From 17c275ff2ce9e94d647e781f6dac6320d088f899 Mon Sep 17 00:00:00 2001 From: Nate Begeman Date: Mon, 8 May 2006 16:51:36 +0000 Subject: [PATCH] Make emission of jump tables a bit less conservative; they are now required to be only 31.25% dense, rather than 75% dense. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28165 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp index 4ea83508bf1..e9ac44693ad 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp @@ -880,9 +880,9 @@ void SelectionDAGLowering::visitSwitch(SwitchInst &I) { const BasicBlock *LLVMBB = CurMBB->getBasicBlock(); Reloc::Model Relocs = TLI.getTargetMachine().getRelocationModel(); - // If the switch has more than 5 blocks, and at least 75% dense, then emit a - // jump table rather than lowering the switch to a binary tree of conditional - // branches. + // If the switch has more than 5 blocks, and at least 31.25% dense, and the + // target supports indirect branches, then emit a jump table rather than + // lowering the switch to a binary tree of conditional branches. // FIXME: Make this work with PIC code if (TLI.isOperationLegal(ISD::BRIND, TLI.getPointerTy()) && (Relocs == Reloc::Static || Relocs == Reloc::DynamicNoPIC) && @@ -891,7 +891,7 @@ void SelectionDAGLowering::visitSwitch(SwitchInst &I) { uint64_t Last = cast(Cases.back().first)->getRawValue(); double Density = (double)Cases.size() / (double)((Last - First) + 1ULL); - if (Density >= 0.75) { + if (Density >= 0.3125) { // Create a new basic block to hold the code for loading the address // of the jump table, and jumping to it. Update successor information; // we will either branch to the default case for the switch, or the jump -- 2.34.1