On Thu, May 17, 2018 at 1:56 AM, Richard Sandiford <richard.sandif...@linaro.org> wrote: > Richard Biener <richard.guent...@gmail.com> writes: >>> @@ -2698,23 +2703,26 @@ convert_mult_to_fma_1 (tree mul_result, >>> } >> >>> if (negate_p) >>> - mulop1 = force_gimple_operand_gsi (&gsi, >>> - build1 (NEGATE_EXPR, >>> - type, mulop1), >>> - true, NULL_TREE, true, >>> - GSI_SAME_STMT); >>> + mulop1 = gimple_build (&seq, NEGATE_EXPR, type, mulop1); >> >>> - fma_stmt = gimple_build_assign (gimple_assign_lhs (use_stmt), >>> - FMA_EXPR, mulop1, op2, addop); >>> + if (seq) >>> + gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT); >>> + fma_stmt = gimple_build_call_internal (IFN_FMA, 3, mulop1, op2, >> addop); >>> + gimple_call_set_lhs (fma_stmt, gimple_assign_lhs (use_stmt)); >>> + gimple_call_set_nothrow (fma_stmt, !stmt_can_throw_internal >> (use_stmt)); >>> + gsi_replace (&gsi, fma_stmt, true); >>> + /* Valueize aggressively so that we generate FMS, FNMA and FNMS >>> + regardless of where the negation occurs. */ >>> + if (fold_stmt (&gsi, aggressive_valueize)) >>> + update_stmt (gsi_stmt (gsi)); >> >> I think it would be nice to be able to use gimple_build () with IFNs so you >> can >> gimple_build () the IFN and then use gsi_replace_with_seq () on it. You >> only need to fold with generated negates, not with negates already in the >> IL? >> The the folding implied with gimple_build will take care of it. > > The idea was to pick up existing negates that feed the multiplication > as well as any added by the pass itself. > > On IRC yesterday we talked about how this should handle the ECF_NOTHROW > flag, and whether things like IFN_SQRT and IFN_FMA should always be > nothrow (like the built-in functions are). But in the end I thought > it'd be better to keep things as they are. We already handle > -fnon-call-exceptions for unfused a * b + c and before the patch also > handled it for FMA_EXPR. It'd seem like a step backwards if the new > internal functions didn't handle it too. If anything it seems like the > built-in functions should change to be closer to the tree_code and > internal_fn way of doing things, if we want to support -fnon-call-exceptions > properly. > > This also surprised me when doing the if-conversion patch I sent yesterday. > We're happy to vectorise: > > for (int i = 0; i < 100; ++i) > x[i] = ... ? sqrt (x[i]) : 0; > > by doing the sqrt unconditionally and selecting on the result, even with > the default maths flags, but refuse to vectorise the simpler: > > for (int i = 0; i < 100; ++i) > x[i] = ... ? x[i] + 1 : 0; > > in the same way. > >> Otherwise can you please move aggressive_valueize to gimple-fold.[ch] >> alongside no_follow_ssa_edges / follow_single_use_edges and maybe >> rename it as follow_all_ssa_edges? > > Ah, yeah, that's definitely a better name. > > I also renamed all_scalar_fma to scalar_all_fma, since I realised > after Andrew's reply that the old name made it sound like it was > "all scalars", whereas it meant to mean "all fmas". > > Tested as before. > > Thanks, > Richard > > 2018-05-17 Richard Sandiford <richard.sandif...@linaro.org> > > gcc/ > * doc/sourcebuild.texi (scalar_all_fma): Document. > * tree.def (FMA_EXPR): Delete. > * internal-fn.def (FMA, FMS, FNMA, FNMS): New internal functions. > * internal-fn.c (ternary_direct): New macro. > (expand_ternary_optab_fn): Likewise. > (direct_ternary_optab_supported_p): Likewise. > * Makefile.in (build/genmatch.o): Depend on case-fn-macros.h. > * builtins.c (fold_builtin_fma): Delete. > (fold_builtin_3): Don't call it. > * cfgexpand.c (expand_debug_expr): Remove FMA_EXPR handling. > * expr.c (expand_expr_real_2): Likewise. > * fold-const.c (operand_equal_p): Likewise. > (fold_ternary_loc): Likewise. > * gimple-pretty-print.c (dump_ternary_rhs): Likewise. > * gimple.c (DEFTREECODE): Likewise. > * gimplify.c (gimplify_expr): Likewise. > * optabs-tree.c (optab_for_tree_code): Likewise. > * tree-cfg.c (verify_gimple_assign_ternary): Likewise. > * tree-eh.c (operation_could_trap_p): Likewise. > (stmt_could_throw_1_p): Likewise. > * tree-inline.c (estimate_operator_cost): Likewise. > * tree-pretty-print.c (dump_generic_node): Likewise. > (op_code_prio): Likewise. > * tree-ssa-loop-im.c (stmt_cost): Likewise. > * tree-ssa-operands.c (get_expr_operands): Likewise. > * tree.c (commutative_ternary_tree_code, add_expr): Likewise. > * fold-const-call.h (fold_fma): Delete. > * fold-const-call.c (fold_const_call_ssss): Handle CFN_FMS, > CFN_FNMA and CFN_FNMS. > (fold_fma): Delete. > * genmatch.c (combined_fn): New enum. > (commutative_ternary_tree_code): Remove FMA_EXPR handling. > (commutative_op): New function. > (commutate): Use it. Handle more than 2 operands. > (dt_operand::gen_gimple_expr): Use commutative_op. > (parser::parse_expr): Allow :c to be used with non-binary > operators if the commutative operand is known. > * gimple-ssa-backprop.c (backprop::process_builtin_call_use): Handle > CFN_FMS, CFN_FNMA and CFN_FNMS. > (backprop::process_assign_use): Remove FMA_EXPR handling. > * hsa-gen.c (gen_hsa_insns_for_operation_assignment): Likewise. > (gen_hsa_fma): New function. > (gen_hsa_insn_for_internal_fn_call): Use it for IFN_FMA, IFN_FMS, > IFN_FNMA and IFN_FNMS. > * match.pd: Add folds for IFN_FMS, IFN_FNMA and IFN_FNMS. > * gimple-fold.h (follow_all_ssa_edges): Declare. > * gimple-fold.c (follow_all_ssa_edges): New function. > * tree-ssa-math-opts.c (convert_mult_to_fma_1): Use the > gimple_build interface and use follow_all_ssa_edges to fold the > result. > (convert_mult_to_fma): Use direct_internal_fn_suppoerted_p > instead of checking for optabs directly. > * config/i386/i386.c (ix86_add_stmt_cost): Recognize FMAs as calls > rather than FMA_EXPRs. > * config/rs6000/rs6000.c (rs6000_gimple_fold_builtin): Create a > call to IFN_FMA instead of an FMA_EXPR. > > gcc/brig/ > * brigfrontend/brig-function.cc > (brig_function::get_builtin_for_hsa_opcode): Use BUILT_IN_FMA > for BRIG_OPCODE_FMA. > (brig_function::get_tree_code_for_hsa_opcode): Treat BUILT_IN_FMA > as a call. > > gcc/c/ > * gimple-parser.c (c_parser_gimple_postfix_expression): Remove > __FMA_EXPR handlng. > > gcc/cp/ > * constexpr.c (cxx_eval_constant_expression): Remove FMA_EXPR > handling. > (potential_constant_expression_1): Likewise. > > gcc/testsuite/ > * lib/target-supports.exp (check_effective_target_scalar_all_fma): > New proc. > * gcc.dg/fma-1.c: New test. > * gcc.dg/fma-2.c: Likewise. > * gcc.dg/fma-3.c: Likewise. > * gcc.dg/fma-4.c: Likewise. > * gcc.dg/fma-5.c: Likewise. > * gcc.dg/fma-6.c: Likewise. > * gcc.dg/fma-7.c: Likewise. > * gcc.dg/gimplefe-26.c: Use .FMA instead of __FMA and require > scalar_all_fma. > * gfortran.dg/reassoc_7.f: Pass -ffp-contract=off. > * gfortran.dg/reassoc_8.f: Likewise. > * gfortran.dg/reassoc_9.f: Likewise. > * gfortran.dg/reassoc_10.f: Likewise. >
This caused: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85881 H.J.