Replace FMA_EXPR with one internal fn per optab
authorRichard Sandiford <richard.sandiford@linaro.org>
Fri, 18 May 2018 08:27:58 +0000 (08:27 +0000)
committerRichard Sandiford <rsandifo@gcc.gnu.org>
Fri, 18 May 2018 08:27:58 +0000 (08:27 +0000)
commitc566cc9f7847785bc709daaa3301649f2f03aef9
tree1cc67fdd0c641bfd3114f12a85a259c154feac00
parenta35f9ec2f83ccdf53fdcbe2b85a2de33cde46f98
Replace FMA_EXPR with one internal fn per optab

There are four optabs for various forms of fused multiply-add:
fma, fms, fnma and fnms.  Of these, only fma had a direct gimple
representation.  For the other three we relied on special pattern-
matching during expand, although tree-ssa-math-opts.c did have
some code to try to second-guess what expand would do.

This patch removes the old FMA_EXPR representation of fma and
introduces four new internal functions, one for each optab.
IFN_FMA is tied to BUILT_IN_FMA* while the other three are
independent directly-mapped internal functions.  It's then
possible to do the pattern-matching in match.pd and
tree-ssa-math-opts.c (via folding) can select the exact
FMA-based operation.

The BRIG & HSA parts are a best guess, but seem relatively simple.

2018-05-18  Richard Sandiford  <richard.sandiford@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.

From-SVN: r260348
52 files changed:
gcc/ChangeLog
gcc/Makefile.in
gcc/brig/ChangeLog
gcc/brig/brigfrontend/brig-function.cc
gcc/builtins.c
gcc/c/ChangeLog
gcc/c/gimple-parser.c
gcc/cfgexpand.c
gcc/config/i386/i386.c
gcc/config/rs6000/rs6000.c
gcc/cp/ChangeLog
gcc/cp/constexpr.c
gcc/doc/sourcebuild.texi
gcc/expr.c
gcc/fold-const-call.c
gcc/fold-const-call.h
gcc/fold-const.c
gcc/genmatch.c
gcc/gimple-fold.c
gcc/gimple-fold.h
gcc/gimple-pretty-print.c
gcc/gimple-ssa-backprop.c
gcc/gimple.c
gcc/gimplify.c
gcc/hsa-gen.c
gcc/internal-fn.c
gcc/internal-fn.def
gcc/match.pd
gcc/optabs-tree.c
gcc/testsuite/ChangeLog
gcc/testsuite/gcc.dg/fma-1.c [new file with mode: 0644]
gcc/testsuite/gcc.dg/fma-2.c [new file with mode: 0644]
gcc/testsuite/gcc.dg/fma-3.c [new file with mode: 0644]
gcc/testsuite/gcc.dg/fma-4.c [new file with mode: 0644]
gcc/testsuite/gcc.dg/fma-5.c [new file with mode: 0644]
gcc/testsuite/gcc.dg/fma-6.c [new file with mode: 0644]
gcc/testsuite/gcc.dg/fma-7.c [new file with mode: 0644]
gcc/testsuite/gcc.dg/gimplefe-26.c
gcc/testsuite/gfortran.dg/reassoc_10.f
gcc/testsuite/gfortran.dg/reassoc_7.f
gcc/testsuite/gfortran.dg/reassoc_8.f
gcc/testsuite/gfortran.dg/reassoc_9.f
gcc/testsuite/lib/target-supports.exp
gcc/tree-cfg.c
gcc/tree-eh.c
gcc/tree-inline.c
gcc/tree-pretty-print.c
gcc/tree-ssa-loop-im.c
gcc/tree-ssa-math-opts.c
gcc/tree-ssa-operands.c
gcc/tree.c
gcc/tree.def