Reland r374450 with Richard Smith's comments and test fixed.

The behavior from the original patch has changed, since we're no longer
allowing LLVM to just ignore the alignment.  Instead, we're just
assuming the maximum possible alignment.

Differential Revision: https://reviews.llvm.org/D68824

llvm-svn: 374562

1 files changed, 1 insertions, 16 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 41b7f2f4b1be..3f9a52ab7638 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -2057,24 +2057,9 @@ void CodeGenFunction::EmitAlignmentAssumption(llvm::Value *PtrValue,
 }
 
 void CodeGenFunction::EmitAlignmentAssumption(llvm::Value *PtrValue,
-                                              QualType Ty, SourceLocation Loc,
-                                              SourceLocation AssumptionLoc,
-                                              unsigned Alignment,
-                                              llvm::Value *OffsetValue) {
-  llvm::Value *TheCheck;
-  llvm::Instruction *Assumption = Builder.CreateAlignmentAssumption(
-      CGM.getDataLayout(), PtrValue, Alignment, OffsetValue, &TheCheck);
-  if (SanOpts.has(SanitizerKind::Alignment)) {
-    llvm::Value *AlignmentVal = llvm::ConstantInt::get(IntPtrTy, Alignment);
-    EmitAlignmentAssumptionCheck(PtrValue, Ty, Loc, AssumptionLoc, AlignmentVal,
-                                 OffsetValue, TheCheck, Assumption);
-  }
-}
-
-void CodeGenFunction::EmitAlignmentAssumption(llvm::Value *PtrValue,
                                               const Expr *E,
                                               SourceLocation AssumptionLoc,
-                                              unsigned Alignment,
+                                              llvm::Value *Alignment,
                                               llvm::Value *OffsetValue) {
   if (auto *CE = dyn_cast<CastExpr>(E))
     E = CE->getSubExprAsWritten();