fix the X86 backend to just drop llvm.declare nodes for VLAs instead of

leaving them in the DAG and then getting selection errors.  This is a 
fix for PR3538.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64382 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 94 insertions, 7 deletions

diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 951742835b..20ae2ed20b 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -1563,17 +1563,29 @@ SDNode *X86DAGToDAGISel::Select(SDValue N) {
       SDValue N1 = Node->getOperand(1);
       SDValue N2 = Node->getOperand(2);
       FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(N1);
-      if (!FINode)
-        break;
+      
+      // FIXME: We need to handle this for VLAs.
+      if (!FINode) {
+        ReplaceUses(N.getValue(0), Chain);
+        return NULL;
+      }
+      
       if (N2.getOpcode() == ISD::ADD &&
           N2.getOperand(0).getOpcode() == X86ISD::GlobalBaseReg)
         N2 = N2.getOperand(1);
-      if (N2.getOpcode() != X86ISD::Wrapper)
-        break;
+      
+      // If N2 is not Wrapper(decriptor) then the llvm.declare is mangled
+      // somehow, just ignore it.
+      if (N2.getOpcode() != X86ISD::Wrapper) {
+        ReplaceUses(N.getValue(0), Chain);
+        return NULL;
+      }
       GlobalAddressSDNode *GVNode =
         dyn_cast<GlobalAddressSDNode>(N2.getOperand(0));
-      if (!GVNode)
-        break;
+      if (GVNode == 0) {
+        ReplaceUses(N.getValue(0), Chain);
+        return NULL;
+      }
       SDValue Tmp1 = CurDAG->getTargetFrameIndex(FINode->getIndex(),
                                                  TLI.getPointerTy());
       SDValue Tmp2 = CurDAG->getTargetGlobalAddress(GVNode->getGlobal(),
@@ -1581,7 +1593,6 @@ SDNode *X86DAGToDAGISel::Select(SDValue N) {
       SDValue Ops[] = { Tmp1, Tmp2, Chain };
       return CurDAG->getTargetNode(TargetInstrInfo::DECLARE, dl,
                                    MVT::Other, Ops, 3);
-      break;
     }
   }
 
diff --git a/test/CodeGen/X86/2009-02-12-DebugInfoVLA.ll b/test/CodeGen/X86/2009-02-12-DebugInfoVLA.ll
new file mode 100644
index 0000000000..b0c4449610
--- /dev/null
+++ b/test/CodeGen/X86/2009-02-12-DebugInfoVLA.ll
@@ -0,0 +1,76 @@
+; RUN: llvm-as < %s | llc
+; RUN: llvm-as < %s | llc -march=x86-64
+; PR3538
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i386-apple-darwin9"
+	%llvm.dbg.anchor.type = type { i32, i32 }
+	%llvm.dbg.basictype.type = type { i32, { }*, i8*, { }*, i32, i64, i64, i64, i32, i32 }
+	%llvm.dbg.block.type = type { i32, { }* }
+	%llvm.dbg.compile_unit.type = type { i32, { }*, i32, i8*, i8*, i8*, i1, i1, i8* }
+	%llvm.dbg.composite.type = type { i32, { }*, i8*, { }*, i32, i64, i64, i64, i32, { }*, { }* }
+	%llvm.dbg.subprogram.type = type { i32, { }*, { }*, i8*, i8*, i8*, { }*, i32, { }*, i1, i1 }
+	%llvm.dbg.subrange.type = type { i32, i64, i64 }
+	%llvm.dbg.variable.type = type { i32, { }*, i8*, { }*, i32, { }* }
+@llvm.dbg.compile_units = linkonce constant %llvm.dbg.anchor.type { i32 458752, i32 17 }, section "llvm.metadata"		; <%llvm.dbg.anchor.type*> [#uses=1]
+@.str = internal constant [4 x i8] c"t.c\00", section "llvm.metadata"		; <[4 x i8]*> [#uses=1]
+@.str1 = internal constant [2 x i8] c".\00", section "llvm.metadata"		; <[2 x i8]*> [#uses=1]
+@.str2 = internal constant [6 x i8] c"clang\00", section "llvm.metadata"		; <[6 x i8]*> [#uses=1]
+@llvm.dbg.compile_unit = internal constant %llvm.dbg.compile_unit.type { i32 458769, { }* bitcast (%llvm.dbg.anchor.type* @llvm.dbg.compile_units to { }*), i32 1, i8* getelementptr ([4 x i8]* @.str, i32 0, i32 0), i8* getelementptr ([2 x i8]* @.str1, i32 0, i32 0), i8* getelementptr ([6 x i8]* @.str2, i32 0, i32 0), i1 false, i1 false, i8* null }, section "llvm.metadata"		; <%llvm.dbg.compile_unit.type*> [#uses=1]
+@.str3 = internal constant [4 x i8] c"int\00", section "llvm.metadata"		; <[4 x i8]*> [#uses=1]
+@llvm.dbg.basictype = internal constant %llvm.dbg.basictype.type { i32 458788, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i8* getelementptr ([4 x i8]* @.str3, i32 0, i32 0), { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 0, i64 32, i64 32, i64 0, i32 0, i32 5 }, section "llvm.metadata"		; <%llvm.dbg.basictype.type*> [#uses=1]
+@llvm.dbg.subprograms = linkonce constant %llvm.dbg.anchor.type { i32 458752, i32 46 }, section "llvm.metadata"		; <%llvm.dbg.anchor.type*> [#uses=1]
+@.str4 = internal constant [5 x i8] c"test\00", section "llvm.metadata"		; <[5 x i8]*> [#uses=1]
+@llvm.dbg.subprogram = internal constant %llvm.dbg.subprogram.type { i32 458798, { }* bitcast (%llvm.dbg.anchor.type* @llvm.dbg.subprograms to { }*), { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i8* getelementptr ([5 x i8]* @.str4, i32 0, i32 0), i8* getelementptr ([5 x i8]* @.str4, i32 0, i32 0), i8* null, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 3, { }* bitcast (%llvm.dbg.basictype.type* @llvm.dbg.basictype to { }*), i1 false, i1 true }, section "llvm.metadata"		; <%llvm.dbg.subprogram.type*> [#uses=1]
+@.str5 = internal constant [2 x i8] c"X\00", section "llvm.metadata"		; <[2 x i8]*> [#uses=1]
+@llvm.dbg.variable = internal constant %llvm.dbg.variable.type { i32 459009, { }* bitcast (%llvm.dbg.subprogram.type* @llvm.dbg.subprogram to { }*), i8* getelementptr ([2 x i8]* @.str5, i32 0, i32 0), { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 3, { }* bitcast (%llvm.dbg.basictype.type* @llvm.dbg.basictype to { }*) }, section "llvm.metadata"		; <%llvm.dbg.variable.type*> [#uses=1]
+@llvm.dbg.block = internal constant %llvm.dbg.block.type { i32 458763, { }* bitcast (%llvm.dbg.subprogram.type* @llvm.dbg.subprogram to { }*) }, section "llvm.metadata"		; <%llvm.dbg.block.type*> [#uses=1]
+@llvm.dbg.subrange = internal constant %llvm.dbg.subrange.type { i32 458785, i64 0, i64 0 }, section "llvm.metadata"		; <%llvm.dbg.subrange.type*> [#uses=1]
+@llvm.dbg.array = internal constant [1 x { }*] [{ }* bitcast (%llvm.dbg.subrange.type* @llvm.dbg.subrange to { }*)], section "llvm.metadata"		; <[1 x { }*]*> [#uses=1]
+@llvm.dbg.composite = internal constant %llvm.dbg.composite.type { i32 458753, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i8* null, { }* null, i32 0, i64 0, i64 32, i64 0, i32 0, { }* bitcast (%llvm.dbg.basictype.type* @llvm.dbg.basictype to { }*), { }* bitcast ([1 x { }*]* @llvm.dbg.array to { }*) }, section "llvm.metadata"		; <%llvm.dbg.composite.type*> [#uses=1]
+@.str6 = internal constant [2 x i8] c"Y\00", section "llvm.metadata"		; <[2 x i8]*> [#uses=1]
+@llvm.dbg.variable7 = internal constant %llvm.dbg.variable.type { i32 459008, { }* bitcast (%llvm.dbg.block.type* @llvm.dbg.block to { }*), i8* getelementptr ([2 x i8]* @.str6, i32 0, i32 0), { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 4, { }* bitcast (%llvm.dbg.composite.type* @llvm.dbg.composite to { }*) }, section "llvm.metadata"		; <%llvm.dbg.variable.type*> [#uses=1]
+
+define i32 @test(i32 %X) nounwind {
+entry:
+	%retval = alloca i32		; <i32*> [#uses=1]
+	%X.addr = alloca i32		; <i32*> [#uses=3]
+	%saved_stack = alloca i8*		; <i8**> [#uses=2]
+	call void @llvm.dbg.func.start({ }* bitcast (%llvm.dbg.subprogram.type* @llvm.dbg.subprogram to { }*))
+	store i32 %X, i32* %X.addr
+	%0 = bitcast i32* %X.addr to { }*		; <{ }*> [#uses=1]
+	call void @llvm.dbg.declare({ }* %0, { }* bitcast (%llvm.dbg.variable.type* @llvm.dbg.variable to { }*))
+	call void @llvm.dbg.region.start({ }* bitcast (%llvm.dbg.block.type* @llvm.dbg.block to { }*))
+	call void @llvm.dbg.stoppoint(i32 4, i32 3, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
+	%1 = call i8* @llvm.stacksave()		; <i8*> [#uses=1]
+	store i8* %1, i8** %saved_stack
+	%tmp = load i32* %X.addr		; <i32> [#uses=1]
+	%2 = mul i32 4, %tmp		; <i32> [#uses=1]
+	%vla = alloca i8, i32 %2		; <i8*> [#uses=1]
+	%tmp1 = bitcast i8* %vla to i32*		; <i32*> [#uses=1]
+	%3 = bitcast i32* %tmp1 to { }*		; <{ }*> [#uses=1]
+	call void @llvm.dbg.declare({ }* %3, { }* bitcast (%llvm.dbg.variable.type* @llvm.dbg.variable7 to { }*))
+	call void @llvm.dbg.stoppoint(i32 5, i32 1, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
+	call void @llvm.dbg.region.end({ }* bitcast (%llvm.dbg.block.type* @llvm.dbg.block to { }*))
+	br label %cleanup
+
+cleanup:		; preds = %entry
+	%tmp2 = load i8** %saved_stack		; <i8*> [#uses=1]
+	call void @llvm.stackrestore(i8* %tmp2)
+	call void @llvm.dbg.region.end({ }* bitcast (%llvm.dbg.subprogram.type* @llvm.dbg.subprogram to { }*))
+	%4 = load i32* %retval		; <i32> [#uses=1]
+	ret i32 %4
+}
+
+declare void @llvm.dbg.func.start({ }*) nounwind
+
+declare void @llvm.dbg.declare({ }*, { }*) nounwind
+
+declare void @llvm.dbg.region.start({ }*) nounwind
+
+declare void @llvm.dbg.stoppoint(i32, i32, { }*) nounwind
+
+declare i8* @llvm.stacksave() nounwind
+
+declare void @llvm.stackrestore(i8*) nounwind
+
+declare void @llvm.dbg.region.end({ }*) nounwind