From 66c04c48debfd4357beaf9310346b2b24046b685 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Thu, 12 Nov 2009 05:24:05 +0000
Subject: use getPredicateOnEdge to fold comparisons through PHI nodes, which
 implements GCC PR18046.  This also gets us 360 more jump threads on 176.gcc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86953 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Transforms/JumpThreading/basic.ll | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

(limited to 'test/Transforms/JumpThreading/basic.ll')

diff --git a/test/Transforms/JumpThreading/basic.ll b/test/Transforms/JumpThreading/basic.ll
index 03ce12ef9e..07b3b0c386 100644
--- a/test/Transforms/JumpThreading/basic.ll
+++ b/test/Transforms/JumpThreading/basic.ll
@@ -349,6 +349,38 @@ BB4:
 	ret i32 4
 }
 
+;; Correlated value through boolean expression.  GCC PR18046.
+define void @test12(i32 %A) {
+; CHECK: @test12
+entry:
+  %cond = icmp eq i32 %A, 0
+  br i1 %cond, label %bb, label %bb1
+; Should branch to the return block instead of through BB1.
+; CHECK: entry:
+; CHECK-NEXT: %cond = icmp eq i32 %A, 0
+; CHECK-NEXT: br i1 %cond, label %bb1, label %return
+
+bb:                   
+  %B = call i32 @test10f2()
+  br label %bb1
+
+bb1:
+  %C = phi i32 [ %A, %entry ], [ %B, %bb ]
+  %cond4 = icmp eq i32 %C, 0
+  br i1 %cond4, label %bb2, label %return
+
+; CHECK: bb1:
+; CHECK-NEXT: %B = call i32 @test10f2()
+; CHECK-NEXT: %cond4 = icmp eq i32 %B, 0
+; CHECK-NEXT: br i1 %cond4, label %bb2, label %return
+
+bb2:
+  %D = call i32 @test10f2()
+  ret void
+
+return:
+  ret void
+}
 
 
 ;;; Duplicate condition to avoid xor of cond.
-- 
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