From 6bfba2e5af163442a1c6b11fe14aa9df9101cfd7 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Wed, 20 Apr 2011 18:19:48 +0000 Subject: Prefer cheap registers for busy live ranges. On the x86-64 and thumb2 targets, some registers are more expensive to encode than others in the same register class. Add a CostPerUse field to the TableGen register description, and make it available from TRI->getCostPerUse. This represents the cost of a REX prefix or a 32-bit instruction encoding required by choosing a high register. Teach the greedy register allocator to prefer cheap registers for busy live ranges (as indicated by spill weight). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129864 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/RegAllocBasic.cpp | 1 + 1 file changed, 1 insertion(+) (limited to 'lib/CodeGen/RegAllocBasic.cpp') diff --git a/lib/CodeGen/RegAllocBasic.cpp b/lib/CodeGen/RegAllocBasic.cpp index dd5049898d..d92d80f181 100644 --- a/lib/CodeGen/RegAllocBasic.cpp +++ b/lib/CodeGen/RegAllocBasic.cpp @@ -278,6 +278,7 @@ void RegAllocBase::assign(LiveInterval &VirtReg, unsigned PhysReg) { << " to " << PrintReg(PhysReg, TRI) << '\n'); assert(!VRM->hasPhys(VirtReg.reg) && "Duplicate VirtReg assignment"); VRM->assignVirt2Phys(VirtReg.reg, PhysReg); + MRI->setPhysRegUsed(PhysReg); PhysReg2LiveUnion[PhysReg].unify(VirtReg); ++NumAssigned; } -- cgit v1.2.3-70-g09d2