Gentle ping:
https://gcc.gnu.org/pipermail/gcc-patches/2021-December/587309.html
BR,
Kewen
> on 2021/12/23 上午10:06, Kewen.Lin via Gcc-patches wrote:
>> Hi,
>>
>> This patch is to fix one wrong assertion which is too aggressive.
>> Vectorizer can do vec_construct costing for the vector type which
>> only has one unit. For the failed case, the passed-in vector type
>> is "vector(1) int", though it doesn't end up with any construction
>> eventually. We have to handle this kind of input in function
>> rs6000_cost_data::update_target_cost_per_stmt.
>>
>> Bootstrapped and regtested on powerpc64le-linux-gnu P9 and
>> powerpc64-linux-gnu P8.
>>
>> Is it ok for trunk?
>>
>> BR,
>> Kewen
>> -----
>> gcc/ChangeLog:
>>
>> PR target/103702
>> * config/rs6000/rs6000.c
>> (rs6000_cost_data::update_target_cost_per_stmt): Fix one wrong
>> assertion with early return.
>>
>> gcc/testsuite/ChangeLog:
>>
>> PR target/103702
>> * gcc.target/powerpc/pr103702.c: New test.
>> ---
>> gcc/config/rs6000/rs6000.c | 7 ++++--
>> gcc/testsuite/gcc.target/powerpc/pr103702.c | 24 +++++++++++++++++++++
>> 2 files changed, 29 insertions(+), 2 deletions(-)
>> create mode 100644 gcc/testsuite/gcc.target/powerpc/pr103702.c
>>
>> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
>> index 0b09713b2f5..37f07fe5358 100644
>> --- a/gcc/config/rs6000/rs6000.c
>> +++ b/gcc/config/rs6000/rs6000.c
>> @@ -5461,8 +5461,11 @@ rs6000_cost_data::update_target_cost_per_stmt
>> (vect_cost_for_stmt kind,
>> {
>> tree vectype = STMT_VINFO_VECTYPE (stmt_info);
>> unsigned int nunits = vect_nunits_for_cost (vectype);
>> - /* We don't expect strided/elementwise loads for just 1 nunit. */
>> - gcc_assert (nunits > 1);
>> + /* As PR103702 shows, it's possible that vectorizer wants to do
>> + costings for only one unit here, it's no need to do any
>> + penalization for it, so simply early return here. */
>> + if (nunits == 1)
>> + return;
>> /* i386 port adopts nunits * stmt_cost as the penalized cost
>> for this kind of penalization, we used to follow it but
>> found it could result in an unreliable body cost especially
>> diff --git a/gcc/testsuite/gcc.target/powerpc/pr103702.c
>> b/gcc/testsuite/gcc.target/powerpc/pr103702.c
>> new file mode 100644
>> index 00000000000..585946fd64b
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/powerpc/pr103702.c
>> @@ -0,0 +1,24 @@
>> +/* We don't have one powerpc.*_ok for Power6, use altivec_ok
>> conservatively. */
>> +/* { dg-require-effective-target powerpc_altivec_ok } */
>> +/* { dg-options "-mdejagnu-cpu=power6 -O2 -ftree-loop-vectorize
>> -fno-tree-scev-cprop" } */
>> +
>> +/* Verify there is no ICE. */
>> +
>> +unsigned short a, e;
>> +int *b, *d;
>> +int c;
>> +extern int fn2 ();
>> +void
>> +fn1 ()
>> +{
>> + void *f;
>> + for (;;)
>> + {
>> + fn2 ();
>> + b = f;
>> + e = 0;
>> + for (; e < a; ++e)
>> + b[e] = d[e * c];
>> + }
>> +}
>> +
>> --
>> 2.27.0
>>
