2 Commits

Author SHA1 Message Date
Bjorn Pettersson
8ebb3eac02 [test] Use -passes syntax when specifying pipeline in some more tests
The legacy PM is deprecated, so update a bunch of lit tests running
opt to use the new PM syntax when specifying the pipeline.
In this patch focus has been put on test cases for ConstantMerge,
ConstraintElimination, CorrelatedValuePropagation, GlobalDCE,
GlobalOpt, SCCP, TailCallElim and PredicateInfo.

Differential Revision: https://reviews.llvm.org/D114516
2021-11-27 09:52:55 +01:00
Arthur Eubanks
91ef930526 [GlobalOpt] Remove preallocated calls when possible
When possible (e.g. internal linkage), strip preallocated attribute off
parameters/arguments.
This requires removing the "preallocated" operand bundle from the call
site, replacing @llvm.call.preallocated.arg() with an alloca and a
bitcast to i8*, and removing the @llvm.call.preallocated.setup(). Since
@llvm.call.preallocated.arg() can be called multiple times with the same
arg index, we create an alloca per arg index.
We add a @llvm.stacksave() where the @llvm.call.preallocated.setup() was
and a @llvm.stackrestore() after the preallocated call to prevent the
stack from blowing up. This is valid because the argument would normally
not exist on the stack after the call before the transformation.

This does not currently handle all possible preallocated calls. We will
need to figure out where to put @llvm.stackrestore() in the cases where
there is no obvious place to put it, for example conditional
preallocated calls, invokes.

This sort of transformation may need to be moved to somewhere more
accessible to accomodate similar transformations (like inlining) in the
future.

Reviewers: efriedma, hans

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80951
2020-06-18 09:56:13 -07:00