Revert "InstCombine rule to fold trunc when value available"

This reverts commit r273608.

Broke building code with sanitizers, where apparently these kinds of
loads, casts, and truncations are common:

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/24502
http://crbug.com/623099

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273703 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 32 deletions

diff --git a/include/llvm/Analysis/Loads.h b/include/llvm/Analysis/Loads.h
index cf1f5bbfb44..9d24b7b2928 100644
--- a/include/llvm/Analysis/Loads.h
+++ b/include/llvm/Analysis/Loads.h
@@ -61,38 +61,6 @@ bool isSafeToLoadUnconditionally(Value *V, unsigned Align,
 /// to scan in the block, used by FindAvailableLoadedValue().
 extern cl::opt<unsigned> DefMaxInstsToScan;
 
-/// Scan the ScanBB block backwards checking to see if we have the value at
-/// the memory address \p Ptr of type \p AccessTy locally available within a
-/// small number of instructions. If the value is available, return it.
-///
-/// If not, return the iterator for the last validated instruction that the
-/// value would be live through.  If we scanned the entire block and didn't
-/// find something that invalidates *Ptr or provides it, ScanFrom would be
-/// left at begin() and this returns null.  ScanFrom could also be left
-///
-/// MaxInstsToScan specifies the maximum instructions to scan in the block.
-/// If it is set to 0, it will scan the whole block. You can also optionally
-/// specify an alias analysis implementation, which makes this more precise.
-///
-/// If AATags is non-null and a load or store is found, the AA tags from the
-/// load or store are recorded there.  If there are no AA tags or if no access
-/// is found, it is left unmodified.
-///
-/// IsAtomicMemOp specifies the atomicity of the memory operation that accesses
-/// \p *Ptr. We verify atomicity constraints are satisfied when value forwarding
-/// from another memory operation that has value \p *Ptr available.
-///
-/// Note that we assume the \p *Ptr is accessed through a non-volatile but
-/// potentially atomic load. Any other constraints should be verified at the
-/// caller.
-Value *FindAvailableLoadedValue(Value *Ptr, Type *AccessTy, bool IsAtomicMemOp,
-                                BasicBlock *ScanBB,
-                                BasicBlock::iterator &ScanFrom,
-                                unsigned MaxInstsToScan,
-                                AliasAnalysis *AA = nullptr,
-                                AAMDNodes *AATags = nullptr,
-                                bool *IsLoadCSE = nullptr);
-
 /// FindAvailableLoadedValue - Scan the ScanBB block backwards (starting at
 /// the instruction before ScanFrom) checking to see if we have the value at
 /// the memory address *Ptr locally available within a small number of