diff options
| -rw-r--r-- | lib/Target/ARM/ARMConstantIslandPass.cpp | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/lib/Target/ARM/ARMConstantIslandPass.cpp b/lib/Target/ARM/ARMConstantIslandPass.cpp index 763a47cb44..b779093f99 100644 --- a/lib/Target/ARM/ARMConstantIslandPass.cpp +++ b/lib/Target/ARM/ARMConstantIslandPass.cpp @@ -79,14 +79,14 @@ namespace { /// opcode. struct ImmBranch { MachineInstr *MI; - bool isCond; + unsigned MaxDisp : 31; + bool isCond : 1; int UncondBr; - unsigned MaxDisp; - ImmBranch(MachineInstr *mi, bool cond, int ubr, unsigned maxdisp) - : MI(mi), isCond(cond), UncondBr(ubr), MaxDisp(maxdisp) {} + ImmBranch(MachineInstr *mi, unsigned maxdisp, bool cond, int ubr) + : MI(mi), MaxDisp(maxdisp), isCond(cond), UncondBr(ubr) {} }; - /// Branches - Keep track of all the immediate branche instructions. + /// Branches - Keep track of all the immediate branch instructions. /// std::vector<ImmBranch> ImmBranches; @@ -107,7 +107,7 @@ namespace { void SplitBlockBeforeInstr(MachineInstr *MI); void UpdateForInsertedWaterBlock(MachineBasicBlock *NewBB); bool HandleConstantPoolUser(MachineFunction &Fn, CPUser &U); - bool ShortenImmediateBranch(MachineFunction &Fn, ImmBranch &Br); + bool FixUpImmediateBranch(MachineFunction &Fn, ImmBranch &Br); unsigned GetInstSize(MachineInstr *MI) const; unsigned GetOffsetOf(MachineInstr *MI) const; @@ -154,7 +154,7 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &Fn) { for (unsigned i = 0, e = CPUsers.size(); i != e; ++i) MadeChange |= HandleConstantPoolUser(Fn, CPUsers[i]); for (unsigned i = 0, e = ImmBranches.size(); i != e; ++i) - MadeChange |= ShortenImmediateBranch(Fn, ImmBranches[i]); + MadeChange |= FixUpImmediateBranch(Fn, ImmBranches[i]); } while (MadeChange); BBSizes.clear(); @@ -260,7 +260,7 @@ void ARMConstantIslands::InitialFunctionScan(MachineFunction &Fn, break; } unsigned MaxDisp = (1 << (Bits-1)) * Scale; - ImmBranches.push_back(ImmBranch(I, isCond, UOpc, MaxDisp)); + ImmBranches.push_back(ImmBranch(I, MaxDisp, isCond, UOpc)); } // Scan the instructions for constant pool operands. @@ -560,8 +560,13 @@ bool ARMConstantIslands::HandleConstantPoolUser(MachineFunction &Fn, CPUser &U){ return true; } +/// FixUpImmediateBranch - Fix up immediate branches whose destination is too +/// far away to fit in its displacement field. If it is a conditional branch, +/// then it is converted to an inverse conditional branch + an unconditional +/// branch to the destination. If it is an unconditional branch, then it is +/// converted to a branch to a branch. bool -ARMConstantIslands::ShortenImmediateBranch(MachineFunction &Fn, ImmBranch &Br) { +ARMConstantIslands::FixUpImmediateBranch(MachineFunction &Fn, ImmBranch &Br) { MachineInstr *MI = Br.MI; MachineBasicBlock *DestBB = MI->getOperand(0).getMachineBasicBlock(); |