[mlir][llvm] Add llvm.vector.deinterleave2 intrinsic (#91986)

Adds the LLVM vector.deinterleave2 intrinsic to the MLIR LLVM dialect. The 
deinterleave2 intrinsic takes a vector and returns two vectors with the first 
having even elements and the second with odd elements from the input 
vector. The inverse of vector.interleave2.

Author: mub-at-arm

mlir/include/mlir/Dialect/LLVMIR/LLVMIntrinsicOps.td

@@ -1074,6 +1074,12 @@ def LLVM_vector_interleave2
         ]>,
         Arguments<(ins LLVM_AnyVector:$vec1, LLVM_AnyVector:$vec2)>;
 
+def LLVM_vector_deinterleave2
+    : LLVM_OneResultIntrOp<"vector.deinterleave2",
+        /*overloadedResults=*/[], /*overloadedOperands=*/[0],
+        /*traits=*/[Pure]>,
+        Arguments<(ins LLVM_AnyVector:$vec)>;
+
 //
 // LLVM Vector Predication operations.
 //

mlir/test/Dialect/LLVMIR/roundtrip.mlir

@@ -349,6 +349,13 @@ func.func @vector_interleave2(%vec1: vector<[4]xf16>, %vec2 : vector<[4]xf16>) {
   return
 }
 
+// CHECK-LABEL: @vector_deinterleave2
+func.func @vector_deinterleave2(%vec: vector<[8]xf16>) {
+  // CHECK: = "llvm.intr.vector.deinterleave2"({{.*}}) : (vector<[8]xf16>) -> !llvm.struct<(vector<[4]xf16>, vector<[4]xf16>)>
+  %0 = "llvm.intr.vector.deinterleave2"(%vec) : (vector<[8]xf16>) -> !llvm.struct<(vector<[4]xf16>, vector<[4]xf16>)>
+  return
+}
+
 // CHECK-LABEL: @alloca
 func.func @alloca(%size : i64) {
   // CHECK: llvm.alloca %{{.*}} x i32 : (i64) -> !llvm.ptr

mlir/test/Target/LLVMIR/Import/intrinsic.ll

@@ -786,6 +786,15 @@ define void @vector_extract(<vscale x 4 x float> %0) {
   ret void
 }
 
+; CHECK-LABEL: llvm.func @vector_deinterleave2
+define void @vector_deinterleave2(<4 x double> %0, <vscale x 8 x i32> %1) {
+  ; CHECK: "llvm.intr.vector.deinterleave2"(%{{.*}}) : (vector<4xf64>) -> !llvm.struct<(vector<2xf64>, vector<2xf64>)>
+  %3 = call { <2 x double>, <2 x double> } @llvm.vector.deinterleave2.v4f64(<4 x double> %0);
+  ; CHECK: "llvm.intr.vector.deinterleave2"(%{{.*}}) : (!llvm.vec<? x 8 x i32>) -> !llvm.struct<(vec<? x 4 x i32>, vec<? x 4 x i32>)>
+  %4 = call { <vscale x 4 x i32>, <vscale x 4 x i32> } @llvm.vector.deinterleave2.nxv8i32(<vscale x 8 x i32> %1);
+  ret void
+}
+
 ; CHECK-LABEL:  llvm.func @vector_predication_intrinsics
 define void @vector_predication_intrinsics(<8 x i32> %0, <8 x i32> %1, <8 x float> %2, <8 x float> %3, <8 x i64> %4, <8 x double> %5, <8 x ptr> %6, i32 %7, float %8, ptr %9, ptr %10, <8 x i1> %11, i32 %12) {
   ; CHECK: "llvm.intr.vp.add"(%{{.*}}, %{{.*}}, %{{.*}}, %{{.*}}) : (vector<8xi32>, vector<8xi32>, vector<8xi1>, i32) -> vector<8xi32>

mlir/test/Target/LLVMIR/llvmir-intrinsics.mlir

@@ -942,6 +942,17 @@ llvm.func @vector_insert_extract(%f256: vector<8xi32>, %f128: vector<4xi32>,
   llvm.return
 }
 
+// CHECK-LABEL: @vector_deinterleave2
+llvm.func @vector_deinterleave2(%vec1: vector<4xf64>, %vec2: vector<[8]xi32>) {
+  // CHECK: call { <2 x double>, <2 x double> } @llvm.vector.deinterleave2.v4f64(<4 x double> %{{.*}})
+  %0 = "llvm.intr.vector.deinterleave2" (%vec1) :
+              (vector<4xf64>) -> !llvm.struct<(vector<2xf64>, vector<2xf64>)>
+  // CHECK: call { <vscale x 4 x i32>, <vscale x 4 x i32> } @llvm.vector.deinterleave2.nxv8i32(<vscale x 8 x i32> %{{.*}})
+  %1 = "llvm.intr.vector.deinterleave2" (%vec2) :
+              (vector<[8]xi32>) -> !llvm.struct<(vector<[4]xi32>, vector<[4]xi32>)>
+  llvm.return
+}
+
 // CHECK-LABEL: @lifetime
 llvm.func @lifetime(%p: !llvm.ptr) {
   // CHECK: call void @llvm.lifetime.start
@@ -1148,6 +1159,8 @@ llvm.func @experimental_constrained_fptrunc(%s: f64, %v: vector<4xf32>) {
 // CHECK-DAG: declare <8 x i32> @llvm.vector.extract.v8i32.nxv4i32(<vscale x 4 x i32>, i64 immarg)
 // CHECK-DAG: declare <4 x i32> @llvm.vector.extract.v4i32.nxv4i32(<vscale x 4 x i32>, i64 immarg)
 // CHECK-DAG: declare <2 x i32> @llvm.vector.extract.v2i32.v8i32(<8 x i32>, i64 immarg)
+// CHECK-DAG: declare { <2 x double>, <2 x double> } @llvm.vector.deinterleave2.v4f64(<4 x double>)
+// CHECK-DAG: declare { <vscale x 4 x i32>, <vscale x 4 x i32> } @llvm.vector.deinterleave2.nxv8i32(<vscale x 8 x i32>)
 // CHECK-DAG: declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture)
 // CHECK-DAG: declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture)
 // CHECK-DAG: declare ptr @llvm.invariant.start.p0(i64 immarg, ptr nocapture)