[AArch64][SVE] Fold vector ZExt/SExt into gather loads where possible

[joechrisellis]

Summary

This commit folds sign- or zero-extended offsets into gather loads where
possible with a DAGCombine optimization.

As an example, the following code:

1	#include <arm_sve.h>
2
3	svuint64_t func(svbool_t pred, const int32_t *base, svint64_t offsets) {
4	  return svld1sw_gather_s64offset_u64(
5	    pred, base, svextw_s64_x(pred, offsets)
6	  );
7	}

would previously lower to the following assembly:

sxtw	z0.d, p0/m, z0.d
ld1sw	{ z0.d }, p0/z, [x0, z0.d]
ret

but now lowers to:

ld1sw   { z0.d }, p0/z, [x0, z0.d, sxtw]
ret

[david-arm]

Adding @kmclaughlin as reviewer since she did a lot of the gather/scatter lowering work.

[david-arm]

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

14452

Do we not need to check the type we're extending from here? For example, what if we're extending from a vector of i8s, which isn't tested below?

[peterwaller-arm]

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

14421

This comment (and below) is merely a re-expression of the code on the next line, where a message indicating the intent may be more useful -- something like "Fold sign/zero extensions of vector offsets into GLD1 nodes where possible".

[joechrisellis]

Address comments.

• @david-arm: make sure that we only fold in {u,s}xtws, not just any sign-/zero-extension.
• @peterwaller-arm: comment clarifications.

[joechrisellis]

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

14452

Great spot -- thank you. Turns out we can only fold in {u,s}xtws (w being the key part). :)

[kmclaughlin]

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

14407–14411

nit: I think it might make the code below a bit clearer if these variables were named similarly to the comments accompanying them, i.e. Chain, Pred, Base, etc

14422

Can we remove some of the indentation below by returning SDValue() here if the offset isn't extended instead?

14450

There were some helper functions added for LowerMGATHER which I think you might be able to use here to get the right gather opcode (getGatherVecOpcode & getSignExtendedGatherOpcode).
As an example:

...
case GLD1_MERGE_ZERO:
case GLD1S_MERGE_ZERO:
  getGatherVecOpcode(false /*Scaled*/, OffsetIsSext, true /*NeedsExtend*/);
case GLD1_SCALED_MERGE_ZERO:
case GLD1_SCALED_MERGE_ZERO:
  getGatherVecOpcode(true /*Scaled*/, OffsetIsSext, true /*NeedsExtend*/);
...
if (Opc == GLD1S_MERGE_ZERO || Opc == GLD1S_SCALED_MERGE_ZERO)
  NewOpc = getSignExtendedGatherOpcode(NewOp);

[joechrisellis]

Address review comments.

• @kmclaughlin:
  • better variable names.
  • use helper functions to determine new opcode for gather load.

I've also made the function a little more general, since we might want to extend this function to capture other optimisation patterns in the future.

[joechrisellis]

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

14422

I would prefer to leave this as-is, because this was an intentional decision. It's possible that we might want to extend this function with a new optimisation pattern. It'd be easier to extend the function in its current state than it would be with the early return. 🙂

14450

Thanks, that's cleaned things up a lot. 🙂

[david-arm]

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

14419

Are these opcodes in a range, i.e. could you assert something like:

assert((Opc >= Op1 && Opc <= Op2) || (Opc >= Op3 && Opc <= Op4))

It might make the assert look a bit nicer perhaps?

14430

In fact, you could move the above assert here instead and have something like:

assert(Scaled || Signed || SExt || ZExt)

maybe?

15850

I wonder if you maybe want to make the combine function simpler for now in terms of asserts and checking by only passing in the opcodes that you actually intend to combine? If later on you want to add more then it's easy enough to update. This is just a suggestion though.

[joechrisellis]

Address comments.

• @david-arm: clean up assertion by using ranges instead of explicitly listing all allowed opcodes.

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

14419

Much nicer -- thank you!

I've split it into two ranges -- one for unsigned gather loads, and one for signed gather loads.

assert(((Opc >= AArch64ISD::GLD1_MERGE_ZERO && // unsigned gather loads
         Opc <= AArch64ISD::GLD1_IMM_MERGE_ZERO) ||
        (Opc >= AArch64ISD::GLD1S_MERGE_ZERO && // signed gather loads
         Opc <= AArch64ISD::GLD1S_IMM_MERGE_ZERO)) &&
       "Invalid opcode.");

These ranges are actually adjacent in the enum at the moment but I guess that isn't always guaranteed to be the case.

14430

I am not sure that this will work because it is possible to have an unscaled, unsigned, and unextended opcode -- e.g. AArch64ISD::GLD1_MERGE_ZERO. Although this point is definitely valid if we only consider the optimisation patterns that we're performing at the moment.

15850

I am happy to leave it as-is for now, as long as this isn't a blocker? I think it's nice to be able to add new patterns in for the different ISD nodes without too much wrangling. Just my opinion though --override if you want! 😄

[joechrisellis]

Politely pinging this. 🙂

[kmclaughlin]

LGTM! I think it's probably worth checking if we can do this for scatter stores at some point as well.

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

14420

nit: if SExt & ZExt aren't used anywhere else, could you remove them and just set Extended based on the opcode? i.e.

const bool Extended = Opc == AArch64ISD::GLD1_SXTW_MERGE_ZERO ||
                      Opc == AArch64ISD::GLD1_SXTW_SCALED_MERGE_ZERO ||
                      Opc == AArch64ISD::GLD1_UXTW_MERGE_ZERO ||
                      Opc == AArch64ISD::GLD1_UXTW_SCALED_MERGE_ZERO;

[joechrisellis]

Address code review comments.

• @kmclaughlin: remove SExt and ZExt variables.

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

if (Op1.getOperand(0).getOpcode() == AArch64ISD::UZP1) {
       SDValue Z = Op1.getOperand(0).getOperand(1);
       return DAG.getNode(AArch64ISD::UZP1, DL, ResVT, Op0, Z);
     }
   }
 
   return SDValue();
 }
 
+static SDValue performGLD1Combine(SDNode *N, SelectionDAG &DAG) {
+  unsigned Opc = N->getOpcode();
+
+  assert(((Opc >= AArch64ISD::GLD1_MERGE_ZERO && // unsigned gather loads
+           Opc <= AArch64ISD::GLD1_IMM_MERGE_ZERO) ||
+          (Opc >= AArch64ISD::GLD1S_MERGE_ZERO && // signed gather loads
+           Opc <= AArch64ISD::GLD1S_IMM_MERGE_ZERO)) &&
+         "Invalid opcode.");
+
+  const bool Scaled = Opc == AArch64ISD::GLD1_SCALED_MERGE_ZERO ||
+                      Opc == AArch64ISD::GLD1S_SCALED_MERGE_ZERO;
+  const bool Signed = Opc == AArch64ISD::GLD1S_MERGE_ZERO ||
+                      Opc == AArch64ISD::GLD1S_SCALED_MERGE_ZERO;
+  const bool Extended = Opc == AArch64ISD::GLD1_SXTW_MERGE_ZERO ||
+                        Opc == AArch64ISD::GLD1_SXTW_SCALED_MERGE_ZERO ||
+                        Opc == AArch64ISD::GLD1_UXTW_MERGE_ZERO ||
+                        Opc == AArch64ISD::GLD1_UXTW_SCALED_MERGE_ZERO;
+
+  SDLoc DL(N);
+  SDValue Chain = N->getOperand(0);
+  SDValue Pg = N->getOperand(1);
+  SDValue Base = N->getOperand(2);
+  SDValue Offset = N->getOperand(3);
+  SDValue Ty = N->getOperand(4);
+
+  EVT ResVT = N->getValueType(0);
+
+  const auto OffsetOpc = Offset.getOpcode();
+  const bool OffsetIsZExt =
+      OffsetOpc == AArch64ISD::ZERO_EXTEND_INREG_MERGE_PASSTHRU;
+  const bool OffsetIsSExt =
+      OffsetOpc == AArch64ISD::SIGN_EXTEND_INREG_MERGE_PASSTHRU;
+
+  // Fold sign/zero extensions of vector offsets into GLD1 nodes where possible.
+  if (!Extended && (OffsetIsSExt || OffsetIsZExt)) {
+    SDValue ExtPg = Offset.getOperand(0);
+    VTSDNode *ExtFrom = cast<VTSDNode>(Offset.getOperand(2).getNode());
+    EVT ExtFromEVT = ExtFrom->getVT().getVectorElementType();
+
+    // If the predicate for the sign- or zero-extended offset is the
+    // same as the predicate used for this load and the sign-/zero-extension
+    // was from a 32-bits...
+    if (ExtPg == Pg && ExtFromEVT == MVT::i32) {
+      SDValue UnextendedOffset = Offset.getOperand(1);
+
+      unsigned NewOpc = getGatherVecOpcode(Scaled, OffsetIsSExt, true);
+      if (Signed)
+        NewOpc = getSignExtendedGatherOpcode(NewOpc);
+
+      return DAG.getNode(NewOpc, DL, {ResVT, MVT::Other},
+                         {Chain, Pg, Base, UnextendedOffset, Ty});
+    }
+  }
+
+  return SDValue();
+}
+
 /// Target-specific DAG combine function for post-increment LD1 (lane) and
 /// post-increment LD1R.
 static SDValue performPostLD1Combine(SDNode *N,
                                      TargetLowering::DAGCombinerInfo &DCI,
                                      bool IsLaneOp) {
   if (DCI.isBeforeLegalizeOps())
     return SDValue();
 
SDValue AArch64TargetLowering::PerformDAGCombine(SDNode *N,
   case AArch64ISD::CSEL:
     return performCONDCombine(N, DCI, DAG, 2, 3);
   case AArch64ISD::DUP:
     return performPostLD1Combine(N, DCI, false);
   case AArch64ISD::NVCAST:
     return performNVCASTCombine(N);
   case AArch64ISD::UZP1:
     return performUzpCombine(N, DAG);
+  case AArch64ISD::GLD1_MERGE_ZERO:
+  case AArch64ISD::GLD1_SCALED_MERGE_ZERO:
+  case AArch64ISD::GLD1_UXTW_MERGE_ZERO:
+  case AArch64ISD::GLD1_SXTW_MERGE_ZERO:
+  case AArch64ISD::GLD1_UXTW_SCALED_MERGE_ZERO:
+  case AArch64ISD::GLD1_SXTW_SCALED_MERGE_ZERO:
+  case AArch64ISD::GLD1_IMM_MERGE_ZERO:
+  case AArch64ISD::GLD1S_MERGE_ZERO:
+  case AArch64ISD::GLD1S_SCALED_MERGE_ZERO:
+  case AArch64ISD::GLD1S_UXTW_MERGE_ZERO:
+  case AArch64ISD::GLD1S_SXTW_MERGE_ZERO:
+  case AArch64ISD::GLD1S_UXTW_SCALED_MERGE_ZERO:
+  case AArch64ISD::GLD1S_SXTW_SCALED_MERGE_ZERO:
+  case AArch64ISD::GLD1S_IMM_MERGE_ZERO:
+    return performGLD1Combine(N, DAG);
   case ISD::INSERT_VECTOR_ELT:
     return performPostLD1Combine(N, DCI, true);
   case ISD::EXTRACT_VECTOR_ELT:
     return performExtractVectorEltCombine(N, DAG);
   case ISD::VECREDUCE_ADD:
     return performVecReduceAddCombine(N, DCI.DAG, Subtarget);
   case ISD::INTRINSIC_VOID:
   case ISD::INTRINSIC_W_CHAIN:

llvm/test/CodeGen/AArch64/sve-intrinsics-gather-loads-64bit-scaled-offset.ll

 ; CHECK-NEXT: ret
   %load = call <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.index.nxv2i32(<vscale x 2 x i1> %pg,
                                                                              i32* %base,
                                                                              <vscale x 2 x i64> %b)
   %res = sext <vscale x 2 x i32> %load to <vscale x 2 x i64>
   ret <vscale x 2 x i64> %res
 }
 
+;
+; LD1H, LD1W, LD1D: base + 64-bit sxtw'd scaled offset
+;   e.g. ld1h z0.d, p0/z, [x0, z0.d, sxtw #1]
+;
+
+define <vscale x 2 x i64> @gld1h_index_sxtw(<vscale x 2 x i1> %pg, i16* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1h_index_sxtw
+; CHECK:      ld1h  { z0.d }, p0/z, [x0, z0.d, sxtw #1]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i16> @llvm.aarch64.sve.ld1.gather.index.nxv2i16(<vscale x 2 x i1> %pg,
+                                                                             i16* %base,
+                                                                             <vscale x 2 x i64> %sxtw)
+  %res = zext <vscale x 2 x i16> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1w_index_sxtw(<vscale x 2 x i1> %pg, i32* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1w_index_sxtw
+; CHECK:      ld1w  { z0.d }, p0/z, [x0, z0.d, sxtw #2]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.index.nxv2i32(<vscale x 2 x i1> %pg,
+                                                                             i32* %base,
+                                                                             <vscale x 2 x i64> %sxtw)
+  %res = zext <vscale x 2 x i32> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1d_index_sxtw(<vscale x 2 x i1> %pg, i64* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1d_index_sxtw
+; CHECK:      ld1d  { z0.d }, p0/z, [x0, z0.d, sxtw #3]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i64> @llvm.aarch64.sve.ld1.gather.index.nxv2i64(<vscale x 2 x i1> %pg,
+                                                                             i64* %base,
+                                                                             <vscale x 2 x i64> %sxtw)
+  ret <vscale x 2 x i64> %load
+}
+
+define <vscale x 2 x double> @gld1d_index_double_sxtw(<vscale x 2 x i1> %pg, double* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1d_index_double_sxtw
+; CHECK:      ld1d  { z0.d }, p0/z, [x0, z0.d, sxtw #3]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.index.nxv2f64(<vscale x 2 x i1> %pg,
+                                                                                double* %base,
+                                                                                <vscale x 2 x i64> %sxtw)
+  ret <vscale x 2 x double> %load
+}
+
+;
+; LD1SH, LD1SW: base + 64-bit sxtw'd scaled offset
+;   e.g. ld1sh z0.d, p0/z, [x0, z0.d, sxtw #1]
+;
+
+define <vscale x 2 x i64> @gld1sh_index_sxtw(<vscale x 2 x i1> %pg, i16* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1sh_index_sxtw
+; CHECK:      ld1sh { z0.d }, p0/z, [x0, z0.d, sxtw #1]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i16> @llvm.aarch64.sve.ld1.gather.index.nxv2i16(<vscale x 2 x i1> %pg,
+                                                                             i16* %base,
+                                                                             <vscale x 2 x i64> %sxtw)
+  %res = sext <vscale x 2 x i16> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1sw_index_sxtw(<vscale x 2 x i1> %pg, i32* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1sw_index_sxtw
+; CHECK:      ld1sw { z0.d }, p0/z, [x0, z0.d, sxtw #2]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.index.nxv2i32(<vscale x 2 x i1> %pg,
+                                                                             i32* %base,
+                                                                             <vscale x 2 x i64> %sxtw)
+  %res = sext <vscale x 2 x i32> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+;
+; LD1H, LD1W, LD1D: base + 64-bit sxtw'd scaled offset
+;   e.g. ld1h z0.d, p0/z, [x0, z0.d, uxtw #1]
+;
+
+define <vscale x 2 x i64> @gld1h_index_uxtw(<vscale x 2 x i1> %pg, i16* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1h_index_uxtw
+; CHECK:      ld1h  { z0.d }, p0/z, [x0, z0.d, uxtw #1]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i16> @llvm.aarch64.sve.ld1.gather.index.nxv2i16(<vscale x 2 x i1> %pg,
+                                                                             i16* %base,
+                                                                             <vscale x 2 x i64> %uxtw)
+  %res = zext <vscale x 2 x i16> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1w_index_uxtw(<vscale x 2 x i1> %pg, i32* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1w_index_uxtw
+; CHECK:      ld1w  { z0.d }, p0/z, [x0, z0.d, uxtw #2]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.index.nxv2i32(<vscale x 2 x i1> %pg,
+                                                                             i32* %base,
+                                                                             <vscale x 2 x i64> %uxtw)
+  %res = zext <vscale x 2 x i32> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1d_index_uxtw(<vscale x 2 x i1> %pg, i64* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1d_index_uxtw
+; CHECK:      ld1d  { z0.d }, p0/z, [x0, z0.d, uxtw #3]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i64> @llvm.aarch64.sve.ld1.gather.index.nxv2i64(<vscale x 2 x i1> %pg,
+                                                                             i64* %base,
+                                                                             <vscale x 2 x i64> %uxtw)
+  ret <vscale x 2 x i64> %load
+}
+
+define <vscale x 2 x double> @gld1d_index_double_uxtw(<vscale x 2 x i1> %pg, double* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1d_index_double_uxtw
+; CHECK:      ld1d  { z0.d }, p0/z, [x0, z0.d, uxtw #3]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.index.nxv2f64(<vscale x 2 x i1> %pg,
+                                                                                double* %base,
+                                                                                <vscale x 2 x i64> %uxtw)
+  ret <vscale x 2 x double> %load
+}
+
+;
+; LD1SH, LD1SW: base + 64-bit uxtw'd scaled offset
+;   e.g. ld1sh z0.d, p0/z, [x0, z0.d, uxtw #1]
+;
+
+define <vscale x 2 x i64> @gld1sh_index_uxtw(<vscale x 2 x i1> %pg, i16* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1sh_index_uxtw
+; CHECK:      ld1sh { z0.d }, p0/z, [x0, z0.d, uxtw #1]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i16> @llvm.aarch64.sve.ld1.gather.index.nxv2i16(<vscale x 2 x i1> %pg,
+                                                                             i16* %base,
+                                                                             <vscale x 2 x i64> %uxtw)
+  %res = sext <vscale x 2 x i16> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1sw_index_uxtw(<vscale x 2 x i1> %pg, i32* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1sw_index_uxtw
+; CHECK:      ld1sw { z0.d }, p0/z, [x0, z0.d, uxtw #2]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.index.nxv2i32(<vscale x 2 x i1> %pg,
+                                                                             i32* %base,
+                                                                             <vscale x 2 x i64> %uxtw)
+  %res = sext <vscale x 2 x i32> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
 declare <vscale x 2 x i16> @llvm.aarch64.sve.ld1.gather.index.nxv2i16(<vscale x 2 x i1>, i16*, <vscale x 2 x i64>)
 declare <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.index.nxv2i32(<vscale x 2 x i1>, i32*, <vscale x 2 x i64>)
 declare <vscale x 2 x i64> @llvm.aarch64.sve.ld1.gather.index.nxv2i64(<vscale x 2 x i1>, i64*, <vscale x 2 x i64>)
 declare <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.index.nxv2f64(<vscale x 2 x i1>, double*, <vscale x 2 x i64>)
+
+declare <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64>, <vscale x 2 x i1>, <vscale x 2 x i64>)
+declare <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64>, <vscale x 2 x i1>, <vscale x 2 x i64>)

llvm/test/CodeGen/AArch64/sve-intrinsics-gather-loads-64bit-unscaled-offset.ll

 ; CHECK-NEXT: ret
   %load = call <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.nxv2i32(<vscale x 2 x i1> %pg,
                                                                        i32* %base,
                                                                        <vscale x 2 x i64> %offsets)
   %res = sext <vscale x 2 x i32> %load to <vscale x 2 x i64>
   ret <vscale x 2 x i64> %res
 }
 
+;
+; LD1B, LD1W, LD1H, LD1D: base + 64-bit sxtw'd unscaled offset
+;   e.g. ld1h { z0.d }, p0/z, [x0, z0.d, sxtw]
+;
+
+define <vscale x 2 x i64> @gld1b_d_sxtw(<vscale x 2 x i1> %pg, i8* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1b_d_sxtw:
+; CHECK: ld1b { z0.d }, p0/z, [x0, z0.d, sxtw]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i8> @llvm.aarch64.sve.ld1.gather.nxv2i8(<vscale x 2 x i1> %pg,
+                                                                     i8* %base,
+                                                                     <vscale x 2 x i64> %sxtw)
+  %res = zext <vscale x 2 x i8> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1h_d_sxtw(<vscale x 2 x i1> %pg, i16* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1h_d_sxtw:
+; CHECK: ld1h { z0.d }, p0/z, [x0, z0.d, sxtw]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i16> @llvm.aarch64.sve.ld1.gather.nxv2i16(<vscale x 2 x i1> %pg,
+                                                                       i16* %base,
+                                                                       <vscale x 2 x i64> %sxtw)
+  %res = zext <vscale x 2 x i16> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1w_d_sxtw(<vscale x 2 x i1> %pg, i32* %base, <vscale x 2 x i64> %offsets) {
+; CHECK-LABEL: gld1w_d_sxtw:
+; CHECK: ld1w { z0.d }, p0/z, [x0, z0.d, sxtw]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %offsets)
+  %load = call <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.nxv2i32(<vscale x 2 x i1> %pg,
+                                                                       i32* %base,
+                                                                       <vscale x 2 x i64> %sxtw)
+  %res = zext <vscale x 2 x i32> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1d_d_sxtw(<vscale x 2 x i1> %pg, i64* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1d_d_sxtw:
+; CHECK: ld1d { z0.d }, p0/z, [x0, z0.d, sxtw]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i64> @llvm.aarch64.sve.ld1.gather.nxv2i64(<vscale x 2 x i1> %pg,
+                                                                       i64* %base,
+                                                                       <vscale x 2 x i64> %sxtw)
+  ret <vscale x 2 x i64> %load
+}
+
+define <vscale x 2 x double> @gld1d_d_double_sxtw(<vscale x 2 x i1> %pg, double* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1d_d_double_sxtw:
+; CHECK: ld1d { z0.d }, p0/z, [x0, z0.d, sxtw]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.nxv2f64(<vscale x 2 x i1> %pg,
+                                                                       double* %base,
+                                                                       <vscale x 2 x i64> %sxtw)
+  ret <vscale x 2 x double> %load
+}
+
+;
+; LD1SB, LD1SW, LD1SH: base + 64-bit sxtw'd unscaled offset
+;   e.g. ld1sh { z0.d }, p0/z, [x0, z0.d]
+;
+
+define <vscale x 2 x i64> @gld1sb_d_sxtw(<vscale x 2 x i1> %pg, i8* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1sb_d_sxtw:
+; CHECK: ld1sb { z0.d }, p0/z, [x0, z0.d, sxtw]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i8> @llvm.aarch64.sve.ld1.gather.nxv2i8(<vscale x 2 x i1> %pg,
+                                                                     i8* %base,
+                                                                     <vscale x 2 x i64> %sxtw)
+  %res = sext <vscale x 2 x i8> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1sh_d_sxtw(<vscale x 2 x i1> %pg, i16* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1sh_d_sxtw:
+; CHECK: ld1sh { z0.d }, p0/z, [x0, z0.d, sxtw]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i16> @llvm.aarch64.sve.ld1.gather.nxv2i16(<vscale x 2 x i1> %pg,
+                                                                       i16* %base,
+                                                                       <vscale x 2 x i64> %sxtw)
+  %res = sext <vscale x 2 x i16> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1sw_d_sxtw(<vscale x 2 x i1> %pg, i32* %base, <vscale x 2 x i64> %offsets) {
+; CHECK-LABEL: gld1sw_d_sxtw:
+; CHECK: ld1sw { z0.d }, p0/z, [x0, z0.d, sxtw]
+; CHECK-NEXT: ret
+  %sxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %offsets)
+  %load = call <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.nxv2i32(<vscale x 2 x i1> %pg,
+                                                                       i32* %base,
+                                                                       <vscale x 2 x i64> %sxtw)
+  %res = sext <vscale x 2 x i32> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+;
+; LD1B, LD1W, LD1H, LD1D: base + 64-bit uxtw'd unscaled offset
+;   e.g. ld1h { z0.d }, p0/z, [x0, z0.d, uxtw]
+;
+
+define <vscale x 2 x i64> @gld1b_d_uxtw(<vscale x 2 x i1> %pg, i8* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1b_d_uxtw:
+; CHECK: ld1b { z0.d }, p0/z, [x0, z0.d, uxtw]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i8> @llvm.aarch64.sve.ld1.gather.nxv2i8(<vscale x 2 x i1> %pg,
+                                                                     i8* %base,
+                                                                     <vscale x 2 x i64> %uxtw)
+  %res = zext <vscale x 2 x i8> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1h_d_uxtw(<vscale x 2 x i1> %pg, i16* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1h_d_uxtw:
+; CHECK: ld1h { z0.d }, p0/z, [x0, z0.d, uxtw]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i16> @llvm.aarch64.sve.ld1.gather.nxv2i16(<vscale x 2 x i1> %pg,
+                                                                       i16* %base,
+                                                                       <vscale x 2 x i64> %uxtw)
+  %res = zext <vscale x 2 x i16> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1w_d_uxtw(<vscale x 2 x i1> %pg, i32* %base, <vscale x 2 x i64> %offsets) {
+; CHECK-LABEL: gld1w_d_uxtw:
+; CHECK: ld1w { z0.d }, p0/z, [x0, z0.d, uxtw]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %offsets)
+  %load = call <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.nxv2i32(<vscale x 2 x i1> %pg,
+                                                                       i32* %base,
+                                                                       <vscale x 2 x i64> %uxtw)
+  %res = zext <vscale x 2 x i32> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1d_d_uxtw(<vscale x 2 x i1> %pg, i64* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1d_d_uxtw:
+; CHECK: ld1d { z0.d }, p0/z, [x0, z0.d, uxtw]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i64> @llvm.aarch64.sve.ld1.gather.nxv2i64(<vscale x 2 x i1> %pg,
+                                                                       i64* %base,
+                                                                       <vscale x 2 x i64> %uxtw)
+  ret <vscale x 2 x i64> %load
+}
+
+define <vscale x 2 x double> @gld1d_d_double_uxtw(<vscale x 2 x i1> %pg, double* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1d_d_double_uxtw:
+; CHECK: ld1d { z0.d }, p0/z, [x0, z0.d, uxtw]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.nxv2f64(<vscale x 2 x i1> %pg,
+                                                                       double* %base,
+                                                                       <vscale x 2 x i64> %uxtw)
+  ret <vscale x 2 x double> %load
+}
+
+;
+; LD1SB, LD1SW, LD1SH: base + 64-bit uxtw'd unscaled offset
+;   e.g. ld1sh { z0.d }, p0/z, [x0, z0.d]
+;
+
+define <vscale x 2 x i64> @gld1sb_d_uxtw(<vscale x 2 x i1> %pg, i8* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1sb_d_uxtw:
+; CHECK: ld1sb { z0.d }, p0/z, [x0, z0.d, uxtw]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i8> @llvm.aarch64.sve.ld1.gather.nxv2i8(<vscale x 2 x i1> %pg,
+                                                                     i8* %base,
+                                                                     <vscale x 2 x i64> %uxtw)
+  %res = sext <vscale x 2 x i8> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1sh_d_uxtw(<vscale x 2 x i1> %pg, i16* %base, <vscale x 2 x i64> %b) {
+; CHECK-LABEL: gld1sh_d_uxtw:
+; CHECK: ld1sh { z0.d }, p0/z, [x0, z0.d, uxtw]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %b)
+  %load = call <vscale x 2 x i16> @llvm.aarch64.sve.ld1.gather.nxv2i16(<vscale x 2 x i1> %pg,
+                                                                       i16* %base,
+                                                                       <vscale x 2 x i64> %uxtw)
+  %res = sext <vscale x 2 x i16> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
+define <vscale x 2 x i64> @gld1sw_d_uxtw(<vscale x 2 x i1> %pg, i32* %base, <vscale x 2 x i64> %offsets) {
+; CHECK-LABEL: gld1sw_d_uxtw:
+; CHECK: ld1sw { z0.d }, p0/z, [x0, z0.d, uxtw]
+; CHECK-NEXT: ret
+  %uxtw = call <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64> undef,
+                                                                 <vscale x 2 x i1> %pg,
+                                                                 <vscale x 2 x i64> %offsets)
+  %load = call <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.nxv2i32(<vscale x 2 x i1> %pg,
+                                                                       i32* %base,
+                                                                       <vscale x 2 x i64> %uxtw)
+  %res = sext <vscale x 2 x i32> %load to <vscale x 2 x i64>
+  ret <vscale x 2 x i64> %res
+}
+
 declare <vscale x 2 x i8> @llvm.aarch64.sve.ld1.gather.nxv2i8(<vscale x 2 x i1>, i8*, <vscale x 2 x i64>)
 declare <vscale x 2 x i16> @llvm.aarch64.sve.ld1.gather.nxv2i16(<vscale x 2 x i1>, i16*, <vscale x 2 x i64>)
 declare <vscale x 2 x i32> @llvm.aarch64.sve.ld1.gather.nxv2i32(<vscale x 2 x i1>, i32*, <vscale x 2 x i64>)
 declare <vscale x 2 x i64> @llvm.aarch64.sve.ld1.gather.nxv2i64(<vscale x 2 x i1>, i64*, <vscale x 2 x i64>)
 declare <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.nxv2f64(<vscale x 2 x i1>, double*, <vscale x 2 x i64>)
+
+declare <vscale x 2 x i64> @llvm.aarch64.sve.sxtw.nxv2i64(<vscale x 2 x i64>, <vscale x 2 x i1>, <vscale x 2 x i64>)
+declare <vscale x 2 x i64> @llvm.aarch64.sve.uxtw.nxv2i64(<vscale x 2 x i64>, <vscale x 2 x i1>, <vscale x 2 x i64>)