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
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 008edbe..432e3ee 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -5257,6 +5257,23 @@
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 @@
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 @@
/// 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,