From e8e1fa3a7cf8a9500a39702cce71cde8aa2960f0 Mon Sep 17 00:00:00 2001 From: Ahmed Bougacha Date: Tue, 21 Mar 2017 23:42:50 +0000 Subject: [GlobalISel] Don't translate br to layout successor. MI can represent fallthrough to layout successor blocks, and our post-isel representation uses that extensively. We might as well use it too, to avoid translating and carrying along unnecessary branches. llvm-svn: 298459 --- llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'llvm/lib/CodeGen') diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp index b6e6fbd03d0..b3f131b5eeb 100644 --- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp +++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp @@ -223,10 +223,13 @@ bool IRTranslator::translateBr(const User &U, MachineIRBuilder &MIRBuilder) { const BasicBlock &BrTgt = *cast(BrInst.getSuccessor(Succ)); MachineBasicBlock &TgtBB = getMBB(BrTgt); - MIRBuilder.buildBr(TgtBB); + MachineBasicBlock &CurBB = MIRBuilder.getMBB(); + + // If the unconditional target is the layout successor, fallthrough. + if (!CurBB.isLayoutSuccessor(&TgtBB)) + MIRBuilder.buildBr(TgtBB); // Link successors. - MachineBasicBlock &CurBB = MIRBuilder.getMBB(); for (const BasicBlock *Succ : BrInst.successors()) CurBB.addSuccessor(&getMBB(*Succ)); return true; -- cgit v1.2.3