hanchenye-llvm-project/llvm/test/Analysis
Mikhail Maltsev ffaa8a8781 [IR] Do not assume that function pointers are aligned
Summary:
The value tracking analysis uses function alignment to infer that the
least significant bits of function pointers are known to be zero.
Unfortunately, this is not correct for ARM targets: the least
significant bit of a function pointer stores the ARM/Thumb state
information (i.e., the LSB is set for Thumb functions and cleared for
ARM functions).

The original approach (https://reviews.llvm.org/D44781) introduced a
new field for function pointer alignment in the DataLayout structure
to address this. But it seems unlikely that optimizations based on
function pointer alignment would bring much benefit in practice to
justify the additional maintenance burden, so this patch simply
assumes that function pointer alignment is always unknown.

Reviewers: javed.absar, efriedma

Reviewed By: efriedma

Subscribers: kristof.beyls, llvm-commits, hfinkel, rogfer01

Differential Revision: https://reviews.llvm.org/D46110

llvm-svn: 331025
2018-04-27 09:12:12 +00:00
..
AliasSet
AssumptionCache
BasicAA [BasicAA] Return MayAlias for the pointer plus variable offset to 2018-04-16 01:58:39 +00:00
BlockFrequencyInfo
BranchProbabilityInfo
CFLAliasAnalysis
CallGraph
ConstantFolding [ConstantFolding, InstSimplify] Handle more vector GEPs 2018-03-15 16:00:29 +00:00
CostModel [TTI, AArch64] Add transpose shuffle kind 2018-04-26 13:48:33 +00:00
Delinearization
DemandedBits
DependenceAnalysis [DA] Improve alias checking in dependence analysis 2018-04-10 11:37:21 +00:00
DivergenceAnalysis AMDGPU: Dimension-aware image intrinsics 2018-04-04 10:58:54 +00:00
DominanceFrontier
Dominators
GlobalsModRef
IVUsers
LazyCallGraph
LazyValueAnalysis
Lint
LoopAccessAnalysis
LoopInfo
MemoryDependenceAnalysis
MemorySSA [MemorySSA] Consider callsite args for hashing and equality. 2018-03-29 00:54:39 +00:00
MustExecute [MustExecute] Shwo the effect of using full loop info variant 2018-03-20 23:00:54 +00:00
PostDominators
ProfileSummary
RegionInfo
ScalarEvolution Revert "[SCEV] Make computeExitLimit more simple and more powerful" 2018-04-26 02:07:40 +00:00
ScopedNoAliasAA
TypeBasedAliasAnalysis
ValueTracking [IR] Do not assume that function pointers are aligned 2018-04-27 09:12:12 +00:00
alias-analysis-uses.ll