2 files changed, 21 insertions, 0 deletions
diff --git a/test/CodeGen/X86/subreg-to-reg-0.ll b/test/CodeGen/X86/subreg-to-reg-0.ll
new file mode 100644
index 0000000..6b60f65
--- /dev/null
+++ b/test/CodeGen/X86/subreg-to-reg-0.ll
@@ -0,0 +1,11 @@
+; RUN: llvm-as < %s | llc -march=x86-64 | grep mov | count 1
+
+; Do eliminate the zero-extension instruction and rely on
+; x86-64's implicit zero-extension!
+
+define i64 @foo(i32* %p) nounwind {
+  %t = load i32* %p
+  %n = add i32 %t, 1
+  %z = zext i32 %n to i64
+  ret i64 %z
+}
diff --git a/test/CodeGen/X86/subreg-to-reg-1.ll b/test/CodeGen/X86/subreg-to-reg-1.ll
new file mode 100644
index 0000000..4e487e1
--- /dev/null
+++ b/test/CodeGen/X86/subreg-to-reg-1.ll
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | llc -march=x86-64 | grep {movl	%e.\*, %e.\*} | count 1
+
+; Don't eliminate or coalesce away the explicit zero-extension!
+
+define i64 @foo(i64 %a) {
+  %b = add i64 %a, 4294967295
+  %c = and i64 %b, 4294967295
+  %d = add i64 %c, 1
+  ret i64 %d
+}