15 Commits

Author SHA1 Message Date
Kristof Beyls
bece65fd18 [GlobalISel] Support vector-of-pointers in LLT
This fixes PR32471.

As comment 10 on that bug report highlights
(https://bugs.llvm.org//show_bug.cgi?id=32471#c10), there are quite a
few different defendable design tradeoffs that could be made, including
not representing pointers at all in LLT.

I decided to go for representing vector-of-pointer as a concept in LLT,
while keeping the size of the LLT type 64 bits (this is an increase from
48 bits before). My rationale for keeping pointers explicit is that on
some targets probably it's very handy to have the distinction between
pointer and non-pointer (e.g. 68K has a different register bank for
pointers IIRC). If we keep a scalar pointer, it probably is easiest to
also have a vector-of-pointers to keep LLT relatively conceptually clean
and orthogonal, while we don't have a very strong reason to break that
orthogonality.  Once we gain more experience on the use of LLT, we can
of course reconsider this direction.

Rejecting vector-of-pointer types in the IRTranslator is also an option
to avoid the crash reported in PR32471, but that is only a very
short-term solution; also needs quite a bit of code tweaks in places,
and is probably fragile. Therefore I didn't consider this the best
option.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300664 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-19 07:23:57 +00:00
Kristof Beyls
0d04c2b2a9 Revert "[GlobalISel] Support vector-of-pointers in LLT"
This reverts r300535 and r300537.
The newly added tests in test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
produces slightly different code between LLVM versions being built with different compilers.
E.g., dependent on the compiler LLVM is built with, either one of the following
can be produced:

remark: <unknown>:0:0: unable to legalize instruction: %vreg0<def>(p0) = G_EXTRACT_VECTOR_ELT %vreg1, %vreg2; (in function: vector_of_pointers_extractelement)
remark: <unknown>:0:0: unable to legalize instruction: %vreg2<def>(p0) = G_EXTRACT_VECTOR_ELT %vreg1, %vreg0; (in function: vector_of_pointers_extractelement)

Non-determinism like this is clearly a bad thing, so reverting this until
I can find and fix the root cause of the non-determinism.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300538 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-18 09:26:36 +00:00
Kristof Beyls
d18725e897 [GlobalISel] Support vector-of-pointers in LLT
This fixes PR32471.

As comment 10 on that bug report highlights
(https://bugs.llvm.org//show_bug.cgi?id=32471#c10), there are quite a
few different defendable design tradeoffs that could be made, including
not representing pointers at all in LLT.

I decided to go for representing vector-of-pointer as a concept in LLT,
while keeping the size of the LLT type 64 bits (this is an increase from
48 bits before). My rationale for keeping pointers explicit is that on
some targets probably it's very handy to have the distinction between
pointer and non-pointer (e.g. 68K has a different register bank for
pointers IIRC). If we keep a scalar pointer, it probably is easiest to
also have a vector-of-pointers to keep LLT relatively conceptually clean
and orthogonal, while we don't have a very strong reason to break that
orthogonality. Once we gain more experience on the use of LLT, we can
of course reconsider this direction.

Rejecting vector-of-pointer types in the IRTranslator is also an option
to avoid the crash reported in PR32471, but that is only a very
short-term solution; also needs quite a bit of code tweaks in places,
and is probably fragile. Therefore I didn't consider this the best
option.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300535 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-18 08:12:45 +00:00
Daniel Sanders
35c6dd2400 Recommit: [globalisel] Change LLT constructor string into an LLT-based object that knows how to generate it.
Summary:
This will allow future patches to inspect the details of the LLT. The implementation is now split between
the Support and CodeGen libraries to allow TableGen to use this class without introducing layering concerns.

Thanks to Ahmed Bougacha for finding a reasonable way to avoid the layering issue and providing the version of this patch without that problem.

The problem with the previous commit appears to have been that TableGen was including CodeGen/LowLevelType.h instead of Support/LowLevelTypeImpl.h.

Reviewers: t.p.northover, qcolombet, rovka, aditya_nandakumar, ab, javed.absar

Subscribers: arsenm, nhaehnle, mgorny, dberris, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D30046



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297241 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-07 23:20:35 +00:00
Daniel Sanders
428e17c613 Revert r297177: Change LLT constructor string into an LLT-based object ...
More module problems. This time it only showed up in the stage 2 compile of
clang-x86_64-linux-selfhost-modules-2 but not the stage 1 compile.

Somehow, this change causes the build to need Attributes.gen before it's been
generated.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297188 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-07 19:21:23 +00:00
Daniel Sanders
86bbf4372b [globalisel] Change LLT constructor string into an LLT-based object that knows how to generate it.
Summary:
This will allow future patches to inspect the details of the LLT. The implementation is now split between
the Support and CodeGen libraries to allow TableGen to use this class without introducing layering concerns.

Thanks to Ahmed Bougacha for finding a reasonable way to avoid the layering issue and providing the version of this patch without that problem.

Reviewers: t.p.northover, qcolombet, rovka, aditya_nandakumar, ab, javed.absar

Subscribers: arsenm, nhaehnle, mgorny, dberris, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D30046

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297177 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-07 18:32:25 +00:00
Daniel Sanders
1e598cbf73 Revert r296474 - [globalisel] Change LLT constructor string into an LLT subclass that knows how to generate it.
There's a circular dependency that's only revealed when LLVM_ENABLE_MODULES=1.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296478 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-28 15:00:27 +00:00
Daniel Sanders
e0180ef4b8 [globalisel] Change LLT constructor string into an LLT subclass that knows how to generate it.
Summary:
This will allow future patches to inspect the details of the LLT. The implementation is now split between
the Support and CodeGen libraries to allow TableGen to use this class without introducing layering concerns.

Thanks to Ahmed Bougacha for finding a reasonable way to avoid the layering issue and providing the version of this patch without that problem.

Reviewers: t.p.northover, qcolombet, rovka, aditya_nandakumar, ab, javed.absar

Subscribers: arsenm, nhaehnle, mgorny, dberris, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D30046

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296474 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-28 14:21:31 +00:00
Tim Northover
3d94178ab6 GlobalISel: remove "unsized" LLT
It was only really there as a sentinel when instructions had to have precisely
one type. Now that registers are typed, each register really has to have a type
that is sized.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281599 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-15 10:09:59 +00:00
Tim Northover
cdce758a72 GlobalISel: cache pointer sizes in LLT
Otherwise everything that needs to work out what size they are has to keep a
DataLayout handy, which is a bit silly and very annoying.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281597 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-15 09:20:34 +00:00
Tim Northover
b430a4adda GlobalISel: support loads and stores of strange types.
Before we mischaracterized structs and i1 types as a scalar with size 0 in
various ways.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278744 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-15 21:13:17 +00:00
Tim Northover
5b8a0c5c72 GlobalISel: refuse to halve size of 1-byte & odd-sized LLTs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277768 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-04 20:54:05 +00:00
Ahmed Bougacha
eda1b46b87 [GlobalISel] Add LLT::operator!=().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277162 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-29 16:11:04 +00:00
Ahmed Bougacha
ade60aa452 [GlobalISel] Fix LLT::unsized to match LLT(LabelTy).
When coming from an IR label type, we set a 0 NumElements, but not
when constructing an LLT using unsized(), causing comparisons to fail.

Pick one variant and fix the other.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277161 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-29 16:11:02 +00:00
Ahmed Bougacha
1147bf697d [GlobalISel] Add unittests for LowLevelType.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277160 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-29 16:10:57 +00:00