From 9a5c22cc5e741bc3022366e85825ba99236027ed Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Fri, 27 Nov 2009 18:08:30 +0000
Subject: [PATCH] add two simple test cases we now optimize (to one load in the
 loop each) and one we don't (corresponding to the fixme I added yesterday).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90012 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Transforms/GVN/pre-load.ll | 121 ++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)

diff --git a/test/Transforms/GVN/pre-load.ll b/test/Transforms/GVN/pre-load.ll
index 3cb67135acc..672adaaaeb0 100644
--- a/test/Transforms/GVN/pre-load.ll
+++ b/test/Transforms/GVN/pre-load.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -gvn -enable-load-pre -S | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
 
 define i32 @test1(i32* %p, i1 %C) {
 ; CHECK: @test1
@@ -107,3 +108,123 @@ block4:
 ; CHECK-NOT: load
 ; CHECK: ret i32
 }
+
+;void test5(int N, double *G) {
+;  int j;
+;  for (j = 0; j < N - 1; j++)
+;    G[j] = G[j] + G[j+1];
+;}
+
+define void @test5(i32 %N, double* nocapture %G) nounwind ssp {
+; CHECK: @test5
+entry:
+  %0 = add i32 %N, -1           
+  %1 = icmp sgt i32 %0, 0       
+  br i1 %1, label %bb.nph, label %return
+
+bb.nph:                         
+  %tmp = zext i32 %0 to i64     
+  br label %bb
+
+; CHECK: bb.nph:
+; CHECK: load double*
+; CHECK: br label %bb
+
+bb:             
+  %indvar = phi i64 [ 0, %bb.nph ], [ %tmp6, %bb ]
+  %tmp6 = add i64 %indvar, 1                    
+  %scevgep = getelementptr double* %G, i64 %tmp6
+  %scevgep7 = getelementptr double* %G, i64 %indvar
+  %2 = load double* %scevgep7, align 8
+  %3 = load double* %scevgep, align 8 
+  %4 = fadd double %2, %3             
+  store double %4, double* %scevgep7, align 8
+  %exitcond = icmp eq i64 %tmp6, %tmp 
+  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
+}
+
+;void test6(int N, double *G) {
+;  int j;
+;  for (j = 0; j < N - 1; j++)
+;    G[j+1] = G[j] + G[j+1];
+;}
+
+define void @test6(i32 %N, double* nocapture %G) nounwind ssp {
+; CHECK: @test6
+entry:
+  %0 = add i32 %N, -1           
+  %1 = icmp sgt i32 %0, 0       
+  br i1 %1, label %bb.nph, label %return
+
+bb.nph:                         
+  %tmp = zext i32 %0 to i64     
+  br label %bb
+
+; CHECK: bb.nph:
+; CHECK: load double*
+; CHECK: br label %bb
+
+bb:             
+  %indvar = phi i64 [ 0, %bb.nph ], [ %tmp6, %bb ]
+  %tmp6 = add i64 %indvar, 1                    
+  %scevgep = getelementptr double* %G, i64 %tmp6
+  %scevgep7 = getelementptr double* %G, i64 %indvar
+  %2 = load double* %scevgep7, align 8
+  %3 = load double* %scevgep, align 8 
+  %4 = fadd double %2, %3             
+  store double %4, double* %scevgep, align 8
+  %exitcond = icmp eq i64 %tmp6, %tmp 
+  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
+}
+
+
+
+;;; --- todo
+
+;; Here the loaded address isn't available in 'block2' at all.
+define i32 @testX(i32* %p, i32* %q, i32** %Hack, i1 %C) {
+; CHECK: @testX
+block1:
+	br i1 %C, label %block2, label %block3
+
+block2:
+ br label %block4
+; HECK: block2:
+; HECK:   load i32*
+; HECK:   br label %block4
+
+block3:
+  %A = getelementptr i32* %p, i32 1
+  store i32 0, i32* %A
+  br label %block4
+
+block4:
+  %P2 = phi i32* [%p, %block3], [%q, %block2]
+  %P3 = getelementptr i32* %P2, i32 1
+  %PRE = load i32* %P3
+  ret i32 %PRE
+; HECK: block4:
+; HECK-NEXT: phi i32 [
+; HECK-NOT: load
+; HECK: ret i32
+}
+
+
-- 
2.34.1