Do not try to create a MVT type of width 0.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72557 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 3bc9cf0..4c1710d 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4937,6 +4937,8 @@
APInt Imm = cast<ConstantSDNode>(N1)->getAPIntValue();
if (Opc == ISD::AND)
Imm ^= APInt::getAllOnesValue(BitWidth);
+ if (Imm == 0 || Imm.isAllOnesValue())
+ return SDValue();
unsigned ShAmt = Imm.countTrailingZeros();
unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
unsigned NewBW = NextPowerOf2(MSB - ShAmt);
diff --git a/test/CodeGen/X86/2009-05-28-DAGCombineCrash.ll b/test/CodeGen/X86/2009-05-28-DAGCombineCrash.ll
new file mode 100644
index 0000000..7bdfcb3
--- /dev/null
+++ b/test/CodeGen/X86/2009-05-28-DAGCombineCrash.ll
@@ -0,0 +1,38 @@
+; RUN: llvm-as < %s | llc -march=x86-64
+
+ %struct.tempsym_t = type { i8*, i8*, i8*, i8*, i32, i32, i32, i32, i32 }
+
+define fastcc signext i8 @S_next_symbol(%struct.tempsym_t* %symptr) nounwind ssp {
+entry:
+ br label %bb116
+
+bb: ; preds = %bb116
+ switch i8 undef, label %bb14 [
+ i8 9, label %bb116
+ i8 32, label %bb116
+ i8 10, label %bb116
+ i8 13, label %bb116
+ i8 12, label %bb116
+ ]
+
+bb14: ; preds = %bb
+ br i1 undef, label %bb75, label %bb115
+
+bb75: ; preds = %bb14
+ %srcval16 = load i448* null, align 8 ; <i448> [#uses=1]
+ %tmp = zext i32 undef to i448 ; <i448> [#uses=1]
+ %tmp15 = shl i448 %tmp, 288 ; <i448> [#uses=1]
+ %mask = and i448 %srcval16, -2135987035423586845985235064014169866455883682256196619149693890381755748887481053010428711403521 ; <i448> [#uses=1]
+ %ins = or i448 %tmp15, %mask ; <i448> [#uses=1]
+ store i448 %ins, i448* null, align 8
+ ret i8 1
+
+bb115: ; preds = %bb14
+ ret i8 1
+
+bb116: ; preds = %bb, %bb, %bb, %bb, %bb, %entry
+ br i1 undef, label %bb, label %bb117
+
+bb117: ; preds = %bb116
+ ret i8 0
+}