Following some recent discussions, this changes the representation
of callbrs in IR. The current blockaddress arguments are replaced
with `!` label constraints that refer directly to callbr indirect
destinations:
; Before:
%res = callbr i8* asm "", "=r,r,i"(i8* %x, i8* blockaddress(@test8, %foo))
to label %asm.fallthrough [label %foo]
; After:
%res = callbr i8* asm "", "=r,r,!i"(i8* %x)
to label %asm.fallthrough [label %foo]
The benefit of this is that we can easily update the successors of
a callbr, without having to worry about also updating blockaddress
references. This should allow us to remove some limitations:
* Allow unrolling/peeling/rotation of callbr, or any other
clone-based optimizations
(https://github.com/llvm/llvm-project/issues/41834)
* Allow duplicate successors
(https://github.com/llvm/llvm-project/issues/45248)
This is just the IR representation change though, I will follow up
with patches to remove limtations in various transformation passes
that are no longer needed.
Differential Revision: https://reviews.llvm.org/D129288
In D115311, we're looking to modify clang to emit i constraints rather
than X constraints for callbr's indirect destinations. Prior to doing
so, update all of the existing tests in llvm/ to match.
Reviewed By: void, jyknight
Differential Revision: https://reviews.llvm.org/D115410
A ConstantStruct is renamed when the LLVM context sees a new one. This
makes global variable initializers appear different when they aren't.
Instead, check the ConstantStruct for equivalence.
Differential Revision: https://reviews.llvm.org/D104734
Global initializers may be ConstantArrays. They need to be checked
explicitly, because different-yet-still-equivalent type names may be
used for each, and/or a GEP instruction may appear in one.
The only wrinkle is that we can't process the "blockaddress" arguments
of the callbr until the blocks have been equated. So we force them to be
"unified" before checking.
This was left out when the callbr instruction was added.
Differential Revision: https://reviews.llvm.org/D104606
Summary:
llvm-diff incorrectly reports that there's a diff when input IR contains undef/zeroinitializer/constantvector/indirectbr.
(This happens even if two identical files are given, e.g. `llvm-diff x.ll x.ll`)
This is fix to the bug report https://bugs.llvm.org/show_bug.cgi?id=33623 .
Reviewers: dexonsmith, rjmccall
Reviewed By: rjmccall
Subscribers: chenwj, mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D34856
llvm-svn: 329957
