[Hexagon] Implement MI-level constant propagation
llvm-svn: 277028
diff --git a/llvm/test/CodeGen/Hexagon/constp-rewrite-branches.ll b/llvm/test/CodeGen/Hexagon/constp-rewrite-branches.ll
new file mode 100644
index 0000000..dfac49c
--- /dev/null
+++ b/llvm/test/CodeGen/Hexagon/constp-rewrite-branches.ll
@@ -0,0 +1,17 @@
+; RUN: llc -O2 -march hexagon < %s | FileCheck %s
+
+define i32 @foo(i32 %x) {
+ %p = icmp eq i32 %x, 0
+ br i1 %p, label %zero, label %nonzero
+nonzero:
+ %v1 = add i32 %x, 1
+ %c = icmp eq i32 %x, %v1
+; This branch will be rewritten by HCP. A bug would cause both branches to
+; go away, leaving no path to "ret -1".
+ br i1 %c, label %zero, label %other
+zero:
+ ret i32 0
+other:
+; CHECK: -1
+ ret i32 -1
+}