From 8c79b49cd4fa742f7be739dd21fd2aa040cc1ba3 Mon Sep 17 00:00:00 2001 From: Andrew Pinski Date: Fri, 14 Jul 2023 15:55:34 -0700 Subject: [PATCH] [PATCH] Fix tree-opt/110252: wrong code due to phiopt using flow sensitive info during match Match will query ranger via tree_nonzero_bits/get_nonzero_bits for 2 and 3rd operand of the COND_EXPR and phiopt tries to do create the COND_EXPR even if we moving one statement. That one statement could have some flow sensitive information on it based on the condition that is for the COND_EXPR but that might create wrong code if the statement was moved out. This is similar to the previous version of the patch except now we use flow_sensitive_info_storage instead of manually doing the save/restore and also handle all defs on a gimple statement rather than just for lhs of the gimple statement. Oh and a few more testcases were added that was failing before. OK? Bootsrapped and tested on x86_64-linux-gnu with no regressions. PR tree-optimization/110252 gcc/ChangeLog: * tree-ssa-phiopt.cc (class auto_flow_sensitive): New class. (auto_flow_sensitive::auto_flow_sensitive): New constructor. (auto_flow_sensitive::~auto_flow_sensitive): New deconstructor. (match_simplify_replacement): Temporarily remove the flow sensitive info on the two statements that might be moved. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/phi-opt-25b.c: Updated as __builtin_parity loses the nonzerobits info. * gcc.c-torture/execute/pr110252-1.c: New test. * gcc.c-torture/execute/pr110252-2.c: New test. * gcc.c-torture/execute/pr110252-3.c: New test. * gcc.c-torture/execute/pr110252-4.c: New test. --- .../gcc.c-torture/execute/pr110252-1.c | 15 ++++++ .../gcc.c-torture/execute/pr110252-2.c | 10 ++++ .../gcc.c-torture/execute/pr110252-3.c | 13 +++++ .../gcc.c-torture/execute/pr110252-4.c | 8 +++ gcc/testsuite/gcc.dg/tree-ssa/phi-opt-25b.c | 6 +-- gcc/tree-ssa-phiopt.cc | 51 +++++++++++++++++-- 6 files changed, 96 insertions(+), 7 deletions(-) create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr110252-1.c create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr110252-2.c create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr110252-3.c create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr110252-4.c diff --git a/gcc/testsuite/gcc.c-torture/execute/pr110252-1.c b/gcc/testsuite/gcc.c-torture/execute/pr110252-1.c new file mode 100644 index 00000000000..4ae93ca0647 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr110252-1.c @@ -0,0 +1,15 @@ +/* This is reduced from sel-sched.cc which was noticed was being miscompiled too. */ +int g(int min_need_stall) __attribute__((__noipa__)); +int g(int min_need_stall) +{ + return min_need_stall < 0 ? 1 : ((min_need_stall) < (1) ? (min_need_stall) : (1)); +} +int main(void) +{ + for(int i = -100; i <= 100; i++) + { + int t = g(i); + if (t != (i!=0)) + __builtin_abort(); + } +} diff --git a/gcc/testsuite/gcc.c-torture/execute/pr110252-2.c b/gcc/testsuite/gcc.c-torture/execute/pr110252-2.c new file mode 100644 index 00000000000..7f1a7dbf134 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr110252-2.c @@ -0,0 +1,10 @@ +signed char f() __attribute__((__noipa__)); +signed char f() { return 0; } +int main() +{ + int g = f() - 1; + int e = g < 0 ? 1 : ((g >> (8-2))!=0); + asm("":"+r"(e)); + if (e != 1) + __builtin_abort(); +} diff --git a/gcc/testsuite/gcc.c-torture/execute/pr110252-3.c b/gcc/testsuite/gcc.c-torture/execute/pr110252-3.c new file mode 100644 index 00000000000..c24bf1ab1e4 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr110252-3.c @@ -0,0 +1,13 @@ + +unsigned int a = 1387579096U; +void sinkandcheck(unsigned b) __attribute__((noipa)); +void sinkandcheck(unsigned b) +{ + if (a != b) + __builtin_abort(); +} +int main() { + a = 1 < (~a) ? 1 : (~a); + sinkandcheck(1); + return 0; +} diff --git a/gcc/testsuite/gcc.c-torture/execute/pr110252-4.c b/gcc/testsuite/gcc.c-torture/execute/pr110252-4.c new file mode 100644 index 00000000000..f97edd3f069 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr110252-4.c @@ -0,0 +1,8 @@ + +int a, b = 2, c = 2; +int main() { + b = ~(1 % (a ^ (b - (1 && c) || c & b))); + if (b < -1) + __builtin_abort(); + return 0; +} diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-25b.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-25b.c index 7298da0c96e..0fd9b004a03 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-25b.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-25b.c @@ -65,8 +65,6 @@ int test_popcountll(unsigned long long x, unsigned long long y) return x ? __builtin_popcountll(y) : 0; } -/* 3 types of functions (not including parity), each with 3 types and there are 2 goto each */ -/* { dg-final { scan-tree-dump-times "goto " 18 "optimized" } } */ +/* 4 types of functions, each with 3 types and there are 2 goto each */ +/* { dg-final { scan-tree-dump-times "goto " 24 "optimized" } } */ /* { dg-final { scan-tree-dump-times "x_..D. != 0" 12 "optimized" } } */ -/* parity case will be optimized to x!=0 & parity(y) . */ -/* { dg-final { scan-tree-dump-times " & " 3 "optimized" } } */ diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc index 467c9fd108a..9d542fd345f 100644 --- a/gcc/tree-ssa-phiopt.cc +++ b/gcc/tree-ssa-phiopt.cc @@ -708,6 +708,45 @@ move_stmt (gimple *stmt, gimple_stmt_iterator *gsi, auto_bitmap &inserted_exprs) reset_flow_sensitive_info (name); } +/* RAII style class to temporarily remove flow sensitive + from ssa names defined by a gimple statement. */ +class auto_flow_sensitive +{ +public: + auto_flow_sensitive (gimple *s); + ~auto_flow_sensitive (); +private: + auto_vec, 2> stack; +}; + +/* Constructor for auto_flow_sensitive. Saves + off the ssa names' flow sensitive information + that was defined by gimple statement S and + resets it to be non-flow based ones. */ + +auto_flow_sensitive::auto_flow_sensitive (gimple *s) +{ + if (!s) + return; + ssa_op_iter it; + tree def; + FOR_EACH_SSA_TREE_OPERAND (def, s, it, SSA_OP_DEF) + { + flow_sensitive_info_storage storage; + storage.save_and_clear (def); + stack.safe_push (std::make_pair (def, storage)); + } +} + +/* Deconstructor, restores the flow sensitive information + for the SSA names that had been saved off. */ + +auto_flow_sensitive::~auto_flow_sensitive () +{ + for (auto p : stack) + p.second.restore (p.first); +} + /* The function match_simplify_replacement does the main work of doing the replacement using match and simplify. Return true if the replacement is done. Otherwise return false. @@ -793,9 +832,15 @@ match_simplify_replacement (basic_block cond_bb, basic_block middle_bb, return false; tree type = TREE_TYPE (gimple_phi_result (phi)); - result = gimple_simplify_phiopt (early_p, type, stmt, - arg_true, arg_false, - &seq); + { + auto_flow_sensitive s1(stmt_to_move); + auto_flow_sensitive s_alt(stmt_to_move_alt); + + result = gimple_simplify_phiopt (early_p, type, stmt, + arg_true, arg_false, + &seq); + } + if (!result) return false;