[ARM] Lower i1 concat via MVETRUNC

The MVETRUNC operation can perform the same truncate of two vectors, without
requiring lane inserts/extracts from every vector lane. This moves the concat
i1 lowering to use it for v8i1 and v16i1 result types, trading a bit of extra
stack space for less instructions.

Author: davemgreen

llvm/lib/Target/ARM/ARMISelLowering.cpp

@@ -9095,13 +9095,21 @@ static SDValue LowerCONCAT_VECTORS_i1(SDValue Op, SelectionDAG &DAG,
         getVectorTyFromPredicateVector(VT).getScalarType().getSimpleVT();
     unsigned NumElts = 2 * Op1VT.getVectorNumElements();
 
+    EVT ConcatVT = MVT::getVectorVT(ElType, NumElts);
+    if (Op1VT == MVT::v4i1 || Op1VT == MVT::v8i1) {
+      // Use MVETRUNC to truncate the combined NewV1::NewV2 into the smaller
+      // ConcatVT.
+      SDValue ConVec =
+          DAG.getNode(ARMISD::MVETRUNC, dl, ConcatVT, NewV1, NewV2);
+      return DAG.getNode(ARMISD::VCMPZ, dl, VT, ConVec,
+                         DAG.getConstant(ARMCC::NE, dl, MVT::i32));
+    }
+
     // Extract the vector elements from Op1 and Op2 one by one and truncate them
     // to be the right size for the destination. For example, if Op1 is v4i1
     // then the promoted vector is v4i32. The result of concatenation gives a
     // v8i1, which when promoted is v8i16. That means each i32 element from Op1
     // needs truncating to i16 and inserting in the result.
-    EVT ConcatVT = MVT::getVectorVT(ElType, NumElts);
-    SDValue ConVec = DAG.getNode(ISD::UNDEF, dl, ConcatVT);
     auto ExtractInto = [&DAG, &dl](SDValue NewV, SDValue ConVec, unsigned &j) {
       EVT NewVT = NewV.getValueType();
       EVT ConcatVT = ConVec.getValueType();
@@ -9119,6 +9127,7 @@ static SDValue LowerCONCAT_VECTORS_i1(SDValue Op, SelectionDAG &DAG,
       return ConVec;
     };
     unsigned j = 0;
+    SDValue ConVec = DAG.getNode(ISD::UNDEF, dl, ConcatVT);
     ConVec = ExtractInto(NewV1, ConVec, j);
     ConVec = ExtractInto(NewV2, ConVec, j);
 

llvm/test/CodeGen/ARM/fadd-select-fneg-combine.ll

@@ -284,40 +284,33 @@ define half @fadd_select_fneg_posk_f16(i32 %arg0, half %x, half %y) {
 define <8 x half> @fadd_vselect_fneg_posk_v8f16(<8 x i32> %arg0, <8 x half> %x, <8 x half> %y) {
 ; CHECK-LABEL: fadd_vselect_fneg_posk_v8f16:
 ; CHECK:       @ %bb.0:
-; CHECK-NEXT:    push {r4, r5, r6, lr}
+; CHECK-NEXT:    sub sp, sp, #16
 ; CHECK-NEXT:    vmov d0, r0, r1
-; CHECK-NEXT:    vmov.i8 q1, #0xff
-; CHECK-NEXT:    vmov d1, r2, r3
 ; CHECK-NEXT:    add r0, sp, #16
+; CHECK-NEXT:    vmov d1, r2, r3
+; CHECK-NEXT:    vldrw.u32 q3, [r0]
 ; CHECK-NEXT:    vcmp.i32 eq, q0, zr
 ; CHECK-NEXT:    vmov.i8 q0, #0x0
+; CHECK-NEXT:    vmov.i8 q1, #0xff
+; CHECK-NEXT:    mov r0, sp
 ; CHECK-NEXT:    vpsel q2, q1, q0
-; CHECK-NEXT:    vldrw.u32 q3, [r0]
-; CHECK-NEXT:    vmov r2, r1, d4
-; CHECK-NEXT:    add r12, sp, #32
-; CHECK-NEXT:    vmov r4, r5, d5
-; CHECK-NEXT:    vmov.16 q2[0], r2
-; CHECK-NEXT:    vmov.16 q2[1], r1
 ; CHECK-NEXT:    vcmp.i32 eq, q3, zr
-; CHECK-NEXT:    vpsel q1, q1, q0
-; CHECK-NEXT:    vmov.16 q2[2], r4
-; CHECK-NEXT:    vmov r3, r0, d2
-; CHECK-NEXT:    vmov.16 q2[3], r5
-; CHECK-NEXT:    vmov.16 q2[4], r3
-; CHECK-NEXT:    vmov r6, lr, d3
-; CHECK-NEXT:    vmov.16 q2[5], r0
-; CHECK-NEXT:    vldrw.u32 q1, [r12]
-; CHECK-NEXT:    vmov.16 q2[6], r6
-; CHECK-NEXT:    vmov.i16 q0, #0xc400
-; CHECK-NEXT:    vmov.16 q2[7], lr
+; CHECK-NEXT:    vpsel q0, q1, q0
+; CHECK-NEXT:    vstrh.32 q2, [r0]
+; CHECK-NEXT:    vstrh.32 q0, [r0, #8]
+; CHECK-NEXT:    add r1, sp, #32
+; CHECK-NEXT:    vldrw.u32 q2, [r0]
+; CHECK-NEXT:    vldrw.u32 q0, [r1]
+; CHECK-NEXT:    vmov.i16 q1, #0xc400
 ; CHECK-NEXT:    add r0, sp, #48
 ; CHECK-NEXT:    vcmp.i16 ne, q2, zr
-; CHECK-NEXT:    vpsel q0, q1, q0
+; CHECK-NEXT:    vpsel q0, q0, q1
 ; CHECK-NEXT:    vldrw.u32 q1, [r0]
 ; CHECK-NEXT:    vsub.f16 q0, q1, q0
 ; CHECK-NEXT:    vmov r0, r1, d0
 ; CHECK-NEXT:    vmov r2, r3, d1
-; CHECK-NEXT:    pop {r4, r5, r6, pc}
+; CHECK-NEXT:    add sp, sp, #16
+; CHECK-NEXT:    bx lr
   %cmp = icmp eq <8 x i32> %arg0, zeroinitializer
   %neg.x = fneg <8 x half> %x
   %select = select <8 x i1> %cmp, <8 x half> %neg.x, <8 x half> <half 4.0, half 4.0, half 4.0, half 4.0, half 4.0, half 4.0, half 4.0, half 4.0>

llvm/test/CodeGen/Thumb2/active_lane_mask.ll

@@ -146,54 +146,47 @@ define <7 x i32> @v7i32(i32 %index, i32 %TC, <7 x i32> %V1, <7 x i32> %V2) {
 define <8 x i16> @v8i16(i32 %index, i32 %TC, <8 x i16> %V1, <8 x i16> %V2) {
 ; CHECK-LABEL: v8i16:
 ; CHECK:       @ %bb.0:
-; CHECK-NEXT:    vpush {d8, d9}
+; CHECK-NEXT:    push {r4, lr}
+; CHECK-NEXT:    sub sp, #16
 ; CHECK-NEXT:    adr.w r12, .LCPI3_0
 ; CHECK-NEXT:    vdup.32 q1, r1
 ; CHECK-NEXT:    vldrw.u32 q0, [r12]
-; CHECK-NEXT:    vmov.i8 q2, #0x0
-; CHECK-NEXT:    vmov.i8 q3, #0xff
+; CHECK-NEXT:    vmov.i8 q2, #0xff
+; CHECK-NEXT:    mov r4, sp
+; CHECK-NEXT:    adr r1, .LCPI3_1
 ; CHECK-NEXT:    vqadd.u32 q0, q0, r0
 ; CHECK-NEXT:    vcmp.u32 hi, q1, q0
-; CHECK-NEXT:    vpsel q4, q3, q2
-; CHECK-NEXT:    vmov r1, r12, d8
-; CHECK-NEXT:    vmov.16 q0[0], r1
-; CHECK-NEXT:    vmov.16 q0[1], r12
-; CHECK-NEXT:    vmov r1, r12, d9
-; CHECK-NEXT:    vmov.16 q0[2], r1
-; CHECK-NEXT:    adr r1, .LCPI3_1
-; CHECK-NEXT:    vldrw.u32 q4, [r1]
-; CHECK-NEXT:    vmov.16 q0[3], r12
-; CHECK-NEXT:    vqadd.u32 q4, q4, r0
-; CHECK-NEXT:    vcmp.u32 hi, q1, q4
-; CHECK-NEXT:    vpsel q1, q3, q2
-; CHECK-NEXT:    vmov r0, r1, d2
-; CHECK-NEXT:    vmov.16 q0[4], r0
-; CHECK-NEXT:    vmov.16 q0[5], r1
-; CHECK-NEXT:    vmov r0, r1, d3
-; CHECK-NEXT:    vmov.16 q0[6], r0
-; CHECK-NEXT:    add r0, sp, #24
-; CHECK-NEXT:    vmov.16 q0[7], r1
+; CHECK-NEXT:    vmov.i8 q0, #0x0
+; CHECK-NEXT:    vpsel q3, q2, q0
+; CHECK-NEXT:    vstrh.32 q3, [r4, #8]
+; CHECK-NEXT:    vldrw.u32 q3, [r1]
+; CHECK-NEXT:    vqadd.u32 q3, q3, r0
+; CHECK-NEXT:    add r0, sp, #32
+; CHECK-NEXT:    vcmp.u32 hi, q1, q3
 ; CHECK-NEXT:    vldrw.u32 q1, [r0]
-; CHECK-NEXT:    vcmp.i16 ne, q0, zr
-; CHECK-NEXT:    vldr d1, [sp, #16]
+; CHECK-NEXT:    vpsel q0, q2, q0
+; CHECK-NEXT:    vstrh.32 q0, [r4]
+; CHECK-NEXT:    vldr d1, [sp, #24]
+; CHECK-NEXT:    vldrw.u32 q2, [r4]
 ; CHECK-NEXT:    vmov d0, r2, r3
+; CHECK-NEXT:    vcmp.i16 ne, q2, zr
 ; CHECK-NEXT:    vpsel q0, q0, q1
 ; CHECK-NEXT:    vmov r0, r1, d0
 ; CHECK-NEXT:    vmov r2, r3, d1
-; CHECK-NEXT:    vpop {d8, d9}
-; CHECK-NEXT:    bx lr
+; CHECK-NEXT:    add sp, #16
+; CHECK-NEXT:    pop {r4, pc}
 ; CHECK-NEXT:    .p2align 4
 ; CHECK-NEXT:  @ %bb.1:
 ; CHECK-NEXT:  .LCPI3_0:
-; CHECK-NEXT:    .long 0 @ 0x0
-; CHECK-NEXT:    .long 1 @ 0x1
-; CHECK-NEXT:    .long 2 @ 0x2
-; CHECK-NEXT:    .long 3 @ 0x3
-; CHECK-NEXT:  .LCPI3_1:
 ; CHECK-NEXT:    .long 4 @ 0x4
 ; CHECK-NEXT:    .long 5 @ 0x5
 ; CHECK-NEXT:    .long 6 @ 0x6
 ; CHECK-NEXT:    .long 7 @ 0x7
+; CHECK-NEXT:  .LCPI3_1:
+; CHECK-NEXT:    .long 0 @ 0x0
+; CHECK-NEXT:    .long 1 @ 0x1
+; CHECK-NEXT:    .long 2 @ 0x2
+; CHECK-NEXT:    .long 3 @ 0x3
   %active.lane.mask = call <8 x i1> @llvm.get.active.lane.mask.v8i1.i32(i32 %index, i32 %TC)
   %select = select <8 x i1> %active.lane.mask, <8 x i16> %V1, <8 x i16> %V2
   ret <8 x i16> %select
@@ -202,122 +195,79 @@ define <8 x i16> @v8i16(i32 %index, i32 %TC, <8 x i16> %V1, <8 x i16> %V2) {
 define <16 x i8> @v16i8(i32 %index, i32 %TC, <16 x i8> %V1, <16 x i8> %V2) {
 ; CHECK-LABEL: v16i8:
 ; CHECK:       @ %bb.0:
-; CHECK-NEXT:    vpush {d8, d9, d10, d11}
+; CHECK-NEXT:    push {r4, r5, r7, lr}
+; CHECK-NEXT:    sub sp, #48
 ; CHECK-NEXT:    adr.w r12, .LCPI4_0
-; CHECK-NEXT:    vdup.32 q3, r1
+; CHECK-NEXT:    vdup.32 q2, r1
 ; CHECK-NEXT:    vldrw.u32 q0, [r12]
 ; CHECK-NEXT:    vmov.i8 q1, #0xff
+; CHECK-NEXT:    add r5, sp, #16
+; CHECK-NEXT:    adr r1, .LCPI4_1
 ; CHECK-NEXT:    vqadd.u32 q0, q0, r0
-; CHECK-NEXT:    vcmp.u32 hi, q3, q0
+; CHECK-NEXT:    adr r4, .LCPI4_3
+; CHECK-NEXT:    vcmp.u32 hi, q2, q0
 ; CHECK-NEXT:    vmov.i8 q0, #0x0
-; CHECK-NEXT:    vpsel q4, q1, q0
-; CHECK-NEXT:    vmov r1, r12, d8
-; CHECK-NEXT:    vmov.16 q2[0], r1
-; CHECK-NEXT:    vmov.16 q2[1], r12
-; CHECK-NEXT:    vmov r1, r12, d9
-; CHECK-NEXT:    vmov.16 q2[2], r1
-; CHECK-NEXT:    adr r1, .LCPI4_1
-; CHECK-NEXT:    vldrw.u32 q4, [r1]
-; CHECK-NEXT:    vmov.16 q2[3], r12
-; CHECK-NEXT:    vqadd.u32 q4, q4, r0
-; CHECK-NEXT:    vcmp.u32 hi, q3, q4
-; CHECK-NEXT:    vpsel q4, q1, q0
-; CHECK-NEXT:    vmov r1, r12, d8
-; CHECK-NEXT:    vmov.16 q2[4], r1
-; CHECK-NEXT:    vmov.16 q2[5], r12
-; CHECK-NEXT:    vmov r1, r12, d9
-; CHECK-NEXT:    vmov.16 q2[6], r1
-; CHECK-NEXT:    vmov.16 q2[7], r12
-; CHECK-NEXT:    vcmp.i16 ne, q2, zr
-; CHECK-NEXT:    vpsel q4, q1, q0
-; CHECK-NEXT:    vmov.u16 r1, q4[0]
-; CHECK-NEXT:    vmov.8 q2[0], r1
-; CHECK-NEXT:    vmov.u16 r1, q4[1]
-; CHECK-NEXT:    vmov.8 q2[1], r1
-; CHECK-NEXT:    vmov.u16 r1, q4[2]
-; CHECK-NEXT:    vmov.8 q2[2], r1
-; CHECK-NEXT:    vmov.u16 r1, q4[3]
-; CHECK-NEXT:    vmov.8 q2[3], r1
-; CHECK-NEXT:    vmov.u16 r1, q4[4]
-; CHECK-NEXT:    vmov.8 q2[4], r1
-; CHECK-NEXT:    vmov.u16 r1, q4[5]
-; CHECK-NEXT:    vmov.8 q2[5], r1
-; CHECK-NEXT:    vmov.u16 r1, q4[6]
-; CHECK-NEXT:    vmov.8 q2[6], r1
-; CHECK-NEXT:    vmov.u16 r1, q4[7]
-; CHECK-NEXT:    vmov.8 q2[7], r1
+; CHECK-NEXT:    vpsel q3, q1, q0
+; CHECK-NEXT:    vstrh.32 q3, [r5, #8]
+; CHECK-NEXT:    vldrw.u32 q3, [r1]
 ; CHECK-NEXT:    adr r1, .LCPI4_2
-; CHECK-NEXT:    vldrw.u32 q4, [r1]
-; CHECK-NEXT:    vqadd.u32 q4, q4, r0
-; CHECK-NEXT:    vcmp.u32 hi, q3, q4
-; CHECK-NEXT:    vpsel q5, q1, q0
-; CHECK-NEXT:    vmov r1, r12, d10
-; CHECK-NEXT:    vmov.16 q4[0], r1
-; CHECK-NEXT:    vmov.16 q4[1], r12
-; CHECK-NEXT:    vmov r1, r12, d11
-; CHECK-NEXT:    vmov.16 q4[2], r1
-; CHECK-NEXT:    adr r1, .LCPI4_3
-; CHECK-NEXT:    vldrw.u32 q5, [r1]
-; CHECK-NEXT:    vmov.16 q4[3], r12
-; CHECK-NEXT:    vqadd.u32 q5, q5, r0
-; CHECK-NEXT:    vcmp.u32 hi, q3, q5
+; CHECK-NEXT:    vqadd.u32 q3, q3, r0
+; CHECK-NEXT:    vcmp.u32 hi, q2, q3
+; CHECK-NEXT:    vpsel q3, q1, q0
+; CHECK-NEXT:    vstrh.32 q3, [r5]
+; CHECK-NEXT:    vldrw.u32 q3, [r1]
+; CHECK-NEXT:    mov r1, sp
+; CHECK-NEXT:    vqadd.u32 q3, q3, r0
+; CHECK-NEXT:    vcmp.u32 hi, q2, q3
 ; CHECK-NEXT:    vpsel q3, q1, q0
-; CHECK-NEXT:    vmov r0, r1, d6
-; CHECK-NEXT:    vmov.16 q4[4], r0
-; CHECK-NEXT:    vmov.16 q4[5], r1
-; CHECK-NEXT:    vmov r0, r1, d7
-; CHECK-NEXT:    vmov.16 q4[6], r0
-; CHECK-NEXT:    vmov.16 q4[7], r1
-; CHECK-NEXT:    vcmp.i16 ne, q4, zr
+; CHECK-NEXT:    vstrh.32 q3, [r1, #8]
+; CHECK-NEXT:    vldrw.u32 q3, [r4]
+; CHECK-NEXT:    vqadd.u32 q3, q3, r0
+; CHECK-NEXT:    add r0, sp, #32
+; CHECK-NEXT:    vcmp.u32 hi, q2, q3
+; CHECK-NEXT:    vpsel q2, q1, q0
+; CHECK-NEXT:    vstrh.32 q2, [r1]
+; CHECK-NEXT:    vldrw.u32 q2, [r5]
+; CHECK-NEXT:    vcmp.i16 ne, q2, zr
+; CHECK-NEXT:    vpsel q2, q1, q0
+; CHECK-NEXT:    vstrb.16 q2, [r0, #8]
+; CHECK-NEXT:    vldrw.u32 q2, [r1]
+; CHECK-NEXT:    add r1, sp, #72
+; CHECK-NEXT:    vcmp.i16 ne, q2, zr
 ; CHECK-NEXT:    vpsel q0, q1, q0
-; CHECK-NEXT:    vmov.u16 r0, q0[0]
-; CHECK-NEXT:    vmov.8 q2[8], r0
-; CHECK-NEXT:    vmov.u16 r0, q0[1]
-; CHECK-NEXT:    vmov.8 q2[9], r0
-; CHECK-NEXT:    vmov.u16 r0, q0[2]
-; CHECK-NEXT:    vmov.8 q2[10], r0
-; CHECK-NEXT:    vmov.u16 r0, q0[3]
-; CHECK-NEXT:    vmov.8 q2[11], r0
-; CHECK-NEXT:    vmov.u16 r0, q0[4]
-; CHECK-NEXT:    vmov.8 q2[12], r0
-; CHECK-NEXT:    vmov.u16 r0, q0[5]
-; CHECK-NEXT:    vmov.8 q2[13], r0
-; CHECK-NEXT:    vmov.u16 r0, q0[6]
-; CHECK-NEXT:    vmov.8 q2[14], r0
-; CHECK-NEXT:    vmov.u16 r0, q0[7]
-; CHECK-NEXT:    vmov.8 q2[15], r0
-; CHECK-NEXT:    add r0, sp, #40
-; CHECK-NEXT:    vldr d1, [sp, #32]
-; CHECK-NEXT:    vldrw.u32 q1, [r0]
-; CHECK-NEXT:    vcmp.i8 ne, q2, zr
+; CHECK-NEXT:    vldrw.u32 q1, [r1]
+; CHECK-NEXT:    vstrb.16 q0, [r0]
+; CHECK-NEXT:    vldr d1, [sp, #64]
+; CHECK-NEXT:    vldrw.u32 q2, [r0]
 ; CHECK-NEXT:    vmov d0, r2, r3
+; CHECK-NEXT:    vcmp.i8 ne, q2, zr
 ; CHECK-NEXT:    vpsel q0, q0, q1
 ; CHECK-NEXT:    vmov r0, r1, d0
 ; CHECK-NEXT:    vmov r2, r3, d1
-; CHECK-NEXT:    vpop {d8, d9, d10, d11}
-; CHECK-NEXT:    bx lr
+; CHECK-NEXT:    add sp, #48
+; CHECK-NEXT:    pop {r4, r5, r7, pc}
 ; CHECK-NEXT:    .p2align 4
 ; CHECK-NEXT:  @ %bb.1:
 ; CHECK-NEXT:  .LCPI4_0:
-; CHECK-NEXT:    .long 0 @ 0x0
-; CHECK-NEXT:    .long 1 @ 0x1
-; CHECK-NEXT:    .long 2 @ 0x2
-; CHECK-NEXT:    .long 3 @ 0x3
+; CHECK-NEXT:    .long 12 @ 0xc
+; CHECK-NEXT:    .long 13 @ 0xd
+; CHECK-NEXT:    .long 14 @ 0xe
+; CHECK-NEXT:    .long 15 @ 0xf
 ; CHECK-NEXT:  .LCPI4_1:
-; CHECK-NEXT:    .long 4 @ 0x4
-; CHECK-NEXT:    .long 5 @ 0x5
-; CHECK-NEXT:    .long 6 @ 0x6
-; CHECK-NEXT:    .long 7 @ 0x7
-; CHECK-NEXT:  .LCPI4_2:
 ; CHECK-NEXT:    .long 8 @ 0x8
 ; CHECK-NEXT:    .long 9 @ 0x9
 ; CHECK-NEXT:    .long 10 @ 0xa
 ; CHECK-NEXT:    .long 11 @ 0xb
+; CHECK-NEXT:  .LCPI4_2:
+; CHECK-NEXT:    .long 4 @ 0x4
+; CHECK-NEXT:    .long 5 @ 0x5
+; CHECK-NEXT:    .long 6 @ 0x6
+; CHECK-NEXT:    .long 7 @ 0x7
 ; CHECK-NEXT:  .LCPI4_3:
-; CHECK-NEXT:    .long 12 @ 0xc
-; CHECK-NEXT:    .long 13 @ 0xd
-; CHECK-NEXT:    .long 14 @ 0xe
-; CHECK-NEXT:    .long 15 @ 0xf
+; CHECK-NEXT:    .long 0 @ 0x0
+; CHECK-NEXT:    .long 1 @ 0x1
+; CHECK-NEXT:    .long 2 @ 0x2
+; CHECK-NEXT:    .long 3 @ 0x3
   %active.lane.mask = call <16 x i1> @llvm.get.active.lane.mask.v16i1.i32(i32 %index, i32 %TC)
   %select = select <16 x i1> %active.lane.mask, <16 x i8> %V1, <16 x i8> %V2
   ret <16 x i8> %select