Hi, Richi. I have fully tested in RISC-V port with adding gcc_unreachable () in V4 patch: https://gcc.gnu.org/pipermail/gcc-patches/2023-August/626133.html Bootstrap and regression on X86 passed. juzhe.zhong@rivai.ai From: Richard Biener Date: 2023-08-02 16:33 To: juzhe.zhong@rivai.ai CC: richard.sandiford; gcc-patches Subject: Re: Re: [PATCH V2] VECT: Support CALL vectorization for COND_LEN_* On Wed, 2 Aug 2023, juzhe.zhong@rivai.ai wrote: > Thanks Richard so much. > > Forgive me asking question again :) > > Is this following code correct for you ? Well, I wonder what kind of testcase runs into the reduc_idx >= 0 case. The point is I don't _know_ whether the code is correct, in fact it looked suspicious ;) > + if (len_loop_p) > + { > + if (len_opno >= 0) > + { > + ifn = cond_len_fn; > + /* COND_* -> COND_LEN_* takes 2 extra arguments:LEN,BIAS. */ > + vect_nargs += 2; > + } > + else if (reduc_idx >= 0) > + gcc_unreachable (); > + } > > Thanks. > > > juzhe.zhong@rivai.ai > > From: Richard Biener > Date: 2023-08-02 15:49 > To: ??? > CC: richard.sandiford; gcc-patches > Subject: Re: Re: [PATCH V2] VECT: Support CALL vectorization for COND_LEN_* > On Mon, 31 Jul 2023, ??? wrote: > > > Oh, Thanks a lot. > > I can test it in RISC-V backend now. > > > > But I have another questions: > > >> I'm a bit confused (but also by the existing mask code), whether > > >>vect_nargs needs adjustment depends on the IFN in the IL we analyze. > > >>If if-conversion recognizes a .COND_ADD then we need to add nothing > > >>for masking (that is, ifn == cond_fn already). In your code above > > >>you either use cond_len_fn or get_len_internal_fn (cond_fn) but > > >>isn't that the very same?! So how come you in one case add two > > >>and in the other add four args? > > >>Please make sure to place gcc_unreachable () in each arm and check > > >>you have test coverage. I believe that the else arm is unreachable > > >>but when you vectorize .FMA you will need to add 4 and when you > > >>vectorize .COND_FMA you will need to add two arguments (as said, > > >>no idea why we special case reduc_idx >= 0 at the moment). > > > > Do you mean I add gcc_unreachable in else like this: > > > > if (len_loop_p) > > { > > if (len_opno >= 0) > > { > > ifn = cond_len_fn; > > /* COND_* -> COND_LEN_* takes 2 extra arguments:LEN,BIAS. */ > > vect_nargs += 2; > > } > > else if (reduc_idx >= 0) > > { > > /* FMA -> COND_LEN_FMA takes 4 extra arguments:MASK,ELSE,LEN,BIAS. */ > > ifn = get_len_internal_fn (cond_fn); > > vect_nargs += 4; > > no, a gcc_unreachable () here. That is, make sure you have test coverage > for the above two cases (to me the len_opno >= 0 case is obvious) > > > } > > else > > gcc_unreachable (); > > } > > > > Thanks. > > > > > > juzhe.zhong@rivai.ai > > > > From: Richard Biener > > Date: 2023-07-31 21:58 > > To: ??? > > CC: richard.sandiford; gcc-patches > > Subject: Re: Re: [PATCH V2] VECT: Support CALL vectorization for COND_LEN_* > > On Mon, 31 Jul 2023, ??? wrote: > > > > > Yeah. I have tried this case too. > > > > > > But this case doesn't need to be vectorized as COND_FMA, am I right? > > > > Only when you enable loop masking. Alternatively use > > > > double foo (double *a, double *b, double *c) > > { > > double result = 0.0; > > for (int i = 0; i < 1024; ++i) > > result += i & 1 ? __builtin_fma (a[i], b[i], c[i]) : 0.0; > > return result; > > } > > > > but then for me if-conversion produces > > > > iftmp.0_18 = __builtin_fma (_8, _10, _5); > > _ifc__43 = _26 ? iftmp.0_18 : 0.0; > > > > with -ffast-math (probably rightfully so). I then get .FMAs > > vectorized and .COND_FMA folded. > > > > > The thing I wonder is that whether this condtion: > > > > > > if (mask_opno >= 0 && reduc_idx >= 0) > > > > > > or similar as len > > > if (len_opno >= 0 && reduc_idx >= 0) > > > > > > Whether they are redundant in vectorizable_call ? > > > > > > > > > juzhe.zhong@rivai.ai > > > > > > From: Richard Biener > > > Date: 2023-07-31 21:33 > > > To: juzhe.zhong@rivai.ai > > > CC: richard.sandiford; gcc-patches > > > Subject: Re: Re: [PATCH V2] VECT: Support CALL vectorization for COND_LEN_* > > > On Mon, 31 Jul 2023, juzhe.zhong@rivai.ai wrote: > > > > > > > Hi, Richi. > > > > > > > > >> I think you need to use fma from math.h together with -ffast-math > > > > >>to get fma. > > > > > > > > As you said, this is one of the case I tried: > > > > https://godbolt.org/z/xMzrrv5dT > > > > GCC failed to vectorize. > > > > > > > > Could you help me with this? > > > > > > double foo (double *a, double *b, double *c) > > > { > > > double result = 0.0; > > > for (int i = 0; i < 1024; ++i) > > > result += __builtin_fma (a[i], b[i], c[i]); > > > return result; > > > } > > > > > > with -mavx2 -mfma -Ofast this is vectorized on x86_64 to > > > > > > ... > > > vect__9.13_27 = MEM [(double *)vectp_a.11_29]; > > > _9 = *_8; > > > vect__10.14_26 = .FMA (vect__7.10_30, vect__9.13_27, vect__4.7_33); > > > vect_result_17.15_25 = vect__10.14_26 + vect_result_20.4_36; > > > ... > > > > > > but ifcvt still shows > > > > > > _9 = *_8; > > > _10 = __builtin_fma (_7, _9, _4); > > > result_17 = _10 + result_20; > > > > > > still vectorizable_call has IFN_FMA with > > > > > > /* First try using an internal function. */ > > > code_helper convert_code = MAX_TREE_CODES; > > > if (cfn != CFN_LAST > > > && (modifier == NONE > > > || (modifier == NARROW > > > && simple_integer_narrowing (vectype_out, vectype_in, > > > &convert_code)))) > > > ifn = vectorizable_internal_function (cfn, callee, vectype_out, > > > vectype_in); > > > > > > from CFN_BUILT_IN_FMA > > > > > > > > > > > > > Thanks. > > > > > > > > > > > > juzhe.zhong@rivai.ai > > > > > > > > From: Richard Biener > > > > Date: 2023-07-31 20:00 > > > > To: juzhe.zhong@rivai.ai > > > > CC: richard.sandiford; gcc-patches > > > > Subject: Re: Re: [PATCH V2] VECT: Support CALL vectorization for COND_LEN_* > > > > On Mon, 31 Jul 2023, juzhe.zhong@rivai.ai wrote: > > > > > > > > > Ok . Thanks Richard. > > > > > > > > > > Could you give me a case that SVE can vectorize a reduction with FMA? > > > > > Meaning it will go into vectorize_call and vectorize FMA into COND_FMA ? > > > > > > > > > > I tried many times to reproduce such cases but I failed. > > > > > > > > I think you need to use fma from math.h together with -ffast-math > > > > to get fma. > > > > > > > > Richard. > > > > > > > > > Thanks. > > > > > > > > > > > > > > > juzhe.zhong@rivai.ai > > > > > > > > > > From: Richard Sandiford > > > > > Date: 2023-07-31 18:19 > > > > > To: Juzhe-Zhong > > > > > CC: gcc-patches; rguenther > > > > > Subject: Re: [PATCH V2] VECT: Support CALL vectorization for COND_LEN_* > > > > > Juzhe-Zhong writes: > > > > > > Hi, Richard and Richi. > > > > > > > > > > > > Base on the suggestions from Richard: > > > > > > https://gcc.gnu.org/pipermail/gcc-patches/2023-July/625396.html > > > > > > > > > > > > This patch choose (1) approach that Richard provided, meaning: > > > > > > > > > > > > RVV implements cond_* optabs as expanders. RVV therefore supports > > > > > > both IFN_COND_ADD and IFN_COND_LEN_ADD. No dummy length arguments > > > > > > are needed at the gimple level. > > > > > > > > > > > > Such approach can make codes much cleaner and reasonable. > > > > > > > > > > > > Consider this following case: > > > > > > void foo (float * __restrict a, float * __restrict b, int * __restrict cond, int n) > > > > > > { > > > > > > for (int i = 0; i < n; i++) > > > > > > if (cond[i]) > > > > > > a[i] = b[i] + a[i]; > > > > > > } > > > > > > > > > > > > > > > > > > Output of RISC-V (32-bits) gcc (trunk) (Compiler #3) > > > > > > :5:21: missed: couldn't vectorize loop > > > > > > :5:21: missed: not vectorized: control flow in loop. > > > > > > > > > > > > ARM SVE: > > > > > > > > > > > > ... > > > > > > mask__27.10_51 = vect__4.9_49 != { 0, ... }; > > > > > > ... > > > > > > vec_mask_and_55 = loop_mask_49 & mask__27.10_51; > > > > > > ... > > > > > > vect__9.17_62 = .COND_ADD (vec_mask_and_55, vect__6.13_56, vect__8.16_60, vect__6.13_56); > > > > > > > > > > > > For RVV, we want IR as follows: > > > > > > > > > > > > ... > > > > > > _68 = .SELECT_VL (ivtmp_66, POLY_INT_CST [4, 4]); > > > > > > ... > > > > > > mask__27.10_51 = vect__4.9_49 != { 0, ... }; > > > > > > ... > > > > > > vect__9.17_60 = .COND_LEN_ADD (mask__27.10_51, vect__6.13_55, vect__8.16_59, vect__6.13_55, _68, 0); > > > > > > ... > > > > > > > > > > > > Both len and mask of COND_LEN_ADD are real not dummy. > > > > > > > > > > > > This patch has been fully tested in RISC-V port with supporting both COND_* and COND_LEN_*. > > > > > > > > > > > > And also, Bootstrap and Regression on X86 passed. > > > > > > > > > > > > OK for trunk? > > > > > > > > > > > > gcc/ChangeLog: > > > > > > > > > > > > * internal-fn.cc (FOR_EACH_LEN_FN_PAIR): New macro. > > > > > > (get_len_internal_fn): New function. > > > > > > (CASE): Ditto. > > > > > > * internal-fn.h (get_len_internal_fn): Ditto. > > > > > > * tree-vect-stmts.cc (vectorizable_call): Support CALL vectorization with COND_LEN_*. > > > > > > > > > > > > --- > > > > > > gcc/internal-fn.cc | 46 ++++++++++++++++++++++ > > > > > > gcc/internal-fn.h | 1 + > > > > > > gcc/tree-vect-stmts.cc | 87 +++++++++++++++++++++++++++++++++++++----- > > > > > > 3 files changed, 125 insertions(+), 9 deletions(-) > > > > > > > > > > > > diff --git a/gcc/internal-fn.cc b/gcc/internal-fn.cc > > > > > > index 8e294286388..379220bebc7 100644 > > > > > > --- a/gcc/internal-fn.cc > > > > > > +++ b/gcc/internal-fn.cc > > > > > > @@ -4443,6 +4443,52 @@ get_conditional_internal_fn (internal_fn fn) > > > > > > } > > > > > > } > > > > > > > > > > > > +/* Invoke T(IFN) for each internal function IFN that also has an > > > > > > + IFN_COND_LEN_* or IFN_MASK_LEN_* form. */ > > > > > > +#define FOR_EACH_LEN_FN_PAIR(T) \ > > > > > > + T (MASK_LOAD, MASK_LEN_LOAD) \ > > > > > > + T (MASK_STORE, MASK_LEN_STORE) \ > > > > > > + T (MASK_GATHER_LOAD, MASK_LEN_GATHER_LOAD) \ > > > > > > + T (MASK_SCATTER_STORE, MASK_LEN_SCATTER_STORE) \ > > > > > > + T (COND_ADD, COND_LEN_ADD) \ > > > > > > + T (COND_SUB, COND_LEN_SUB) \ > > > > > > + T (COND_MUL, COND_LEN_MUL) \ > > > > > > + T (COND_DIV, COND_LEN_DIV) \ > > > > > > + T (COND_MOD, COND_LEN_MOD) \ > > > > > > + T (COND_RDIV, COND_LEN_RDIV) \ > > > > > > + T (COND_FMIN, COND_LEN_FMIN) \ > > > > > > + T (COND_FMAX, COND_LEN_FMAX) \ > > > > > > + T (COND_MIN, COND_LEN_MIN) \ > > > > > > + T (COND_MAX, COND_LEN_MAX) \ > > > > > > + T (COND_AND, COND_LEN_AND) \ > > > > > > + T (COND_IOR, COND_LEN_IOR) \ > > > > > > + T (COND_XOR, COND_LEN_XOR) \ > > > > > > + T (COND_SHL, COND_LEN_SHL) \ > > > > > > + T (COND_SHR, COND_LEN_SHR) \ > > > > > > + T (COND_NEG, COND_LEN_NEG) \ > > > > > > + T (COND_FMA, COND_LEN_FMA) \ > > > > > > + T (COND_FMS, COND_LEN_FMS) \ > > > > > > + T (COND_FNMA, COND_LEN_FNMA) \ > > > > > > + T (COND_FNMS, COND_LEN_FNMS) > > > > > > > > > > With the earlier patch to add DEF_INTERNAL_COND_FN and > > > > > DEF_INTERNAL_SIGNED_COND_FN, I think we should use those to handle > > > > > the COND_* cases, rather than putting them in this macro. > > > > > > > > > > Thanks, > > > > > Richard > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- Richard Biener SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)