[PPC] Check for PPC64 when emitting 64bit specific VSX nodes when pattern matching built vectors

[ZarkoCA]

Summary

Some of the pattern matching in PPCInstrVSX.td and node lowering involving vectors assumes 64bit mode. This patch disables some of the unsafe pattern matching and lowering of BUILD_VECTOR in 32bit mode.

[ZarkoCA]

Ping.

[Xiangling_L]

llvm/lib/Target/PowerPC/PPCISelLowering.cpp

9389–9390

minor: Is that better to adjust the comment accordingly like:
Under 64-bit mode, BUILD_VECTOR nodes that ...

llvm/lib/Target/PowerPC/PPCInstrVSX.td

2412

I am wondering why do we leave alone [HasVSX, IsBigEndian] and [HasVSX, HasOnlySwappingMemOps, IsBigEndian] and HasVSX, HasP8Vector, NoP9Vector, IsBigEndian]?

2427–2428

minor: This line should follow #2425?

llvm/test/CodeGen/PowerPC/ppc-32bit-build-vector.ll

4

It seems -mcpu=pwr8 already implies HasAltivec and HasVSX enabled, so -mattr=+altivec and -mattr=+vsx are not necessary.

68

Suggestion: The testcase can be further simplified into the following by removing tedious zext instruction and shortening the numbers of vector.

define dso_local fastcc void @BuildVectorICE() unnamed_addr #0 {
  entry:
    br label %while.body
    while.body:                                       ; preds = %while.body, %entry
    %newelement = phi i32 [ 0, %entry ], [ %5, %while.body ]
    %0 = insertelement <4 x i32> <i32 undef, i32 0, i32 0, i32 0>, i32 %newelement, i32 0
    %1 = load <4 x i32>, <4 x i32>* undef, align 1
    %2 = add <4 x i32> %1, %0
    %3 = shufflevector <4 x i32> %2, <4 x i32> undef, <4 x i32> <i32 1, i32 undef, i32 undef, i32 undef>
    %4 = add <4 x i32> %2, %3
    %5 = extractelement <4 x i32> %4, i32 0
    br label %while.body
}

[ZarkoCA]

llvm/lib/Target/PowerPC/PPCInstrVSX.td

2412

That's a good question, I tried disabling these so as to have minimal disruption to existing code. And did it by elimination.

So, as far as I can see the potentially big problem in the pattern matching is later implementations like [HasVSX, IsISA3_0, HasDirectMove, IsBigEndian] were implemented without considering 32bit codegen and I added a check there and moved on to earlier ones. At some point, I started hitting test case failures and found that codegen in those cases was correct. And in those cases I found that there were checks added for 32bit like in this patch: https://reviews.llvm.org/D17711.

In short, I tried to do the safe thing for 32bit VSX without major disruption to existing test cases and codegen unless I could plainly tell it wasn't correct. Which in those cases I wasn't able to.

llvm/test/CodeGen/PowerPC/ppc-32bit-build-vector.ll

68

Thanks a lot! That simplifies it and I'm still able to get the compiler error without the patch.

[ZarkoCA]

Addressed comments:

• simplified and modified test case per suggestion
• added comment

[Xiangling_L]

llvm/lib/Target/PowerPC/PPCInstrVSX.td

2412

I see your point here. I am asking because I tried adding IsPPC64 for [HasVSX, HasP8Vector, NoP9Vector, IsBigEndian] and found no regressions. So I feel the current situation is kinda messy by having partial fixes and disablement for 32bit mode. But I understand that you want this patch to be conservative correct.

I am wondering Is that possible for us to add IsPPC64 for all predicates where no existing testcases would be failed? But if it would take you too much time, I can live with that for now. Since as we discussed offline that we do have plan to verify them one by one for 32bit mode in the near future.

llvm/test/CodeGen/PowerPC/ppc-32bit-build-vector.ll

65

Sorry that I forgot to mention, attributes attributes #0 are also not necessary.

[ZarkoCA]

llvm/lib/Target/PowerPC/PPCInstrVSX.td

2412

I see your point here. I am asking because I tried adding IsPPC64 for [HasVSX, HasP8Vector, NoP9Vector, IsBigEndian] and found no regressions. So I feel the current situation is kinda messy by having partial fixes and disablement for 32bit mode. But I understand that you want this patch to be conservative correct.

Ah ok, I likely missed this instance. I will have a look and update the patch. Thanks.

And yes, the plan is to enable 32Bit VSX over time either by extending the implementation here if possible.

[ZarkoCA]

Added further IsPPC64 checks for Big Endian VSX
removed function attributes from test case.

[Xiangling_L]

LGTM. Thanks!

llvm/lib/Target/PowerPC/PPCISelLowering.cpp

if (InputLoad && DAG.isSplatValue(Op, true)) {
             Ops, LD->getMemoryVT(), LD->getMemOperand());
         // Replace all uses of the output chain of the original load with the
         // output chain of the new load.
         DAG.ReplaceAllUsesOfValueWith(InputLoad->getValue(1),
                                       LdSplt.getValue(1));
         return LdSplt;
       }
     }
 
-    // BUILD_VECTOR nodes that are not constant splats of up to 32-bits can be
-    // lowered to VSX instructions under certain conditions.
+    // In 64BIT mode BUILD_VECTOR nodes that are not constant splats of up to
+    // 32-bits can be lowered to VSX instructions under certain conditions.
     // Without VSX, there is no pattern more efficient than expanding the node.
-    if (Subtarget.hasVSX() &&
+    if (Subtarget.hasVSX() && Subtarget.isPPC64() &&
         haveEfficientBuildVectorPattern(BVN, Subtarget.hasDirectMove(),
                                         Subtarget.hasP8Vector()))
       return Op;
     return SDValue();
   }
 
   uint64_t SplatBits = APSplatBits.getZExtValue();
   uint64_t SplatUndef = APSplatUndef.getZExtValue();

llvm/lib/Target/PowerPC/PPCInstrVSX.td

def PPCldsplat : SDNode<"PPCISD::LD_SPLAT", SDT_PPCldsplat,
                         [SDNPHasChain, SDNPMayLoad, SDNPMemOperand]>;
 def PPCSToV : SDNode<"PPCISD::SCALAR_TO_VECTOR_PERMUTED",
                      SDTypeProfile<1, 1, []>, []>;
 
 //-------------------------- Predicate definitions ---------------------------//
 def HasVSX : Predicate<"Subtarget->hasVSX()">;
 def IsLittleEndian : Predicate<"Subtarget->isLittleEndian()">;
 def IsBigEndian : Predicate<"!Subtarget->isLittleEndian()">;
+def IsPPC64 : Predicate<"Subtarget->isPPC64()">;
 def HasOnlySwappingMemOps : Predicate<"!Subtarget->hasP9Vector()">;
 def HasP8Vector : Predicate<"Subtarget->hasP8Vector()">;
 def HasDirectMove : Predicate<"Subtarget->hasDirectMove()">;
 def NoP9Vector : Predicate<"!Subtarget->hasP9Vector()">;
 def HasP9Vector : Predicate<"Subtarget->hasP9Vector()">;
 def NoP9Altivec : Predicate<"!Subtarget->hasP9Altivec()">;
 
 //--------------------- VSX-specific instruction formats ---------------------//

 // is finer for various reasons. For example, we have Power8Vector,
 // Power8Altivec, DirectMove that all came in with ISA 2.07. The situation is
 // similar with ISA 3.0 with Power9Vector, Power9Altivec, IsISA3_0. Then there
 // are orthogonal predicates such as endianness for which the order was
 // arbitrarily chosen to be Big, Little.
 //
 // Predicate combinations available:
 // [HasVSX]
 // [HasVSX, IsBigEndian]
 // [HasVSX, IsLittleEndian]
 // [HasVSX, NoP9Vector]
 // [HasVSX, HasOnlySwappingMemOps]
 // [HasVSX, HasOnlySwappingMemOps, IsBigEndian]
 // [HasVSX, HasP8Vector]
-// [HasVSX, HasP8Vector, IsBigEndian]
+// [HasVSX, HasP8Vector, IsBigEndian, IsPPC64]
 // [HasVSX, HasP8Vector, IsLittleEndian]
-// [HasVSX, HasP8Vector, NoP9Vector, IsBigEndian]
+// [HasVSX, HasP8Vector, NoP9Vector, IsBigEndian, IsPPC64]
 // [HasVSX, HasP8Vector, NoP9Vector, IsLittleEndian]
 // [HasVSX, HasDirectMove]
 // [HasVSX, HasDirectMove, IsBigEndian]
 // [HasVSX, HasDirectMove, IsLittleEndian]
-// [HasVSX, HasDirectMove, NoP9Altivec, IsBigEndian]
+// [HasVSX, HasDirectMove, NoP9Altivec, IsBigEndian, IsPPC64]
+// [HasVSX, HasDirectMove, NoP9Vector, IsBigEndian, IsPPC64]
 // [HasVSX, HasDirectMove, NoP9Altivec, IsLittleEndian]
-// [HasVSX, HasDirectMove, NoP9Vector, IsBigEndian]
 // [HasVSX, HasDirectMove, NoP9Vector, IsLittleEndian]
 // [HasVSX, HasP9Vector]
-// [HasVSX, HasP9Vector, IsBigEndian]
+// [HasVSX, HasP9Vector, IsBigEndian, IsPPC64]
 // [HasVSX, HasP9Vector, IsLittleEndian]
 // [HasVSX, HasP9Altivec]
-// [HasVSX, HasP9Altivec, IsBigEndian]
+// [HasVSX, HasP9Altivec, IsBigEndian, IsPPC64]
 // [HasVSX, HasP9Altivec, IsLittleEndian]
-// [HasVSX, IsISA3_0, HasDirectMove, IsBigEndian]
+// [HasVSX, IsISA3_0, HasDirectMove, IsBigEndian, IsPPC64]
 // [HasVSX, IsISA3_0, HasDirectMove, IsLittleEndian]
 
 let AddedComplexity = 400 in {
 // Valid for any VSX subtarget, regardless of endianness.
 let Predicates = [HasVSX] in {
 def : Pat<(v4i32 (vnot_ppc v4i32:$A)),
           (v4i32 (XXLNOR $A, $A))>;
 def : Pat<(v4i32 (or (and (vnot_ppc v4i32:$C), v4i32:$A),
let Predicates = [HasVSX, HasOnlySwappingMemOps] in {
   def : Pat<(v2f64 (PPClxvd2x xoaddr:$src)), (LXVD2X xoaddr:$src)>;
 
   // Stores.
   def : Pat<(int_ppc_vsx_stxvd2x v2f64:$rS, xoaddr:$dst),
             (STXVD2X $rS, xoaddr:$dst)>;
   def : Pat<(PPCstxvd2x v2f64:$rS, xoaddr:$dst), (STXVD2X $rS, xoaddr:$dst)>;
 } // HasVSX, HasOnlySwappingMemOps
 
-// Big endian VSX subtarget that only has loads and stores that always load
-// in big endian order. Really big endian pre-Power9 subtargets.
+// Big endian VSX subtarget that only has loads and stores that always
+// load in big endian order. Really big endian pre-Power9 subtargets.
 let Predicates = [HasVSX, HasOnlySwappingMemOps, IsBigEndian] in {
   def : Pat<(v2f64 (load xoaddr:$src)), (LXVD2X xoaddr:$src)>;
   def : Pat<(v2i64 (load xoaddr:$src)), (LXVD2X xoaddr:$src)>;
   def : Pat<(v4i32 (load xoaddr:$src)), (LXVW4X xoaddr:$src)>;
   def : Pat<(v4i32 (int_ppc_vsx_lxvw4x xoaddr:$src)), (LXVW4X xoaddr:$src)>;
   def : Pat<(store v2f64:$rS, xoaddr:$dst), (STXVD2X $rS, xoaddr:$dst)>;
   def : Pat<(store v2i64:$rS, xoaddr:$dst), (STXVD2X $rS, xoaddr:$dst)>;
   def : Pat<(store v4i32:$XT, xoaddr:$dst), (STXVW4X $XT, xoaddr:$dst)>;
def : Pat<(v2i64 (bitconvert (v16i8 immAllOnesV))),
           (v2i64 (COPY_TO_REGCLASS(XXLEQVOnes), VSRC))>;
 def : Pat<(v8i16 (bitconvert (v16i8 immAllOnesV))),
           (v8i16 (COPY_TO_REGCLASS(XXLEQVOnes), VSRC))>;
 def : Pat<(v16i8 (bitconvert (v16i8 immAllOnesV))),
           (v16i8 (COPY_TO_REGCLASS(XXLEQVOnes), VSRC))>;
 } // HasVSX, HasP8Vector
 
 // Big endian Power8 VSX subtarget.
-let Predicates = [HasVSX, HasP8Vector, IsBigEndian] in {
+let Predicates = [HasVSX, HasP8Vector, IsBigEndian, IsPPC64] in {
 def : Pat<DWToSPExtractConv.El0SS1,
           (f32 (XSCVSXDSP (COPY_TO_REGCLASS $S1, VSFRC)))>;
 def : Pat<DWToSPExtractConv.El1SS1,
           (f32 (XSCVSXDSP (COPY_TO_REGCLASS (XXPERMDI $S1, $S1, 2), VSFRC)))>;
 def : Pat<DWToSPExtractConv.El0US1,
           (f32 (XSCVUXDSP (COPY_TO_REGCLASS $S1, VSFRC)))>;
 def : Pat<DWToSPExtractConv.El1US1,
           (f32 (XSCVUXDSP (COPY_TO_REGCLASS (XXPERMDI $S1, $S1, 2), VSFRC)))>;

 foreach Idx = [ [0,3], [2,1], [3,2] ] in {
   def : Pat<(store (i32 (extractelt v4i32:$A, !head(Idx))), xoaddr:$src),
             (STIWX (EXTRACT_SUBREG (XXSLDWI $A, $A, !head(!tail(Idx))),
                                    sub_64), xoaddr:$src)>;
   def : Pat<(store (f32 (extractelt v4f32:$A, !head(Idx))), xoaddr:$src),
             (STIWX (EXTRACT_SUBREG (XXSLDWI $A, $A, !head(!tail(Idx))),
                                    sub_64), xoaddr:$src)>;
 }
-} // HasVSX, HasP8Vector, IsBigEndian
+} // HasVSX, HasP8Vector, IsBigEndian, IsPPC64
 
 // Little endian Power8 VSX subtarget.
 let Predicates = [HasVSX, HasP8Vector, IsLittleEndian] in {
 def : Pat<DWToSPExtractConv.El0SS1,
           (f32 (XSCVSXDSP (COPY_TO_REGCLASS (XXPERMDI $S1, $S1, 2), VSFRC)))>;
 def : Pat<DWToSPExtractConv.El1SS1,
           (f32 (XSCVSXDSP (COPY_TO_REGCLASS
                             (f64 (COPY_TO_REGCLASS $S1, VSRC)), VSFRC)))>;
def : Pat<(store (i32 (extractelt v4i32:$A, !head(Idx))), xoaddr:$src),
                                    sub_64), xoaddr:$src)>;
   def : Pat<(store (f32 (extractelt v4f32:$A, !head(Idx))), xoaddr:$src),
             (STIWX (EXTRACT_SUBREG (XXSLDWI $A, $A, !head(!tail(Idx))),
                                    sub_64), xoaddr:$src)>;
 }
 } // HasVSX, HasP8Vector, IsLittleEndian
 
 // Big endian pre-Power9 VSX subtarget.
-let Predicates = [HasVSX, HasP8Vector, NoP9Vector, IsBigEndian] in {
+let Predicates = [HasVSX, HasP8Vector, NoP9Vector, IsBigEndian, IsPPC64] in {
 def : Pat<(store (i64 (extractelt v2i64:$A, 0)), xoaddr:$src),
           (XFSTOREf64 (EXTRACT_SUBREG $A, sub_64), xoaddr:$src)>;
 def : Pat<(store (f64 (extractelt v2f64:$A, 0)), xoaddr:$src),
           (XFSTOREf64 (EXTRACT_SUBREG $A, sub_64), xoaddr:$src)>;
 def : Pat<(store (i64 (extractelt v2i64:$A, 1)), xoaddr:$src),
           (XFSTOREf64 (EXTRACT_SUBREG (XXPERMDI $A, $A, 2), sub_64),
                       xoaddr:$src)>;
 def : Pat<(store (f64 (extractelt v2f64:$A, 1)), xoaddr:$src),
           (XFSTOREf64 (EXTRACT_SUBREG (XXPERMDI $A, $A, 2), sub_64),
                       xoaddr:$src)>;
-} // HasVSX, HasP8Vector, NoP9Vector, IsBigEndian
+} // HasVSX, HasP8Vector, NoP9Vector, IsBigEndian, IsPPC64
 
 // Little endian pre-Power9 VSX subtarget.
 let Predicates = [HasVSX, HasP8Vector, NoP9Vector, IsLittleEndian] in {
 def : Pat<(store (i64 (extractelt v2i64:$A, 0)), xoaddr:$src),
           (XFSTOREf64 (EXTRACT_SUBREG (XXPERMDI $A, $A, 2), sub_64),
                       xoaddr:$src)>;
 def : Pat<(store (f64 (extractelt v2f64:$A, 0)), xoaddr:$src),
           (XFSTOREf64 (EXTRACT_SUBREG (XXPERMDI $A, $A, 2), sub_64),

 def : Pat<(i32 (vector_extract v4i32:$S, 2)),
           (i32 VectorExtractions.LE_WORD_2)>;
 def : Pat<(i32 (vector_extract v4i32:$S, 3)),
           (i32 VectorExtractions.LE_WORD_3)>;
 def : Pat<(i32 (vector_extract v4i32:$S, i64:$Idx)),
           (i32 VectorExtractions.LE_VARIABLE_WORD)>;
 } // HasVSX, HasDirectMove, NoP9Altivec, IsLittleEndian
 
-// Big endian pre-Power9 VSX subtarget that has direct moves.
-let Predicates = [HasVSX, HasDirectMove, NoP9Vector, IsBigEndian] in {
+// Big endian pre-Power9 64Bit VSX subtarget that has direct moves.
+let Predicates = [HasVSX, HasDirectMove, NoP9Vector, IsBigEndian, IsPPC64] in {
 // Big endian integer vectors using direct moves.
 def : Pat<(v2i64 (build_vector i64:$A, i64:$B)),
           (v2i64 (XXPERMDI
                     (COPY_TO_REGCLASS (MTVSRD $A), VSRC),
                     (COPY_TO_REGCLASS (MTVSRD $B), VSRC), 0))>;
 def : Pat<(v4i32 (build_vector i32:$A, i32:$B, i32:$C, i32:$D)),
           (XXPERMDI
             (COPY_TO_REGCLASS
               (MTVSRD (RLDIMI AnyExts.B, AnyExts.A, 32, 0)), VSRC),
             (COPY_TO_REGCLASS
               (MTVSRD (RLDIMI AnyExts.D, AnyExts.C, 32, 0)), VSRC), 0)>;
 def : Pat<(v4i32 (build_vector i32:$A, i32:$A, i32:$A, i32:$A)),
           (XXSPLTW (COPY_TO_REGCLASS (MTVSRWZ $A), VSRC), 1)>;
-} // HasVSX, HasDirectMove, NoP9Vector, IsBigEndian
+} // HasVSX, HasDirectMove, NoP9Vector, IsBigEndian, IsPPC64
 
 // Little endian pre-Power9 VSX subtarget that has direct moves.
 let Predicates = [HasVSX, HasDirectMove, NoP9Vector, IsLittleEndian] in {
 // Little endian integer vectors using direct moves.
 def : Pat<(v2i64 (build_vector i64:$A, i64:$B)),
           (v2i64 (XXPERMDI
                     (COPY_TO_REGCLASS (MTVSRD $B), VSRC),
                     (COPY_TO_REGCLASS (MTVSRD $A), VSRC), 0))>;
(SUBREG_TO_REG
      (i64 1),
      (XSCVDPUXDS (COPY_TO_REGCLASS (DFLOADf32 iaddrX4:$A), VSFRC)), sub_64)>;
 def : Pat<(v4f32 (PPCldsplat xoaddr:$A)),
           (v4f32 (LXVWSX xoaddr:$A))>;
 def : Pat<(v4i32 (PPCldsplat xoaddr:$A)),
           (v4i32 (LXVWSX xoaddr:$A))>;
 } // HasVSX, HasP9Vector
 
-// Big endian Power9 subtarget.
-let Predicates = [HasVSX, HasP9Vector, IsBigEndian] in {
+// Big endian 64Bit Power9 subtarget.
+let Predicates = [HasVSX, HasP9Vector, IsBigEndian, IsPPC64] in {
 def : Pat<(f32 (PPCfcfidus (f64 (PPCmtvsrz (i32 (extractelt v4i32:$A, 0)))))),
           (f32 (XSCVUXDSP (XXEXTRACTUW $A, 0)))>;
 def : Pat<(f32 (PPCfcfidus (f64 (PPCmtvsrz (i32 (extractelt v4i32:$A, 1)))))),
           (f32 (XSCVUXDSP (XXEXTRACTUW $A, 4)))>;
 def : Pat<(f32 (PPCfcfidus (f64 (PPCmtvsrz (i32 (extractelt v4i32:$A, 2)))))),
           (f32 (XSCVUXDSP (XXEXTRACTUW $A, 8)))>;
 def : Pat<(f32 (PPCfcfidus (f64 (PPCmtvsrz (i32 (extractelt v4i32:$A, 3)))))),
           (f32 (XSCVUXDSP (XXEXTRACTUW $A, 12)))>;
def : Pat<(f128 (uint_to_fp
             (f128 (XSCVUDQP
                     (EXTRACT_SUBREG (VEXTRACTUB Idx, $src), sub_64)))>;
 }
 
 // Unsiged int in vsx register -> QP
 def : Pat<(f128 (uint_to_fp (i32 (PPCmfvsr f64:$src)))),
           (f128 (XSCVUDQP
                   (XXEXTRACTUW (SUBREG_TO_REG (i64 1), $src, sub_64), 4)))>;
-} // HasVSX, HasP9Vector, IsBigEndian
+} // HasVSX, HasP9Vector, IsBigEndian, IsPPC64
 
 // Little endian Power9 subtarget.
 let Predicates = [HasVSX, HasP9Vector, IsLittleEndian] in {
 def : Pat<(f32 (PPCfcfidus (f64 (PPCmtvsrz (i32 (extractelt v4i32:$A, 0)))))),
           (f32 (XSCVUXDSP (XXEXTRACTUW $A, 12)))>;
 def : Pat<(f32 (PPCfcfidus (f64 (PPCmtvsrz (i32 (extractelt v4i32:$A, 1)))))),
           (f32 (XSCVUXDSP (XXEXTRACTUW $A, 8)))>;
 def : Pat<(f32 (PPCfcfidus (f64 (PPCmtvsrz (i32 (extractelt v4i32:$A, 2)))))),
def : Pat<(v16i8 (PPCvabsd v16i8:$A, v16i8:$B, (i32 0))),
           (v16i8 (VABSDUB $A, $B))>;
 
 // As PPCVABSD description, the last operand indicates whether do the
 // sign bit flip.
 def : Pat<(v4i32 (PPCvabsd v4i32:$A, v4i32:$B, (i32 1))),
           (v4i32 (VABSDUW (XVNEGSP $A), (XVNEGSP $B)))>;
 } // HasVSX, HasP9Altivec
 
-// Big endian Power9 VSX subtargets with P9 Altivec support.
-let Predicates = [HasVSX, HasP9Altivec, IsBigEndian] in {
+// Big endian Power9 64Bit VSX subtargets with P9 Altivec support.
+let Predicates = [HasVSX, HasP9Altivec, IsBigEndian, IsPPC64] in {
 def : Pat<(i64 (anyext (i32 (vector_extract v16i8:$S, i64:$Idx)))),
           (VEXTUBLX $Idx, $S)>;
 
 def : Pat<(i64 (anyext (i32 (vector_extract v8i16:$S, i64:$Idx)))),
           (VEXTUHLX (RLWINM8 $Idx, 1, 28, 30), $S)>;
 def : Pat<(i64 (anyext (i32 (vector_extract v8i16:$S, 0)))),
           (VEXTUHLX (LI8 0), $S)>;
 def : Pat<(i64 (anyext (i32 (vector_extract v8i16:$S, 1)))),

 def : Pat<(v4i32 (build_vector HWordToWord.BE_A0, HWordToWord.BE_A1,
                   HWordToWord.BE_A2, HWordToWord.BE_A3)),
           (v4i32 (VEXTSH2W $A))>;
 def : Pat<(v4i32 (build_vector ByteToWord.BE_A0, ByteToWord.BE_A1,
                   ByteToWord.BE_A2, ByteToWord.BE_A3)),
           (v4i32 (VEXTSB2W $A))>;
 def : Pat<(v2i64 (build_vector ByteToDWord.BE_A0, ByteToDWord.BE_A1)),
           (v2i64 (VEXTSB2D $A))>;
-} // HasVSX, HasP9Altivec, IsBigEndian
+} // HasVSX, HasP9Altivec, IsBigEndian, IsPPC64
 
 // Little endian Power9 VSX subtargets with P9 Altivec support.
 let Predicates = [HasVSX, HasP9Altivec, IsLittleEndian] in {
 def : Pat<(i64 (anyext (i32 (vector_extract v16i8:$S, i64:$Idx)))),
           (VEXTUBRX $Idx, $S)>;
 
 def : Pat<(i64 (anyext (i32 (vector_extract v8i16:$S, i64:$Idx)))),
           (VEXTUHRX (RLWINM8 $Idx, 1, 28, 30), $S)>;
def : Pat<(v4i32 (build_vector HWordToWord.LE_A0, HWordToWord.LE_A1,
           (v4i32 (VEXTSH2W $A))>;
 def : Pat<(v4i32 (build_vector ByteToWord.LE_A0, ByteToWord.LE_A1,
                   ByteToWord.LE_A2, ByteToWord.LE_A3)),
           (v4i32 (VEXTSB2W $A))>;
 def : Pat<(v2i64 (build_vector ByteToDWord.LE_A0, ByteToDWord.LE_A1)),
           (v2i64 (VEXTSB2D $A))>;
 } // HasVSX, HasP9Altivec, IsLittleEndian
 
-// Big endian VSX subtarget that supports additional direct moves from ISA3.0.
-let Predicates = [HasVSX, IsISA3_0, HasDirectMove, IsBigEndian] in {
+// Big endian 64Bit VSX subtarget that supports additional direct moves from
+// ISA3.0.
+let Predicates = [HasVSX, IsISA3_0, HasDirectMove, IsBigEndian, IsPPC64] in {
 def : Pat<(i64 (extractelt v2i64:$A, 1)),
           (i64 (MFVSRLD $A))>;
 // Better way to build integer vectors if we have MTVSRDD. Big endian.
 def : Pat<(v2i64 (build_vector i64:$rB, i64:$rA)),
           (v2i64 (MTVSRDD $rB, $rA))>;
 def : Pat<(v4i32 (build_vector i32:$A, i32:$B, i32:$C, i32:$D)),
           (MTVSRDD
             (RLDIMI AnyExts.B, AnyExts.A, 32, 0),
             (RLDIMI AnyExts.D, AnyExts.C, 32, 0))>;
 
 def : Pat<(f128 (PPCbuild_fp128 i64:$rB, i64:$rA)),
           (f128 (COPY_TO_REGCLASS (MTVSRDD $rB, $rA), VRRC))>;
-} // HasVSX, IsISA3_0, HasDirectMove, IsBigEndian
+} // HasVSX, IsISA3_0, HasDirectMove, IsBigEndian, IsPPC64
 
 // Little endian VSX subtarget that supports direct moves from ISA3.0.
 let Predicates = [HasVSX, IsISA3_0, HasDirectMove, IsLittleEndian] in {
 def : Pat<(i64 (extractelt v2i64:$A, 0)),
           (i64 (MFVSRLD $A))>;
 // Better way to build integer vectors if we have MTVSRDD. Little endian.
 def : Pat<(v2i64 (build_vector i64:$rA, i64:$rB)),
           (v2i64 (MTVSRDD $rB, $rA))>;

llvm/test/CodeGen/PowerPC/ppc-32bit-build-vector.ll

+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -verify-machineinstrs -mtriple=powerpc -mcpu=pwr8 < %s |\
+; RUN: FileCheck %s --check-prefix=32BIT
+
+; RUN: llc -verify-machineinstrs -mtriple=powerpc64 -mcpu=pwr8 < %s |\
+; RUN: FileCheck %s --check-prefix=64BIT
+
+define dso_local fastcc void @BuildVectorICE() unnamed_addr {
+; 32BIT-LABEL: BuildVectorICE:
+; 32BIT:       # %bb.0: # %entry
+; 32BIT-NEXT:    stwu 1, -64(1)
+; 32BIT-NEXT:    .cfi_def_cfa_offset 64
+; 32BIT-NEXT:    lxvw4x 34, 0, 3
+; 32BIT-NEXT:    li 3, 0
+; 32BIT-NEXT:    addi 4, 1, 16
+; 32BIT-NEXT:    addi 5, 1, 32
+; 32BIT-NEXT:    addi 6, 1, 48
+; 32BIT-NEXT:    li 7, 0
+; 32BIT-NEXT:    .p2align 4
+; 32BIT-NEXT:  .LBB0_1: # %while.body
+; 32BIT-NEXT:    #
+; 32BIT-NEXT:    stw 7, 16(1)
+; 32BIT-NEXT:    stw 3, 32(1)
+; 32BIT-NEXT:    lxvw4x 0, 0, 4
+; 32BIT-NEXT:    lxvw4x 1, 0, 5
+; 32BIT-NEXT:    xxsldwi 0, 1, 0, 1
+; 32BIT-NEXT:    xxspltw 1, 1, 0
+; 32BIT-NEXT:    xxsldwi 35, 0, 1, 3
+; 32BIT-NEXT:    vadduwm 3, 2, 3
+; 32BIT-NEXT:    xxspltw 36, 35, 1
+; 32BIT-NEXT:    vadduwm 3, 3, 4
+; 32BIT-NEXT:    stxvw4x 35, 0, 6
+; 32BIT-NEXT:    lwz 7, 48(1)
+; 32BIT-NEXT:    b .LBB0_1
+;
+; 64BIT-LABEL: BuildVectorICE:
+; 64BIT:       # %bb.0: # %entry
+; 64BIT-NEXT:    li 3, 0
+; 64BIT-NEXT:    lxvw4x 34, 0, 3
+; 64BIT-NEXT:    rldimi 3, 3, 32, 0
+; 64BIT-NEXT:    mtfprd 0, 3
+; 64BIT-NEXT:    li 3, 0
+; 64BIT-NEXT:    .p2align 4
+; 64BIT-NEXT:  .LBB0_1: # %while.body
+; 64BIT-NEXT:    #
+; 64BIT-NEXT:    li 4, 0
+; 64BIT-NEXT:    rldimi 4, 3, 32, 0
+; 64BIT-NEXT:    mtfprd 1, 4
+; 64BIT-NEXT:    xxmrghd 35, 1, 0
+; 64BIT-NEXT:    vadduwm 3, 2, 3
+; 64BIT-NEXT:    xxspltw 36, 35, 1
+; 64BIT-NEXT:    vadduwm 3, 3, 4
+; 64BIT-NEXT:    xxsldwi 1, 35, 35, 3
+; 64BIT-NEXT:    mffprwz 3, 1
+; 64BIT-NEXT:    b .LBB0_1
+    entry:
+     br label %while.body
+     while.body:                                       ; preds = %while.body, %entry
+     %newelement = phi i32 [ 0, %entry ], [ %5, %while.body ]
+     %0 = insertelement <4 x i32> <i32 undef, i32 0, i32 0, i32 0>, i32 %newelement, i32 0
+     %1 = load <4 x i32>, <4 x i32>* undef, align 1
+     %2 = add <4 x i32> %1, %0
+     %3 = shufflevector <4 x i32> %2, <4 x i32> undef, <4 x i32> <i32 1, i32 undef, i32 undef, i32 undef>
+     %4 = add <4 x i32> %2, %3
+     %5 = extractelement <4 x i32> %4, i32 0
+     br label %while.body
+}