From 265ca5dff5ad21add569fadab435f64423861793 Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Mon, 3 Nov 2008 19:38:07 +0000
Subject: [PATCH] Ignore conditions that are outside the loop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58631 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/LoopUnswitch.cpp        |  6 ++-
 .../LoopUnswitch/2008-11-03-Invariant.ll      | 47 +++++++++++++++++++
 2 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 test/Transforms/LoopUnswitch/2008-11-03-Invariant.ll

diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp
index 65034f5577c..31e875275b8 100644
--- a/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -167,8 +167,10 @@ static Value *FindLIVLoopCondition(Value *Cond, Loop *L, bool &Changed) {
 
   // TODO: Handle: br (VARIANT|INVARIANT).
   // TODO: Hoist simple expressions out of loops.
-  if (L->isLoopInvariant(Cond)) return Cond;
-  
+  if (Instruction *I = dyn_cast<Instruction>(Cond))
+    if (!L->contains(I->getParent()))
+      return 0;
+
   if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Cond))
     if (BO->getOpcode() == Instruction::And ||
         BO->getOpcode() == Instruction::Or) {
diff --git a/test/Transforms/LoopUnswitch/2008-11-03-Invariant.ll b/test/Transforms/LoopUnswitch/2008-11-03-Invariant.ll
new file mode 100644
index 00000000000..430ada4e8c1
--- /dev/null
+++ b/test/Transforms/LoopUnswitch/2008-11-03-Invariant.ll
@@ -0,0 +1,47 @@
+; RUN: llvm-as < %s | opt -loop-unswitch -stats | not grep loop-unswitch
+
+
+define void @test_fc_while_continue_or(float %x, float %y, float* %result) nounwind {
+entry:
+	br label %bb2.outer
+
+bb:		; preds = %bb2
+	%0 = add float %5, %z.0		; <float> [#uses=3]
+	%1 = fcmp oeq float %0, 0.000000e+00		; <i1> [#uses=1]
+	br i1 %1, label %bb2, label %bb1
+
+bb1:		; preds = %bb
+	%.lcssa = phi float [ %0, %bb ]		; <float> [#uses=1]
+	%z.0.lcssa1 = phi float [ %z.0, %bb ]		; <float> [#uses=0]
+	%2 = add float %x_addr.0.ph, 1.000000e+00		; <float> [#uses=1]
+	br label %bb2.outer
+
+bb2.outer:		; preds = %bb1, %entry
+	%z.0.ph = phi float [ 0.000000e+00, %entry ], [ %.lcssa, %bb1 ]		; <float> [#uses=1]
+	%x_addr.0.ph = phi float [ %x, %entry ], [ %2, %bb1 ]		; <float> [#uses=3]
+	%3 = fcmp une float %x_addr.0.ph, 0.000000e+00		; <i1> [#uses=1]
+	%4 = fcmp une float %y, 0.000000e+00		; <i1> [#uses=1]
+	%or.cond = or i1 %3, %4		; <i1> [#uses=1]
+	%5 = mul float %x_addr.0.ph, %y		; <float> [#uses=1]
+	br label %bb2
+
+bb2:		; preds = %bb2.outer, %bb
+	%z.0 = phi float [ %0, %bb ], [ %z.0.ph, %bb2.outer ]		; <float> [#uses=3]
+	br i1 %or.cond, label %bb, label %bb4
+
+bb4:		; preds = %bb2
+	%z.0.lcssa = phi float [ %z.0, %bb2 ]		; <float> [#uses=1]
+	store float %z.0.lcssa, float* %result, align 4
+	ret void
+}
+
+define i32 @main() nounwind {
+entry:
+	%z = alloca [10 x i32]		; <[10 x i32]*> [#uses=2]
+	%0 = call i32 (...)* @test_fc_while_or(i32 0, i32 0, [10 x i32]* %z) nounwind		; <i32> [#uses=0]
+	%1 = getelementptr [10 x i32]* %z, i32 0, i32 0		; <i32*> [#uses=1]
+	%2 = load i32* %1, align 4		; <i32> [#uses=1]
+	ret i32 %2
+}
+
+declare i32 @test_fc_while_or(...)