From 55bdeb7bc783a48c9970a48949de10fb802cba96 Mon Sep 17 00:00:00 2001
From: Brendon Cahoon <bcahoon@codeaurora.org>
Date: Mon, 27 Apr 2015 14:16:43 +0000
Subject: [Hexagon] Use constant extenders to fix up hardware loops

Use a loop instruction with a constant extender for a hardware
loop instruction that is too far away from the start of the loop.
This is cheaper than changing the SA register value.

Differential Revision: http://reviews.llvm.org/D9262

llvm-svn: 235882
---
 llvm/test/CodeGen/Hexagon/hwloop-range.ll | 36 +++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 llvm/test/CodeGen/Hexagon/hwloop-range.ll

(limited to 'llvm/test/CodeGen/Hexagon/hwloop-range.ll')

diff --git a/llvm/test/CodeGen/Hexagon/hwloop-range.ll b/llvm/test/CodeGen/Hexagon/hwloop-range.ll
new file mode 100644
index 00000000000..5e6fe78d0e0
--- /dev/null
+++ b/llvm/test/CodeGen/Hexagon/hwloop-range.ll
@@ -0,0 +1,36 @@
+; RUN: llc -march=hexagon -hexagon-loop-range=0 < %s | FileCheck %s
+
+; Test that the loop start address operand uses a constant extender
+; if the offset is out of range.
+
+; CHECK: loop0(##.LBB
+; CHECK: endloop0
+
+@g = external global i32, align 4
+
+define void @test(i32* nocapture %a, i32* nocapture readonly %b, i32 %n) #0 {
+entry:
+  %cmp6 = icmp slt i32 %n, 1
+  br i1 %cmp6, label %for.end, label %for.body.preheader
+
+for.body.preheader:
+  br label %for.body
+
+for.body:
+  %i.07 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
+  %arrayidx = getelementptr inbounds i32, i32* %b, i32 %i.07
+  %0 = load i32, i32* %arrayidx, align 4
+  %1 = load i32, i32* @g, align 4
+  %mul = mul nsw i32 %1, %0
+  %arrayidx1 = getelementptr inbounds i32, i32* %a, i32 %i.07
+  store i32 %mul, i32* %arrayidx1, align 4
+  %inc = add nuw nsw i32 %i.07, 1
+  %exitcond = icmp eq i32 %inc, %n
+  br i1 %exitcond, label %for.end.loopexit, label %for.body
+
+for.end.loopexit:
+  br label %for.end
+
+for.end:
+  ret void
+}
-- 
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