Remove the SavePoint infrastructure from fast isel, replace

with just an insert point from the MachineBasicBlock and let
the location be updated as we access it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165049 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 85 insertions, 20 deletions

diff --git a/include/llvm/CodeGen/FastISel.h b/include/llvm/CodeGen/FastISel.h
index 7cb96952aa..7f240f563a 100644
--- a/include/llvm/CodeGen/FastISel.h
+++ b/include/llvm/CodeGen/FastISel.h
@@ -131,17 +131,12 @@ public:
   /// into the current block.
   void recomputeInsertPt();
 
-  struct SavePoint {
-    MachineBasicBlock::iterator InsertPt;
-    DebugLoc DL;
-  };
-
   /// enterLocalValueArea - Prepare InsertPt to begin inserting instructions
   /// into the local value area and return the old insert position.
-  SavePoint enterLocalValueArea();
+  MachineBasicBlock::iterator enterLocalValueArea();
 
   /// leaveLocalValueArea - Reset InsertPt to the given old insert position.
-  void leaveLocalValueArea(SavePoint Old);
+  void leaveLocalValueArea(MachineBasicBlock::iterator Old);
 
   virtual ~FastISel();
 
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 683fac6744..818940490f 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -149,13 +149,13 @@ unsigned FastISel::getRegForValue(const Value *V) {
        !FuncInfo.StaticAllocaMap.count(cast<AllocaInst>(V))))
     return FuncInfo.InitializeRegForValue(V);
 
-  SavePoint SaveInsertPt = enterLocalValueArea();
+  MachineBasicBlock::iterator SaveIter = enterLocalValueArea();
 
   // Materialize the value in a register. Emit any instructions in the
   // local value area.
   Reg = materializeRegForValue(V, VT);
 
-  leaveLocalValueArea(SaveInsertPt);
+  leaveLocalValueArea(SaveIter);
 
   return Reg;
 }
@@ -238,7 +238,16 @@ unsigned FastISel::lookUpRegForValue(const Value *V) {
   DenseMap<const Value *, unsigned>::iterator I = FuncInfo.ValueMap.find(V);
   if (I != FuncInfo.ValueMap.end())
     return I->second;
-  return LocalValueMap[V];
+  unsigned Reg = LocalValueMap[V];
+
+  // If we managed to find a register here then go ahead and replace the
+  // current location with the location we're currently emitted for,
+  // 'moving' the value to a place that's closer to where it originally
+  // started.
+  if (Reg)
+    MRI.getVRegDef(Reg)->setDebugLoc(DL);
+
+  return Reg;
 }
 
 /// UpdateValueMap - Update the value map to include the new mapping for this
@@ -316,22 +325,18 @@ void FastISel::removeDeadCode(MachineBasicBlock::iterator I,
   recomputeInsertPt();
 }
 
-FastISel::SavePoint FastISel::enterLocalValueArea() {
+MachineBasicBlock::iterator FastISel::enterLocalValueArea() {
   MachineBasicBlock::iterator OldInsertPt = FuncInfo.InsertPt;
-  DebugLoc OldDL = DL;
   recomputeInsertPt();
-  DL = DebugLoc();
-  SavePoint SP = { OldInsertPt, OldDL };
-  return SP;
+  return OldInsertPt;
 }
 
-void FastISel::leaveLocalValueArea(SavePoint OldInsertPt) {
+void FastISel::leaveLocalValueArea(MachineBasicBlock::iterator I) {
   if (FuncInfo.InsertPt != FuncInfo.MBB->begin())
     LastLocalValue = llvm::prior(FuncInfo.InsertPt);
 
   // Restore the previous insert position.
-  FuncInfo.InsertPt = OldInsertPt.InsertPt;
-  DL = OldInsertPt.DL;
+  FuncInfo.InsertPt = I;
 }
 
 /// SelectBinaryOp - Select and emit code for a binary operator instruction,
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 54704d84a9..83f2f6a202 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -545,7 +545,7 @@ bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) {
         StubAM.GVOpFlags = GVFlags;
 
         // Prepare for inserting code in the local-value area.
-        SavePoint SaveInsertPt = enterLocalValueArea();
+	MachineBasicBlock::iterator SaveIter = enterLocalValueArea();
 
         if (TLI.getPointerTy() == MVT::i64) {
           Opc = X86::MOV64rm;
@@ -564,7 +564,7 @@ bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) {
         addFullAddress(LoadMI, StubAM);
 
         // Ok, back to normal mode.
-        leaveLocalValueArea(SaveInsertPt);
+        leaveLocalValueArea(SaveIter);
 
         // Prevent loading GV stub multiple times in same MBB.
         LocalValueMap[V] = LoadReg;
diff --git a/test/DebugInfo/X86/constant-mat.ll b/test/DebugInfo/X86/constant-mat.ll
new file mode 100644
index 0000000000..8cf2d16fa4
--- /dev/null
+++ b/test/DebugInfo/X86/constant-mat.ll
@@ -0,0 +1,65 @@
+; RUN: llc -disable-fp-elim -O0 %s -mtriple x86_64-unknown-linux-gnu -o - | FileCheck %s
+
+; int callme(int);
+;
+; int isel_line_test(int arg)
+; {
+;   callme(100);
+;   if (arg > 5000)
+;     callme(200);
+;   callme(300);
+;   return 0;
+; }
+
+define i32 @isel_line_test(i32 %arg) nounwind uwtable {
+; The start of each non-entry block (or sub-block) should get a .loc directive.
+; CHECK:       isel_line_test:
+; CHECK:       # BB#1:
+; CHECK-NEXT:  .loc 1 7 5
+; CHECK:       LBB0_2:
+; CHECK-NEXT:  .loc 1 8 3
+; CHECK:       callq callme
+; CHECK-NEXT:  .loc 1 9 3
+
+entry:
+  %arg.addr = alloca i32, align 4
+  store i32 %arg, i32* %arg.addr, align 4
+  call void @llvm.dbg.declare(metadata !{i32* %arg.addr}, metadata !10), !dbg !11
+  %call = call i32 @callme(i32 100), !dbg !12
+  %0 = load i32* %arg.addr, align 4, !dbg !14
+  %cmp = icmp sgt i32 %0, 5000, !dbg !14
+  br i1 %cmp, label %if.then, label %if.end, !dbg !14
+
+if.then:                                          ; preds = %entry
+  %call1 = call i32 @callme(i32 200), !dbg !15
+  br label %if.end, !dbg !15
+
+if.end:                                           ; preds = %if.then, %entry
+  %call2 = call i32 @callme(i32 300), !dbg !16
+  ret i32 0, !dbg !17
+}
+
+declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
+
+declare i32 @callme(i32)
+
+!llvm.dbg.cu = !{!0}
+
+!0 = metadata !{i32 786449, i32 0, i32 12, metadata !"foo.c", metadata !"/usr/local/google/home/echristo/tmp", metadata !"clang version 3.2 (trunk 164952) (llvm/trunk 164949)", i1 true, i1 false, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !1} ; [ DW_TAG_compile_unit ] [/usr/local/google/home/echristo/tmp/foo.c] [DW_LANG_C99]
+!1 = metadata !{metadata !2}
+!2 = metadata !{i32 0}
+!3 = metadata !{metadata !4}
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 786478, i32 0, metadata !6, metadata !"isel_line_test", metadata !"isel_line_test", metadata !"", metadata !6, i32 3, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (i32)* @isel_line_test, null, null, metadata !1, i32 4} ; [ DW_TAG_subprogram ] [line 3] [def] [scope 4] [isel_line_test]
+!6 = metadata !{i32 786473, metadata !"foo.c", metadata !"/usr/local/google/home/echristo/tmp", null} ; [ DW_TAG_file_type ]
+!7 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, i32 0} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!8 = metadata !{metadata !9, metadata !9}
+!9 = metadata !{i32 786468, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!10 = metadata !{i32 786689, metadata !5, metadata !"arg", metadata !6, i32 16777219, metadata !9, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [arg] [line 3]
+!11 = metadata !{i32 3, i32 24, metadata !5, null}
+!12 = metadata !{i32 5, i32 3, metadata !13, null}
+!13 = metadata !{i32 786443, metadata !5, i32 4, i32 1, metadata !6, i32 0} ; [ DW_TAG_lexical_block ] [/usr/local/google/home/echristo/tmp/foo.c]
+!14 = metadata !{i32 6, i32 3, metadata !13, null}
+!15 = metadata !{i32 7, i32 5, metadata !13, null}
+!16 = metadata !{i32 8, i32 3, metadata !13, null}
+!17 = metadata !{i32 9, i32 3, metadata !13, null}