Print instructions before register allocation is performed. Also fix

bug where spill instructions were added to the next basic block
instead of the end of the current one if the instruction that required
the spill was the last in the block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10272 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 6 deletions

diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index 91d8533ae8..6a8dd6572e 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -203,6 +203,23 @@ bool RA::runOnMachineFunction(MachineFunction &fn) {
     v2pMap_.clear();
     v2ssMap_.clear();
 
+    DEBUG(
+        for (MachineBasicBlockPtrs::iterator
+                 mbbi = mbbs_.begin(), mbbe = mbbs_.end();
+             mbbi != mbbe; ++mbbi) {
+            MachineBasicBlock* mbb = *mbbi;
+            std::cerr << mbb->getBasicBlock()->getName() << '\n';
+            for (MachineBasicBlock::iterator
+                     ii = mbb->begin(), ie = mbb->end();
+                 ii != ie; ++ii) {
+                MachineInstr* instr = *ii;
+                     
+                std::cerr << "\t";
+                instr->print(std::cerr, *tm_);
+            }
+        }
+        );
+
     // FIXME: this will work only for the X86 backend. I need to
     // device an algorthm to select the minimal (considering register
     // aliasing) number of temp registers to reserve so that we have 2
@@ -276,12 +293,6 @@ bool RA::runOnMachineFunction(MachineFunction &fn) {
 
             DEBUG(std::cerr << "\tinstruction: ";
                   (*currentInstr_)->print(std::cerr, *tm_););
-            DEBUG(std::cerr << "\t\tspilling temporarily defined operands "
-                  "of previous instruction:\n");
-            for (unsigned i = 0, e = tempDefOperands_.size(); i != e; ++i) {
-                spillVirtReg(tempDefOperands_[i]);
-            }
-            tempDefOperands_.clear();
 
             // use our current mapping and actually replace and
             // virtual register with its allocated physical registers
@@ -422,6 +433,15 @@ bool RA::runOnMachineFunction(MachineFunction &fn) {
                     (*currentInstr_)->SetMachineOperandReg(1, regA);
                 }
             }
+
+            DEBUG(std::cerr << "\t\tspilling temporarily defined operands "
+                  "of this instruction:\n");
+            ++currentInstr_; // we want to insert after this instruction
+            for (unsigned i = 0, e = tempDefOperands_.size(); i != e; ++i) {
+                spillVirtReg(tempDefOperands_[i]);
+            }
+            --currentInstr_; // restore currentInstr_ iterator
+            tempDefOperands_.clear();
         }
 
         for (unsigned i = 0, e = p2vMap_.size(); i != e; ++i) {