Fix PR2808. When regalloc runs out of register, it spill a physical register around the live interval being allocated. Do not continue to try to spill another register, just grab the physical register and move on.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56381 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index 000dd41b97..df9d393a8f 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -855,9 +855,12 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur)
     // All registers must have inf weight. Just grab one!
     minReg = BestPhysReg ? BestPhysReg : *RC->allocation_order_begin(*mf_);
     if (cur->weight == HUGE_VALF ||
-        li_->getApproximateInstructionCount(*cur) == 0)
+        li_->getApproximateInstructionCount(*cur) == 0) {
       // Spill a physical register around defs and uses.
       li_->spillPhysRegAroundRegDefsUses(*cur, minReg, *vrm_);
+      assignRegOrStackSlotAtInterval(cur);
+      return;
+    }
   }
 
   // Find up to 3 registers to consider as spill candidates.