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[DAGCombiner] Don't make a BUILD_VECTOR with operands of illegal type. 

When DAGCombiner visits a SIGN_EXTEND_INREG of a BUILD_VECTOR with
constant operands, a new BUILD_VECTOR node will be created transformed
constants.

Llvm-stress found a case where the new BUILD_VECTOR had constant operands
of an illegal type, because the (legal) element type is in fact not a legal
scalar type.

This patch changes this so that the new BUILD_VECTOR has the same operand
type as the old one.

Review: Eli Friedman, Nirav Dave
https://bugs.llvm.org//show_bug.cgi?id=32422

llvm-svn: 299540
This commit is contained in:
Jonas Paulsson 2017-04-05 13:45:37 +00:00
parent 8090e6f004
commit 38a2da92bc
2 changed files with 32 additions and 6 deletions
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12
llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
View File

@ -4188,29 +4188,29 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
assert(EVT.bitsLE(VT) && "Not extending!");
if (EVT == VT) return N1; // Not actually extending
auto SignExtendInReg = [&](APInt Val) {
auto SignExtendInReg = [&](APInt Val, llvm::EVT ConstantVT) {
unsigned FromBits = EVT.getScalarSizeInBits();
Val <<= Val.getBitWidth() - FromBits;
Val = Val.ashr(Val.getBitWidth() - FromBits);
return getConstant(Val, DL, VT.getScalarType());
return getConstant(Val, DL, ConstantVT);
};
if (N1C) {
const APInt &Val = N1C->getAPIntValue();
return SignExtendInReg(Val);
return SignExtendInReg(Val, VT);
}
if (ISD::isBuildVectorOfConstantSDNodes(N1.getNode())) {
SmallVector<SDValue, 8> Ops;
llvm::EVT OpVT = N1.getOperand(0).getValueType();
for (int i = 0, e = VT.getVectorNumElements(); i != e; ++i) {
SDValue Op = N1.getOperand(i);
if (Op.isUndef()) {
Ops.push_back(getUNDEF(VT.getScalarType()));
Ops.push_back(getUNDEF(OpVT));
continue;
}
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
APInt Val = C->getAPIntValue();
Val = Val.zextOrTrunc(VT.getScalarSizeInBits());
Ops.push_back(SignExtendInReg(Val));
Ops.push_back(SignExtendInReg(Val, OpVT));
continue;
}
break;

26
llvm/test/CodeGen/SystemZ/DAGCombiner_illegal_BUILD_VECTOR.ll Normal file
View File

@ -0,0 +1,26 @@
; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z13 | FileCheck %s
;
; Check that DAGCombiner does not crash after producing an illegal
; BUILD_VECTOR node.
define void @pr32422() {
; CHECK: cdbr %f0, %f0
; CHECK: jo .LBB0_1
BB:
%I = insertelement <8 x i8> zeroinitializer, i8 -95, i32 3
%I8 = insertelement <8 x i8> zeroinitializer, i8 -119, i32 2
%FC = uitofp <8 x i8> %I8 to <8 x float>
%Cmp18 = fcmp uno <8 x float> zeroinitializer, %FC
%I22 = insertelement <8 x i1> %Cmp18, i1 true, i32 5
br label %CF
CF: ; preds = %CF, %BB
%Cmp40 = fcmp uno double 0xC663C682E9619F00, undef
br i1 %Cmp40, label %CF, label %CF353
CF353: ; preds = %CF
%E195 = extractelement <8 x i1> %I22, i32 4
ret void
}