Revert "[AssumeBundles] Use operand bundles to encode alignment assumptions"

Assume bundle can have more than one entry with the same name,
but at least AlignmentFromAssumptionsPass::extractAlignmentInfo() uses
getOperandBundle("align"), which internally assumes that it isn't the
case, and happily crashes otherwise.

Minimal reduced reproducer: run `opt -alignment-from-assumptions` on

target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%0 = type { i64, %1*, i8*, i64, %2, i32, %3*, i8* }
%1 = type opaque
%2 = type { i8, i8, i16 }
%3 = type { i32, i32, i32, i32 }

; Function Attrs: nounwind
define i32 @f(%0* noalias nocapture readonly %arg, %0* noalias %arg1) local_unnamed_addr #0 {
bb:
  call void @llvm.assume(i1 true) [ "align"(%0* %arg, i64 8), "align"(%0* %arg1, i64 8) ]
  ret i32 0
}

; Function Attrs: nounwind willreturn
declare void @llvm.assume(i1) #1

attributes #0 = { nounwind "reciprocal-estimates"="none" }
attributes #1 = { nounwind willreturn }


This is what we'd have with -mllvm -enable-knowledge-retention

This reverts commit c95ffadb2474a4d8c4f598d94d35a9f31d9606cb.

1 files changed, 5 insertions, 31 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index cfd32d1..babb0ea 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -2154,39 +2154,13 @@ void CodeGenFunction::emitAlignmentAssumption(llvm::Value *PtrValue,
                                               SourceLocation AssumptionLoc,
                                               llvm::Value *Alignment,
                                               llvm::Value *OffsetValue) {
-  if (Alignment->getType() != IntPtrTy)
-    Alignment =
-        Builder.CreateIntCast(Alignment, IntPtrTy, false, "casted.align");
-  if (OffsetValue && OffsetValue->getType() != IntPtrTy)
-    OffsetValue =
-        Builder.CreateIntCast(OffsetValue, IntPtrTy, true, "casted.offset");
-  llvm::Value *TheCheck = nullptr;
+  llvm::Value *TheCheck;
+  llvm::Instruction *Assumption = Builder.CreateAlignmentAssumption(
+      CGM.getDataLayout(), PtrValue, Alignment, OffsetValue, &TheCheck);
   if (SanOpts.has(SanitizerKind::Alignment)) {
-    llvm::Value *PtrIntValue =
-        Builder.CreatePtrToInt(PtrValue, IntPtrTy, "ptrint");
-
-    if (OffsetValue) {
-      bool IsOffsetZero = false;
-      if (const auto *CI = dyn_cast<llvm::ConstantInt>(OffsetValue))
-        IsOffsetZero = CI->isZero();
-
-      if (!IsOffsetZero)
-        PtrIntValue = Builder.CreateSub(PtrIntValue, OffsetValue, "offsetptr");
-    }
-
-    llvm::Value *Zero = llvm::ConstantInt::get(IntPtrTy, 0);
-    llvm::Value *Mask =
-        Builder.CreateSub(Alignment, llvm::ConstantInt::get(IntPtrTy, 1));
-    llvm::Value *MaskedPtr = Builder.CreateAnd(PtrIntValue, Mask, "maskedptr");
-    TheCheck = Builder.CreateICmpEQ(MaskedPtr, Zero, "maskcond");
+    emitAlignmentAssumptionCheck(PtrValue, Ty, Loc, AssumptionLoc, Alignment,
+                                 OffsetValue, TheCheck, Assumption);
   }
-  llvm::Instruction *Assumption = Builder.CreateAlignmentAssumption(
-      CGM.getDataLayout(), PtrValue, Alignment, OffsetValue);
-
-  if (!SanOpts.has(SanitizerKind::Alignment))
-    return;
-  emitAlignmentAssumptionCheck(PtrValue, Ty, Loc, AssumptionLoc, Alignment,
-                               OffsetValue, TheCheck, Assumption);
 }
 
 void CodeGenFunction::emitAlignmentAssumption(llvm::Value *PtrValue,