Use vld1 / vst2 for unaligned v2f64 load / store. e.g. Use vld1.16 for 2-byte
aligned address. Based on patch by David Peixotto.
Also use vld1.64 / vst1.64 with 128-bit alignment to take advantage of alignment
hints. rdar://12090772, rdar://12238782
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164089 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index f530c5d..9ef33b8 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -9025,8 +9025,8 @@
}
bool ARMTargetLowering::allowsUnalignedMemoryAccesses(EVT VT) const {
- if (!Subtarget->allowsUnalignedMem())
- return false;
+ // The AllowsUnaliged flag models the SCTLR.A setting in ARM cpus
+ bool AllowsUnaligned = Subtarget->allowsUnalignedMem();
switch (VT.getSimpleVT().SimpleTy) {
default:
@@ -9034,10 +9034,14 @@
case MVT::i8:
case MVT::i16:
case MVT::i32:
- return true;
+ // Unaligned access can use (for example) LRDB, LRDH, LDR
+ return AllowsUnaligned;
case MVT::f64:
- return Subtarget->hasNEON();
- // FIXME: VLD1 etc with standard alignment is legal.
+ case MVT::v2f64:
+ // For any little-endian targets with neon, we can support unaligned ld/st
+ // of D and Q (e.g. {D0,D1}) registers by using vld1.i8/vst1.i8.
+ // A big-endian target may also explictly support unaligned accesses
+ return Subtarget->hasNEON() && (AllowsUnaligned || isLittleEndian());
}
}