From 8d78b0597b3931786c0f740098488e07443af7df Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Tue, 5 Feb 2008 20:04:18 +0000
Subject: [PATCH] If a vr is already marked alive in a bb, then it has PHI uses
 that are visited earlier, then it is not killed in the def block (i.e. not
 dead).

llvm-svn: 46763
---
 llvm/lib/CodeGen/LiveVariables.cpp            |  5 +-
 .../PowerPC/2008-02-05-LiveIntervalsAssert.ll | 67 +++++++++++++++++++
 2 files changed, 70 insertions(+), 2 deletions(-)
 create mode 100644 llvm/test/CodeGen/PowerPC/2008-02-05-LiveIntervalsAssert.ll

diff --git a/llvm/lib/CodeGen/LiveVariables.cpp b/llvm/lib/CodeGen/LiveVariables.cpp
index b39e48d44236..70c191d9e09e 100644
--- a/llvm/lib/CodeGen/LiveVariables.cpp
+++ b/llvm/lib/CodeGen/LiveVariables.cpp
@@ -436,8 +436,9 @@ bool LiveVariables::runOnMachineFunction(MachineFunction &mf) {
         if (MO.isRegister() && MO.isDef() && MO.getReg()) {
           if (MRegisterInfo::isVirtualRegister(MO.getReg())) {
             VarInfo &VRInfo = getVarInfo(MO.getReg());
-            // Defaults to dead
-            VRInfo.Kills.push_back(MI);
+            if (VRInfo.AliveBlocks.none())
+              // If vr is not alive in any block, then defaults to dead.
+              VRInfo.Kills.push_back(MI);
           } else if (MRegisterInfo::isPhysicalRegister(MO.getReg()) &&
                      !ReservedRegisters[MO.getReg()]) {
             HandlePhysRegDef(MO.getReg(), MI);
diff --git a/llvm/test/CodeGen/PowerPC/2008-02-05-LiveIntervalsAssert.ll b/llvm/test/CodeGen/PowerPC/2008-02-05-LiveIntervalsAssert.ll
new file mode 100644
index 000000000000..5b9cd1d8408f
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/2008-02-05-LiveIntervalsAssert.ll
@@ -0,0 +1,67 @@
+; RUN: llvm-as < %s | llc -mtriple=powerpc-apple-darwin
+
+	%struct.Handle = type { %struct.oopDesc** }
+	%struct.JNI_ArgumentPusher = type { %struct.SignatureIterator, %struct.JavaCallArguments* }
+	%struct.JNI_ArgumentPusherArray = type { %struct.JNI_ArgumentPusher, %struct.JvmtiEventEnabled* }
+	%struct.JavaCallArguments = type { [9 x i32], [9 x i32], i32*, i32*, i32, i32, i32 }
+	%struct.JvmtiEventEnabled = type { i64 }
+	%struct.KlassHandle = type { %struct.Handle }
+	%struct.SignatureIterator = type { i32 (...)**, %struct.KlassHandle, i32, i32, i32 }
+	%struct.instanceOopDesc = type { %struct.oopDesc }
+	%struct.oopDesc = type { %struct.instanceOopDesc*, %struct.instanceOopDesc* }
+@.str = external constant [44 x i8]		; <[44 x i8]*> [#uses=1]
+
+define void @_ZN23JNI_ArgumentPusherArray7iterateEy(%struct.JNI_ArgumentPusherArray* %this, i64 %fingerprint) nounwind  {
+entry:
+	br label %bb113
+
+bb22.preheader:		; preds = %bb113
+	ret void
+
+bb32.preheader:		; preds = %bb113
+	ret void
+
+bb42.preheader:		; preds = %bb113
+	ret void
+
+bb52:		; preds = %bb113
+	br label %bb113
+
+bb62.preheader:		; preds = %bb113
+	ret void
+
+bb72.preheader:		; preds = %bb113
+	ret void
+
+bb82:		; preds = %bb113
+	br label %bb113
+
+bb93:		; preds = %bb113
+	br label %bb113
+
+bb103.preheader:		; preds = %bb113
+	ret void
+
+bb113:		; preds = %bb113, %bb93, %bb82, %bb52, %entry
+	%fingerprint_addr.0.reg2mem.9 = phi i64 [ 0, %entry ], [ 0, %bb52 ], [ 0, %bb82 ], [ 0, %bb93 ], [ %tmp118, %bb113 ]		; <i64> [#uses=1]
+	tail call void @_Z28report_should_not_reach_herePKci( i8* getelementptr ([44 x i8]* @.str, i32 0, i32 0), i32 817 ) nounwind 
+	%tmp118 = lshr i64 %fingerprint_addr.0.reg2mem.9, 4		; <i64> [#uses=2]
+	%tmp21158 = and i64 %tmp118, 15		; <i64> [#uses=1]
+	switch i64 %tmp21158, label %bb113 [
+		 i64 1, label %bb22.preheader
+		 i64 2, label %bb52
+		 i64 3, label %bb32.preheader
+		 i64 4, label %bb42.preheader
+		 i64 5, label %bb62.preheader
+		 i64 6, label %bb82
+		 i64 7, label %bb93
+		 i64 8, label %bb103.preheader
+		 i64 9, label %bb72.preheader
+		 i64 10, label %UnifiedReturnBlock
+	]
+
+UnifiedReturnBlock:		; preds = %bb113
+	ret void
+}
+
+declare void @_Z28report_should_not_reach_herePKci(i8*, i32)