From d32d8b972617cffffa35588cbf546c44cc4da655 Mon Sep 17 00:00:00 2001 From: Duraid Madina Date: Wed, 27 Jun 2007 09:01:14 +0000 Subject: [PATCH] ok, this is something of a dirty hack, but it seems to work. (fixes e.g. the SPASS miscompilation) llvm-svn: 37750 --- lib/CodeGen/RegAllocBigBlock.cpp | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/lib/CodeGen/RegAllocBigBlock.cpp b/lib/CodeGen/RegAllocBigBlock.cpp index 400d72ae514..c7f23f51d4b 100644 --- a/lib/CodeGen/RegAllocBigBlock.cpp +++ b/lib/CodeGen/RegAllocBigBlock.cpp @@ -459,9 +459,23 @@ unsigned RABigBlock::chooseReg(MachineBasicBlock &MBB, MachineInstr *I, } } } + + if(PhysReg == 0) { // ok, now we're desperate. We couldn't choose + // a register to spill by looking through the + // read timetable, so now we just spill the + // first allocatable register we find. + + // for all physical regs in the RC, + for(TargetRegisterClass::iterator pReg = RC->begin(); + pReg != RC->end(); ++pReg) { + // if we find a register we can spill + if(PhysRegsUsed[*pReg]>=-1) + PhysReg = *pReg; // choose it to be spilled + } + } - assert(PhysReg && "couldn't grab a register from the table?"); - // TODO: assert that RC->contains(PhysReg) / handle aliased registers + assert(PhysReg && "couldn't choose a register to spill :( "); + // TODO: assert that RC->contains(PhysReg) / handle aliased registers? // since we needed to look in the table we need to spill this register. spillPhysReg(MBB, I, PhysReg);