Local register allocator shouldn't assume only the entry and landing pad basic blocks...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63323 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp
index 9fc5f73..a8c6900 100644 (file)
--- a/lib/CodeGen/RegAllocLocal.cpp
+++ b/lib/CodeGen/RegAllocLocal.cpp
@@ -710,24 +710,21 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) {
   DEBUG(const BasicBlock *LBB = MBB.getBasicBlock();
         if (LBB) DOUT << "\nStarting RegAlloc of BB: " << LBB->getName());
 
-  // If this is the first basic block in the machine function, add live-in
-  // registers as active.
-  if (&MBB == &*MF->begin() || MBB.isLandingPad()) {
-    for (MachineBasicBlock::livein_iterator I = MBB.livein_begin(),
+  // Add live-in registers as active.
+  for (MachineBasicBlock::livein_iterator I = MBB.livein_begin(),
          E = MBB.livein_end(); I != E; ++I) {
-      unsigned Reg = *I;
-      MF->getRegInfo().setPhysRegUsed(Reg);
-      PhysRegsUsed[Reg] = 0;            // It is free and reserved now
-      AddToPhysRegsUseOrder(Reg); 
-      for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);
-           *SubRegs; ++SubRegs) {
-        if (PhysRegsUsed[*SubRegs] != -2) {
-          AddToPhysRegsUseOrder(*SubRegs); 
-          PhysRegsUsed[*SubRegs] = 0;  // It is free and reserved now
-          MF->getRegInfo().setPhysRegUsed(*SubRegs);
-        }
+    unsigned Reg = *I;
+    MF->getRegInfo().setPhysRegUsed(Reg);
+    PhysRegsUsed[Reg] = 0;            // It is free and reserved now
+    AddToPhysRegsUseOrder(Reg); 
+    for (const unsigned *SubRegs = TRI->getSubRegisters(Reg);
+         *SubRegs; ++SubRegs) {
+      if (PhysRegsUsed[*SubRegs] != -2) {
+        AddToPhysRegsUseOrder(*SubRegs); 
+        PhysRegsUsed[*SubRegs] = 0;  // It is free and reserved now
+        MF->getRegInfo().setPhysRegUsed(*SubRegs);
       }
-    }    
+    }
   }
   
   ComputeLocalLiveness(MBB);

diff --git a/test/CodeGen/X86/2009-01-29-LocalRegAllocBug.ll b/test/CodeGen/X86/2009-01-29-LocalRegAllocBug.ll
new file mode 100644 (file)
index 0000000..b7f37c9
--- /dev/null
+++ b/test/CodeGen/X86/2009-01-29-LocalRegAllocBug.ll
@@ -0,0 +1,38 @@
+; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin9.6 -regalloc=local -disable-fp-elim
+; rdar://6538384
+
+       %struct.FILE = type { i8*, i32, i32, i16, i16, %struct.__sbuf, i32, i8*, i32 (i8*)*, i32 (i8*, i8*, i32)*, i64 (i8*, i64, i32)*, i32 (i8*, i8*, i32)*, %struct.__sbuf, %struct.__sFILEX*, i32, [3 x i8], [1 x i8], %struct.__sbuf, i32, i64 }
+       %struct.Lit = type { i32 }
+       %struct.StreamBuffer = type { %struct.FILE*, [1048576 x i8], i32, i32 }
+       %struct.__sFILEX = type opaque
+       %struct.__sbuf = type { i8*, i32 }
+
+declare fastcc i32 @_Z8parseIntI12StreamBufferEiRT_(%struct.StreamBuffer*)
+
+declare i8* @llvm.eh.exception() nounwind
+
+define i32 @main(i32 %argc, i8** nocapture %argv) noreturn {
+entry:
+       %0 = invoke fastcc i32 @_Z8parseIntI12StreamBufferEiRT_(%struct.StreamBuffer* null)
+                       to label %bb1.i16.i.i unwind label %lpad.i.i            ; <i32> [#uses=0]
+
+bb1.i16.i.i:           ; preds = %entry
+       br i1 false, label %bb.i.i.i.i, label %_ZN3vecI3LitE4pushERKS0_.exit.i.i.i
+
+bb.i.i.i.i:            ; preds = %bb1.i16.i.i
+       br label %_ZN3vecI3LitE4pushERKS0_.exit.i.i.i
+
+_ZN3vecI3LitE4pushERKS0_.exit.i.i.i:           ; preds = %bb.i.i.i.i, %bb1.i16.i.i
+       %lits.i.i.0.0 = phi %struct.Lit* [ null, %bb1.i16.i.i ], [ null, %bb.i.i.i.i ]          ; <%struct.Lit*> [#uses=1]
+       %1 = invoke fastcc i32 @_Z8parseIntI12StreamBufferEiRT_(%struct.StreamBuffer* null)
+                       to label %.noexc21.i.i unwind label %lpad.i.i           ; <i32> [#uses=0]
+
+.noexc21.i.i:          ; preds = %_ZN3vecI3LitE4pushERKS0_.exit.i.i.i
+       unreachable
+
+lpad.i.i:              ; preds = %_ZN3vecI3LitE4pushERKS0_.exit.i.i.i, %entry
+       %lits.i.i.0.3 = phi %struct.Lit* [ %lits.i.i.0.0, %_ZN3vecI3LitE4pushERKS0_.exit.i.i.i ], [ null, %entry ]              ; <%struct.Lit*> [#uses=1]
+       %eh_ptr.i.i = call i8* @llvm.eh.exception()             ; <i8*> [#uses=0]
+       free %struct.Lit* %lits.i.i.0.3
+       unreachable
+}