[PowerPC] Fix a DAG replacement bug in PPCTargetLowering::DAGCombineExtBoolTrunc

While promoting nodes in PPCTargetLowering::DAGCombineExtBoolTrunc, it is
possible for one of the nodes to be replaced by another. To make sure we do not
visit the deleted nodes, and to make sure we visit the replacement nodes, use a
list of HandleSDNodes to track the to-be-promoted nodes during the promotion
process.

The same fix has been applied to the analogous code in
PPCTargetLowering::DAGCombineTruncBoolExt.

Fixes PR26985.

llvm-svn: 269272

1 files changed, 38 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/PowerPC/ext-bool-trunc-repl.ll b/llvm/test/CodeGen/PowerPC/ext-bool-trunc-repl.ll
new file mode 100644
index 00000000000..df67ecd7a63
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/ext-bool-trunc-repl.ll
@@ -0,0 +1,38 @@
+; RUN: llc -O0 < %s | FileCheck %s
+target datalayout = "e-m:e-i64:64-n32:64"
+target triple = "powerpc64le-unknown-linux-gnu"
+
+@c = external global i32, align 4
+@d = external global [2 x i32], align 4
+
+; Function Attrs: norecurse nounwind
+define void @fn2() #0 {
+; CHECK-LABEL: @fn2
+
+  br i1 undef, label %1, label %10
+
+; <label>:1:                                      ; preds = %0
+  br i1 undef, label %3, label %2
+
+; <label>:2:                                      ; preds = %2, %1
+  br i1 undef, label %3, label %2
+
+; <label>:3:                                      ; preds = %2, %1
+  br i1 undef, label %8, label %4
+
+; <label>:4:                                      ; preds = %4, %3
+  %5 = phi i64 [ %6, %4 ], [ undef, %3 ]
+  %6 = and i64 %5, and (i64 and (i64 and (i64 and (i64 and (i64 and (i64 and (i64 sext (i32 select (i1 icmp slt (i16 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i16), i16 0), i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 lshr (i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 6)) to i64), i64 sext (i32 select (i1 icmp slt (i16 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i16), i16 0), i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 lshr (i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 6)) to i64)), i64 sext (i32 select (i1 icmp slt (i16 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i16), i16 0), i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 lshr (i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 6)) to i64)), i64 sext (i32 select (i1 icmp slt (i16 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i16), i16 0), i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 lshr (i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 6)) to i64)), i64 sext (i32 select (i1 icmp slt (i16 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i16), i16 0), i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 lshr (i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 6)) to i64)), i64 sext (i32 select (i1 icmp slt (i16 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i16), i16 0), i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 lshr (i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 6)) to i64)), i64 sext (i32 select (i1 icmp slt (i16 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i16), i16 0), i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 lshr (i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 6)) to i64)), i64 sext (i32 select (i1 icmp slt (i16 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i16), i16 0), i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 lshr (i32 zext (i1 icmp eq (i32* getelementptr inbounds ([2 x i32], [2 x i32]* @d, i64 0, i64 1), i32* @c) to i32), i32 6)) to i64))
+  %7 = icmp slt i32 undef, 6
+  br i1 %7, label %4, label %8
+
+; <label>:8:                                      ; preds = %4, %3
+  %9 = phi i64 [ undef, %3 ], [ %6, %4 ]
+  br label %10
+
+; <label>:10:                                     ; preds = %8, %0
+  ret void
+}
+
+attributes #0 = { norecurse nounwind "target-cpu"="ppc64le" }
+