[llvm] r295762 - Fix PR31896.

[Evgenii Stepanov via llvm-commits]

Could this change be merged to 4.0?

On Tue, Feb 21, 2017 at 12:17 PM, Evgeniy Stepanov via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: eugenis
> Date: Tue Feb 21 14:17:34 2017
> New Revision: 295762
>
> URL: http://llvm.org/viewvc/llvm-project?rev=295762&view=rev
> Log:
> Fix PR31896.
>
> Address of an alias of a global with offset is incorrectly lowered as an address of the global (i.e. ignoring offset).
>
> Added:
>     llvm/trunk/test/CodeGen/ARM/alias_store.ll
> Modified:
>     llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp
>
> Modified: llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp?rev=295762&r1=295761&r2=295762&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp (original)
> +++ llvm/trunk/lib/Target/ARM/ARMISelLowering.cpp Tue Feb 21 14:17:34 2017
> @@ -3077,17 +3077,20 @@ static SDValue promoteToConstantPool(con
>    return DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
>  }
>
> +static bool isReadOnly(const GlobalValue *GV) {
> +  if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV))
> +    GV = GA->getBaseObject();
> +  return (isa<GlobalVariable>(GV) && cast<GlobalVariable>(GV)->isConstant()) ||
> +         isa<Function>(GV);
> +}
> +
>  SDValue ARMTargetLowering::LowerGlobalAddressELF(SDValue Op,
>                                                   SelectionDAG &DAG) const {
>    EVT PtrVT = getPointerTy(DAG.getDataLayout());
>    SDLoc dl(Op);
>    const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
>    const TargetMachine &TM = getTargetMachine();
> -  if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV))
> -    GV = GA->getBaseObject();
> -  bool IsRO =
> -      (isa<GlobalVariable>(GV) && cast<GlobalVariable>(GV)->isConstant()) ||
> -      isa<Function>(GV);
> +  bool IsRO = isReadOnly(GV);
>
>    // promoteToConstantPool only if not generating XO text section
>    if (TM.shouldAssumeDSOLocal(*GV->getParent(), GV) && !Subtarget->genExecuteOnly())
>
> Added: llvm/trunk/test/CodeGen/ARM/alias_store.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/alias_store.ll?rev=295762&view=auto
> ==============================================================================
> --- llvm/trunk/test/CodeGen/ARM/alias_store.ll (added)
> +++ llvm/trunk/test/CodeGen/ARM/alias_store.ll Tue Feb 21 14:17:34 2017
> @@ -0,0 +1,16 @@
> +; RUN: llc < %s -mtriple=arm-linux-gnueabi | FileCheck %s
> +
> + at X = constant {i8, i8 } { i8 0, i8 0 }
> + at XA = alias i8, getelementptr inbounds ({ i8, i8 }, {i8, i8}* @X, i32 0, i32 1)
> +
> +define void @f(i8** %p) align 2 {
> +entry:
> +  store i8* @XA, i8 **%p, align 4
> +  ret void
> +}
> +
> +; CHECK: f:
> +; CHECK: ldr r{{.*}}, [[L:.*]]
> +; CHECK: [[L]]:
> +; CHECK-NEXT: .long XA
> +; CHECK: XA = X+1
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits