> -----Original Message-----
> From: Richard Biener <rguent...@suse.de>
> Sent: Friday, January 8, 2021 10:17 AM
> To: Tamar Christina <tamar.christ...@arm.com>
> Cc: gcc-patches@gcc.gnu.org; nd <n...@arm.com>; o...@ucw.cz
> Subject: RE: [PATCH 6/8 v9]middle-end slp: support complex FMA and
> complex FMA conjugate
>
> On Fri, 8 Jan 2021, Tamar Christina wrote:
>
> > Hi Richi,
> >
> > > -----Original Message-----
> > > From: Richard Biener <rguent...@suse.de>
> > > Sent: Friday, January 8, 2021 9:45 AM
> > > To: Tamar Christina <tamar.christ...@arm.com>
> > > Cc: gcc-patches@gcc.gnu.org; nd <n...@arm.com>; o...@ucw.cz
> > > Subject: Re: [PATCH 6/8 v9]middle-end slp: support complex FMA and
> > > complex FMA conjugate
> > >
> > > 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..6d5a98c4946d3ff4c2b8abea5c
> > > 2
> > > 9
> > > > caa6863fd3f7 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..305450e026d4b94ab62ceb9c
> > > a719
> > > > ec5570ff43eb 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..8e2758d685ed85e02df10dac
> > > 571e
> > > > b40d45a294ed 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..3625a80c08e3d70fd362fc52e1
> > > 7e
> > > > 65b3b2c7da83 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.
> > >
> >
> > How so? An FMA doesn't have a TWO_OPERANDS node as the root since
> the operations
> > Are always two PLUS operations.
> >
> > The corresponding tree is
> >
> > note: SLP size 10 vs. limit 24.
> > note: Final SLP tree for instance 0x48f68d0:
> > note: node 0x4809870 (max_nunits=4, refcnt=2)
> > note: op template: REALPART_EXPR <*_3> = _31;
> > note: stmt 0 REALPART_EXPR <*_3> = _31;
> > note: stmt 1 IMAGPART_EXPR <*_3> = _32;
> > note: children 0x48098f8
> > note: node 0x48098f8 (max_nunits=4, refcnt=2)
> > note: op template: _31 = _12 + _29;
> > note: stmt 0 _31 = _12 + _29;
> > note: stmt 1 _32 = _11 + _30;
> > note: children 0x4809980 0x4809a08
> > note: node 0x4809980 (max_nunits=4, refcnt=2)
> > note: op template: _12 = REALPART_EXPR <*_3>;
> > note: stmt 0 _12 = REALPART_EXPR <*_3>;
> > note: stmt 1 _11 = IMAGPART_EXPR <*_3>;
> > note: load permutation { 0 1 }
> > note: node 0x4809a08 (max_nunits=4, refcnt=2)
> > note: op: VEC_PERM_EXPR
> > note: stmt 0 _29 = _25 - _26;
> > note: stmt 1 _30 = _27 + _28;
> > note: lane permutation { 0[0] 1[1] }
> > note: children 0x4809dc0 0x4809e48
> > note: node 0x4809dc0 (max_nunits=1, refcnt=1)
> > note: op template: _29 = _25 - _26;
> > note: { }
> > note: children 0x4809a90 0x4809c28
> > note: node 0x4809a90 (max_nunits=4, refcnt=3)
> > note: op template: _25 = _19 * _22;
> > note: stmt 0 _25 = _19 * _22;
> > note: stmt 1 _27 = _20 * _22;
> > note: children 0x4809b18 0x4809ba0
> > note: node 0x4809b18 (max_nunits=4, refcnt=2)
> > note: op template: _19 = REALPART_EXPR <*_7>;
> > note: stmt 0 _19 = REALPART_EXPR <*_7>;
> > note: stmt 1 _20 = IMAGPART_EXPR <*_7>;
> > note: load permutation { 0 1 }
> > note: node 0x4809ba0 (max_nunits=4, refcnt=2)
> > note: op template: _22 = REALPART_EXPR <*_5>;
> > note: stmt 0 _22 = REALPART_EXPR <*_5>;
> > note: stmt 1 _22 = REALPART_EXPR <*_5>;
> > note: load permutation { 0 0 }
> > note: node 0x4809c28 (max_nunits=4, refcnt=3)
> > note: op template: _26 = _20 * _21;
> > note: stmt 0 _26 = _20 * _21;
> > note: stmt 1 _28 = _19 * _21;
> > note: children 0x4809cb0 0x4809d38
> > note: node 0x4809cb0 (max_nunits=4, refcnt=2)
> > note: op template: _20 = IMAGPART_EXPR <*_7>;
> > note: stmt 0 _20 = IMAGPART_EXPR <*_7>;
> > note: stmt 1 _19 = REALPART_EXPR <*_7>;
> > note: load permutation { 1 0 }
> > note: node 0x4809d38 (max_nunits=4, refcnt=2)
> > note: op template: _21 = IMAGPART_EXPR <*_5>;
> > note: stmt 0 _21 = IMAGPART_EXPR <*_5>;
> > note: stmt 1 _21 = IMAGPART_EXPR <*_5>;
> > note: load permutation { 1 1 }
> > note: node 0x4809e48 (max_nunits=1, refcnt=1)
> > note: op template: _30 = _27 + _28;
> > note: { }
> > note: children 0x4809a90 0x4809c28
> >
> > and after matching the MUL all you have are the ADD node going into a
> COMPLEX_MUL node.
>
> So the above is the original tree - how does the tree look like
> at the point you need to rule out 0x4809e48 (and thus have those
> COMPLEX_MUL ones)?
>
> As said, !SLP_TREE_SCALAR_STMTS (vnode).exists () is not a good test.
Agreed, Sorry I need to start drinking coffee.. I read the above
> > > But then it shouldn't match this (the vect_match_expression_p should
> only
> > > ever match SLP_TREE_CODE (vnode) != VEC_PERM_EXPR) anyway.
>
as SLP_TREE_CODE (vnode) == VEC_PERM_EXPR...
I will go respin patches 😊
Thanks!
> If complex pattern detection doesn't want to see the direct(?) children
> of permute nodes then the pattern machinery should provide means
> to do this. Likewise if the pattern should not contain parents
> outside of the supposed match the machinery should provide means
> to restrict matches to single entry SLP subgraphs (here the
> children of the plus have an alternate "entry").
>
> > > > + 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.
> >
> > The previous pass detecting COMPLEX_MUL would have marked the
> > Instructions as being inside of a MUL pattern. These need to be unmarked
> > As being part of the COMPLEX_MUL and instead be marked as
> COMPLEX_FMA.
>
> The scalar pattern code adjusts this at the point it marks the
> pattern "consuming" the earlier pattern. We should try follow that
> style here I think.
>
> > > Having no testcases with this patch makes it impossible for me to dig in
> > > myself :/
> >
> > Sorry, the tests would have made the file too big again.. The previous test
> for complex add
> > Added gcc/testsuite/gcc.dg/vect/complex/complex-operations.c which is
> an overarching test
> > Testing everything in one go.
> >
> > The individual tests are split off from that large test.
> >
> > >
> > > 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 <rguent...@suse.de>
> > > SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409
> > > Nuernberg, Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
> >
>
> --
> Richard Biener <rguent...@suse.de>
> SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409
> Nuernberg,
> Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
