From 9d2238cb0f6f67ed6883a0e9f98a835c523724da Mon Sep 17 00:00:00 2001 From: Bill Schmidt Date: Fri, 30 Aug 2013 23:31:33 +0000 Subject: [PATCH] [PowerPC] Add integer truncation support to fast-isel. This is the last substantive patch I'm planning for fast-isel in the near future, adding fast selection of integer truncates. There are certainly more things that can be improved (many of which are called out in FIXMEs), but for now we are catching most of the important cases. I'll document some of the remaining work in a cleanup patch shortly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189706 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/PowerPC/PPCFastISel.cpp | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/lib/Target/PowerPC/PPCFastISel.cpp b/lib/Target/PowerPC/PPCFastISel.cpp index 0276668e3ec..0e789cc397a 100644 --- a/lib/Target/PowerPC/PPCFastISel.cpp +++ b/lib/Target/PowerPC/PPCFastISel.cpp @@ -116,6 +116,7 @@ class PPCFastISel : public FastISel { bool SelectBinaryIntOp(const Instruction *I, unsigned ISDOpcode); bool SelectCall(const Instruction *I); bool SelectRet(const Instruction *I); + bool SelectTrunc(const Instruction *I); bool SelectIntExt(const Instruction *I); // Utility routines. @@ -1667,6 +1668,34 @@ bool PPCFastISel::SelectCmp(const Instruction *I) { return true; } +// Attempt to fast-select an integer truncate instruction. +bool PPCFastISel::SelectTrunc(const Instruction *I) { + Value *Src = I->getOperand(0); + EVT SrcVT = TLI.getValueType(Src->getType(), true); + EVT DestVT = TLI.getValueType(I->getType(), true); + + if (SrcVT != MVT::i64 && SrcVT != MVT::i32 && SrcVT != MVT::i16) + return false; + + if (DestVT != MVT::i32 && DestVT != MVT::i16 && DestVT != MVT::i8) + return false; + + unsigned SrcReg = getRegForValue(Src); + if (!SrcReg) + return false; + + // The only interesting case is when we need to switch register classes. + if (SrcVT == MVT::i64) { + unsigned ResultReg = createResultReg(&PPC::GPRCRegClass); + BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY), + ResultReg).addReg(SrcReg, 0, PPC::sub_32); + SrcReg = ResultReg; + } + + UpdateValueMap(I, SrcReg); + return true; +} + // Attempt to fast-select an integer extend instruction. bool PPCFastISel::SelectIntExt(const Instruction *I) { Type *DestTy = I->getType(); @@ -1743,6 +1772,8 @@ bool PPCFastISel::TargetSelectInstruction(const Instruction *I) { return SelectCall(I); case Instruction::Ret: return SelectRet(I); + case Instruction::Trunc: + return SelectTrunc(I); case Instruction::ZExt: case Instruction::SExt: return SelectIntExt(I); -- 2.11.0