From 358dec51804ee52e47ea3a47c9248086e458ad7c Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Mon, 15 Jun 2009 08:28:29 +0000 Subject: Part 1. - Change register allocation hint to a pair of unsigned integers. The hint type is zero (which means prefer the register specified as second part of the pair) or entirely target dependent. - Allow targets to specify alternative register allocation orders based on allocation hint. Part 2. - Use the register allocation hint system to implement more aggressive load / store multiple formation. - Aggressively form LDRD / STRD. These are formed *before* register allocation. It has to be done this way to shorten live interval of base and offset registers. e.g. v1025 = LDR v1024, 0 v1026 = LDR v1024, 0 => v1025,v1026 = LDRD v1024, 0 If this transformation isn't done before allocation, v1024 will overlap v1025 which means it more difficult to allocate a register pair. - Even with the register allocation hint, it may not be possible to get the desired allocation. In that case, the post-allocation load / store multiple pass must fix the ldrd / strd instructions. They can either become ldm / stm instructions or back to a pair of ldr / str instructions. This is work in progress, not yet enabled. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73381 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/MachineRegisterInfo.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/CodeGen/MachineRegisterInfo.cpp') diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp index 9649c4c44c..544d83a33f 100644 --- a/lib/CodeGen/MachineRegisterInfo.cpp +++ b/lib/CodeGen/MachineRegisterInfo.cpp @@ -65,7 +65,7 @@ MachineRegisterInfo::createVirtualRegister(const TargetRegisterClass *RegClass){ // Add a reg, but keep track of whether the vector reallocated or not. void *ArrayBase = VRegInfo.empty() ? 0 : &VRegInfo[0]; VRegInfo.push_back(std::make_pair(RegClass, (MachineOperand*)0)); - RegAllocHints.push_back(std::make_pair(RA_None, 0)); + RegAllocHints.push_back(std::make_pair(0, 0)); if (!((&VRegInfo[0] == ArrayBase || VRegInfo.size() == 1))) // The vector reallocated, handle this now. -- cgit v1.2.3-18-g5258