When inferring that a GEP of a global variable is inbounds because
there is no notional overindexing, we need to check that the
global value type and the GEP source element type match.
This was not necessary with typed pointers (because we would have
a bitcast in between), but is necessary with opaque pointers.
We should be able to recover some of the safe cases by performing
an offset based inbounds inference in DL-aware ConstantFolding.
Had constantexprs be mangled by the opaquify script; had to update
those lines manually:
NVPTX/bug31948.ll
AMDGPU/old-pass-regressions.ll
AMDGPU/old-pass-regressions-inseltpoison.ll
AMDGPU/infer-address-space.ll
Required re-reunning update_test_checks:
AMDGPU/redundant-addrspacecast.ll
In AMDGPU/insert-pos-assert.ll, bitcast_insert_pos_assert_2 deleted a
getelementptr of 0 which I'm guessing was relevant. Replaced with an
offset 1 GEP to ensure another addrspacecast is inserted.
AMDGPU/infer-getelementptr.ll had one case improve by introducing an
inbounds.
Summary:
- Constant expressions may not be added in strict postorder as the
forward instruction scan order. Thus, for a constant express (CE0), if
its operand (CE1) is used in an previous instruction, they are not in
postorder. However, different from
`cloneInstructionWithNewAddressSpace`,
`cloneConstantExprWithNewAddressSpace` doesn't bookkeep uninferred
instructions for later resolving. That results in failure of inferring
constant address.
- This patch adds the support to infer constant expression operand
recursively, since there won't be loop, if that operand is another
constant expression.
Reviewers: arsenm
Subscribers: jholewinski, jvesely, wdng, nhaehnle, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61760
llvm-svn: 360431
As it's causing some bot failures (and per request from kbarton).
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.
llvm-svn: 358546
Eliminates some more cases where some subset of the addressing
computation remains flat. Some cases with addrspacecasts
in nested constant expressions are still left behind however.
llvm-svn: 301704
Fixes leaving intermediate flat addressing computations
where a GEP instruction's source is a constant expression.
Still leaves behind a trivial addrspacecast + gep pair that
instcombine is able to handle, which ideally could be folded
here directly.
llvm-svn: 301044
