diff options
| -rw-r--r-- | llvm/lib/CodeGen/RegisterCoalescer.cpp | 40 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/sret-implicit.ll | 2 |
2 files changed, 34 insertions, 8 deletions
diff --git a/llvm/lib/CodeGen/RegisterCoalescer.cpp b/llvm/lib/CodeGen/RegisterCoalescer.cpp index 9e3cf415e44..c04437e21df 100644 --- a/llvm/lib/CodeGen/RegisterCoalescer.cpp +++ b/llvm/lib/CodeGen/RegisterCoalescer.cpp @@ -2733,13 +2733,17 @@ bool RegisterCoalescer::applyTerminalRule(const MachineInstr &Copy) const { return false; // Check if the destination of this copy has any other affinity. unsigned DstReg = Copy.getOperand(0).getReg(); + unsigned SrcReg = Copy.getOperand(1).getReg(); if (TargetRegisterInfo::isPhysicalRegister(DstReg) || + // If SrcReg is a physical register, the copy won't be coalesced. + // Ignoring it may have other side effect (like missing + // rematerialization). So keep it. + TargetRegisterInfo::isPhysicalRegister(SrcReg) || !isTerminalReg(DstReg, Copy, MRI)) return false; // DstReg is a terminal node. Check if it inteferes with any other // copy involving SrcReg. - unsigned SrcReg = Copy.getOperand(1).getReg(); const MachineBasicBlock *OrigBB = Copy.getParent(); const LiveInterval &DstLI = LIS->getInterval(DstReg); for (const MachineInstr &MI : MRI->reg_nodbg_instructions(SrcReg)) { @@ -2775,25 +2779,45 @@ RegisterCoalescer::copyCoalesceInMBB(MachineBasicBlock *MBB) { // yet, it might invalidate the iterator. const unsigned PrevSize = WorkList.size(); if (JoinGlobalCopies) { + SmallVector<MachineInstr*, 2> LocalTerminals; + SmallVector<MachineInstr*, 2> GlobalTerminals; // Coalesce copies bottom-up to coalesce local defs before local uses. They // are not inherently easier to resolve, but slightly preferable until we // have local live range splitting. In particular this is required by // cmp+jmp macro fusion. for (MachineBasicBlock::iterator MII = MBB->begin(), E = MBB->end(); MII != E; ++MII) { - if (!MII->isCopyLike() || applyTerminalRule(*MII)) + if (!MII->isCopyLike()) continue; - if (isLocalCopy(&(*MII), LIS)) - LocalWorkList.push_back(&(*MII)); - else - WorkList.push_back(&(*MII)); + bool ApplyTerminalRule = applyTerminalRule(*MII); + if (isLocalCopy(&(*MII), LIS)) { + if (ApplyTerminalRule) + LocalTerminals.push_back(&(*MII)); + else + LocalWorkList.push_back(&(*MII)); + } else { + if (ApplyTerminalRule) + GlobalTerminals.push_back(&(*MII)); + else + WorkList.push_back(&(*MII)); + } } + // Append the copies evicted by the terminal rule at the end of the list. + LocalWorkList.append(LocalTerminals.begin(), LocalTerminals.end()); + WorkList.append(GlobalTerminals.begin(), GlobalTerminals.end()); } else { + SmallVector<MachineInstr*, 2> Terminals; for (MachineBasicBlock::iterator MII = MBB->begin(), E = MBB->end(); MII != E; ++MII) - if (MII->isCopyLike() && !applyTerminalRule(*MII)) - WorkList.push_back(MII); + if (MII->isCopyLike()) { + if (applyTerminalRule(*MII)) + Terminals.push_back(&(*MII)); + else + WorkList.push_back(MII); + } + // Append the copies evicted by the terminal rule at the end of the list. + WorkList.append(Terminals.begin(), Terminals.end()); } // Try coalescing the collected copies immediately, and remove the nulls. // This prevents the WorkList from getting too large since most copies are diff --git a/llvm/test/CodeGen/X86/sret-implicit.ll b/llvm/test/CodeGen/X86/sret-implicit.ll index 3fade1de0cf..56809525407 100644 --- a/llvm/test/CodeGen/X86/sret-implicit.ll +++ b/llvm/test/CodeGen/X86/sret-implicit.ll @@ -1,5 +1,7 @@ ; RUN: llc -mtriple=x86_64-apple-darwin8 < %s | FileCheck %s ; RUN: llc -mtriple=x86_64-pc-linux < %s | FileCheck %s +; RUN: llc -mtriple=x86_64-apple-darwin8 -terminal-rule < %s | FileCheck %s +; RUN: llc -mtriple=x86_64-pc-linux -terminal-rule < %s | FileCheck %s ; CHECK-LABEL: return32 ; CHECK-DAG: movq $0, (%rdi) |
