Index: lib/CodeGen/RegisterCoalescer.cpp
===================================================================
--- lib/CodeGen/RegisterCoalescer.cpp
+++ lib/CodeGen/RegisterCoalescer.cpp
@@ -1209,10 +1209,10 @@
   }
 
   LiveInterval &JoinVInt = LIS->getInterval(CP.getSrcReg());
-  if (CP.isFlipped() && JoinVInt.containsOneValue())
+  if (JoinVInt.containsOneValue())
     return true;
 
-  DEBUG(dbgs() << "\tCannot join defs into reserved register.\n");
+  DEBUG(dbgs() << "\tCannot join complex intervals into reserved register.\n");
   return false;
 }
 
@@ -1431,8 +1431,7 @@
   LiveInterval &RHS = LIS->getInterval(CP.getSrcReg());
   DEBUG(dbgs() << "\t\tRHS = " << RHS << '\n');
 
-  assert(CP.isFlipped() && RHS.containsOneValue() &&
-         "Invalid join with reserved register");
+  assert(RHS.containsOneValue() && "Invalid join with reserved register");
 
   // Optimization for reserved registers like ESP. We can only merge with a
   // reserved physreg if RHS has a single value that is a copy of CP.DstReg().
@@ -1453,7 +1452,18 @@
   // defs are there.
 
   // Delete the identity copy.
-  MachineInstr *CopyMI = MRI->getVRegDef(RHS.reg);
+  MachineInstr *CopyMI;
+  if (CP.isFlipped()) {
+    CopyMI = MRI->getVRegDef(RHS.reg);
+  } else {
+    if (!MRI->hasOneNonDBGUse(RHS.reg)) {
+      DEBUG(dbgs() << "\t\tMultiple vreg uses\n");
+      return false;
+    }
+
+    CopyMI = &*MRI->use_instr_nodbg_begin(RHS.reg);
+  }
+  
   LIS->RemoveMachineInstrFromMaps(CopyMI);
   CopyMI->eraseFromParent();
 
Index: test/CodeGen/ARM/dyn-stackalloc.ll
===================================================================
--- test/CodeGen/ARM/dyn-stackalloc.ll
+++ test/CodeGen/ARM/dyn-stackalloc.ll
@@ -1,4 +1,4 @@
-; RUN: llc -mtriple=arm-eabi %s -o /dev/null
+; RUN: llc -mcpu=generic -mtriple=arm-eabi < %s | FileCheck %s
 
 %struct.comment = type { i8**, i32*, i32, i8* }
 %struct.info = type { i32, i32, i32, i32, i32, i32, i32, i8* }
@@ -7,6 +7,18 @@
 @str215 = external global [2 x i8]
 
 define void @t1(%struct.state* %v) {
+
+; Make sure we generate:
+;   sub	sp, sp, r1
+; instead of:
+;   sub	r1, sp, r1
+;   mov	sp, r1
+
+; CHECK-LABEL: @t1
+; CHECK: bic [[REG1:r[0-9]+]],
+; CHECK-NOT: sub r{{[0-9]+}}, sp, [[REG1]]
+; CHECK: sub sp, sp, [[REG1]]
+
   %tmp6 = load i32* null
   %tmp8 = alloca float, i32 %tmp6
   store i32 1, i32* null
Index: test/CodeGen/X86/2009-02-12-DebugInfoVLA.ll
===================================================================
--- test/CodeGen/X86/2009-02-12-DebugInfoVLA.ll
+++ test/CodeGen/X86/2009-02-12-DebugInfoVLA.ll
@@ -1,9 +1,19 @@
 ; RUN: llc < %s
-; RUN: llc < %s -march=x86-64
+; RUN: llc < %s -march=x86-64 | FileCheck %s
 ; PR3538
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
 target triple = "i386-apple-darwin9"
 define signext i8 @foo(i8* %s1) nounwind ssp {
+
+; Make sure we generate:
+;  movq	-40(%rbp), %rsp
+; Instead of:
+;  movq	-40(%rbp), %rax
+;  movq	%rax, %rsp
+
+; CHECK-LABEL: @foo
+; CHECK: movq	-40(%rbp), %rsp
+
 entry:
   %s1_addr = alloca i8*                           ; <i8**> [#uses=2]
   %retval = alloca i32                            ; <i32*> [#uses=2]