Commit 6e83d91d authored by Hans Wennborg's avatar Hans Wennborg
Browse files

Merging r310071: 

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r310071 | rnk | 2017-08-04 10:09:11 -0700 (Fri, 04 Aug 2017) | 8 lines

[ArgPromotion] Preserve alignment of byval argument in new alloca

The frontend may have requested a higher alignment for any reason, and
downstream optimizations may already have taken advantage of it.  We
should keep the same alignment when moving the allocation from the
parameter area to the local variable area.

Fixes PR34038
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llvm-svn: 310292
parent 8bfea7d1

llvm/lib/Transforms/IPO/ArgumentPromotion.cpp

+1 −1
Original line number Diff line number Diff line
@@ -356,7 +356,7 @@ doPromotion(Function *F, SmallPtrSetImpl<Argument *> &ArgsToPromote, 
      // Just add all the struct element types.

      Type *AgTy = cast<PointerType>(I->getType())->getElementType();

      Value *TheAlloca = new AllocaInst(AgTy, DL.getAllocaAddrSpace(), nullptr,

                                        "", InsertPt);

                                        I->getParamAlignment(), "", InsertPt);

      StructType *STy = cast<StructType>(AgTy);

      Value *Idxs[2] = {ConstantInt::get(Type::getInt32Ty(F->getContext()), 0),

                        nullptr};

llvm/test/Transforms/ArgumentPromotion/byval.ll

+30 −9
Original line number Diff line number Diff line
@@ -6,24 +6,45 @@ target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:1 
%struct.ss = type { i32, i64 }



define internal void @f(%struct.ss* byval  %b) nounwind  {

entry:

  %tmp = getelementptr %struct.ss, %struct.ss* %b, i32 0, i32 0

  %tmp1 = load i32, i32* %tmp, align 4

  %tmp2 = add i32 %tmp1, 1

  store i32 %tmp2, i32* %tmp, align 4

  ret void

}



; CHECK-LABEL: define internal void @f(i32 %b.0, i64 %b.1)

; CHECK: alloca %struct.ss{{$}}

; CHECK: store i32 %b.0

; CHECK: store i64 %b.1



define internal void @g(%struct.ss* byval align 32 %b) nounwind {

entry:

  %tmp = getelementptr %struct.ss, %struct.ss* %b, i32 0, i32 0		; <i32*> [#uses=2]

  %tmp1 = load i32, i32* %tmp, align 4		; <i32> [#uses=1]

  %tmp2 = add i32 %tmp1, 1		; <i32> [#uses=1]

  %tmp = getelementptr %struct.ss, %struct.ss* %b, i32 0, i32 0

  %tmp1 = load i32, i32* %tmp, align 4

  %tmp2 = add i32 %tmp1, 1

  store i32 %tmp2, i32* %tmp, align 4

  ret void

}



; CHECK-LABEL: define internal void @g(i32 %b.0, i64 %b.1)

; CHECK: alloca %struct.ss, align 32

; CHECK: store i32 %b.0

; CHECK: store i64 %b.1



define i32 @main() nounwind  {

; CHECK-LABEL: define i32 @main

entry:

  %S = alloca %struct.ss		; <%struct.ss*> [#uses=4]

  %tmp1 = getelementptr %struct.ss, %struct.ss* %S, i32 0, i32 0		; <i32*> [#uses=1]

  %S = alloca %struct.ss

  %tmp1 = getelementptr %struct.ss, %struct.ss* %S, i32 0, i32 0

  store i32 1, i32* %tmp1, align 8

  %tmp4 = getelementptr %struct.ss, %struct.ss* %S, i32 0, i32 1		; <i64*> [#uses=1]

  %tmp4 = getelementptr %struct.ss, %struct.ss* %S, i32 0, i32 1

  store i64 2, i64* %tmp4, align 4

  call void @f(%struct.ss* byval %S) nounwind

; CHECK: call void @f(i32 %{{.*}}, i64 %{{.*}})

  call void @g(%struct.ss* byval %S) nounwind

  ret i32 0

}



; CHECK-LABEL: define i32 @main

; CHECK: call void @f(i32 %{{.*}}, i64 %{{.*}})

; CHECK: call void @g(i32 %{{.*}}, i64 %{{.*}})