Avoid commuting a def MI in order to coalesce a copy instruction away if any use of the same val# is a copy instruction that has already been coalesced.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48833 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 49 insertions, 0 deletions

diff --git a/test/CodeGen/X86/2007-03-26-CoalescerBug.ll b/test/CodeGen/X86/2007-03-26-CoalescerBug.ll
new file mode 100644
index 0000000..7ce0584
--- /dev/null
+++ b/test/CodeGen/X86/2007-03-26-CoalescerBug.ll
@@ -0,0 +1,49 @@
+; RUN: llvm-as < %s | llc -march=x86
+
+@data = external global [339 x i64]
+
+define void @foo(...) {
+bb1:
+	%t43 = load i64* getelementptr ([339 x i64]* @data, i32 0, i64 212), align 4
+	br i1 false, label %bb80, label %bb6
+bb6:
+	br i1 false, label %bb38, label %bb265
+bb265:
+	ret void
+bb38:
+	br i1 false, label %bb80, label %bb49
+bb80:
+	br i1 false, label %bb146, label %bb268
+bb49:
+	ret void
+bb113:
+	ret void
+bb268:
+	%t1062 = shl i64 %t43, 3
+	%t1066 = shl i64 0, 3
+	br label %bb85
+bb85:
+	%t1025 = phi i64 [ 0, %bb268 ], [ %t102.0, %bb234 ]
+	%t1028 = phi i64 [ 0, %bb268 ], [ %t1066, %bb234 ]
+	%t1031 = phi i64 [ 0, %bb268 ], [ %t103.0, %bb234 ]
+	%t1034 = phi i64 [ 0, %bb268 ], [ %t1066, %bb234 ]
+	%t102.0 = add i64 %t1028, %t1025
+	%t103.0 = add i64 %t1034, %t1031
+	br label %bb86
+bb86:
+	%t108.0 = phi i64 [ %t102.0, %bb85 ], [ %t1139, %bb248 ]
+	%t110.0 = phi i64 [ %t103.0, %bb85 ], [ %t1142, %bb248 ]
+	br label %bb193
+bb193:
+	%t1081 = add i64 %t110.0, -8
+	%t1087 = add i64 %t108.0, -8
+	br i1 false, label %bb193, label %bb248
+bb248:
+	%t1139 = add i64 %t108.0, %t1062
+	%t1142 = add i64 %t110.0, %t1062
+	br i1 false, label %bb86, label %bb234
+bb234:
+	br i1 false, label %bb85, label %bb113
+bb146:
+	ret void
+}