From a73adac52e08f88e350b6e5c2687c559bf68bffa Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sun, 29 Nov 2009 01:04:40 +0000
Subject: [PATCH] add a testcase for

void test9(int N, double* G) {
  long j;
  for (j = 1; j < N - 1; j++)
      G[j+1] = G[j] + G[j+1];
}

llvm-svn: 90047
---
 llvm/test/Transforms/GVN/pre-load.ll | 45 ++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/llvm/test/Transforms/GVN/pre-load.ll b/llvm/test/Transforms/GVN/pre-load.ll
index aa9e2b0cb085..d904e9532c68 100644
--- a/llvm/test/Transforms/GVN/pre-load.ll
+++ b/llvm/test/Transforms/GVN/pre-load.ll
@@ -268,4 +268,49 @@ block4:
 ; CHECK: ret i32
 }
 
+;void test9(int N, double* G) {
+;  long j;
+;  for (j = 1; j < N - 1; j++)
+;      G[j+1] = G[j] + G[j+1];
+;}
+
+; This requires phi translation of the adds.
+define void @test9(i32 %N, double* nocapture %G) nounwind ssp {
+entry:
+  add i32 0, 0
+  %1 = add i32 %N, -1                             
+  %2 = icmp sgt i32 %1, 1                         
+  br i1 %2, label %bb.nph, label %return
+
+bb.nph:                                           
+  %tmp = sext i32 %1 to i64                       
+  %tmp7 = add i64 %tmp, -1                        
+  br label %bb
+
+; CHECK: bb.nph:
+; CHECK:   load double*
+; CHECK:   br label %bb
+
+bb:                                               
+  %indvar = phi i64 [ 0, %bb.nph ], [ %tmp9, %bb ] 
+  %tmp8 = add i64 %indvar, 2                      
+  %scevgep = getelementptr double* %G, i64 %tmp8  
+  %tmp9 = add i64 %indvar, 1                      
+  %scevgep10 = getelementptr double* %G, i64 %tmp9 
+  %3 = load double* %scevgep10, align 8           
+  %4 = load double* %scevgep, align 8             
+  %5 = fadd double %3, %4                         
+  store double %5, double* %scevgep, align 8
+  %exitcond = icmp eq i64 %tmp9, %tmp7            
+  br i1 %exitcond, label %return, label %bb
+
+; Should only be one load in the loop.
+; CHECK: bb:
+; CHECK: load double*
+; CHECK-NOT: load double*
+; CHECK: br i1 %exitcond
+
+return:                                           
+  ret void
+}