On Mon, 28 Dec 2020, Tamar Christina wrote:
> Hi All,
>
> This adds support for FMA and FMA conjugated to the slp pattern matcher.
>
> Bootstrapped Regtested on aarch64-none-linux-gnu, x86_64-pc-linux-gnu
> and no issues.
>
> Ok for master?
>
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> * internal-fn.def (COMPLEX_FMA, COMPLEX_FMA_CONJ): New.
> * optabs.def (cmla_optab, cmla_conj_optab): New.
> * doc/md.texi: Document them.
> * tree-vect-slp-patterns.c (vect_match_call_p,
> class complex_fma_pattern, vect_slp_reset_pattern,
> complex_fma_pattern::matches, complex_fma_pattern::recognize,
> complex_fma_pattern::build): New.
>
> --- inline copy of patch --
> diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
> index
> b8cc90e1a75e402abbf8a8cf2efefc1a333f8b3a..6d5a98c4946d3ff4c2b8abea5c29caa6863fd3f7
> 100644
> --- a/gcc/doc/md.texi
> +++ b/gcc/doc/md.texi
> @@ -6202,6 +6202,51 @@ The operation is only supported for vector modes
> @var{m}.
>
> This pattern is not allowed to @code{FAIL}.
>
> +@cindex @code{cmla@var{m}4} instruction pattern
> +@item @samp{cmla@var{m}4}
> +Perform a vector multiply and accumulate that is semantically the same as
> +a multiply and accumulate of complex numbers.
> +
> +@smallexample
> + complex TYPE c[N];
> + complex TYPE a[N];
> + complex TYPE b[N];
> + for (int i = 0; i < N; i += 1)
> + @{
> + c[i] += a[i] * b[i];
> + @}
> +@end smallexample
> +
> +In GCC lane ordering the real part of the number must be in the even lanes
> with
> +the imaginary part in the odd lanes.
> +
> +The operation is only supported for vector modes @var{m}.
> +
> +This pattern is not allowed to @code{FAIL}.
> +
> +@cindex @code{cmla_conj@var{m}4} instruction pattern
> +@item @samp{cmla_conj@var{m}4}
> +Perform a vector multiply by conjugate and accumulate that is semantically
> +the same as a multiply and accumulate of complex numbers where the second
> +multiply arguments is conjugated.
> +
> +@smallexample
> + complex TYPE c[N];
> + complex TYPE a[N];
> + complex TYPE b[N];
> + for (int i = 0; i < N; i += 1)
> + @{
> + c[i] += a[i] * conj (b[i]);
> + @}
> +@end smallexample
> +
> +In GCC lane ordering the real part of the number must be in the even lanes
> with
> +the imaginary part in the odd lanes.
> +
> +The operation is only supported for vector modes @var{m}.
> +
> +This pattern is not allowed to @code{FAIL}.
> +
> @cindex @code{cmul@var{m}4} instruction pattern
> @item @samp{cmul@var{m}4}
> Perform a vector multiply that is semantically the same as multiply of
> diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def
> index
> 5a0bbe3fe5dee591d54130e60f6996b28164ae38..305450e026d4b94ab62ceb9ca719ec5570ff43eb
> 100644
> --- a/gcc/internal-fn.def
> +++ b/gcc/internal-fn.def
> @@ -288,6 +288,8 @@ DEF_INTERNAL_FLT_FN (LDEXP, ECF_CONST, ldexp, binary)
>
> /* Ternary math functions. */
> DEF_INTERNAL_FLT_FLOATN_FN (FMA, ECF_CONST, fma, ternary)
> +DEF_INTERNAL_OPTAB_FN (COMPLEX_FMA, ECF_CONST, cmla, ternary)
> +DEF_INTERNAL_OPTAB_FN (COMPLEX_FMA_CONJ, ECF_CONST, cmla_conj, ternary)
>
> /* Unary integer ops. */
> DEF_INTERNAL_INT_FN (CLRSB, ECF_CONST | ECF_NOTHROW, clrsb, unary)
> diff --git a/gcc/optabs.def b/gcc/optabs.def
> index
> e82396bae1117c6de91304761a560b7fbcb69ce1..8e2758d685ed85e02df10dac571eb40d45a294ed
> 100644
> --- a/gcc/optabs.def
> +++ b/gcc/optabs.def
> @@ -294,6 +294,8 @@ OPTAB_D (cadd90_optab, "cadd90$a3")
> OPTAB_D (cadd270_optab, "cadd270$a3")
> OPTAB_D (cmul_optab, "cmul$a3")
> OPTAB_D (cmul_conj_optab, "cmul_conj$a3")
> +OPTAB_D (cmla_optab, "cmla$a4")
> +OPTAB_D (cmla_conj_optab, "cmla_conj$a4")
> OPTAB_D (cos_optab, "cos$a2")
> OPTAB_D (cosh_optab, "cosh$a2")
> OPTAB_D (exp10_optab, "exp10$a2")
> diff --git a/gcc/tree-vect-slp-patterns.c b/gcc/tree-vect-slp-patterns.c
> index
> 82721acbab8cf81c4d6f9954c98fb913a7bb6282..3625a80c08e3d70fd362fc52e17e65b3b2c7da83
> 100644
> --- a/gcc/tree-vect-slp-patterns.c
> +++ b/gcc/tree-vect-slp-patterns.c
> @@ -325,6 +325,24 @@ vect_match_expression_p (slp_tree node, tree_code code)
> return true;
> }
>
> +/* Checks to see if the expression represented by NODE is a call to the
> internal
> + function FN. */
> +
> +static inline bool
> +vect_match_call_p (slp_tree node, internal_fn fn)
> +{
> + if (!node
> + || !SLP_TREE_REPRESENTATIVE (node))
> + return false;
> +
> + gimple* expr = STMT_VINFO_STMT (SLP_TREE_REPRESENTATIVE (node));
> + if (!expr
> + || !gimple_call_internal_p (expr, fn))
> + return false;
> +
> + return true;
> +}
> +
> /* Check if the given lane permute in PERMUTES matches an alternating
> sequence
> of {even odd even odd ...}. This to account for unrolled loops. Further
> mode there resulting permute must be linear. */
> @@ -1081,6 +1099,161 @@ complex_mul_pattern::build (vec_info *vinfo)
> complex_pattern::build (vinfo);
> }
>
> +/*******************************************************************************
> + * complex_fma_pattern class
> +
> ******************************************************************************/
> +
> +class complex_fma_pattern : public complex_pattern
> +{
> + protected:
> + complex_fma_pattern (slp_tree *node, vec<slp_tree> *m_ops, internal_fn
> ifn)
> + : complex_pattern (node, m_ops, ifn)
> + {
> + this->m_num_args = 3;
> + }
> +
> + public:
> + void build (vec_info *);
> + static internal_fn
> + matches (complex_operation_t op, slp_tree_to_load_perm_map_t *, slp_tree
> *,
> + vec<slp_tree> *);
> +
> + static vect_pattern*
> + recognize (slp_tree_to_load_perm_map_t *, slp_tree *);
> +
> + static vect_pattern*
> + mkInstance (slp_tree *node, vec<slp_tree> *m_ops, internal_fn ifn)
> + {
> + return new complex_fma_pattern (node, m_ops, ifn);
> + }
> +};
> +
> +/* Helper function to "reset" a previously matched node and undo the changes
> + made enough so that the node is treated as an irrelevant node. */
> +
> +static inline void
> +vect_slp_reset_pattern (slp_tree node)
> +{
> + stmt_vec_info stmt_info = vect_orig_stmt (SLP_TREE_REPRESENTATIVE (node));
> + STMT_VINFO_IN_PATTERN_P (stmt_info) = false;
> + STMT_SLP_TYPE (stmt_info) = pure_slp;
> + SLP_TREE_REPRESENTATIVE (node) = stmt_info;
> +}
> +
> +/* Pattern matcher for trying to match complex multiply and accumulate
> + and multiply and subtract patterns in SLP tree.
> + If the operation matches then IFN is set to the operation it matched and
> + the arguments to the two replacement statements are put in m_ops.
> +
> + If no match is found then IFN is set to IFN_LAST and m_ops is unchanged.
> +
> + This function matches the patterns shaped as:
> +
> + double ax = (b[i+1] * a[i]) + (b[i] * a[i]);
> + double bx = (a[i+1] * b[i]) - (a[i+1] * b[i+1]);
> +
> + c[i] = c[i] - ax;
> + c[i+1] = c[i+1] + bx;
> +
> + If a match occurred then TRUE is returned, else FALSE. The match is
> + performed after COMPLEX_MUL which would have done the majority of the
> work.
> + This function merely matches an ADD with a COMPLEX_MUL IFN. The initial
> + match is expected to be in OP1 and the initial match operands in args0.
> */
> +
> +internal_fn
> +complex_fma_pattern::matches (complex_operation_t op,
> + slp_tree_to_load_perm_map_t * /* perm_cache */,
> + slp_tree *ref_node, vec<slp_tree> *ops)
> +{
> + internal_fn ifn = IFN_LAST;
> +
> + /* Find the two components. We match Complex MUL first which reduces the
> + amount of work this pattern has to do. After that we just match the
> + head node and we're done.:
> +
> + * FMA: + +.
> +
> + We need to ignore the two_operands nodes that may also match.
> + For that we can check if they have any scalar statements and also
> + check that it's not a permute node as we're looking for a normal
> + PLUS_EXPR operation. */
> + if (op != CMPLX_NONE)
> + return IFN_LAST;
> +
> + /* Find the two components. We match Complex MUL first which reduces the
> + amount of work this pattern has to do. After that we just match the
> + head node and we're done.:
> +
> + * FMA: + + on a non-two_operands node. */
> + slp_tree vnode = *ref_node;
> + if (SLP_TREE_LANE_PERMUTATION (vnode).exists ()
> + /* Need to exclude the plus two-operands node. These are not marked
> + so we have to infer it based on conditions. */
> + || !SLP_TREE_SCALAR_STMTS (vnode).exists ()
as said earlier we shouldn't test this. The existing lane permute
should already cover this - where the test would better be
SLP_TREE_CODE (vnode) == VEC_PERM_EXPR
> + || !vect_match_expression_p (vnode, PLUS_EXPR))
But then it shouldn't match this (the vect_match_expression_p should
only ever match SLP_TREE_CODE (vnode) != VEC_PERM_EXPR) anyway.
> + return IFN_LAST;
> +
> + slp_tree node = SLP_TREE_CHILDREN (vnode)[1];
> +
> + if (vect_match_call_p (node, IFN_COMPLEX_MUL))
> + ifn = IFN_COMPLEX_FMA;
> + else if (vect_match_call_p (node, IFN_COMPLEX_MUL_CONJ))
> + ifn = IFN_COMPLEX_FMA_CONJ;
> + else
> + return IFN_LAST;
> +
> + if (!vect_pattern_validate_optab (ifn, vnode))
> + return IFN_LAST;
> +
> + vect_slp_reset_pattern (node);
I don't understand this ... it deserves a comment at least.
Having no testcases with this patch makes it impossible for
me to dig in myself :/
Otherwise looks OK.
Thanks,
Richard.
> + ops->truncate (0);
> + ops->create (3);
> +
> + if (ifn == IFN_COMPLEX_FMA)
> + {
> + ops->quick_push (SLP_TREE_CHILDREN (vnode)[0]);
> + ops->quick_push (SLP_TREE_CHILDREN (node)[1]);
> + ops->quick_push (SLP_TREE_CHILDREN (node)[0]);
> + }
> + else
> + {
> + ops->quick_push (SLP_TREE_CHILDREN (vnode)[0]);
> + ops->quick_push (SLP_TREE_CHILDREN (node)[0]);
> + ops->quick_push (SLP_TREE_CHILDREN (node)[1]);
> + }
> +
> + return ifn;
> +}
> +
> +/* Attempt to recognize a complex mul pattern. */
> +
> +vect_pattern*
> +complex_fma_pattern::recognize (slp_tree_to_load_perm_map_t *perm_cache,
> + slp_tree *node)
> +{
> + auto_vec<slp_tree> ops;
> + complex_operation_t op
> + = vect_detect_pair_op (*node, true, &ops);
> + internal_fn ifn
> + = complex_fma_pattern::matches (op, perm_cache, node, &ops);
> + if (ifn == IFN_LAST)
> + return NULL;
> +
> + return new complex_fma_pattern (node, &ops, ifn);
> +}
> +
> +/* Perform a replacement of the detected complex mul pattern with the new
> + instruction sequences. */
> +
> +void
> +complex_fma_pattern::build (vec_info *vinfo)
> +{
> + SLP_TREE_CHILDREN (*this->m_node).truncate (0);
> + SLP_TREE_CHILDREN (*this->m_node).safe_splice (this->m_ops);
> +
> + complex_pattern::build (vinfo);
> +}
> +
>
> /*******************************************************************************
> * Pattern matching definitions
>
> ******************************************************************************/
>
>
>
--
Richard Biener <[email protected]>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
