ARM ISel: Don't create illegal types during LowerMUL

The transformation happening here is that we want to turn a
"mul(ext(X), ext(X))" into a "vmull(X, X)", stripping off the extension. We have
to make sure that X still has a valid vector type - possibly recreate an
extension to a smaller type. In case of a extload of a memory type smaller than
64 bit we used create a ext(load()). The problem with doing this - instead of
recreating an extload - is that an illegal type is exposed.

This patch fixes this by creating extloads instead of ext(load()) sequences.

Fixes PR15970.

radar://13871383

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181842 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Arnold Schwaighofer 2013-05-14 22:33:24 +00:00
parent 5150270d07
commit 101a36117c
2 changed files with 56 additions and 25 deletions

View File

@ -5257,6 +5257,23 @@ static bool isZeroExtended(SDNode *N, SelectionDAG &DAG) {
return false;
}
static EVT getExtensionTo64Bits(const EVT &OrigVT) {
if (OrigVT.getSizeInBits() >= 64)
return OrigVT;
assert(OrigVT.isSimple() && "Expecting a simple value type");
MVT::SimpleValueType OrigSimpleTy = OrigVT.getSimpleVT().SimpleTy;
switch (OrigSimpleTy) {
default: llvm_unreachable("Unexpected Vector Type");
case MVT::v2i8:
case MVT::v2i16:
return MVT::v2i32;
case MVT::v4i8:
return MVT::v4i16;
}
}
/// AddRequiredExtensionForVMULL - Add a sign/zero extension to extend the total
/// value size to 64 bits. We need a 64-bit D register as an operand to VMULL.
/// We insert the required extension here to get the vector to fill a D register.
@ -5272,18 +5289,8 @@ static SDValue AddRequiredExtensionForVMULL(SDValue N, SelectionDAG &DAG,
return N;
// Must extend size to at least 64 bits to be used as an operand for VMULL.
MVT::SimpleValueType OrigSimpleTy = OrigTy.getSimpleVT().SimpleTy;
EVT NewVT;
switch (OrigSimpleTy) {
default: llvm_unreachable("Unexpected Orig Vector Type");
case MVT::v2i8:
case MVT::v2i16:
NewVT = MVT::v2i32;
break;
case MVT::v4i8:
NewVT = MVT::v4i16;
break;
}
EVT NewVT = getExtensionTo64Bits(OrigTy);
return DAG.getNode(ExtOpcode, N->getDebugLoc(), NewVT, N);
}
@ -5293,22 +5300,22 @@ static SDValue AddRequiredExtensionForVMULL(SDValue N, SelectionDAG &DAG,
/// reach a total size of 64 bits. We have to add the extension separately
/// because ARM does not have a sign/zero extending load for vectors.
static SDValue SkipLoadExtensionForVMULL(LoadSDNode *LD, SelectionDAG& DAG) {
SDValue NonExtendingLoad =
DAG.getLoad(LD->getMemoryVT(), LD->getDebugLoc(), LD->getChain(),
EVT ExtendedTy = getExtensionTo64Bits(LD->getMemoryVT());
// The load already has the right type.
if (ExtendedTy == LD->getMemoryVT())
return DAG.getLoad(LD->getMemoryVT(), LD->getDebugLoc(), LD->getChain(),
LD->getBasePtr(), LD->getPointerInfo(), LD->isVolatile(),
LD->isNonTemporal(), LD->isInvariant(),
LD->getAlignment());
unsigned ExtOp = 0;
switch (LD->getExtensionType()) {
default: llvm_unreachable("Unexpected LoadExtType");
case ISD::EXTLOAD:
case ISD::SEXTLOAD: ExtOp = ISD::SIGN_EXTEND; break;
case ISD::ZEXTLOAD: ExtOp = ISD::ZERO_EXTEND; break;
}
MVT::SimpleValueType MemType = LD->getMemoryVT().getSimpleVT().SimpleTy;
MVT::SimpleValueType ExtType = LD->getValueType(0).getSimpleVT().SimpleTy;
return AddRequiredExtensionForVMULL(NonExtendingLoad, DAG,
MemType, ExtType, ExtOp);
// We need to create a zextload/sextload. We cannot just create a load
// followed by a zext/zext node because LowerMUL is also run during normal
// operation legalization where we can't create illegal types.
return DAG.getExtLoad(LD->getExtensionType(), LD->getDebugLoc(), ExtendedTy,
LD->getChain(), LD->getBasePtr(), LD->getPointerInfo(),
LD->getMemoryVT(), LD->isVolatile(),
LD->isNonTemporal(), LD->getAlignment());
}
/// SkipExtensionForVMULL - For a node that is a SIGN_EXTEND, ZERO_EXTEND,

View File

@ -599,3 +599,27 @@ for.end179: ; preds = %for.cond.loopexit,
declare <8 x i16> @llvm.arm.neon.vrshiftu.v8i16(<8 x i16>, <8 x i16>) nounwind readnone
declare <8 x i16> @llvm.arm.neon.vqsubu.v8i16(<8 x i16>, <8 x i16>) nounwind readnone
declare <8 x i8> @llvm.arm.neon.vqmovnu.v8i8(<8 x i16>) nounwind readnone
; vmull lowering would create a zext(v4i8 load()) instead of a zextload(v4i8),
; creating an illegal type during legalization and causing an assert.
; PR15970
define void @no_illegal_types_vmull_sext(<4 x i32> %a) {
entry:
%wide.load283.i = load <4 x i8>* undef, align 1
%0 = sext <4 x i8> %wide.load283.i to <4 x i32>
%1 = sub nsw <4 x i32> %0, %a
%2 = mul nsw <4 x i32> %1, %1
%predphi290.v.i = select <4 x i1> undef, <4 x i32> undef, <4 x i32> %2
store <4 x i32> %predphi290.v.i, <4 x i32>* undef, align 4
ret void
}
define void @no_illegal_types_vmull_zext(<4 x i32> %a) {
entry:
%wide.load283.i = load <4 x i8>* undef, align 1
%0 = zext <4 x i8> %wide.load283.i to <4 x i32>
%1 = sub nsw <4 x i32> %0, %a
%2 = mul nsw <4 x i32> %1, %1
%predphi290.v.i = select <4 x i1> undef, <4 x i32> undef, <4 x i32> %2
store <4 x i32> %predphi290.v.i, <4 x i32>* undef, align 4
ret void
}