6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-16 12:24:03 +00:00
Code Issues Projects Releases Wiki Activity

TwoAddressInstructionPass doesn't really know how to merge live intervals when

Browse Source 
lowering REG_SEQUENCE instructions.

Insert copies for REG_SEQUENCE sources not killed to avoid breaking later passes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104146 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen
2010-05-19 20:08:00 +00:00
parent 139c9e1f85
commit 3437352887
2 changed files with 23 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
lib/CodeGen/TwoAddressInstructionPass.cpp
View File

@ -1275,9 +1275,10 @@ bool TwoAddressInstructionPass::EliminateRegSequences() {
if (!Seen.insert(SrcReg) ||
MI->getParent() != DefMI->getParent() ||
!MI->getOperand(i).isKill() ||
HasOtherRegSequenceUses(SrcReg, MI, MRI)) {
// REG_SEQUENCE cannot have duplicated operands, add a copy.
// Also add an copy if the source if live-in the block. We don't want
// Also add an copy if the source is live-in the block. We don't want
// to end up with a partial-redef of a livein, e.g.
// BB0:
// reg1051:10<def> =
@ -1287,6 +1288,10 @@ bool TwoAddressInstructionPass::EliminateRegSequences() {
// BB2:
// reg1051:9<def> =
// LiveIntervalAnalysis won't like it.
//
// If the REG_SEQUENCE doesn't kill its source, keeping live variables
// correctly up to date becomes very difficult. Insert a copy.
//
const TargetRegisterClass *RC = MRI->getRegClass(SrcReg);
unsigned NewReg = MRI->createVirtualRegister(RC);
MachineBasicBlock::iterator InsertLoc = MI;