From 97b5beb7fe7bb776654b04ae6c18af6ea15c74f7 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Tue, 10 Jan 2012 02:02:58 +0000
Subject: Allow machine-cse to look across MBB boundary when cse'ing
 instructions that define physical registers. It's currently very restrictive,
 only catching cases where the CE is in an immediate (and only) predecessor.
 But it catches a surprising large number of cases.

rdar://10660865


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147827 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/CodeGen/ARM/machine-cse-cmp.ll | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

(limited to 'test/CodeGen/ARM/machine-cse-cmp.ll')

diff --git a/test/CodeGen/ARM/machine-cse-cmp.ll b/test/CodeGen/ARM/machine-cse-cmp.ll
index c77402f..f566974 100644
--- a/test/CodeGen/ARM/machine-cse-cmp.ll
+++ b/test/CodeGen/ARM/machine-cse-cmp.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=arm | FileCheck %s
+; RUN: llc < %s -mtriple=armv7-apple-ios | FileCheck %s
 ;rdar://8003725
 
 @G1 = external global i32
@@ -6,6 +6,7 @@
 
 define i32 @f1(i32 %cond1, i32 %x1, i32 %x2, i32 %x3) {
 entry:
+; CHECK: f1:
 ; CHECK: cmp
 ; CHECK: moveq
 ; CHECK-NOT: cmp
@@ -16,3 +17,31 @@ entry:
     %tmp4 = add i32 %tmp2, %tmp3
     ret i32 %tmp4
 }
+
+@foo = external global i32
+@bar = external global [250 x i8], align 1
+
+; CSE of cmp across BB boundary
+; rdar://10660865
+define void @f2() nounwind ssp {
+entry:
+; CHECK: f2:
+; CHECK: cmp
+; CHECK: poplt
+; CHECK-NOT: cmp
+; CHECK: movle
+  %0 = load i32* @foo, align 4
+  %cmp28 = icmp sgt i32 %0, 0
+  br i1 %cmp28, label %for.body.lr.ph, label %for.cond1.preheader
+
+for.body.lr.ph:                                   ; preds = %entry
+  %1 = icmp sgt i32 %0, 1
+  %smax = select i1 %1, i32 %0, i32 1
+  call void @llvm.memset.p0i8.i32(i8* getelementptr inbounds ([250 x i8]* @bar, i32 0, i32 0), i8 0, i32 %smax, i32 1, i1 false)
+  unreachable
+
+for.cond1.preheader:                              ; preds = %entry
+  ret void
+}
+
+declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) nounwind
-- 
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