[Hexagon] Generate more hardware loops

Refactored parts of the hardware loop pass to generate
more. Also, added more tests.

Differential Revision: http://reviews.llvm.org/D9568

llvm-svn: 236896
diff --git a/llvm/test/CodeGen/Hexagon/hwloop2.ll b/llvm/test/CodeGen/Hexagon/hwloop2.ll
new file mode 100644
index 0000000..d411d97
--- /dev/null
+++ b/llvm/test/CodeGen/Hexagon/hwloop2.ll
@@ -0,0 +1,37 @@
+; RUN: llc -disable-lsr -march=hexagon < %s | FileCheck %s
+
+; Test for multiple phis with induction variables.
+
+; CHECK: loop0(.LBB{{.}}_{{.}}, r{{[0-9]+}})
+; CHECK: endloop0
+
+define i32 @hwloop4(i32* nocapture %s, i32* nocapture %a, i32 %n) {
+entry:
+  %cmp3 = icmp eq i32 %n, 0
+  br i1 %cmp3, label %for.end, label %for.body.lr.ph
+
+for.body.lr.ph:
+  %.pre = load i32, i32* %s, align 4
+  br label %for.body
+
+for.body:
+  %0 = phi i32 [ %.pre, %for.body.lr.ph ], [ %add1, %for.body ]
+  %j.05 = phi i32 [ 0, %for.body.lr.ph ], [ %add2, %for.body ]
+  %lsr.iv = phi i32 [ %lsr.iv.next, %for.body ], [ %n, %for.body.lr.ph ]
+  %lsr.iv1 = phi i32* [ %scevgep, %for.body ], [ %a, %for.body.lr.ph ]
+  %1 = load i32, i32* %lsr.iv1, align 4
+  %add1 = add nsw i32 %0, %1
+  store i32 %add1, i32* %s, align 4
+  %add2 = add nsw i32 %j.05, 1
+  %lsr.iv.next = add i32 %lsr.iv, -1
+  %scevgep = getelementptr i32, i32* %lsr.iv1, i32 1
+  %cmp = icmp eq i32 %lsr.iv.next, 0
+  br i1 %cmp, label %for.end.loopexit, label %for.body
+
+for.end.loopexit:
+  br label %for.end
+
+for.end:
+  %j.0.lcssa = phi i32 [ 0, %entry ], [ %add2, %for.end.loopexit ]
+  ret i32 %j.0.lcssa
+}