From 4cef3fb022ddcd6d6d1f2f6894f3661f3000d022 Mon Sep 17 00:00:00 2001 From: Bill Schmidt Date: Mon, 9 Jun 2014 16:06:29 +0000 Subject: [PPC64LE] Generate correct little-endian code for v16i8 multiply The existing code in PPCTargetLowering::LowerMUL() for multiplying two v16i8 values assumes that vector elements are numbered in big-endian order. For little-endian targets, the vector element numbering is reversed, but the vmuleub, vmuloub, and vperm instructions still assume big-endian numbering. To account for this, we must adjust the permute control vector and reverse the order of the input registers on the vperm instruction. The existing test/CodeGen/PowerPC/vec_mul.ll is updated to be executed on powerpc64 and powerpc64le targets as well as the original powerpc (32-bit) target. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210474 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/PowerPC/PPCISelLowering.cpp | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'lib') diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp index d5a685d9f4..91366e2cce 100644 --- a/lib/Target/PowerPC/PPCISelLowering.cpp +++ b/lib/Target/PowerPC/PPCISelLowering.cpp @@ -6059,6 +6059,7 @@ SDValue PPCTargetLowering::LowerMUL(SDValue Op, SelectionDAG &DAG) const { LHS, RHS, Zero, DAG, dl); } else if (Op.getValueType() == MVT::v16i8) { SDValue LHS = Op.getOperand(0), RHS = Op.getOperand(1); + bool isLittleEndian = PPCSubTarget.isLittleEndian(); // Multiply the even 8-bit parts, producing 16-bit sums. SDValue EvenParts = BuildIntrinsicOp(Intrinsic::ppc_altivec_vmuleub, @@ -6070,13 +6071,24 @@ SDValue PPCTargetLowering::LowerMUL(SDValue Op, SelectionDAG &DAG) const { LHS, RHS, DAG, dl, MVT::v8i16); OddParts = DAG.getNode(ISD::BITCAST, dl, MVT::v16i8, OddParts); - // Merge the results together. + // Merge the results together. Because vmuleub and vmuloub are + // instructions with a big-endian bias, we must reverse the + // element numbering and reverse the meaning of "odd" and "even" + // when generating little endian code. int Ops[16]; for (unsigned i = 0; i != 8; ++i) { - Ops[i*2 ] = 2*i+1; - Ops[i*2+1] = 2*i+1+16; + if (isLittleEndian) { + Ops[i*2 ] = 2*i; + Ops[i*2+1] = 2*i+16; + } else { + Ops[i*2 ] = 2*i+1; + Ops[i*2+1] = 2*i+1+16; + } } - return DAG.getVectorShuffle(MVT::v16i8, dl, EvenParts, OddParts, Ops); + if (isLittleEndian) + return DAG.getVectorShuffle(MVT::v16i8, dl, OddParts, EvenParts, Ops); + else + return DAG.getVectorShuffle(MVT::v16i8, dl, EvenParts, OddParts, Ops); } else { llvm_unreachable("Unknown mul to lower!"); } -- cgit v1.2.3