Commit 84bd8511 authored by Amara Emerson's avatar Amara Emerson
Browse files

[GlobalISel][IRTranslator] When translating vector geps, splat the base pointer if required. 

We can have geps that have a scalar base pointer, and a vector index value, which
means that the base pointer must be splatted into a vector of pointers.

This fixes crashes on arm64 GlobalISel with optimizations enabled.
parent 3b23453b

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

+12 −0
Original line number Diff line number Diff line
@@ -1062,6 +1062,18 @@ bool IRTranslator::translateGetElementPtr(const User &U, 
  if (auto *VT = dyn_cast<VectorType>(U.getType()))

    VectorWidth = VT->getNumElements();



  // We might need to splat the base pointer into a vector if the offsets

  // are vectors.

  if (VectorWidth && !PtrTy.isVector()) {

    BaseReg =

        MIRBuilder.buildSplatVector(LLT::vector(VectorWidth, PtrTy), BaseReg)

            .getReg(0);

    PtrIRTy = VectorType::get(PtrIRTy, VectorWidth);

    PtrTy = getLLTForType(*PtrIRTy, *DL);

    OffsetIRTy = DL->getIntPtrType(PtrIRTy);

    OffsetTy = getLLTForType(*OffsetIRTy, *DL);

  }



  int64_t Offset = 0;

  for (gep_type_iterator GTI = gep_type_begin(&U), E = gep_type_end(&U);

       GTI != E; ++GTI) {

llvm/test/CodeGen/AArch64/GlobalISel/translate-gep.ll

+21 −0
Original line number Diff line number Diff line
@@ -117,3 +117,24 @@ define i32* @var_then_const(%type1* %addr, i64 %idx) { 
  %res = getelementptr %type1, %type1* %addr, i64 %idx, i32 2, i32 2

  ret i32* %res

}



@arr = external global [8 x i32]



define <2 x i32*> @vec_gep_scalar_base(<2 x i64> %offs) {

  ; CHECK-LABEL: name: vec_gep_scalar_base

  ; CHECK: bb.1.entry:

  ; CHECK:   liveins: $q0

  ; CHECK:   [[COPY:%[0-9]+]]:_(<2 x s64>) = COPY $q0

  ; CHECK:   [[GV:%[0-9]+]]:_(p0) = G_GLOBAL_VALUE @arr

  ; CHECK:   [[BUILD_VECTOR:%[0-9]+]]:_(<2 x p0>) = G_BUILD_VECTOR [[GV]](p0), [[GV]](p0)

  ; CHECK:   [[C:%[0-9]+]]:_(s64) = G_CONSTANT i64 4

  ; CHECK:   [[BUILD_VECTOR1:%[0-9]+]]:_(<2 x s64>) = G_BUILD_VECTOR [[C]](s64), [[C]](s64)

  ; CHECK:   [[MUL:%[0-9]+]]:_(<2 x s64>) = G_MUL [[COPY]], [[BUILD_VECTOR1]]

  ; CHECK:   [[PTR_ADD:%[0-9]+]]:_(<2 x p0>) = G_PTR_ADD [[BUILD_VECTOR]], [[MUL]](<2 x s64>)

  ; CHECK:   [[COPY1:%[0-9]+]]:_(<2 x p0>) = COPY [[PTR_ADD]](<2 x p0>)

  ; CHECK:   $q0 = COPY [[COPY1]](<2 x p0>)

  ; CHECK:   RET_ReallyLR implicit $q0

entry:

  %0 = getelementptr inbounds [8 x i32], [8 x i32]* @arr, i64 0, <2 x i64> %offs

  ret <2 x i32*> %0

}