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Re: [PATCH PR68542]
- From: Yuri Rumyantsev <ysrumyan at gmail dot com>
- To: Richard Biener <richard dot guenther at gmail dot com>
- Cc: gcc-patches <gcc-patches at gcc dot gnu dot org>, Igor Zamyatin <izamyatin at gmail dot com>, Kirill Yukhin <kirill dot Yukhin at gmail dot com>
- Date: Mon, 11 Jan 2016 13:06:24 +0300
- Subject: Re: [PATCH PR68542]
- Authentication-results: sourceware.org; auth=none
- References: <CAEoMCqQT9xxV-1sZPEQPfbuVrTvCVsCyWc4pEbiuph_tXMMqFw at mail dot gmail dot com> <CAFiYyc1BRb0-u5mmzT-M6PJk1JUVKLxJHMCJYoxi3f9ABjNhBw at mail dot gmail dot com> <CAEoMCqTV297wcT9D=0M0oG4MryMoG9iU9563BRA=9LHza46xMA at mail dot gmail dot com> <CAFiYyc0Kip21M=rLOZZ2=wAMdXCKAsw1KVJQEW5JZ+-CS4BXUw at mail dot gmail dot com> <CAEoMCqQ9mJUvVsiGLE-ay0iS17Qn-BP2BX8DSLfzAwUqW_Jgtg at mail dot gmail dot com> <CAFiYyc0hTOC74FpjeZuruOuwDZQzXua2xiGjSLCJNJ8XphGmDQ at mail dot gmail dot com> <CAEoMCqRcLz2_X1yZdSzEbxequR0CPMmmX=8UkgyMoZi5_XLoRg at mail dot gmail dot com>
Hi Richard,
Did you have anu chance to look at updated patch?
Thanks.
Yuri.
2015-12-18 13:20 GMT+03:00 Yuri Rumyantsev <ysrumyan@gmail.com>:
> Hi Richard,
>
> Here is updated patch for middle-end part of the whole patch which
> fixes all your remarks I hope.
>
> Regression testing and bootstrapping did not show any new failures.
> Is it OK for trunk?
>
> Yuri.
>
> ChangeLog:
> 2015-12-18 Yuri Rumyantsev <ysrumyan@gmail.com>
>
> PR middle-end/68542
> * fold-const.c (fold_binary_op_with_conditional_arg): Bail out for case
> of mixind vector and scalar types.
> (fold_relational_const): Add handling of vector
> comparison with boolean result.
> * tree-cfg.c (verify_gimple_comparison): Add argument CODE, allow
> comparison of vector operands with boolean result for EQ/NE only.
> (verify_gimple_assign_binary): Adjust call for verify_gimple_comparison.
> (verify_gimple_cond): Likewise.
> * tree-ssa-forwprop.c (combine_cond_expr_cond): Do not perform
> combining for non-compatible vector types.
> * tree-vrp.c (register_edge_assert_for): VRP does not track ranges for
> vector types.
>
> 2015-12-16 16:37 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
>> On Fri, Dec 11, 2015 at 3:03 PM, Yuri Rumyantsev <ysrumyan@gmail.com> wrote:
>>> Richard.
>>> Thanks for your review.
>>> I re-designed fix for assert by adding additional checks for vector
>>> comparison with boolean result to fold_binary_op_with_conditional_arg
>>> and remove early exit to combine_cond_expr_cond.
>>> Unfortunately, I am not able to provide you with test-case since it is
>>> in my second patch related to back-end patch which I sent earlier
>>> (12-08).
>>>
>>> Bootstrapping and regression testing did not show any new failures.
>>> Is it OK for trunk?
>>
>> + else if (TREE_CODE (type) == VECTOR_TYPE)
>> {
>> tree testtype = TREE_TYPE (cond);
>> test = cond;
>> true_value = constant_boolean_node (true, testtype);
>> false_value = constant_boolean_node (false, testtype);
>> }
>> + else
>> + {
>> + test = cond;
>> + cond_type = type;
>> + true_value = boolean_true_node;
>> + false_value = boolean_false_node;
>> + }
>>
>> So this is, say, vec1 != vec2 with scalar vs. vector result. If we have
>> scalar result and thus, say, scalar + vec1 != vec2. I believe rather
>> than doing the above (not seeing how this not would generate wrong
>> code eventually) we should simply detect the case of mixing vector
>> and scalar types and bail out. At least without some comments
>> your patch makes the function even more difficult to understand than
>> it is already.
>>
>> @@ -3448,10 +3448,17 @@ verify_gimple_comparison (tree type, tree op0, tree op1)
>> if (TREE_CODE (op0_type) == VECTOR_TYPE
>> || TREE_CODE (op1_type) == VECTOR_TYPE)
>> {
>> - error ("vector comparison returning a boolean");
>> - debug_generic_expr (op0_type);
>> - debug_generic_expr (op1_type);
>> - return true;
>> + /* Allow vector comparison returning boolean if operand types
>> + are boolean or integral and CODE is EQ/NE. */
>> + if (code != EQ_EXPR && code != NE_EXPR
>> + && !VECTOR_BOOLEAN_TYPE_P (op0_type)
>> + && !VECTOR_INTEGER_TYPE_P (op0_type))
>> + {
>> + error ("type mismatch for vector comparison returning a boolean");
>> + debug_generic_expr (op0_type);
>> + debug_generic_expr (op1_type);
>> + return true;
>> + }
>> }
>> }
>> /* Or a boolean vector type with the same element count
>>
>> as said before please merge the cascaded if()s. Better wording for
>> the error is "unsupported operation or type for vector comparison
>> returning a boolean"
>>
>> Otherwise the patch looks sensible to me though it shows that overloading of
>> EQ/NE_EXPR for scalar result and vector operands might have some more unexpected
>> fallout (which is why I originally prefered the view-convert to large
>> integer type variant).
>>
>> Thanks,
>> Richard.
>>
>>
>>> ChangeLog:
>>> 2015-12-11 Yuri Rumyantsev <ysrumyan@gmail.com>
>>>
>>> PR middle-end/68542
>>> * fold-const.c (fold_binary_op_with_conditional_arg): Add checks oh
>>> vector comparison with boolean result to avoid ICE.
>>> (fold_relational_const): Add handling of vector
>>> comparison with boolean result.
>>> * tree-cfg.c (verify_gimple_comparison): Add argument CODE, allow
>>> comparison of vector operands with boolean result for EQ/NE only.
>>> (verify_gimple_assign_binary): Adjust call for verify_gimple_comparison.
>>> (verify_gimple_cond): Likewise.
>>> * tree-ssa-forwprop.c (combine_cond_expr_cond): Do not perform
>>> combining for non-compatible vector types.
>>> * tree-vrp.c (register_edge_assert_for): VRP does not track ranges for
>>> vector types.
>>>
>>> 2015-12-10 16:36 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
>>>> On Fri, Dec 4, 2015 at 4:07 PM, Yuri Rumyantsev <ysrumyan@gmail.com> wrote:
>>>>> Hi Richard.
>>>>>
>>>>> Thanks a lot for your review.
>>>>> Below are my answers.
>>>>>
>>>>> You asked why I inserted additional check to
>>>>> ++ b/gcc/tree-ssa-forwprop.c
>>>>> @@ -373,6 +373,11 @@ combine_cond_expr_cond (gimple *stmt, enum
>>>>> tree_code code, tree type,
>>>>>
>>>>> gcc_assert (TREE_CODE_CLASS (code) == tcc_comparison);
>>>>>
>>>>> + /* Do not perform combining it types are not compatible. */
>>>>> + if (TREE_CODE (TREE_TYPE (op0)) == VECTOR_TYPE
>>>>> + && !tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (op0))))
>>>>> + return NULL_TREE;
>>>>> +
>>>>>
>>>>> again, how does this happen?
>>>>>
>>>>> This is because without it I've got assert in fold_convert_loc
>>>>> gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
>>>>> && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
>>>>>
>>>>> since it tries to convert vector of bool to scalar bool.
>>>>> Here is essential part of call-stack:
>>>>>
>>>>> #0 internal_error (gmsgid=0x1e48397 "in %s, at %s:%d")
>>>>> at ../../gcc/diagnostic.c:1259
>>>>> #1 0x0000000001743ada in fancy_abort (
>>>>> file=0x1847fc3 "../../gcc/fold-const.c", line=2217,
>>>>> function=0x184b9d0 <fold_convert_loc(unsigned int, tree_node*,
>>>>> tree_node*)::__FUNCTION__> "fold_convert_loc") at
>>>>> ../../gcc/diagnostic.c:1332
>>>>> #2 0x00000000009c8330 in fold_convert_loc (loc=0, type=0x7ffff18a9d20,
>>>>> arg=0x7ffff1a7f488) at ../../gcc/fold-const.c:2216
>>>>> #3 0x00000000009f003f in fold_ternary_loc (loc=0, code=VEC_COND_EXPR,
>>>>> type=0x7ffff18a9d20, op0=0x7ffff1a7f460, op1=0x7ffff18c2000,
>>>>> op2=0x7ffff18c2030) at ../../gcc/fold-const.c:11453
>>>>> #4 0x00000000009f2f94 in fold_build3_stat_loc (loc=0, code=VEC_COND_EXPR,
>>>>> type=0x7ffff18a9d20, op0=0x7ffff1a7f460, op1=0x7ffff18c2000,
>>>>> op2=0x7ffff18c2030) at ../../gcc/fold-const.c:12394
>>>>> #5 0x00000000009d870c in fold_binary_op_with_conditional_arg (loc=0,
>>>>> code=EQ_EXPR, type=0x7ffff18a9d20, op0=0x7ffff1a7f460,
>>>>> op1=0x7ffff1a48780, cond=0x7ffff1a7f460, arg=0x7ffff1a48780,
>>>>> cond_first_p=1) at ../../gcc/fold-const.c:6465
>>>>> #6 0x00000000009e3407 in fold_binary_loc (loc=0, code=EQ_EXPR,
>>>>> type=0x7ffff18a9d20, op0=0x7ffff1a7f460, op1=0x7ffff1a48780)
>>>>> at ../../gcc/fold-const.c:9211
>>>>> #7 0x0000000000ecb8fa in combine_cond_expr_cond (stmt=0x7ffff1a487d0,
>>>>> code=EQ_EXPR, type=0x7ffff18a9d20, op0=0x7ffff1a7f460,
>>>>> op1=0x7ffff1a48780, invariant_only=true)
>>>>> at ../../gcc/tree-ssa-forwprop.c:382
>>>>
>>>> Ok, but that only shows that
>>>>
>>>> /* Convert A ? 1 : 0 to simply A. */
>>>> if ((code == VEC_COND_EXPR ? integer_all_onesp (op1)
>>>> : (integer_onep (op1)
>>>> && !VECTOR_TYPE_P (type)))
>>>> && integer_zerop (op2)
>>>> /* If we try to convert OP0 to our type, the
>>>> call to fold will try to move the conversion inside
>>>> a COND, which will recurse. In that case, the COND_EXPR
>>>> is probably the best choice, so leave it alone. */
>>>> && type == TREE_TYPE (arg0))
>>>> return pedantic_non_lvalue_loc (loc, arg0);
>>>>
>>>> /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
>>>> over COND_EXPR in cases such as floating point comparisons. */
>>>> if (integer_zerop (op1)
>>>> && (code == VEC_COND_EXPR ? integer_all_onesp (op2)
>>>> : (integer_onep (op2)
>>>> && !VECTOR_TYPE_P (type)))
>>>> && truth_value_p (TREE_CODE (arg0)))
>>>> return pedantic_non_lvalue_loc (loc,
>>>> fold_convert_loc (loc, type,
>>>> invert_truthvalue_loc (loc,
>>>> arg0)));
>>>>
>>>> are wrong? I can't say for sure without a testcase.
>>>>
>>>> That said, papering over this in tree-ssa-forwprop.c is not the
>>>> correct thing to do.
>>>>
>>>>> Secondly, I did not catch your idea to implement GCC Vector Extension
>>>>> for vector comparison with bool result since
>>>>> such extension completely depends on comparison context, e.g. for your
>>>>> example, result type of comparison depends on using - for
>>>>> if-comparison it is scalar, but for c = (a==b) - result type is
>>>>> vector. I don't think that this is reasonable for current release.
>>>>
>>>> The idea was to be able to write testcases exercising different EQ/NE vector
>>>> compares. But yes, if that's non-trivial the it's not appropriate for stage3.
>>>>
>>>> Can you add a testcase for the forwprop issue and try to fix the offending
>>>> bogus folders instead?
>>>>
>>>> Thanks,
>>>> Richard.
>>>>
>>>>> And finally about AMD performance. I checked that this transformation
>>>>> works for "-march=bdver4" option and regression for 481.wrf must
>>>>> disappear too.
>>>>>
>>>>> Thanks.
>>>>> Yuri.
>>>>>
>>>>> 2015-12-04 15:18 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
>>>>>> On Mon, Nov 30, 2015 at 2:11 PM, Yuri Rumyantsev <ysrumyan@gmail.com> wrote:
>>>>>>> Hi All,
>>>>>>>
>>>>>>> Here is a patch for 481.wrf preformance regression for avx2 which is
>>>>>>> sligthly modified mask store optimization. This transformation allows
>>>>>>> perform unpredication for semi-hammock containing masked stores, other
>>>>>>> words if we have a loop like
>>>>>>> for (i=0; i<n; i++)
>>>>>>> if (c[i]) {
>>>>>>> p1[i] += 1;
>>>>>>> p2[i] = p3[i] +2;
>>>>>>> }
>>>>>>>
>>>>>>> then it will be transformed to
>>>>>>> if (!mask__ifc__42.18_165 == { 0, 0, 0, 0, 0, 0, 0, 0 }) {
>>>>>>> vect__11.19_170 = MASK_LOAD (vectp_p1.20_168, 0B, mask__ifc__42.18_165);
>>>>>>> vect__12.22_172 = vect__11.19_170 + vect_cst__171;
>>>>>>> MASK_STORE (vectp_p1.23_175, 0B, mask__ifc__42.18_165, vect__12.22_172);
>>>>>>> vect__18.25_182 = MASK_LOAD (vectp_p3.26_180, 0B, mask__ifc__42.18_165);
>>>>>>> vect__19.28_184 = vect__18.25_182 + vect_cst__183;
>>>>>>> MASK_STORE (vectp_p2.29_187, 0B, mask__ifc__42.18_165, vect__19.28_184);
>>>>>>> }
>>>>>>> i.e. it will put all computations related to masked stores to semi-hammock.
>>>>>>>
>>>>>>> Bootstrapping and regression testing did not show any new failures.
>>>>>>
>>>>>> Can you please split out the middle-end support for vector equality compares?
>>>>>>
>>>>>> @@ -3448,10 +3448,17 @@ verify_gimple_comparison (tree type, tree op0, tree op1)
>>>>>> if (TREE_CODE (op0_type) == VECTOR_TYPE
>>>>>> || TREE_CODE (op1_type) == VECTOR_TYPE)
>>>>>> {
>>>>>> - error ("vector comparison returning a boolean");
>>>>>> - debug_generic_expr (op0_type);
>>>>>> - debug_generic_expr (op1_type);
>>>>>> - return true;
>>>>>> + /* Allow vector comparison returning boolean if operand types
>>>>>> + are equal and CODE is EQ/NE. */
>>>>>> + if ((code != EQ_EXPR && code != NE_EXPR)
>>>>>> + || !(VECTOR_BOOLEAN_TYPE_P (op0_type)
>>>>>> + || VECTOR_INTEGER_TYPE_P (op0_type)))
>>>>>> + {
>>>>>> + error ("type mismatch for vector comparison returning a boolean");
>>>>>> + debug_generic_expr (op0_type);
>>>>>> + debug_generic_expr (op1_type);
>>>>>> + return true;
>>>>>> + }
>>>>>> }
>>>>>> }
>>>>>>
>>>>>> please merge the conditions with a &&
>>>>>>
>>>>>> @@ -13888,6 +13888,25 @@ fold_relational_const (enum tree_code code,
>>>>>> tree type, tree op0, tree op1)
>>>>>>
>>>>>> if (TREE_CODE (op0) == VECTOR_CST && TREE_CODE (op1) == VECTOR_CST)
>>>>>> {
>>>>>> + if (INTEGRAL_TYPE_P (type)
>>>>>> + && (TREE_CODE (type) == BOOLEAN_TYPE
>>>>>> + || TYPE_PRECISION (type) == 1))
>>>>>> + {
>>>>>> + /* Have vector comparison with scalar boolean result. */
>>>>>> + bool result = true;
>>>>>> + gcc_assert (code == EQ_EXPR || code == NE_EXPR);
>>>>>> + gcc_assert (VECTOR_CST_NELTS (op0) == VECTOR_CST_NELTS (op1));
>>>>>> + for (unsigned i = 0; i < VECTOR_CST_NELTS (op0); i++)
>>>>>> + {
>>>>>> + tree elem0 = VECTOR_CST_ELT (op0, i);
>>>>>> + tree elem1 = VECTOR_CST_ELT (op1, i);
>>>>>> + tree tmp = fold_relational_const (code, type, elem0, elem1);
>>>>>> + result &= integer_onep (tmp);
>>>>>> + if (code == NE_EXPR)
>>>>>> + result = !result;
>>>>>> + return constant_boolean_node (result, type);
>>>>>>
>>>>>> ... just assumes it is either EQ_EXPR or NE_EXPR. I believe you want
>>>>>> to change the
>>>>>> guarding condition to just
>>>>>>
>>>>>> if (! VECTOR_TYPE_P (type))
>>>>>>
>>>>>> and assert the boolean/precision. Please also merge the asserts into
>>>>>> one with &&
>>>>>>
>>>>>> diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
>>>>>> index b82ae3c..73ee3be 100644
>>>>>> --- a/gcc/tree-ssa-forwprop.c
>>>>>> +++ b/gcc/tree-ssa-forwprop.c
>>>>>> @@ -373,6 +373,11 @@ combine_cond_expr_cond (gimple *stmt, enum
>>>>>> tree_code code, tree type,
>>>>>>
>>>>>> gcc_assert (TREE_CODE_CLASS (code) == tcc_comparison);
>>>>>>
>>>>>> + /* Do not perform combining it types are not compatible. */
>>>>>> + if (TREE_CODE (TREE_TYPE (op0)) == VECTOR_TYPE
>>>>>> + && !tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (op0))))
>>>>>> + return NULL_TREE;
>>>>>> +
>>>>>>
>>>>>> again, how does this happen?
>>>>>>
>>>>>> diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
>>>>>> index e67048e..1605520c 100644
>>>>>> --- a/gcc/tree-vrp.c
>>>>>> +++ b/gcc/tree-vrp.c
>>>>>> @@ -5760,6 +5760,12 @@ register_edge_assert_for (tree name, edge e,
>>>>>> gimple_stmt_iterator si,
>>>>>> &comp_code, &val))
>>>>>> return;
>>>>>>
>>>>>> + /* Use of vector comparison in gcond is very restricted and used to check
>>>>>> + that the mask in masked store is zero, so assert for such comparison
>>>>>> + is not implemented yet. */
>>>>>> + if (TREE_CODE (TREE_TYPE (name)) == VECTOR_TYPE)
>>>>>> + return;
>>>>>> +
>>>>>>
>>>>>> VECTOR_TYPE_P
>>>>>>
>>>>>> I believe the comment should simply say that VRP doesn't track ranges for
>>>>>> vector types.
>>>>>>
>>>>>> In the previous review I suggested you should make sure that RTL expansion
>>>>>> ends up using a well-defined optab for these compares. To make sure
>>>>>> this happens across targets I suggest you make these comparisons available
>>>>>> via the GCC vector extension. Thus allow
>>>>>>
>>>>>> typedef int v4si __attribute__((vector_size(16)));
>>>>>>
>>>>>> int foo (v4si a, v4si b)
>>>>>> {
>>>>>> if (a == b)
>>>>>> return 4;
>>>>>> }
>>>>>>
>>>>>> and != and also using floating point vectors.
>>>>>>
>>>>>> Otherwise it's hard to see the impact of this change. Obvious choices
>>>>>> are the eq/ne optabs for FP compares and [u]cmp optabs for integer
>>>>>> compares.
>>>>>>
>>>>>> A half-way implementation like your VRP comment suggests (only
>>>>>> ==/!= zero against integer vectors is implemented?!) this doesn't sound
>>>>>> good without also limiting the feature this way in the verifier.
>>>>>>
>>>>>> Btw, the regression with WRF is >50% on AMD Bulldozer (which only
>>>>>> has AVX, not AVX2).
>>>>>>
>>>>>> Thanks,
>>>>>> Richard.
>>>>>>
>>>>>>> ChangeLog:
>>>>>>> 2015-11-30 Yuri Rumyantsev <ysrumyan@gmail.com>
>>>>>>>
>>>>>>> PR middle-end/68542
>>>>>>> * config/i386/i386.c (ix86_expand_branch): Implement integral vector
>>>>>>> comparison with boolean result.
>>>>>>> * config/i386/sse.md (define_expand "cbranch<mode>4): Add define-expand
>>>>>>> for vector comparion with eq/ne only.
>>>>>>> * fold-const.c (fold_relational_const): Add handling of vector
>>>>>>> comparison with boolean result.
>>>>>>> * tree-cfg.c (verify_gimple_comparison): Add argument CODE, allow
>>>>>>> comparison of vector operands with boolean result for EQ/NE only.
>>>>>>> (verify_gimple_assign_binary): Adjust call for verify_gimple_comparison.
>>>>>>> (verify_gimple_cond): Likewise.
>>>>>>> * tree-ssa-forwprop.c (combine_cond_expr_cond): Do not perform
>>>>>>> combining for non-compatible vector types.
>>>>>>> * tree-vect-loop.c (is_valid_sink): New function.
>>>>>>> (optimize_mask_stores): Likewise.
>>>>>>> * tree-vect-stmts.c (vectorizable_mask_load_store): Initialize
>>>>>>> has_mask_store field of vect_info.
>>>>>>> * tree-vectorizer.c (vectorize_loops): Invoke optimaze_mask_stores for
>>>>>>> vectorized loops having masked stores.
>>>>>>> * tree-vectorizer.h (loop_vec_info): Add new has_mask_store field and
>>>>>>> correspondent macros.
>>>>>>> (optimize_mask_stores): Add prototype.
>>>>>>> * tree-vrp.c (register_edge_assert_for): Do not handle NAME with vector
>>>>>>> type.
>>>>>>>
>>>>>>> gcc/testsuite/ChangeLog:
>>>>>>> * gcc.target/i386/avx2-vect-mask-store-move1.c: New test.