llvm-project.git/llvm/test/Bitcode/callbr.ll, branch users/nico/python-2

[Bitcode] Remove auto-detection for typed pointers

2022-12-14T12:38:20+00:00

Always read bitcode according to the -opaque-pointers mode. Do not
perform auto-detection to implicitly switch to typed pointers.

This is a step towards removing typed pointer support, and also
eliminates the class of problems where linking may fail if a typed
pointer module is loaded before an opaque pointer module. (The
latest place where this was encountered is D139924, but this has
previously been fixed in other places doing bitcode linking as well.)

Differential Revision: https://reviews.llvm.org/D139940

[IR] Don't use blockaddresses as callbr arguments

2022-07-15T08:18:17+00:00

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

[Bitcode] Add additional callbr tests (NFC)

2022-07-11T14:46:21+00:00

Additional coverage for the auto-upgrade code in D129288.

[llvm][test] rewrite callbr to use i rather than X constraint NFC

2022-01-11T19:31:08+00:00

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

[Opaqueptrs][IR Serialization] Improve inlineasm [de]serialization

2021-12-30T10:54:37+00:00

The bitcode reader expected that the pointers are typed,
so that it can extract the function type for the assembly
so `bitc::CST_CODE_INLINEASM` did not explicitly store said function type.

I'm not really sure how the upgrade path will look for existing bitcode,
but i think we can easily support opaque pointers going forward,
by simply storing the function type.

Reviewed By: #opaque-pointers, nikic

Differential Revision: https://reviews.llvm.org/D116341

Implementation of asm-goto support in LLVM

2019-02-08T20:48:56+00:00

This patch accompanies the RFC posted here:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html

This patch adds a new CallBr IR instruction to support asm-goto
inline assembly like gcc as used by the linux kernel. This
instruction is both a call instruction and a terminator
instruction with multiple successors. Only inline assembly
usage is supported today.

This also adds a new INLINEASM_BR opcode to SelectionDAG and
MachineIR to represent an INLINEASM block that is also
considered a terminator instruction.

There will likely be more bug fixes and optimizations to follow
this, but we felt it had reached a point where we would like to
switch to an incremental development model.

Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii

Differential Revision: https://reviews.llvm.org/D53765

llvm-svn: 353563