[mips] Define patterns for the atomic_{load,store}_{8,16,32,64} nodes.

Summary:
Without these patterns we would generate a complete LL/SC sequence.
This would be problematic for memory regions marked as WRITE-only or
READ-only, as the instructions LL/SC would read/write to the protected
memory regions correspondingly.

Reviewers: dsanders

Subscribers: llvm-commits, dsanders

Differential Revision: http://reviews.llvm.org/D14397

llvm-svn: 252293
diff --git a/llvm/lib/Target/Mips/Mips64InstrInfo.td b/llvm/lib/Target/Mips/Mips64InstrInfo.td
index e928f4e..ec0953c 100644
--- a/llvm/lib/Target/Mips/Mips64InstrInfo.td
+++ b/llvm/lib/Target/Mips/Mips64InstrInfo.td
@@ -546,6 +546,18 @@
               (BBIT132 i64:$lhs, (Log2HI PowerOf2HI:$mask), bb:$dst)>;
 }
 
+// Atomic load patterns.
+def : MipsPat<(atomic_load_8 addr:$a), (LB64 addr:$a)>;
+def : MipsPat<(atomic_load_16 addr:$a), (LH64 addr:$a)>;
+def : MipsPat<(atomic_load_32 addr:$a), (LW64 addr:$a)>;
+def : MipsPat<(atomic_load_64 addr:$a), (LD addr:$a)>;
+
+// Atomic store patterns.
+def : MipsPat<(atomic_store_8 addr:$a, GPR64:$v), (SB64 GPR64:$v, addr:$a)>;
+def : MipsPat<(atomic_store_16 addr:$a, GPR64:$v), (SH64 GPR64:$v, addr:$a)>;
+def : MipsPat<(atomic_store_32 addr:$a, GPR64:$v), (SW64 GPR64:$v, addr:$a)>;
+def : MipsPat<(atomic_store_64 addr:$a, GPR64:$v), (SD GPR64:$v, addr:$a)>;
+
 //===----------------------------------------------------------------------===//
 // Instruction aliases
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/Target/Mips/MipsISelLowering.cpp b/llvm/lib/Target/Mips/MipsISelLowering.cpp
index b88af5a..75dc2f1 100644
--- a/llvm/lib/Target/Mips/MipsISelLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsISelLowering.cpp
@@ -391,10 +391,10 @@
   setOperationAction(ISD::STACKSAVE,         MVT::Other, Expand);
   setOperationAction(ISD::STACKRESTORE,      MVT::Other, Expand);
 
-  setOperationAction(ISD::ATOMIC_LOAD,       MVT::i32,    Expand);
-  setOperationAction(ISD::ATOMIC_LOAD,       MVT::i64,    Expand);
-  setOperationAction(ISD::ATOMIC_STORE,      MVT::i32,    Expand);
-  setOperationAction(ISD::ATOMIC_STORE,      MVT::i64,    Expand);
+  if (!Subtarget.isGP64bit()) {
+    setOperationAction(ISD::ATOMIC_LOAD,     MVT::i64,   Expand);
+    setOperationAction(ISD::ATOMIC_STORE,    MVT::i64,   Expand);
+  }
 
   setInsertFencesForAtomic(true);
 
diff --git a/llvm/lib/Target/Mips/MipsInstrInfo.td b/llvm/lib/Target/Mips/MipsInstrInfo.td
index fb44fcc..4305198 100644
--- a/llvm/lib/Target/Mips/MipsInstrInfo.td
+++ b/llvm/lib/Target/Mips/MipsInstrInfo.td
@@ -2083,6 +2083,16 @@
   }
 }
 
+// Atomic load patterns.
+def : MipsPat<(atomic_load_8 addr:$a), (LB addr:$a)>;
+def : MipsPat<(atomic_load_16 addr:$a), (LH addr:$a)>;
+def : MipsPat<(atomic_load_32 addr:$a), (LW addr:$a)>;
+
+// Atomic store patterns.
+def : MipsPat<(atomic_store_8 addr:$a, GPR32:$v), (SB GPR32:$v, addr:$a)>;
+def : MipsPat<(atomic_store_16 addr:$a, GPR32:$v), (SH GPR32:$v, addr:$a)>;
+def : MipsPat<(atomic_store_32 addr:$a, GPR32:$v), (SW GPR32:$v, addr:$a)>;
+
 //===----------------------------------------------------------------------===//
 // Floating Point Support
 //===----------------------------------------------------------------------===//