Custom lower the memory barrier instructions and add support

for lowering without sse2.  Add a couple of new testcases.

Fixes a few libgomp tests and latent bugs.  Remove a few todos.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109078 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 75 insertions, 18 deletions

diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt
index efc0cd82f2..6034a091d1 100644
--- a/lib/Target/X86/README.txt
+++ b/lib/Target/X86/README.txt
@@ -1135,13 +1135,6 @@ void test(double *P) {
 
 //===---------------------------------------------------------------------===//
 
-handling llvm.memory.barrier on pre SSE2 cpus
-
-should generate:
-lock ; mov %esp, %esp
-
-//===---------------------------------------------------------------------===//
-
 The generated code on x86 for checking for signed overflow on a multiply the
 obvious way is much longer than it needs to be.
 
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index a67331fe77..634c08e54d 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -343,8 +343,9 @@ X86TargetLowering::X86TargetLowering(X86TargetMachine &TM)
   if (Subtarget->hasSSE1())
     setOperationAction(ISD::PREFETCH      , MVT::Other, Legal);
 
-  if (!Subtarget->hasSSE2())
-    setOperationAction(ISD::MEMBARRIER    , MVT::Other, Expand);
+  // We may not have a libcall for MEMBARRIER so we should lower this.
+  setOperationAction(ISD::MEMBARRIER    , MVT::Other, Custom);
+  
   // On X86 and X86-64, atomic operations are lowered to locked instructions.
   // Locked instructions, in turn, have implicit fence semantics (all memory
   // operations are flushed before issuing the locked instruction, and they
@@ -7509,6 +7510,36 @@ SDValue X86TargetLowering::LowerXALUO(SDValue Op, SelectionDAG &DAG) const {
   return Sum;
 }
 
+SDValue X86TargetLowering::LowerMEMBARRIER(SDValue Op, SelectionDAG &DAG) const{
+  DebugLoc dl = Op.getDebugLoc();
+  
+  if (!Subtarget->hasSSE2())
+    return DAG.getNode(X86ISD::MEMBARRIER, dl, MVT::Other, Op.getOperand(0),
+                       DAG.getConstant(0, MVT::i32));
+  
+  unsigned isDev = cast<ConstantSDNode>(Op.getOperand(5))->getZExtValue();
+  if(!isDev)
+    return DAG.getNode(X86ISD::MEMBARRIER, dl, MVT::Other, Op.getOperand(0));
+  else {
+    unsigned Op1 = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
+    unsigned Op2 = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue();
+    unsigned Op3 = cast<ConstantSDNode>(Op.getOperand(3))->getZExtValue();
+    unsigned Op4 = cast<ConstantSDNode>(Op.getOperand(4))->getZExtValue();
+    
+    // def : Pat<(membarrier (i8 0), (i8 0), (i8 0), (i8 1), (i8 1)), (SFENCE)>;
+    if (!Op1 && !Op2 && !Op3 && Op4)
+      return DAG.getNode(X86ISD::SFENCE, dl, MVT::Other, Op.getOperand(0));
+    
+    // def : Pat<(membarrier (i8 1), (i8 0), (i8 0), (i8 0), (i8 1)), (LFENCE)>;
+    if (Op1 && !Op2 && !Op3 && !Op4)
+      return DAG.getNode(X86ISD::LFENCE, dl, MVT::Other, Op.getOperand(0));
+    
+    // def : Pat<(membarrier (i8 imm), (i8 imm), (i8 imm), (i8 imm), (i8 1)), 
+    //           (MFENCE)>;
+    return DAG.getNode(X86ISD::MFENCE, dl, MVT::Other, Op.getOperand(0));
+  }
+}
+
 SDValue X86TargetLowering::LowerCMP_SWAP(SDValue Op, SelectionDAG &DAG) const {
   EVT T = Op.getValueType();
   DebugLoc dl = Op.getDebugLoc();
@@ -7598,6 +7629,7 @@ SDValue X86TargetLowering::LowerLOAD_SUB(SDValue Op, SelectionDAG &DAG) const {
 SDValue X86TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
   switch (Op.getOpcode()) {
   default: llvm_unreachable("Should not custom lower this!");
+  case ISD::MEMBARRIER:         return LowerMEMBARRIER(Op,DAG);
   case ISD::ATOMIC_CMP_SWAP:    return LowerCMP_SWAP(Op,DAG);
   case ISD::ATOMIC_LOAD_SUB:    return LowerLOAD_SUB(Op,DAG);
   case ISD::BUILD_VECTOR:       return LowerBUILD_VECTOR(Op, DAG);
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index 4e4daa4bc5..1809de5344 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -265,7 +265,13 @@ namespace llvm {
       ATOMXOR64_DAG,
       ATOMAND64_DAG,
       ATOMNAND64_DAG,
-      ATOMSWAP64_DAG
+      ATOMSWAP64_DAG,
+      
+      // Memory barrier
+      MEMBARRIER,
+      MFENCE,
+      SFENCE,
+      LFENCE
 
       // WARNING: Do not add anything in the end unless you want the node to
       // have memop! In fact, starting from ATOMADD64_DAG all opcodes will be
@@ -715,6 +721,7 @@ namespace llvm {
     SDValue LowerCMP_SWAP(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerLOAD_SUB(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerREADCYCLECOUNTER(SDValue Op, SelectionDAG &DAG) const;
+    SDValue LowerMEMBARRIER(SDValue Op, SelectionDAG &DAG) const;
 
     virtual SDValue
       LowerFormalArguments(SDValue Chain,
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index 6917a9db64..597356d7b4 100644
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -80,6 +80,21 @@ def SDT_X86EHRET : SDTypeProfile<0, 1, [SDTCisInt<0>]>;
 
 def SDT_X86TCRET : SDTypeProfile<0, 2, [SDTCisPtrTy<0>, SDTCisVT<1, i32>]>;
 
+def SDT_X86MEMBARRIER : SDTypeProfile<0, 0, []>;
+def SDT_X86MEMBARRIERNoSSE : SDTypeProfile<0, 1, [SDTCisInt<0>]>;
+
+def X86MemBarrier : SDNode<"X86ISD::MEMBARRIER", SDT_X86MEMBARRIER,
+                            [SDNPHasChain]>;
+def X86MemBarrierNoSSE : SDNode<"X86ISD::MEMBARRIER", SDT_X86MEMBARRIERNoSSE,
+                                [SDNPHasChain]>;
+def X86MFence : SDNode<"X86ISD::MFENCE", SDT_X86MEMBARRIER,
+                        [SDNPHasChain]>;
+def X86SFence : SDNode<"X86ISD::SFENCE", SDT_X86MEMBARRIER,
+                        [SDNPHasChain]>;
+def X86LFence : SDNode<"X86ISD::LFENCE", SDT_X86MEMBARRIER,
+                        [SDNPHasChain]>;
+
+
 def X86bsf     : SDNode<"X86ISD::BSF",      SDTUnaryArithWithFlags>;
 def X86bsr     : SDNode<"X86ISD::BSR",      SDTUnaryArithWithFlags>;
 def X86shld    : SDNode<"X86ISD::SHLD",     SDTIntShiftDOp>;
@@ -3906,6 +3921,20 @@ def EH_RETURN   : I<0xC3, RawFrm, (outs), (ins GR32:$addr),
 // Atomic support
 //
 
+// Memory barriers
+let hasSideEffects = 1 in {
+def Int_MemBarrier : I<0, Pseudo, (outs), (ins),
+                     "#MEMBARRIER",
+                     [(X86MemBarrier)]>, Requires<[HasSSE2]>;
+
+// TODO: Get this to fold the constant into the instruction.           
+let Uses = [ESP] in
+def Int_MemBarrierNoSSE  : I<0x0B, Pseudo, (outs), (ins GR32:$zero),
+                           "lock\n\t"
+                           "or{l}\t{$zero, (%esp)|(%esp), $zero}",
+                           [(X86MemBarrierNoSSE GR32:$zero)]>, LOCK;
+}
+
 // Atomic swap. These are just normal xchg instructions. But since a memory
 // operand is referenced, the atomicity is ensured.
 let Constraints = "$val = $dst" in {
diff --git a/lib/Target/X86/X86InstrSSE.td b/lib/Target/X86/X86InstrSSE.td
index 804d059232..d8bb435c29 100644
--- a/lib/Target/X86/X86InstrSSE.td
+++ b/lib/Target/X86/X86InstrSSE.td
@@ -2001,6 +2001,7 @@ def PREFETCHNTA  : PSI<0x18, MRM0m, (outs), (ins i8mem:$src),
 // Load, store, and memory fence
 def SFENCE : I<0xAE, MRM_F8, (outs), (ins), "sfence", [(int_x86_sse_sfence)]>,
              TB, Requires<[HasSSE1]>;
+def : Pat<(X86SFence), (SFENCE)>;
 
 // Alias instructions that map zero vector to pxor / xorp* for sse.
 // We set canFoldAsLoad because this can be converted to a constant-pool
@@ -3024,19 +3025,14 @@ def LFENCE : I<0xAE, MRM_E8, (outs), (ins),
                "lfence", [(int_x86_sse2_lfence)]>, TB, Requires<[HasSSE2]>;
 def MFENCE : I<0xAE, MRM_F0, (outs), (ins),
                "mfence", [(int_x86_sse2_mfence)]>, TB, Requires<[HasSSE2]>;
+def : Pat<(X86LFence), (LFENCE)>;
+def : Pat<(X86MFence), (MFENCE)>;
+
 
 // Pause. This "instruction" is encoded as "rep; nop", so even though it
 // was introduced with SSE2, it's backward compatible.
 def PAUSE : I<0x90, RawFrm, (outs), (ins), "pause", []>, REP;
 
-//TODO: custom lower this so as to never even generate the noop
-def : Pat<(membarrier (i8 imm), (i8 imm), (i8 imm), (i8 imm),
-           (i8 0)), (NOOP)>;
-def : Pat<(membarrier (i8 0), (i8 0), (i8 0), (i8 1), (i8 1)), (SFENCE)>;
-def : Pat<(membarrier (i8 1), (i8 0), (i8 0), (i8 0), (i8 1)), (LFENCE)>;
-def : Pat<(membarrier (i8 imm), (i8 imm), (i8 imm), (i8 imm),
-           (i8 1)), (MFENCE)>;
-
 // Alias instructions that map zero vector to pxor / xorp* for sse.
 // We set canFoldAsLoad because this can be converted to a constant-pool
 // load of an all-ones value if folding it would be beneficial.