Fix PR2568: Fix bug that cause redudant kill marker after its live interval has been extended due to coalescing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54346 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 47 insertions, 1 deletions

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 68be3e1..9cb06ce 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -533,14 +533,16 @@ void SimpleRegisterCoalescing::RemoveUnnecessaryKills(unsigned Reg,
     MachineOperand &UseMO = UI.getOperand();
     if (UseMO.isKill()) {
       MachineInstr *UseMI = UseMO.getParent();
+#if 0
       unsigned SReg, DReg;
       if (!tii_->isMoveInstr(*UseMI, SReg, DReg))
         continue;
+#endif
       unsigned UseIdx = li_->getUseIndex(li_->getInstructionIndex(UseMI));
       if (JoinedCopies.count(UseMI))
         continue;
       const LiveRange *UI = LI.getLiveRangeContaining(UseIdx);
-      if (!LI.isKill(UI->valno, UseIdx+1))
+      if (!UI || !LI.isKill(UI->valno, UseIdx+1))
         UseMO.setIsKill(false);
     }
   }
diff --git a/test/CodeGen/X86/2008-08-05-SpillerBug.ll b/test/CodeGen/X86/2008-08-05-SpillerBug.ll
new file mode 100644
index 0000000..ca42f2b
--- /dev/null
+++ b/test/CodeGen/X86/2008-08-05-SpillerBug.ll
@@ -0,0 +1,44 @@
+; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin -disable-fp-elim -stats -info-output-file - | not grep {Number of dead stores elided}
+; PR2568
+
+@g_3 = external global i16		; <i16*> [#uses=1]
+@g_5 = external global i32		; <i32*> [#uses=3]
+
+declare i32 @func_15(i16 signext , i16 signext , i32) nounwind 
+
+define void @func_9_entry_2E_ce(i8 %p_11) nounwind {
+newFuncRoot:
+	br label %entry.ce
+
+entry.ce.ret.exitStub:		; preds = %entry.ce
+	ret void
+
+entry.ce:		; preds = %newFuncRoot
+	load i16* @g_3, align 2		; <i16>:0 [#uses=1]
+	icmp sgt i16 %0, 0		; <i1>:1 [#uses=1]
+	zext i1 %1 to i32		; <i32>:2 [#uses=1]
+	load i32* @g_5, align 4		; <i32>:3 [#uses=4]
+	icmp ugt i32 %2, %3		; <i1>:4 [#uses=1]
+	zext i1 %4 to i32		; <i32>:5 [#uses=1]
+	icmp eq i32 %3, 0		; <i1>:6 [#uses=1]
+	%.0 = select i1 %6, i32 1, i32 %3		; <i32> [#uses=1]
+	urem i32 1, %.0		; <i32>:7 [#uses=2]
+	sext i8 %p_11 to i16		; <i16>:8 [#uses=1]
+	trunc i32 %3 to i16		; <i16>:9 [#uses=1]
+	tail call i32 @func_15( i16 signext  %8, i16 signext  %9, i32 1 ) nounwind 		; <i32>:10 [#uses=0]
+	load i32* @g_5, align 4		; <i32>:11 [#uses=1]
+	trunc i32 %11 to i16		; <i16>:12 [#uses=1]
+	tail call i32 @func_15( i16 signext  %12, i16 signext  1, i32 %7 ) nounwind 		; <i32>:13 [#uses=0]
+	sext i8 %p_11 to i32		; <i32>:14 [#uses=1]
+	%p_11.lobit = lshr i8 %p_11, 7		; <i8> [#uses=1]
+	%tmp = zext i8 %p_11.lobit to i32		; <i32> [#uses=1]
+	%tmp.not = xor i32 %tmp, 1		; <i32> [#uses=1]
+	%.015 = ashr i32 %14, %tmp.not		; <i32> [#uses=2]
+	icmp eq i32 %.015, 0		; <i1>:15 [#uses=1]
+	%.016 = select i1 %15, i32 1, i32 %.015		; <i32> [#uses=1]
+	udiv i32 %7, %.016		; <i32>:16 [#uses=1]
+	icmp ult i32 %5, %16		; <i1>:17 [#uses=1]
+	zext i1 %17 to i32		; <i32>:18 [#uses=1]
+	store i32 %18, i32* @g_5, align 4
+	br label %entry.ce.ret.exitStub
+}