From 2afde7782dfa56b2e46f79598bdb5f1e09471941 Mon Sep 17 00:00:00 2001 From: Manman Ren Date: Wed, 6 Jun 2012 23:53:03 +0000 Subject: [PATCH] Revert r157755. The commit is intended to fix rdar://11540023. It is implemented as part of peephole optimization. We can actually implement this in the SelectionDAG lowering phase. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158122 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Target/TargetInstrInfo.h | 8 ------ lib/CodeGen/PeepholeOptimizer.cpp | 1 - lib/Target/X86/X86InstrInfo.cpp | 38 --------------------------- lib/Target/X86/X86InstrInfo.h | 3 --- test/CodeGen/X86/jump_sign.ll | 11 -------- 5 files changed, 61 deletions(-) diff --git a/include/llvm/Target/TargetInstrInfo.h b/include/llvm/Target/TargetInstrInfo.h index 693166f5522..67b61ec77e3 100644 --- a/include/llvm/Target/TargetInstrInfo.h +++ b/include/llvm/Target/TargetInstrInfo.h @@ -640,14 +640,6 @@ public: return false; } - /// OptimizeSubInstr - See if the SUB instruction can be converted into - /// something more efficient E.g., on X86, we can replace SUB with CMP - /// if the actual result of SUB is not used. - virtual bool OptimizeSubInstr(MachineInstr *SubInstr, - const MachineRegisterInfo *MRI) const { - return false; - } - /// FoldImmediate - 'Reg' is known to be defined by a move immediate /// instruction, try to fold the immediate into the use instruction. virtual bool FoldImmediate(MachineInstr *UseMI, MachineInstr *DefMI, diff --git a/lib/CodeGen/PeepholeOptimizer.cpp b/lib/CodeGen/PeepholeOptimizer.cpp index d7d112f1d97..81cf9011d1d 100644 --- a/lib/CodeGen/PeepholeOptimizer.cpp +++ b/lib/CodeGen/PeepholeOptimizer.cpp @@ -472,7 +472,6 @@ bool PeepholeOptimizer::runOnMachineFunction(MachineFunction &MF) { if (SeenMoveImm) Changed |= foldImmediate(MI, MBB, ImmDefRegs, ImmDefMIs); } - Changed |= TII->OptimizeSubInstr(MI, MRI); First = false; PMII = MII; diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp index 197b9c683dd..7d5b25084e0 100644 --- a/lib/Target/X86/X86InstrInfo.cpp +++ b/lib/Target/X86/X86InstrInfo.cpp @@ -2793,44 +2793,6 @@ void X86InstrInfo::loadRegFromAddr(MachineFunction &MF, unsigned DestReg, NewMIs.push_back(MIB); } -bool X86InstrInfo:: -OptimizeSubInstr(MachineInstr *SubInstr, const MachineRegisterInfo *MRI) const { - // If destination is a memory operand, do not perform this optimization. - if ((SubInstr->getOpcode() != X86::SUB64rr) && - (SubInstr->getOpcode() != X86::SUB32rr) && - (SubInstr->getOpcode() != X86::SUB16rr) && - (SubInstr->getOpcode() != X86::SUB8rr) && - (SubInstr->getOpcode() != X86::SUB64ri32) && - (SubInstr->getOpcode() != X86::SUB64ri8) && - (SubInstr->getOpcode() != X86::SUB32ri) && - (SubInstr->getOpcode() != X86::SUB32ri8) && - (SubInstr->getOpcode() != X86::SUB16ri) && - (SubInstr->getOpcode() != X86::SUB16ri8) && - (SubInstr->getOpcode() != X86::SUB8ri)) - return false; - unsigned DestReg = SubInstr->getOperand(0).getReg(); - if (MRI->use_begin(DestReg) != MRI->use_end()) - return false; - - // There is no use of the destination register, we can replace SUB with CMP. - switch (SubInstr->getOpcode()) { - default: break; - case X86::SUB64rr: SubInstr->setDesc(get(X86::CMP64rr)); break; - case X86::SUB32rr: SubInstr->setDesc(get(X86::CMP32rr)); break; - case X86::SUB16rr: SubInstr->setDesc(get(X86::CMP16rr)); break; - case X86::SUB8rr: SubInstr->setDesc(get(X86::CMP8rr)); break; - case X86::SUB64ri32: SubInstr->setDesc(get(X86::CMP64ri32)); break; - case X86::SUB64ri8: SubInstr->setDesc(get(X86::CMP64ri8)); break; - case X86::SUB32ri: SubInstr->setDesc(get(X86::CMP32ri)); break; - case X86::SUB32ri8: SubInstr->setDesc(get(X86::CMP32ri8)); break; - case X86::SUB16ri: SubInstr->setDesc(get(X86::CMP16ri)); break; - case X86::SUB16ri8: SubInstr->setDesc(get(X86::CMP16ri8)); break; - case X86::SUB8ri: SubInstr->setDesc(get(X86::CMP8ri)); break; - } - SubInstr->RemoveOperand(0); - return true; -} - /// Expand2AddrUndef - Expand a single-def pseudo instruction to a two-addr /// instruction with two undef reads of the register being defined. This is /// used for mapping: diff --git a/lib/Target/X86/X86InstrInfo.h b/lib/Target/X86/X86InstrInfo.h index 088c49f6291..5ae6b99e5af 100644 --- a/lib/Target/X86/X86InstrInfo.h +++ b/lib/Target/X86/X86InstrInfo.h @@ -364,9 +364,6 @@ public: const MachineInstr *DefMI, unsigned DefIdx, const MachineInstr *UseMI, unsigned UseIdx) const; - virtual bool OptimizeSubInstr(MachineInstr *SubInstr, - const MachineRegisterInfo *MRI) const; - private: MachineInstr * convertToThreeAddressWithLEA(unsigned MIOpc, MachineFunction::iterator &MFI, diff --git a/test/CodeGen/X86/jump_sign.ll b/test/CodeGen/X86/jump_sign.ll index cf5408e0710..94cbe5d1937 100644 --- a/test/CodeGen/X86/jump_sign.ll +++ b/test/CodeGen/X86/jump_sign.ll @@ -83,14 +83,3 @@ entry: %cond = select i1 %cmp, i32 %sub, i32 0 ret i32 %cond } -; rdar://11540023 -define i64 @n(i64 %x, i64 %y) nounwind { -entry: -; CHECK: n: -; CHECK-NOT: sub -; CHECK: cmp - %sub = sub nsw i64 %x, %y - %cmp = icmp slt i64 %sub, 0 - %y.x = select i1 %cmp, i64 %y, i64 %x - ret i64 %y.x -} -- 2.34.1