[AArch64] More consistently use buildvector for zero and all-ones constants

[dmgreen]

Summary

The AArch64 backend will use legal BUILDVECTORs for zero vectors or all-ones vectors, so during selection tablegen patterns get rely on immAllZerosV and immAllOnesV pattern frags in patters like vnot. It was not always consistent though, which this patch attempt to fix by recognizing where constant splat + insert vector element is used. The main outcome of this will be that full vector movi v0.2d, #0000000000000000 will be used as opposed to movi d0, #0, as per https://reviews.llvm.org/D53579. This helps simplify what tablegen will see, to make pattern matching simpler.

[david-arm]

Looks sensible to me! I just had one minor comment ...

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

12449

Instead of asking this question for the build vector Vec can you just instead test ConstantValue for 0 or 1 instead, since it's probably cheaper?

[dmgreen]

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

12449

Zero's are simple, but all-ones are a little more complex due to promotion of the constants to 32bits.

[david-arm]

LGTM! Thanks for making the changes @dmgreen. :)

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

bool PreferDUPAndInsert =
       NumDifferentLanes >= NumConstantLanes;
 
   // If there was only one constant value used and for more than one lane,
   // start by splatting that value, then replace the non-constant lanes. This
   // is better than the default, which will perform a separate initialization
   // for each lane.
   if (!PreferDUPAndInsert && NumConstantLanes > 0 && usesOnlyOneConstantValue) {
     // Firstly, try to materialize the splat constant.
-    SDValue Vec = DAG.getSplatBuildVector(VT, dl, ConstantValue),
-            Val = ConstantBuildVector(Vec, DAG);
-    if (!Val) {
+    SDValue Vec = DAG.getSplatBuildVector(VT, dl, ConstantValue);
+    SDValue Val = Vec;
+    if (!ISD::isConstantSplatVectorAllOnes(Vec.getNode()) &&
+        !ISD::isConstantSplatVectorAllZeros(Vec.getNode())) {
+      if (!Val)
         // Otherwise, materialize the constant and splat it.
         Val = DAG.getNode(AArch64ISD::DUP, dl, VT, ConstantValue);
-      DAG.ReplaceAllUsesWith(Vec.getNode(), &Val);
     }
 
     // Now insert the non-constant lanes.
     for (unsigned i = 0; i < NumElts; ++i) {
       SDValue V = Op.getOperand(i);
       SDValue LaneIdx = DAG.getConstant(i, dl, MVT::i64);
       if (!isIntOrFPConstant(V))
         // Note that type legalization likely mucked about with the VT of the

llvm/test/CodeGen/AArch64/build-one-lane.ll

 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc < %s -mtriple=aarch64-- | FileCheck %s
 
 ; Check that building up a vector w/ only one non-zero lane initializes
 ; efficiently.
 
 define <8 x i8> @v8i8z(i8 %t, i8 %s) nounwind {
 ; CHECK-LABEL: v8i8z:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    movi d0, #0000000000000000
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    mov v0.b[7], w1
 ; CHECK-NEXT:    // kill: def $d0 killed $d0 killed $q0
 ; CHECK-NEXT:    ret
   %v = insertelement <8 x i8> <i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 undef>, i8 %s, i32 7
   ret <8 x i8> %v
 }
 
 define <16 x i8> @v16i8z(i8 %t, i8 %s) nounwind {
 ; CHECK-LABEL: v16i8z:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    mov v0.b[15], w1
 ; CHECK-NEXT:    ret
   %v = insertelement <16 x i8> <i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 undef>, i8 %s, i32 15
   ret <16 x i8> %v
 }
 
 define <4 x i16> @v4i16z(i16 %t, i16 %s) nounwind {
 ; CHECK-LABEL: v4i16z:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    movi d0, #0000000000000000
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    mov v0.h[3], w1
 ; CHECK-NEXT:    // kill: def $d0 killed $d0 killed $q0
 ; CHECK-NEXT:    ret
   %v = insertelement <4 x i16> <i16 0, i16 0, i16 0, i16 undef>, i16 %s, i32 3
   ret <4 x i16> %v
 }
 
 define <8 x i16> @v8i16z(i16 %t, i16 %s) nounwind {
 ; CHECK-LABEL: v8i16z:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    mov v0.h[7], w1
 ; CHECK-NEXT:    ret
   %v = insertelement <8 x i16> <i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 0, i16 undef>, i16 %s, i32 7
   ret <8 x i16> %v
 }
 
 define <2 x i32> @v2i32z(i32 %t, i32 %s) nounwind {
 ; CHECK-LABEL: v2i32z:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    movi d0, #0000000000000000
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    mov v0.s[1], w1
 ; CHECK-NEXT:    // kill: def $d0 killed $d0 killed $q0
 ; CHECK-NEXT:    ret
   %v = insertelement <2 x i32> <i32 0, i32 undef>, i32 %s, i32 1
   ret <2 x i32> %v
 }
 
 define <4 x i32> @v4i32z(i32 %t, i32 %s) nounwind {

 }
 
 ; Check that building up a vector w/ only one non-ones lane initializes
 ; efficiently.
 
 define <8 x i8> @v8i8m(i8 %t, i8 %s) nounwind {
 ; CHECK-LABEL: v8i8m:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    movi d0, #0xffffffffffffffff
+; CHECK-NEXT:    movi v0.2d, #0xffffffffffffffff
 ; CHECK-NEXT:    mov v0.b[7], w1
 ; CHECK-NEXT:    // kill: def $d0 killed $d0 killed $q0
 ; CHECK-NEXT:    ret
   %v = insertelement <8 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 undef>, i8 %s, i32 7
   ret <8 x i8> %v
 }
 
 define <16 x i8> @v16i8m(i8 %t, i8 %s) nounwind {
 ; CHECK-LABEL: v16i8m:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    movi v0.2d, #0xffffffffffffffff
 ; CHECK-NEXT:    mov v0.b[15], w1
 ; CHECK-NEXT:    ret
   %v = insertelement <16 x i8> <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 undef>, i8 %s, i32 15
   ret <16 x i8> %v
 }
 
 define <4 x i16> @v4i16m(i16 %t, i16 %s) nounwind {
 ; CHECK-LABEL: v4i16m:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    movi d0, #0xffffffffffffffff
+; CHECK-NEXT:    movi v0.2d, #0xffffffffffffffff
 ; CHECK-NEXT:    mov v0.h[3], w1
 ; CHECK-NEXT:    // kill: def $d0 killed $d0 killed $q0
 ; CHECK-NEXT:    ret
   %v = insertelement <4 x i16> <i16 -1, i16 -1, i16 -1, i16 undef>, i16 %s, i32 3
   ret <4 x i16> %v
 }
 
 define <8 x i16> @v8i16m(i16 %t, i16 %s) nounwind {
 ; CHECK-LABEL: v8i16m:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    movi v0.2d, #0xffffffffffffffff
 ; CHECK-NEXT:    mov v0.h[7], w1
 ; CHECK-NEXT:    ret
   %v = insertelement <8 x i16> <i16 -1, i16 -1, i16 -1, i16 -1, i16 -1, i16 -1, i16 -1, i16 undef>, i16 %s, i32 7
   ret <8 x i16> %v
 }
 
 define <2 x i32> @v2i32m(i32 %t, i32 %s) nounwind {
 ; CHECK-LABEL: v2i32m:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    movi d0, #0xffffffffffffffff
+; CHECK-NEXT:    movi v0.2d, #0xffffffffffffffff
 ; CHECK-NEXT:    mov v0.s[1], w1
 ; CHECK-NEXT:    // kill: def $d0 killed $d0 killed $q0
 ; CHECK-NEXT:    ret
   %v = insertelement <2 x i32> <i32 -1, i32 undef>, i32 %s, i32 1
   ret <2 x i32> %v
 }
 
 define <4 x i32> @v4i32m(i32 %t, i32 %s) nounwind {

llvm/test/CodeGen/AArch64/srem-vector-lkk.ll

 }
 
 ; Don't fold if the divisor is one.
 define <4 x i16> @dont_fold_srem_one(<4 x i16> %x) {
 ; CHECK-LABEL: dont_fold_srem_one:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    // kill: def $d0 killed $d0 def $q0
 ; CHECK-NEXT:    smov w8, v0.h[1]
-; CHECK-NEXT:    smov w9, v0.h[2]
-; CHECK-NEXT:    mov w10, #30865
+; CHECK-NEXT:    mov w9, #30865
+; CHECK-NEXT:    movk w9, #51306, lsl #16
+; CHECK-NEXT:    smov w10, v0.h[2]
 ; CHECK-NEXT:    mov w11, #17097
-; CHECK-NEXT:    movk w10, #51306, lsl #16
-; CHECK-NEXT:    movk w11, #45590, lsl #16
 ; CHECK-NEXT:    mov w12, #654
-; CHECK-NEXT:    smull x10, w8, w10
-; CHECK-NEXT:    smull x11, w9, w11
-; CHECK-NEXT:    lsr x10, x10, #32
+; CHECK-NEXT:    movk w11, #45590, lsl #16
+; CHECK-NEXT:    smull x9, w8, w9
+; CHECK-NEXT:    smull x11, w10, w11
+; CHECK-NEXT:    lsr x9, x9, #32
+; CHECK-NEXT:    add w9, w9, w8
 ; CHECK-NEXT:    lsr x11, x11, #32
-; CHECK-NEXT:    add w10, w10, w8
-; CHECK-NEXT:    add w11, w11, w9
-; CHECK-NEXT:    asr w13, w10, #9
-; CHECK-NEXT:    add w10, w13, w10, lsr #31
-; CHECK-NEXT:    asr w13, w11, #4
-; CHECK-NEXT:    add w11, w13, w11, lsr #31
-; CHECK-NEXT:    smov w13, v0.h[3]
-; CHECK-NEXT:    msub w8, w10, w12, w8
-; CHECK-NEXT:    movi d0, #0000000000000000
-; CHECK-NEXT:    mov w12, #47143
-; CHECK-NEXT:    mov w10, #23
-; CHECK-NEXT:    movk w12, #24749, lsl #16
-; CHECK-NEXT:    msub w9, w11, w10, w9
-; CHECK-NEXT:    smull x10, w13, w12
+; CHECK-NEXT:    asr w13, w9, #9
+; CHECK-NEXT:    add w11, w11, w10
+; CHECK-NEXT:    add w9, w13, w9, lsr #31
+; CHECK-NEXT:    mov w13, #23
+; CHECK-NEXT:    msub w8, w9, w12, w8
+; CHECK-NEXT:    asr w9, w11, #4
+; CHECK-NEXT:    smov w12, v0.h[3]
+; CHECK-NEXT:    add w9, w9, w11, lsr #31
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
+; CHECK-NEXT:    mov w11, #47143
+; CHECK-NEXT:    movk w11, #24749, lsl #16
+; CHECK-NEXT:    msub w9, w9, w13, w10
+; CHECK-NEXT:    smull x10, w12, w11
 ; CHECK-NEXT:    mov v0.h[1], w8
 ; CHECK-NEXT:    lsr x8, x10, #63
 ; CHECK-NEXT:    asr x10, x10, #43
 ; CHECK-NEXT:    add w8, w10, w8
 ; CHECK-NEXT:    mov w10, #5423
 ; CHECK-NEXT:    mov v0.h[2], w9
-; CHECK-NEXT:    msub w8, w8, w10, w13
+; CHECK-NEXT:    msub w8, w8, w10, w12
 ; CHECK-NEXT:    mov v0.h[3], w8
 ; CHECK-NEXT:    // kill: def $d0 killed $d0 killed $q0
 ; CHECK-NEXT:    ret
   %1 = srem <4 x i16> %x, <i16 1, i16 654, i16 23, i16 5423>
   ret <4 x i16> %1
 }
 
 ; Don't fold if the divisor is 2^15.
 define <4 x i16> @dont_fold_srem_i16_smax(<4 x i16> %x) {
 ; CHECK-LABEL: dont_fold_srem_i16_smax:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    // kill: def $d0 killed $d0 def $q0
-; CHECK-NEXT:    smov w8, v0.h[2]
-; CHECK-NEXT:    mov w9, #17097
-; CHECK-NEXT:    movk w9, #45590, lsl #16
+; CHECK-NEXT:    smov w9, v0.h[2]
+; CHECK-NEXT:    mov w8, #17097
+; CHECK-NEXT:    movk w8, #45590, lsl #16
 ; CHECK-NEXT:    smov w10, v0.h[1]
 ; CHECK-NEXT:    smov w12, v0.h[3]
-; CHECK-NEXT:    movi d1, #0000000000000000
 ; CHECK-NEXT:    mov w11, #23
-; CHECK-NEXT:    smull x9, w8, w9
-; CHECK-NEXT:    lsr x9, x9, #32
-; CHECK-NEXT:    add w9, w9, w8
-; CHECK-NEXT:    asr w13, w9, #4
-; CHECK-NEXT:    add w9, w13, w9, lsr #31
+; CHECK-NEXT:    movi v1.2d, #0000000000000000
+; CHECK-NEXT:    smull x8, w9, w8
+; CHECK-NEXT:    lsr x8, x8, #32
+; CHECK-NEXT:    add w8, w8, w9
+; CHECK-NEXT:    asr w13, w8, #4
+; CHECK-NEXT:    add w8, w13, w8, lsr #31
 ; CHECK-NEXT:    negs w13, w10
 ; CHECK-NEXT:    and w10, w10, #0x7fff
 ; CHECK-NEXT:    and w13, w13, #0x7fff
 ; CHECK-NEXT:    csneg w10, w10, w13, mi
 ; CHECK-NEXT:    mov w13, #47143
 ; CHECK-NEXT:    movk w13, #24749, lsl #16
-; CHECK-NEXT:    msub w8, w9, w11, w8
+; CHECK-NEXT:    msub w8, w8, w11, w9
 ; CHECK-NEXT:    smull x9, w12, w13
 ; CHECK-NEXT:    mov v1.h[1], w10
 ; CHECK-NEXT:    lsr x10, x9, #63
 ; CHECK-NEXT:    asr x9, x9, #43
 ; CHECK-NEXT:    add w9, w9, w10
 ; CHECK-NEXT:    mov w10, #5423
 ; CHECK-NEXT:    mov v1.h[2], w8
 ; CHECK-NEXT:    msub w8, w9, w10, w12

llvm/test/CodeGen/AArch64/sve-fixed-length-masked-gather.ll

 ;
 ; LD1H (float)
 ;
 
 define void @masked_gather_v2f16(ptr %a, ptr %b) vscale_range(2,0) #0 {
 ; CHECK-LABEL: masked_gather_v2f16:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    ldr s1, [x0]
-; CHECK-NEXT:    movi d0, #0000000000000000
 ; CHECK-NEXT:    ptrue p0.d, vl4
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    fcmeq v1.4h, v1.4h, #0.0
 ; CHECK-NEXT:    sshll v1.4s, v1.4h, #0
 ; CHECK-NEXT:    fmov w8, s1
 ; CHECK-NEXT:    mov w9, v1.s[1]
 ; CHECK-NEXT:    ldr q1, [x1]
 ; CHECK-NEXT:    mov v0.h[0], w8
 ; CHECK-NEXT:    mov v0.h[1], w9
 ; CHECK-NEXT:    shl v0.4h, v0.4h, #15

llvm/test/CodeGen/AArch64/sve-fixed-length-masked-loads.ll

 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc -aarch64-sve-vector-bits-min=256  < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_256
 ; RUN: llc -aarch64-sve-vector-bits-min=512  < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_512
 ; RUN: llc -aarch64-sve-vector-bits-min=2048 < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_512
 
 target triple = "aarch64-unknown-linux-gnu"
 
 ;
 ; Masked Loads
 ;
 
 define <2 x half> @masked_load_v2f16(ptr %ap, ptr %bp) vscale_range(2,0) #0 {
 ; CHECK-LABEL: masked_load_v2f16:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    ldr s1, [x0]
-; CHECK-NEXT:    movi d0, #0000000000000000
-; CHECK-NEXT:    ldr s2, [x1]
 ; CHECK-NEXT:    ptrue p0.h, vl4
+; CHECK-NEXT:    ldr s2, [x1]
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    fcmeq v1.4h, v1.4h, v2.4h
 ; CHECK-NEXT:    sshll v1.4s, v1.4h, #0
 ; CHECK-NEXT:    fmov w8, s1
 ; CHECK-NEXT:    mov w9, v1.s[1]
 ; CHECK-NEXT:    mov v0.h[0], w8
 ; CHECK-NEXT:    mov v0.h[1], w9
 ; CHECK-NEXT:    cmpne p0.h, p0/z, z0.h, #0
 ; CHECK-NEXT:    ld1h { z0.h }, p0/z, [x0]

llvm/test/CodeGen/AArch64/sve-fixed-length-masked-scatter.ll

 ;
 ; ST1H (float)
 ;
 
 define void @masked_scatter_v2f16(ptr %a, ptr %b) vscale_range(2,0) #0 {
 ; CHECK-LABEL: masked_scatter_v2f16:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    ldr s1, [x0]
-; CHECK-NEXT:    movi d0, #0000000000000000
 ; CHECK-NEXT:    ptrue p0.d, vl4
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    fcmeq v2.4h, v1.4h, #0.0
 ; CHECK-NEXT:    uunpklo z1.s, z1.h
 ; CHECK-NEXT:    sshll v2.4s, v2.4h, #0
 ; CHECK-NEXT:    fmov w8, s2
 ; CHECK-NEXT:    mov w9, v2.s[1]
 ; CHECK-NEXT:    ldr q2, [x1]
 ; CHECK-NEXT:    mov v0.h[0], w8
 ; CHECK-NEXT:    mov v0.h[1], w9

llvm/test/CodeGen/AArch64/sve-fixed-length-masked-stores.ll

 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc -aarch64-sve-vector-bits-min=256  < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_256
 ; RUN: llc -aarch64-sve-vector-bits-min=512  < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_512
 ; RUN: llc -aarch64-sve-vector-bits-min=2048 < %s | FileCheck %s -check-prefixes=CHECK,VBITS_GE_512
 
 target triple = "aarch64-unknown-linux-gnu"
 
 ;
 ; Masked Stores
 ;
 
 define void @masked_store_v2f16(ptr %ap, ptr %bp) vscale_range(2,0) #0 {
 ; CHECK-LABEL: masked_store_v2f16:
 ; CHECK:       // %bb.0:
 ; CHECK-NEXT:    ldr s1, [x0]
-; CHECK-NEXT:    movi d0, #0000000000000000
-; CHECK-NEXT:    ldr s2, [x1]
 ; CHECK-NEXT:    ptrue p0.h, vl4
+; CHECK-NEXT:    ldr s2, [x1]
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    fcmeq v2.4h, v1.4h, v2.4h
 ; CHECK-NEXT:    sshll v2.4s, v2.4h, #0
 ; CHECK-NEXT:    fmov w8, s2
 ; CHECK-NEXT:    mov w9, v2.s[1]
 ; CHECK-NEXT:    mov v0.h[0], w8
 ; CHECK-NEXT:    mov v0.h[1], w9
 ; CHECK-NEXT:    shl v0.4h, v0.4h, #15
 ; CHECK-NEXT:    cmlt v0.4h, v0.4h, #0

llvm/test/CodeGen/AArch64/urem-vector-lkk.ll

 ; CHECK-NEXT:    // kill: def $d0 killed $d0 def $q0
 ; CHECK-NEXT:    umov w8, v0.h[1]
 ; CHECK-NEXT:    mov w9, #13629
 ; CHECK-NEXT:    movk w9, #100, lsl #16
 ; CHECK-NEXT:    umov w10, v0.h[2]
 ; CHECK-NEXT:    mov w11, #25645
 ; CHECK-NEXT:    mov w12, #654
 ; CHECK-NEXT:    movk w11, #2849, lsl #16
-; CHECK-NEXT:    movi d1, #0000000000000000
-; CHECK-NEXT:    umull x9, w8, w9
 ; CHECK-NEXT:    mov w13, #5560
-; CHECK-NEXT:    umull x11, w10, w11
+; CHECK-NEXT:    umull x9, w8, w9
 ; CHECK-NEXT:    movk w13, #12, lsl #16
+; CHECK-NEXT:    umull x11, w10, w11
 ; CHECK-NEXT:    lsr x9, x9, #32
+; CHECK-NEXT:    movi v1.2d, #0000000000000000
 ; CHECK-NEXT:    lsr x11, x11, #32
 ; CHECK-NEXT:    msub w8, w9, w12, w8
 ; CHECK-NEXT:    umov w9, v0.h[3]
 ; CHECK-NEXT:    mov w12, #23
 ; CHECK-NEXT:    msub w10, w11, w12, w10
 ; CHECK-NEXT:    mov w11, #5423
 ; CHECK-NEXT:    mov v1.h[1], w8
 ; CHECK-NEXT:    umull x8, w9, w13

llvm/test/CodeGen/AArch64/vecreduce-add-legalization.ll

 ; CHECK-NEXT:    ret
   %b = call i128 @llvm.vector.reduce.add.v1i128(<1 x i128> %a)
   ret i128 %b
 }
 
 define i8 @test_v3i8(<3 x i8> %a) nounwind {
 ; CHECK-LABEL: test_v3i8:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    movi d0, #0000000000000000
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    mov v0.h[0], w0
 ; CHECK-NEXT:    mov v0.h[1], w1
 ; CHECK-NEXT:    mov v0.h[2], w2
 ; CHECK-NEXT:    addv h0, v0.4h
 ; CHECK-NEXT:    fmov w0, s0
 ; CHECK-NEXT:    ret
   %b = call i8 @llvm.vector.reduce.add.v3i8(<3 x i8> %a)
   ret i8 %b

llvm/test/CodeGen/AArch64/vecreduce-umax-legalization.ll

 ; CHECK-NEXT:    ret
   %b = call i64 @llvm.vector.reduce.umax.v2i64(<2 x i64> %a)
   ret i64 %b
 }
 
 define i8 @test_v3i8(<3 x i8> %a) nounwind {
 ; CHECK-LABEL: test_v3i8:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    movi d0, #0000000000000000
+; CHECK-NEXT:    movi v0.2d, #0000000000000000
 ; CHECK-NEXT:    mov v0.h[0], w0
 ; CHECK-NEXT:    mov v0.h[1], w1
 ; CHECK-NEXT:    mov v0.h[2], w2
 ; CHECK-NEXT:    bic v0.4h, #255, lsl #8
 ; CHECK-NEXT:    umaxv h0, v0.4h
 ; CHECK-NEXT:    fmov w0, s0
 ; CHECK-NEXT:    ret
   %b = call i8 @llvm.vector.reduce.umax.v3i8(<3 x i8> %a)