[PATCH] PowerPC: Implement TARGET_ATOMIC_ASSIGN_EXPAND_FENV
Adhemerval Zanella
azanella@linux.vnet.ibm.com
Tue Sep 2 22:23:00 GMT 2014
Ping.
On 19-08-2014 13:54, Adhemerval Zanella wrote:
> Ping.
>
> On 06-08-2014 17:21, Adhemerval Zanella wrote:
>> On 01-08-2014 12:31, Joseph S. Myers wrote:
>>> On Thu, 31 Jul 2014, David Edelsohn wrote:
>>>
>>>> Thanks for implementing the FENV support. The patch generally looks
>>>> good to me.
>>>>
>>>> My one concern is a detail in the implementation of "update". I do not
>>>> have enough experience with GENERIC to verify the details and it seems
>>>> like it is missing building an outer COMPOUND_EXPR containing
>>>> update_mffs and the CALL_EXPR for update mtfsf.
>>> I suppose what's actually odd there is that you have
>>>
>>> + tree update_mffs = build2 (MODIFY_EXPR, void_type_node, old_fenv, call_mffs);
>>> +
>>> + tree old_llu = build1 (VIEW_CONVERT_EXPR, uint64_type_node, update_mffs);
>>>
>>> so you build a MODIFY_EXPR in void_type_node but then convert it with a
>>> VIEW_CONVERT_EXPR. If you'd built the MODIFY_EXPR in double_type_node
>>> then the VIEW_CONVERT_EXPR would be meaningful (the value of an assignment
>>> a = b being the new value of a), but reinterpreting a void value doesn't
>>> make sense. Or you could probably just use call_mffs directly in the
>>> VIEW_CONVERT_EXPR without explicitly creating the old_fenv variable.
>>>
>> Thanks for the review Josephm. I have changed to avoid the void reinterpretation
>> and use call_mffs directly. I have also removed the the mask generation in 'clear'
>> from your previous message, it is now reusing the mas used in feholdexcept. The
>> testcase patch is the same as before.
>>
>> Checked on both linux-powerpc64/powerpc64le and no regressions found.
>>
>> --
>>
>> 2014-08-06 Adhemerval Zanella <azanella@linux.vnet.ibm.com>
>>
>> gcc:
>> * config/rs6000/rs6000.c (rs6000_atomic_assign_expand_fenv): New
>> function.
>>
>> gcc/testsuite:
>> * gcc.dg/atomic/c11-atomic-exec-5.c
>> (test_main_long_double_add_overflow): Define and run only for
>> LDBL_MANT_DIG != 106.
>> (test_main_complex_long_double_add_overflow): Likewise.
>> (test_main_long_double_sub_overflow): Likewise.
>> (test_main_complex_long_double_sub_overflow): Likewise.
>>
>> ---
>>
>> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
>> index d088ff6..7d66eb1 100644
>> --- a/gcc/config/rs6000/rs6000.c
>> +++ b/gcc/config/rs6000/rs6000.c
>> @@ -1631,6 +1631,9 @@ static const struct attribute_spec rs6000_attribute_table[] =
>>
>> #undef TARGET_CAN_USE_DOLOOP_P
>> #define TARGET_CAN_USE_DOLOOP_P can_use_doloop_if_innermost
>> +
>> +#undef TARGET_ATOMIC_ASSIGN_EXPAND_FENV
>> +#define TARGET_ATOMIC_ASSIGN_EXPAND_FENV rs6000_atomic_assign_expand_fenv
>>
>>
>> /* Processor table. */
>> @@ -33337,6 +33340,80 @@ emit_fusion_gpr_load (rtx *operands)
>> return "";
>> }
>>
>> +/* Implement TARGET_ATOMIC_ASSIGN_EXPAND_FENV hook. */
>> +
>> +static void
>> +rs6000_atomic_assign_expand_fenv (tree *hold, tree *clear, tree *update)
>> +{
>> + if (!TARGET_HARD_FLOAT || !TARGET_FPRS)
>> + return;
>> +
>> + tree mffs = rs6000_builtin_decls[RS6000_BUILTIN_MFFS];
>> + tree mtfsf = rs6000_builtin_decls[RS6000_BUILTIN_MTFSF];
>> + tree call_mffs = build_call_expr (mffs, 0);
>> +
>> + /* Generates the equivalent of feholdexcept (&fenv_var)
>> +
>> + *fenv_var = __builtin_mffs ();
>> + double fenv_hold;
>> + *(uint64_t*)&fenv_hold = *(uint64_t*)fenv_var & 0xffffffff00000007LL;
>> + __builtin_mtfsf (0xff, fenv_hold); */
>> +
>> + /* Mask to clear everything except for the rounding modes and non-IEEE
>> + arithmetic flag. */
>> + const unsigned HOST_WIDE_INT hold_exception_mask =
>> + HOST_WIDE_INT_UC (0xffffffff00000007);
>> +
>> + tree fenv_var = create_tmp_var (double_type_node, NULL);
>> +
>> + tree hold_mffs = build2 (MODIFY_EXPR, void_type_node, fenv_var, call_mffs);
>> +
>> + tree fenv_llu = build1 (VIEW_CONVERT_EXPR, uint64_type_node, fenv_var);
>> + tree fenv_llu_and = build2 (BIT_AND_EXPR, uint64_type_node, fenv_llu,
>> + build_int_cst (uint64_type_node, hold_exception_mask));
>> +
>> + tree fenv_mtfsf = build1 (VIEW_CONVERT_EXPR, double_type_node, fenv_llu_and);
>> +
>> + tree hold_mtfsf = build_call_expr (mtfsf, 2,
>> + build_int_cst (unsigned_type_node, 0xff), fenv_mtfsf);
>> +
>> + *hold = build2 (COMPOUND_EXPR, void_type_node, hold_mffs, hold_mtfsf);
>> +
>> + /* Reload the value of fenv_hold to clear the exceptions. */
>> +
>> + *clear = build_call_expr (mtfsf, 2,
>> + build_int_cst (unsigned_type_node, 0xff), fenv_mtfsf);
>> +
>> + /* Generates the equivalent of feupdateenv (&fenv_var)
>> +
>> + double old_fenv = __builtin_mffs ();
>> + double fenv_update;
>> + *(uint64_t*)&fenv_update = (*(uint64_t*)&old & 0xffffffff1fffff00LL) |
>> + (*(uint64_t*)fenv_var 0x1ff80fff);
>> + __builtin_mtfsf (0xff, fenv_update); */
>> +
>> + const unsigned HOST_WIDE_INT update_exception_mask =
>> + HOST_WIDE_INT_UC (0xffffffff1fffff00);
>> + const unsigned HOST_WIDE_INT new_exception_mask =
>> + HOST_WIDE_INT_UC (0x1ff80fff);
>> +
>> + tree old_llu = build1 (VIEW_CONVERT_EXPR, uint64_type_node, call_mffs);
>> + tree old_llu_and = build2 (BIT_AND_EXPR, uint64_type_node,
>> + old_llu, build_int_cst (uint64_type_node, update_exception_mask));
>> +
>> + tree new_llu_and = build2 (BIT_AND_EXPR, uint64_type_node, fenv_llu,
>> + build_int_cst (uint64_type_node, new_exception_mask));
>> +
>> + tree new_llu_mask = build2 (BIT_IOR_EXPR, uint64_type_node,
>> + old_llu_and, new_llu_and);
>> +
>> + tree fenv_mtfsf_update = build1 (VIEW_CONVERT_EXPR, double_type_node,
>> + new_llu_mask);
>> +
>> + *update = build_call_expr (mtfsf, 2,
>> + build_int_cst (unsigned_type_node, 0xff), fenv_mtfsf_update);
>> +}
>> +
>>
>> struct gcc_target targetm = TARGET_INITIALIZER;
>>
>> diff --git a/gcc/testsuite/gcc.dg/atomic/c11-atomic-exec-5.c b/gcc/testsuite/gcc.dg/atomic/c11-atomic-exec-5.c
>> index b47a228..6bcb302 100644
>> --- a/gcc/testsuite/gcc.dg/atomic/c11-atomic-exec-5.c
>> +++ b/gcc/testsuite/gcc.dg/atomic/c11-atomic-exec-5.c
>> @@ -331,11 +331,11 @@ TEST_FUNCS (complex_double_div_overflow, _Complex double, , /= DBL_MIN, 0,
>> TEST_FUNCS (long_double_add_invalid, long double, , += __builtin_infl (), 0,
>> 0, __builtin_isinf, 0,
>> -__builtin_infl (), FE_INVALID)
>> +#if LDBL_MANT_DIG != 106
>> TEST_FUNCS (long_double_add_overflow, long double, , += LDBL_MAX, 0,
>> LDBL_MAX, __builtin_isinf, FE_OVERFLOW | FE_INEXACT,
>> 0, 0)
>> #define NOT_LDBL_EPSILON_2(X) ((X) != LDBL_EPSILON / 2)
>> -#if LDBL_MANT_DIG != 106
>> TEST_FUNCS (long_double_add_inexact, long double, , += LDBL_EPSILON / 2, 0,
>> 1.0L, NOT_LDBL_EPSILON_2, FE_INEXACT,
>> 0, 0)
>> @@ -348,18 +348,18 @@ TEST_FUNCS (long_double_preinc_inexact, long double, ++, , 0,
>> TEST_FUNCS (long_double_postinc_inexact, long double, , ++, 0,
>> LDBL_EPSILON / 2, NOT_MINUS_1, FE_INEXACT,
>> -1, 0)
>> -#endif
>> TEST_FUNCS (complex_long_double_add_overflow, _Complex long double, , += LDBL_MAX, 0,
>> LDBL_MAX, REAL_ISINF, FE_OVERFLOW | FE_INEXACT,
>> 0, 0)
>> +#endif
>> TEST_FUNCS (long_double_sub_invalid, long double, , -= __builtin_infl (), 0,
>> 0, __builtin_isinf, 0,
>> __builtin_infl (), FE_INVALID)
>> +#if LDBL_MANT_DIG != 106
>> TEST_FUNCS (long_double_sub_overflow, long double, , -= LDBL_MAX, 0,
>> -LDBL_MAX, __builtin_isinf, FE_OVERFLOW | FE_INEXACT,
>> 0, 0)
>> #define NOT_MINUS_LDBL_EPSILON_2(X) ((X) != -LDBL_EPSILON / 2)
>> -#if LDBL_MANT_DIG != 106
>> TEST_FUNCS (long_double_sub_inexact, long double, , -= LDBL_EPSILON / 2, 0,
>> -1.0L, NOT_MINUS_LDBL_EPSILON_2, FE_INEXACT,
>> 0, 0)
>> @@ -372,10 +372,10 @@ TEST_FUNCS (long_double_predec_inexact, long double, --, , 0,
>> TEST_FUNCS (long_double_postdec_inexact, long double, , --, 0,
>> -LDBL_EPSILON / 2, NOT_1, FE_INEXACT,
>> 1, 0)
>> -#endif
>> TEST_FUNCS (complex_long_double_sub_overflow, _Complex long double, , -= LDBL_MAX, 0,
>> -LDBL_MAX, REAL_ISINF, FE_OVERFLOW | FE_INEXACT,
>> 0, 0)
>> +#endif
>> TEST_FUNCS (long_double_mul_invalid, long double, , *= __builtin_infl (), 0,
>> __builtin_infl (), __builtin_isinf, 0,
>> 0, FE_INVALID)
>> @@ -507,23 +507,23 @@ main (void)
>> ret |= test_main_int_div_double_inexact ();
>> ret |= test_main_complex_double_div_overflow ();
>> ret |= test_main_long_double_add_invalid ();
>> - ret |= test_main_long_double_add_overflow ();
>> #if LDBL_MANT_DIG != 106
>> + ret |= test_main_long_double_add_overflow ();
>> ret |= test_main_long_double_add_inexact ();
>> ret |= test_main_long_double_add_inexact_int ();
>> ret |= test_main_long_double_preinc_inexact ();
>> ret |= test_main_long_double_postinc_inexact ();
>> -#endif
>> ret |= test_main_complex_long_double_add_overflow ();
>> +#endif
>> ret |= test_main_long_double_sub_invalid ();
>> - ret |= test_main_long_double_sub_overflow ();
>> #if LDBL_MANT_DIG != 106
>> + ret |= test_main_long_double_sub_overflow ();
>> ret |= test_main_long_double_sub_inexact ();
>> ret |= test_main_long_double_sub_inexact_int ();
>> ret |= test_main_long_double_predec_inexact ();
>> ret |= test_main_long_double_postdec_inexact ();
>> -#endif
>> ret |= test_main_complex_long_double_sub_overflow ();
>> +#endif
>> ret |= test_main_long_double_mul_invalid ();
>> ret |= test_main_long_double_mul_overflow ();
>> ret |= test_main_long_double_mul_overflow_float ();
>>
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