From eb18812f755b634f3e7554c1912aeb2d7476cb53 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Wed, 13 Jan 2010 19:16:39 +0000
Subject: [PATCH] Commit some changes I had managed to lose last night while
 refactoring the code. Avoid change use of PHI instructions because it's not
 legal to insert any instructions before them. This fixes PR6027.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93335 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/OptimizeExts.cpp             |  7 +++-
 test/CodeGen/X86/2010-01-13-OptExtBug.ll | 46 ++++++++++++++++++++++++
 test/CodeGen/X86/stack-color-with-reg.ll |  2 +-
 3 files changed, 53 insertions(+), 2 deletions(-)
 create mode 100644 test/CodeGen/X86/2010-01-13-OptExtBug.ll

diff --git a/lib/CodeGen/OptimizeExts.cpp b/lib/CodeGen/OptimizeExts.cpp
index 844eb232f66..625ff89f90e 100644
--- a/lib/CodeGen/OptimizeExts.cpp
+++ b/lib/CodeGen/OptimizeExts.cpp
@@ -110,6 +110,11 @@ bool OptimizeExts::OptimizeInstr(MachineInstr *MI, MachineBasicBlock *MBB,
       MachineInstr *UseMI = &*UI;
       if (UseMI == MI)
         continue;
+      if (UseMI->getOpcode() == TargetInstrInfo::PHI) {
+        ExtendLife = false;
+        continue;
+      }
+
       MachineBasicBlock *UseMBB = UseMI->getParent();
       if (UseMBB == MBB) {
         // Local uses that come after the extension.
@@ -117,7 +122,7 @@ bool OptimizeExts::OptimizeInstr(MachineInstr *MI, MachineBasicBlock *MBB,
           Uses.push_back(&UseMO);
       } else if (ReachedBBs.count(UseMBB))
         // Non-local uses where the result of extension is used. Always
-        // replace these.
+        // replace these unless it's a PHI.
         Uses.push_back(&UseMO);
       else if (Aggressive && DT->dominates(MBB, UseMBB))
         // We may want to extend live range of the extension result in order
diff --git a/test/CodeGen/X86/2010-01-13-OptExtBug.ll b/test/CodeGen/X86/2010-01-13-OptExtBug.ll
new file mode 100644
index 00000000000..d49e2a8d079
--- /dev/null
+++ b/test/CodeGen/X86/2010-01-13-OptExtBug.ll
@@ -0,0 +1,46 @@
+; RUN: llc < %s -mtriple=i386-pc-linux-gnu
+; PR6027
+
+%class.OlsonTimeZone = type { i16, i32*, i8*, i16 }
+
+define void @XX(%class.OlsonTimeZone* %this) align 2 {
+entry:
+  %call = tail call i8* @_Z15uprv_malloc_4_2v()
+  %0 = bitcast i8* %call to double*
+  %tmp = getelementptr inbounds %class.OlsonTimeZone* %this, i32 0, i32 3
+  %tmp2 = load i16* %tmp
+  %tmp525 = getelementptr inbounds %class.OlsonTimeZone* %this, i32 0, i32 0
+  %tmp626 = load i16* %tmp525
+  %cmp27 = icmp slt i16 %tmp2, %tmp626
+  br i1 %cmp27, label %bb.nph, label %for.end
+
+for.cond:
+  %tmp6 = load i16* %tmp5
+  %cmp = icmp slt i16 %inc, %tmp6
+  %indvar.next = add i32 %indvar, 1
+  br i1 %cmp, label %for.body, label %for.end
+
+bb.nph:
+  %tmp10 = getelementptr inbounds %class.OlsonTimeZone* %this, i32 0, i32 2
+  %tmp17 = getelementptr inbounds %class.OlsonTimeZone* %this, i32 0, i32 1
+  %tmp5 = getelementptr inbounds %class.OlsonTimeZone* %this, i32 0, i32 0
+  %tmp29 = sext i16 %tmp2 to i32
+  %tmp31 = add i16 %tmp2, 1
+  %tmp32 = zext i16 %tmp31 to i32
+  br label %for.body
+
+for.body:
+  %indvar = phi i32 [ 0, %bb.nph ], [ %indvar.next, %for.cond ]
+  %tmp30 = add i32 %indvar, %tmp29
+  %tmp33 = add i32 %indvar, %tmp32
+  %inc = trunc i32 %tmp33 to i16
+  %tmp11 = load i8** %tmp10
+  %arrayidx = getelementptr i8* %tmp11, i32 %tmp30
+  %tmp12 = load i8* %arrayidx
+  br label %for.cond
+
+for.end:
+  ret void
+}
+
+declare i8* @_Z15uprv_malloc_4_2v()
diff --git a/test/CodeGen/X86/stack-color-with-reg.ll b/test/CodeGen/X86/stack-color-with-reg.ll
index be9f3af308a..7d85818d46b 100644
--- a/test/CodeGen/X86/stack-color-with-reg.ll
+++ b/test/CodeGen/X86/stack-color-with-reg.ll
@@ -1,5 +1,5 @@
 ; RUN: llc < %s -mtriple=x86_64-apple-darwin10 -relocation-model=pic -disable-fp-elim -color-ss-with-regs -stats -info-output-file - > %t
-; RUN:   grep stackcoloring %t | grep "stack slot refs replaced with reg refs"  | grep 9
+; RUN:   grep stackcoloring %t | grep "stack slot refs replaced with reg refs"  | grep 14
 
 	type { [62 x %struct.Bitvec*] }		; type %0
 	type { i8* }		; type %1