Fix PR6019. A load has more than one use if it feeds a bitconvert that

has more than one use.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93576 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index e2a53d1118b8f923345f9fea77f1903e1ac6e4dc..13f4030e12c919778fa776ad826889a6cc5c49ca 100644 (file)
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -384,8 +384,11 @@ static void MoveBelowTokenFactor(SelectionDAG *CurDAG, SDValue Load,
 /// 
 static bool isRMWLoad(SDValue N, SDValue Chain, SDValue Address,
                       SDValue &Load) {
-  if (N.getOpcode() == ISD::BIT_CONVERT)
+  if (N.getOpcode() == ISD::BIT_CONVERT) {
+    if (!N.hasOneUse())
+      return false;
     N = N.getOperand(0);
+  }
 
   LoadSDNode *LD = dyn_cast<LoadSDNode>(N);
   if (!LD || LD->isVolatile())

diff --git a/test/CodeGen/X86/2010-01-15-SelectionDAGCycle.ll b/test/CodeGen/X86/2010-01-15-SelectionDAGCycle.ll
new file mode 100644 (file)
index 0000000..5d96e4a
--- /dev/null
+++ b/test/CodeGen/X86/2010-01-15-SelectionDAGCycle.ll
@@ -0,0 +1,28 @@
+; RUN: llc < %s -march=x86-64
+; ModuleID = 'bugpoint-reduced-simplified.bc'
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @numvec_(i32* noalias %ncelet, i32* noalias %ncel, i32* noalias %nfac, i32* noalias %nfabor, i32* noalias %lregis, i32* noalias %irveci, i32* noalias %irvecb, [0 x [2 x i32]]* noalias %ifacel, [0 x i32]* noalias %ifabor, [0 x i32]* noalias %inumfi, [0 x i32]* noalias %inumfb, [1 x i32]* noalias %iworkf, [0 x i32]* noalias %ismbs) {
+"file bug754399.f90, line 1, bb1":
+       %r1037 = bitcast <2 x double> zeroinitializer to <4 x i32>              ; <<4 x i32>> [#uses=1]
+       br label %"file bug754399.f90, line 184, in inner vector loop at depth 0, bb164"
+
+"file bug754399.f90, line 184, in inner vector loop at depth 0, bb164":                ; preds = %"file bug754399.f90, line 184, in inner vector loop at depth 0, bb164", %"file bug754399.f90, line 1, bb1"
+       %tmp641 = add i64 0, 48         ; <i64> [#uses=1]
+       %tmp641642 = inttoptr i64 %tmp641 to <4 x i32>*         ; <<4 x i32>*> [#uses=1]
+       %r1258 = load <4 x i32>* %tmp641642, align 4            ; <<4 x i32>> [#uses=2]
+       %r1295 = extractelement <4 x i32> %r1258, i32 3         ; <i32> [#uses=1]
+       %r1296 = sext i32 %r1295 to i64         ; <i64> [#uses=1]
+       %r1297 = add i64 %r1296, -1             ; <i64> [#uses=1]
+       %r1298183 = getelementptr [0 x i32]* %ismbs, i64 0, i64 %r1297          ; <i32*> [#uses=1]
+       %r1298184 = load i32* %r1298183, align 4                ; <i32> [#uses=1]
+       %r1301 = extractelement <4 x i32> %r1037, i32 3         ; <i32> [#uses=1]
+       %r1302 = mul i32 %r1298184, %r1301              ; <i32> [#uses=1]
+       %r1306 = insertelement <4 x i32> zeroinitializer, i32 %r1302, i32 3             ; <<4 x i32>> [#uses=1]
+       %r1321 = add <4 x i32> %r1306, %r1258           ; <<4 x i32>> [#uses=1]
+       %tmp643 = add i64 0, 48         ; <i64> [#uses=1]
+       %tmp643644 = inttoptr i64 %tmp643 to <4 x i32>*         ; <<4 x i32>*> [#uses=1]
+       store <4 x i32> %r1321, <4 x i32>* %tmp643644, align 4
+       br label %"file bug754399.f90, line 184, in inner vector loop at depth 0, bb164"
+}