[Inline] Use AssumptionCache from the right Function

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! Also to Artur Pilipenko
who also saw a fix for the issue.

rdar://22521387

Differential Revision: http://reviews.llvm.org/D12997

llvm-svn: 248390

llvm/lib/Transforms/Utils/InlineFunction.cpp

@@ -741,7 +741,7 @@ static void AddAlignmentAssumptions(CallSite CS, InlineFunctionInfo &IFI) {
       // 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;
 

llvm/test/Transforms/Inline/inline-assume.ll

@@ -0,0 +1,31 @@
+; 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) {
+; CHECK-LABEL: @bar
+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)