Hi Richard, Thanks for the review and sorry for getting back to you late.
On 4 June 2018 at 18:38, Richard Biener <richard.guent...@gmail.com> wrote: > On Mon, Jun 4, 2018 at 10:18 AM Kugan Vivekanandarajah > <kugan.vivekanandara...@linaro.org> wrote: >> >> Hi Richard, >> >> Thanks for the review. >> >> On 1 June 2018 at 22:20, Richard Biener <richard.guent...@gmail.com> wrote: >> > On Fri, Jun 1, 2018 at 4:12 AM Kugan Vivekanandarajah >> > <kugan.vivekanandara...@linaro.org> wrote: >> >> >> >> Hi Richard, >> >> >> >> This is the revised patch based on the review and the discussion in >> >> https://gcc.gnu.org/ml/gcc/2018-05/msg00179.html. >> >> >> >> In summary: >> >> - I skipped (element_precision (type) < element_precision (TREE_TYPE >> >> (@0))) in the match.pd pattern as this would prevent transformation >> >> for the case in PR. >> >> that is, I am interested in is something like: >> >> char t = (char) ABS_EXPR <(int) x> >> >> and I want to generate >> >> char t = (char) ABSU_EXPR <x> >> >> >> >> - I also haven't added all the necessary match.pd changes for >> >> ABSU_EXPR. I have a patch for that but will submit separately based on >> >> this reveiw. >> >> >> >> - I also tried to add ABSU_EXPRsupport in the places as necessary by >> >> grepping for ABS_EXPR. >> >> >> >> - I also had to add special casing in vectorizer for ABSU_EXP as its >> >> result is unsigned type. >> >> >> >> Is this OK. Patch bootstraps and the regression test is ongoing. >> > >> > The c/c-typeck.c:build_unary_op change looks unnecessary - the >> > C FE should never generate this directly (the c-common one might >> > be triggered by early folding I guess). >> >> The Gimple FE testcase is running into this. > > Ah, OK then. > >> > >> > @@ -1761,6 +1762,9 @@ const_unop (enum tree_code code, tree type, tree >> > arg0) >> > if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST) >> > return fold_abs_const (arg0, type); >> > break; >> > + case ABSU_EXPR: >> > + return fold_convert (type, fold_abs_const (arg0, >> > + signed_type_for >> > (type))); >> > >> > case CONJ_EXPR: >> > >> > I think this will get you bogus TREE_OVERFLOW flags set on ABSU (-INT_MIN). >> > >> > I think you want to change fold_abs_const to properly deal with arg0 being >> > signed and type unsigned. That is, sth like >> > >> > diff --git a/gcc/fold-const.c b/gcc/fold-const.c >> > index 6f80f1b1d69..f60f9c77e91 100644 >> > --- a/gcc/fold-const.c >> > +++ b/gcc/fold-const.c >> > @@ -13843,18 +13843,19 @@ fold_abs_const (tree arg0, tree type) >> > { >> > /* If the value is unsigned or non-negative, then the absolute >> > value >> > is the same as the ordinary value. */ >> > - if (!wi::neg_p (wi::to_wide (arg0), TYPE_SIGN (type))) >> > - t = arg0; >> > + wide_int val = wi::to_wide (arg0); >> > + bool overflow = false; >> > + if (!wi::neg_p (val, TYPE_SIGN (TREE_TYPE (arg0)))) >> > + ; >> > >> > /* If the value is negative, then the absolute value is >> > its negation. */ >> > else >> > - { >> > - bool overflow; >> > - wide_int val = wi::neg (wi::to_wide (arg0), &overflow); >> > - t = force_fit_type (type, val, -1, >> > - overflow | TREE_OVERFLOW (arg0)); >> > - } >> > + wide_int val = wi::neg (val, &overflow); >> > + >> > + /* Force to the destination type, set TREE_OVERFLOW for signed >> > + TYPE only. */ >> > + t = force_fit_type (type, val, 1, overflow | TREE_OVERFLOW (arg0)); >> > } >> > break; >> > >> > and then simply share the const_unop code with ABS_EXPR. >> >> Done. >> >> > diff --git a/gcc/match.pd b/gcc/match.pd >> > index 14386da..7d7c132 100644 >> > --- a/gcc/match.pd >> > +++ b/gcc/match.pd >> > @@ -102,6 +102,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) >> > (match (nop_convert @0) >> > @0) >> > >> > +(simplify (abs (convert @0)) >> > + (if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0)) >> > + && !TYPE_UNSIGNED (TREE_TYPE (@0)) >> > + && !TYPE_UNSIGNED (type)) >> > + (with { tree utype = unsigned_type_for (TREE_TYPE (@0)); } >> > + (convert (absu:utype @0))))) >> > + >> > + >> > >> > please put a comment before the pattern. I believe there's no >> > need to check for !TYPE_UNSIGNED (type). Note this >> > also converts abs ((char)int-var) to (char)absu(int-var) which >> > doesn't make sense. The original issue you want to address >> > here is the case where TYPE_PRECISION of @0 is less than >> > the precision of type. That is, you want to remove language >> > introduced integer promotion of @0 which only is possible >> > with ABSU. So please do add such precision check >> > (I simply suggested the bogus direction of the test). >> >> Done. >> > >> > diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c >> > index 68f4fd3..9b62583 100644 >> > --- a/gcc/tree-cfg.c >> > +++ b/gcc/tree-cfg.c >> > @@ -3685,6 +3685,12 @@ verify_gimple_assign_unary (gassign *stmt) >> > case PAREN_EXPR: >> > case CONJ_EXPR: >> > break; >> > + case ABSU_EXPR: >> > + if (!TYPE_UNSIGNED (lhs_type) >> > + || !ANY_INTEGRAL_TYPE_P (rhs1_type)) >> > >> > if (!ANY_INTEGRAL_TYPE_P (lhs_type) >> > || !TYPE_UNSIGNED (lhs_type) >> > || !ANY_INTEGRAL_TYPE_P (rhs1_type) >> > || TYPE_UNSIGNED (rhs1_type) >> > || element_precision (lhs_type) != element_precision (rhs1_type)) >> > { >> > error ("invalid types for ABSU_EXPR"); >> > debug_generic_expr (lhs_type); >> > debug_generic_expr (rhs1_type); >> > return true; >> > } >> > > > ^^^ you forgot this one. > > >> > + return true; >> > + return false; >> > + break; >> > >> > diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c >> > index 30c6d9e..44b1399 100644 >> > --- a/gcc/tree-eh.c >> > +++ b/gcc/tree-eh.c >> > @@ -2465,6 +2465,7 @@ operation_could_trap_helper_p (enum tree_code op, >> > >> > case NEGATE_EXPR: >> > case ABS_EXPR: >> > + case ABSU_EXPR: >> > case CONJ_EXPR: >> > /* These operations don't trap with floating point. */ >> > if (honor_trapv) >> > >> > ABSU never traps. Please instead unconditionally return false. >> Done. >> >> > >> > diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c >> > index 66c78de..b52d714 100644 >> > --- a/gcc/tree-vect-stmts.c >> > +++ b/gcc/tree-vect-stmts.c >> > @@ -5995,7 +5995,11 @@ vectorizable_operation (gimple *stmt, >> > gimple_stmt_iterator *gsi, >> > "transform binary/unary operation.\n"); >> > >> > /* Handle def. */ >> > - vec_dest = vect_create_destination_var (scalar_dest, vectype); >> > + if (code == ABSU_EXPR) >> > + vec_dest = vect_create_destination_var (scalar_dest, >> > + unsigned_type_for (vectype)); >> > + else >> > + vec_dest = vect_create_destination_var (scalar_dest, vectype); >> > >> > /* POINTER_DIFF_EXPR has pointer arguments which are vectorized as >> > vectors with unsigned elements, but the result is signed. So, we >> > >> > simply use vectype_out for creation of vec_dest. >> Done. > > /* Handle def. */ > - vec_dest = vect_create_destination_var (scalar_dest, vectype); > + if (code == ABSU_EXPR) > + vec_dest = vect_create_destination_var (scalar_dest, vectype_out); > + else > + vec_dest = vect_create_destination_var (scalar_dest, vectype); > > I meant _always_ vectype_out. Thus unconditionally > > vec_dest = vect_create_destination_var (scalar_dest, vectype_out); Some testcases are failing with the changes. gcc:gcc.dg/tree-ssa/pr83329.c (internal compiler error) : This seems to be due to POINTER_DIFF_EXPR (?) There is also gcc:gcc.target/i386/avx2-vshift-1.c (internal compiler error) gcc:gcc.target/i386/xop-vshift-1.c (internal compiler error) Example: /home/tcwg-buildslave/workspace/tcwg-buildfarm_2/tcwg-x86_32-build/snapshots/gcc.git~master_rev_bfa6b77/gcc/testsuite/gcc.target/i386/xop-vshift-1.c:73:1: error: type mismatch in binary expression^M vector(4) long long unsigned int^M ^M vector(4) long long int^M ^M vector(4) long long int^M ^M vect_patt_17.54_21 = vect__2.53_16 & vect_cst__20;^M during GIMPLE pass: vect^M Thanks, Kugan > > OK with those two changes. > > Thanks, > Richard. > >> > >> > diff --git a/gcc/tree.def b/gcc/tree.def >> > index c660b2c..5fec781 100644 >> > --- a/gcc/tree.def >> > +++ b/gcc/tree.def >> > @@ -760,6 +760,7 @@ DEFTREECODE (MAX_EXPR, "max_expr", tcc_binary, 2) >> > An ABS_EXPR must have either an INTEGER_TYPE or a REAL_TYPE. The >> > operand of the ABS_EXPR must have the same type. */ >> > DEFTREECODE (ABS_EXPR, "abs_expr", tcc_unary, 1) >> > +DEFTREECODE (ABSU_EXPR, "absu_expr", tcc_unary, 1) >> > >> > /* Shift operations for shift and rotate. >> > Shift means logical shift if done on an >> > >> > You can clearly see that the comment before ABS_EXPR doesn't apply to >> > ABSU_EXPR >> > so please add an appropriate one. I suggest >> > >> > /* Represents the unsigned absolute value of the operand. >> > An ABSU_EXPR must have unsigned INTEGER_TYPE. The operand of the >> > ABSU_EXPR >> > must have the corresponding signed type. */ >> >> Done. >> >> Here is the reviesed patch. Is this OK? >> >> Thanks, >> Kugan >> >> > >> > Otherwise looks OK. (I didn't explicitely check for missing ABSU_EXPR >> > handling this time) >> > >> > Thanks, >> > Richard. >> > >> > >> >> Thanks, >> >> Kugan >> >> >> >> >> >> On 18 May 2018 at 12:36, Kugan Vivekanandarajah >> >> <kugan.vivekanandara...@linaro.org> wrote: >> >> > Hi Richard, >> >> > >> >> > Thanks for the review. I am revising the patch based on Andrew's >> >> > comments too. >> >> > >> >> > On 17 May 2018 at 20:36, Richard Biener <richard.guent...@gmail.com> >> >> > wrote: >> >> >> On Thu, May 17, 2018 at 4:56 AM Andrew Pinski <pins...@gmail.com> >> >> >> wrote: >> >> >> >> >> >>> On Wed, May 16, 2018 at 7:14 PM, Kugan Vivekanandarajah >> >> >>> <kugan.vivekanandara...@linaro.org> wrote: >> >> >>> > As mentioned in the PR, I am trying to add ABSU_EXPR to fix this >> >> >>> > issue. In the attached patch, in fold_cond_expr_with_comparison I am >> >> >>> > generating ABSU_EXPR for these cases. As I understand, absu_expr is >> >> >>> > well defined in RTL. So, the issue is generating absu_expr and >> >> >>> > transferring to RTL in the correct way. I am not sure I am not doing >> >> >>> > all that is needed. I will clean up and add more test-cases based on >> >> >>> > the feedback. >> >> >> >> >> >> >> >> >>> diff --git a/gcc/optabs-tree.c b/gcc/optabs-tree.c >> >> >>> index 71e172c..2b812e5 100644 >> >> >>> --- a/gcc/optabs-tree.c >> >> >>> +++ b/gcc/optabs-tree.c >> >> >>> @@ -235,6 +235,7 @@ optab_for_tree_code (enum tree_code code, >> >> >>> const_tree >> >> >> type, >> >> >>> return trapv ? negv_optab : neg_optab; >> >> >> >> >> >>> case ABS_EXPR: >> >> >>> + case ABSU_EXPR: >> >> >>> return trapv ? absv_optab : abs_optab; >> >> >> >> >> >> >> >> >>> This part is not correct, it should something like this: >> >> >> >> >> >>> case ABS_EXPR: >> >> >>> return trapv ? absv_optab : abs_optab; >> >> >>> + case ABSU_EXPR: >> >> >>> + return abs_optab ; >> >> >> >> >> >>> Because ABSU is not undefined at the TYPE_MAX. >> >> >> >> >> >> Also >> >> >> >> >> >> /* Unsigned abs is simply the operand. Testing here means we >> >> >> don't >> >> >> risk generating incorrect code below. */ >> >> >> - if (TYPE_UNSIGNED (type)) >> >> >> + if (TYPE_UNSIGNED (type) >> >> >> + && (code != ABSU_EXPR)) >> >> >> return op0; >> >> >> >> >> >> is wrong. ABSU of an unsigned number is still just that number. >> >> >> >> >> >> The change to fold_cond_expr_with_comparison looks odd to me >> >> >> (premature optimization). It should be done separately - it seems >> >> >> you are doing >> >> > >> >> > FE seems to be using this to generate ABS_EXPR from >> >> > c_fully_fold_internal to fold_build3_loc and so on. I changed this to >> >> > generate ABSU_EXPR for the case in the testcase. So the question >> >> > should be, in what cases do we need ABS_EXPR and in what cases do we >> >> > need ABSU_EXPR. It is not very clear to me. >> >> > >> >> > >> >> >> >> >> >> (simplify (abs (convert @0)) (convert (absu @0))) >> >> >> >> >> >> here. >> >> >> >> >> >> You touch one other place in fold-const.c but there seem to be many >> >> >> more that need ABSU_EXPR handling (you touched the one needed >> >> >> for correctness) - esp. you should at least handle constant folding >> >> >> in const_unop and the nonnegative predicate. >> >> > >> >> > OK. >> >> >> >> >> >> @@ -3167,6 +3167,9 @@ verify_expr (tree *tp, int *walk_subtrees, void >> >> >> *data >> >> >> ATTRIBUTE_UNUSED) >> >> >> CHECK_OP (0, "invalid operand to unary operator"); >> >> >> break; >> >> >> >> >> >> + case ABSU_EXPR: >> >> >> + break; >> >> >> + >> >> >> case REALPART_EXPR: >> >> >> case IMAGPART_EXPR: >> >> >> >> >> >> verify_expr is no more. Did you test this recently against trunk? >> >> > >> >> > This patch is against slightly older trunk. I will rebase it. >> >> > >> >> >> >> >> >> @@ -3937,6 +3940,9 @@ verify_gimple_assign_unary (gassign *stmt) >> >> >> case PAREN_EXPR: >> >> >> case CONJ_EXPR: >> >> >> break; >> >> >> + case ABSU_EXPR: >> >> >> + /* FIXME. */ >> >> >> + return false; >> >> >> >> >> >> no - please not! Please add verification here - ABSU should be only >> >> >> called on INTEGRAL, vector or complex INTEGRAL types and the >> >> >> type of the LHS should be always the unsigned variant of the >> >> >> argument type. >> >> > >> >> > OK. >> >> >> >> >> >> if (is_gimple_val (cond_expr)) >> >> >> return cond_expr; >> >> >> >> >> >> - if (TREE_CODE (cond_expr) == ABS_EXPR) >> >> >> + if (TREE_CODE (cond_expr) == ABS_EXPR >> >> >> + || TREE_CODE (cond_expr) == ABSU_EXPR) >> >> >> { >> >> >> rhs1 = TREE_OPERAND (cond_expr, 1); >> >> >> STRIP_USELESS_TYPE_CONVERSION (rhs1); >> >> >> >> >> >> err, but the next line just builds a ABS_EXPR ... >> >> >> >> >> >> How did you identify spots that need adjustment? I would expect that >> >> >> once folding generates ABSU_EXPR that you need to adjust frontends >> >> >> (C++ constexpr handling for example). Also I miss adjustments >> >> >> to gimple-pretty-print.c and the GIMPLE FE parser. >> >> > >> >> > I will add this. >> >> >> >> >> >> recursively grepping throughout the whole gcc/ tree doesn't reveal too >> >> >> many >> >> >> cases of ABS_EXPR so I think it's reasonable to audit all of them. >> >> >> >> >> >> I also miss some trivial absu simplifications in match.pd. There are >> >> >> not >> >> >> a lot of abs cases but similar ones would be good to have initially. >> >> > >> >> > I will add them in the next version. >> >> > >> >> > Thanks, >> >> > Kugan >> >> > >> >> >> >> >> >> Thanks for tackling this! >> >> >> Richard. >> >> >> >> >> >>> Thanks, >> >> >>> Andrew >> >> >> >> >> >>> > >> >> >>> > Thanks, >> >> >>> > Kugan >> >> >>> > >> >> >>> > >> >> >>> > gcc/ChangeLog: >> >> >>> > >> >> >>> > 2018-05-13 Kugan Vivekanandarajah >> >> >>> > <kugan.vivekanandara...@linaro.org> >> >> >>> > >> >> >>> > * expr.c (expand_expr_real_2): Handle ABSU_EXPR. >> >> >>> > * fold-const.c (fold_cond_expr_with_comparison): Generate >> >> >>> > ABSU_EXPR >> >> >>> > (fold_unary_loc): Handle ABSU_EXPR. >> >> >>> > * optabs-tree.c (optab_for_tree_code): Likewise. >> >> >>> > * tree-cfg.c (verify_expr): Likewise. >> >> >>> > (verify_gimple_assign_unary): Likewise. >> >> >>> > * tree-if-conv.c (fold_build_cond_expr): Likewise. >> >> >>> > * tree-inline.c (estimate_operator_cost): Likewise. >> >> >>> > * tree-pretty-print.c (dump_generic_node): Likewise. >> >> >>> > * tree.def (ABSU_EXPR): New. >> >> >>> > >> >> >>> > gcc/testsuite/ChangeLog: >> >> >>> > >> >> >>> > 2018-05-13 Kugan Vivekanandarajah >> >> >>> > <kugan.vivekanandara...@linaro.org> >> >> >>> > >> >> >>> > * gcc.dg/absu.c: New test.
