Enable machine cse of instructions which define physical registers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105308 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp
index 6f4f7a8834097b78bb175016a96d8adf0aeef5e9..d8e2ec64da8146bb28575d9d00b4ebff878397e9 100644 (file)
--- a/lib/CodeGen/MachineCSE.cpp
+++ b/lib/CodeGen/MachineCSE.cpp
@@ -31,9 +31,6 @@ using namespace llvm;
 STATISTIC(NumCoalesces, "Number of copies coalesced");
 STATISTIC(NumCSEs,      "Number of common subexpression eliminated");
 
-static cl::opt<bool> CSEPhysDef("machine-cse-phys-defs",
-                                cl::init(false), cl::Hidden);
-
 namespace {
   class MachineCSE : public MachineFunctionPass {
     const TargetInstrInfo *TII;
@@ -376,7 +373,7 @@ bool MachineCSE::ProcessBlock(MachineBasicBlock *MBB) {
 
       // ... Unless the CS is local and it also defines the physical register
       // which is not clobbered in between.
-      if (PhysDef && CSEPhysDef) {
+      if (PhysDef) {
         unsigned CSVN = VNT.lookup(MI);
         MachineInstr *CSMI = Exps[CSVN];
         if (PhysRegDefReaches(CSMI, MI, PhysDef))

diff --git a/test/CodeGen/ARM/machine-cse-cmp.ll b/test/CodeGen/ARM/machine-cse-cmp.ll
new file mode 100644 (file)
index 0000000..c77402f
--- /dev/null
+++ b/test/CodeGen/ARM/machine-cse-cmp.ll
@@ -0,0 +1,18 @@
+; RUN: llc < %s -march=arm | FileCheck %s
+;rdar://8003725
+
+@G1 = external global i32
+@G2 = external global i32
+
+define i32 @f1(i32 %cond1, i32 %x1, i32 %x2, i32 %x3) {
+entry:
+; CHECK: cmp
+; CHECK: moveq
+; CHECK-NOT: cmp
+; CHECK: moveq
+    %tmp1 = icmp eq i32 %cond1, 0
+    %tmp2 = select i1 %tmp1, i32 %x1, i32 %x2
+    %tmp3 = select i1 %tmp1, i32 %x2, i32 %x3
+    %tmp4 = add i32 %tmp2, %tmp3
+    ret i32 %tmp4
+}