If all sources of a PHI node are defined by an implicit_def, just emit an implicit_def instead of a copy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50927 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 25 insertions, 0 deletions

diff --git a/test/CodeGen/X86/2008-05-09-PHIElimBug.ll b/test/CodeGen/X86/2008-05-09-PHIElimBug.ll
new file mode 100644
index 0000000000..c0b1961131
--- /dev/null
+++ b/test/CodeGen/X86/2008-05-09-PHIElimBug.ll
@@ -0,0 +1,25 @@
+; RUN: llvm-as < %s | llc -march=x86
+
+	%struct.V = type { <4 x float>, <4 x float>, <4 x float>, <4 x float>, <4 x float>, <4 x float>, <4 x float>, <4 x i32>, float*, float*, float*, float*, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, float, i32, i32, i32, i32, i32, i32, i32, i32 }
+
+define fastcc void @t() nounwind  {
+entry:
+	br i1 false, label %bb23816.preheader, label %bb23821
+
+bb23816.preheader:		; preds = %entry
+	%tmp23735 = and i32 0, 2		; <i32> [#uses=0]
+	br label %bb23830
+
+bb23821:		; preds = %entry
+	br i1 false, label %bb23830, label %bb23827
+
+bb23827:		; preds = %bb23821
+	%tmp23829 = getelementptr %struct.V* null, i32 0, i32 42		; <i32*> [#uses=0]
+	br label %bb23830
+
+bb23830:		; preds = %bb23827, %bb23821, %bb23816.preheader
+	%scaledInDst.2.reg2mem.5 = phi i8 [ undef, %bb23827 ], [ undef, %bb23821 ], [ undef, %bb23816.preheader ]		; <i8> [#uses=1]
+	%toBool35047 = icmp eq i8 %scaledInDst.2.reg2mem.5, 0		; <i1> [#uses=1]
+	%bothcond39107 = or i1 %toBool35047, false		; <i1> [#uses=0]
+	unreachable
+}