[Inline] Use AssumptionCache from the right Function

[vsk]

Summary

This changes the behavior of AddAligntmentAssumptions to match its
comment. I.e, prove the asserted alignment in the context of the caller,
not the callee.

Thanks to Mehdi Amini for seeing the issue here!

[vsk]

• Fix CHECK line typo.

[mehdi_amini]

test/Transforms/Inline/inline-assume.ll

12

You don't really check that bar was indeed inlined, because this would match the content of bar.
I think there should be *after* that a CHECK-LABEL for bar()

[vsk]

• Check whether @bar is actually inlined.

[hfinkel]

This is the same fix as D12957, and also LGTM.

lib/Transforms/Utils/InlineFunction.cpp

                                                ->getParent()));
         DTCalculated = true;
       }
 
       // If we can already prove the asserted alignment in the context of the
       // caller, then don't bother inserting the assumption.
       Value *Arg = CS.getArgument(I->getArgNo());
       if (getKnownAlignment(Arg, DL, CS.getInstruction(),
-                            &IFI.ACT->getAssumptionCache(*CalledFunc),
+                            &IFI.ACT->getAssumptionCache(*CS.getCaller()),
                             &DT) >= Align)
         continue;
 
       IRBuilder<>(CS.getInstruction())
           .CreateAlignmentAssumption(DL, Arg, Align);
     }
   }
 }

test/Transforms/Inline/inline-assume.ll

+; RUN: opt -inline -S -o - < %s | FileCheck %s
+
+%0 = type opaque
+%struct.Foo = type { i32, %0* }
+
+; Test that we don't crash when inlining @bar (rdar://22521387).
+define void @foo(%struct.Foo* align 4 %a) {
+entry:
+  call fastcc void @bar(%struct.Foo* nonnull align 4 undef)
+
+; CHECK: call void @llvm.assume(i1 undef)
+; CHECK: unreachable
+
+  ret void
+}
+
+define fastcc void @bar(%struct.Foo* align 4 %a) {
+entry:
+  %b = getelementptr inbounds %struct.Foo, %struct.Foo* %a, i32 0, i32 1
+  br i1 undef, label %if.end, label %if.then.i.i
+
+if.then.i.i:
+  call void @llvm.assume(i1 undef)
+  unreachable
+
+if.end:
+  ret void
+}
+
+declare void @llvm.assume(i1)