summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorNadav Rotem <nrotem@apple.com>2012-10-18 18:06:48 +0000
committerNadav Rotem <nrotem@apple.com>2012-10-18 18:06:48 +0000
commit1c5bf3f429927c31b9ffc1308ea1ada7a58ee1c0 (patch)
tree77ea17ecec57bf22165c5696e581d0bb7eee2feb
parentbef36ac2a47dd647af332b8594031df6fe2522c5 (diff)
In SimplifySelectOps we pulled two loads through a select node despite the fact that one was dependent on the other.
rdar://12513091 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166196 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/CodeGen/SelectionDAG/DAGCombiner.cpp4
-rw-r--r--test/CodeGen/X86/2012-10-18-crash-dagco.ll61
2 files changed, 65 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index f2d3a8d4fe9..22270968e3f 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -9075,6 +9075,10 @@ bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
(RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
return false;
+ // The loads must not depend on one another.
+ if (LLD->isPredecessorOf(RLD) ||
+ RLD->isPredecessorOf(LLD))
+ return false;
Addr = DAG.getNode(ISD::SELECT, TheSelect->getDebugLoc(),
LLD->getBasePtr().getValueType(),
TheSelect->getOperand(0), LLD->getBasePtr(),
diff --git a/test/CodeGen/X86/2012-10-18-crash-dagco.ll b/test/CodeGen/X86/2012-10-18-crash-dagco.ll
new file mode 100644
index 00000000000..5b98624a37b
--- /dev/null
+++ b/test/CodeGen/X86/2012-10-18-crash-dagco.ll
@@ -0,0 +1,61 @@
+; RUN: llc -march=x86-64 -mcpu=corei7 -disable-cgp-select2branch < %s
+
+; We should not crash on this test.
+
+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-n8:16:32"
+target triple = "i386-apple-darwin9.0.0"
+
+@global = external constant [411 x i8], align 1
+
+define void @snork() nounwind {
+bb:
+ br i1 undef, label %bb26, label %bb27
+
+bb26: ; preds = %bb48, %bb26, %bb
+ switch i32 undef, label %bb26 [
+ i32 142771596, label %bb28
+ ]
+
+bb27: ; preds = %bb48, %bb
+ switch i32 undef, label %bb49 [
+ i32 142771596, label %bb28
+ ]
+
+bb28: ; preds = %bb27, %bb26
+ %tmp = load i32* null
+ %tmp29 = trunc i32 %tmp to i8
+ store i8* undef, i8** undef
+ %tmp30 = load i32* null
+ %tmp31 = icmp eq i32 %tmp30, 0
+ %tmp32 = getelementptr inbounds [411 x i8]* @global, i32 0, i32 undef
+ %tmp33 = load i8* %tmp32, align 1
+ %tmp34 = getelementptr inbounds [411 x i8]* @global, i32 0, i32 0
+ %tmp35 = load i8* %tmp34, align 1
+ %tmp36 = select i1 %tmp31, i8 %tmp35, i8 %tmp33
+ %tmp37 = select i1 undef, i8 %tmp29, i8 %tmp36
+ %tmp38 = zext i8 %tmp37 to i32
+ %tmp39 = select i1 undef, i32 0, i32 %tmp38
+ %tmp40 = getelementptr inbounds i32* null, i32 %tmp39
+ %tmp41 = load i32* %tmp40, align 4
+ %tmp42 = load i32* undef, align 4
+ %tmp43 = load i32* undef
+ %tmp44 = xor i32 %tmp42, %tmp43
+ %tmp45 = lshr i32 %tmp44, 8
+ %tmp46 = lshr i32 %tmp44, 7
+ call void @spam()
+ unreachable
+
+bb47: ; No predecessors!
+ ret void
+
+bb48: ; No predecessors!
+ br i1 undef, label %bb27, label %bb26
+
+bb49: ; preds = %bb49, %bb27
+ br label %bb49
+
+bb50: ; preds = %bb50
+ br label %bb50
+}
+
+declare void @spam() noreturn nounwind