duplicate, not actually replacing)", dump_file); + stmt_to_print = c->cand_stmt; + } } else { - tree rhs1, rhs2; - if (cand_code != NEGATE_EXPR) { - rhs1 = gimple_assign_rhs1 (c->cand_stmt); - rhs2 = gimple_assign_rhs2 (c->cand_stmt); - } - if (cand_code != NEGATE_EXPR - && ((operand_equal_p (rhs1, basis_name, 0) - && operand_equal_p (rhs2, bump_tree, 0)) - || (operand_equal_p (rhs1, bump_tree, 0) - && operand_equal_p (rhs2, basis_name, 0)))) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fputs ("(duplicate, not actually replacing)", dump_file); - stmt_to_print = c->cand_stmt; - } - } - else - { - gimple_stmt_iterator gsi = gsi_for_stmt (c->cand_stmt); - gimple_assign_set_rhs_with_ops (&gsi, code, - basis_name, bump_tree); - update_stmt (gsi_stmt (gsi)); - c->cand_stmt = gsi_stmt (gsi); - if (dump_file && (dump_flags & TDF_DETAILS)) - stmt_to_print = gsi_stmt (gsi); - } + gimple_stmt_iterator gsi = gsi_for_stmt (c->cand_stmt); + gimple_assign_set_rhs_with_ops (&gsi, code, + basis_name, bump_tree); + update_stmt (gsi_stmt (gsi)); + c->cand_stmt = gsi_stmt (gsi); + if (dump_file && (dump_flags & TDF_DETAILS)) + stmt_to_print = gsi_stmt (gsi); } + } - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fputs ("With: ", dump_file); - print_gimple_stmt (dump_file, stmt_to_print, 0, 0); - fputs ("\n", dump_file); - } + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fputs ("With: ", dump_file); + print_gimple_stmt (dump_file, stmt_to_print, 0, 0); + fputs ("\n", dump_file); } } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 00747512c05b..b3ce0469ee5e 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,13 @@ +2017-09-05 Bill Schmidt + + Backport from mainline + 2017-08-29 Bill Schmidt + Jakub Jelinek + Richard Biener + + PR tree-optimization/81503 + * gcc.c-torture/execute/pr81503.c: New file. + 2017-09-02 Janus Weil Backport from trunk diff --git a/gcc/testsuite/gcc.c-torture/execute/pr81503.c b/gcc/testsuite/gcc.c-torture/execute/pr81503.c new file mode 100644 index 000000000000..5fc6cb0e83c9 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr81503.c @@ -0,0 +1,15 @@ +unsigned short a = 41461; +unsigned short b = 3419; +int c = 0; + +void foo() { + if (a + b * ~(0 != 5)) + c = -~(b * ~(0 != 5)) + 2147483647; +} + +int main() { + foo(); + if (c != 2147476810) + return -1; + return 0; +}