Introduce element-wise atomic memcpy intrinsic

This change adds a new intrinsic which is intended to provide memcpy functionality
with additional atomicity guarantees. Please refer to the review thread
or language reference for further details.

Differential Revision: https://reviews.llvm.org/D27133

llvm-svn: 290708

1 files changed, 23 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index afa3fa98ad8..003311b157f 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -361,6 +361,11 @@ static void InitLibcallNames(const char **Names, const Triple &TT) {
   Names[RTLIB::MEMCPY] = "memcpy";
   Names[RTLIB::MEMMOVE] = "memmove";
   Names[RTLIB::MEMSET] = "memset";
+  Names[RTLIB::MEMCPY_ELEMENT_ATOMIC_1] = "__llvm_memcpy_element_atomic_1";
+  Names[RTLIB::MEMCPY_ELEMENT_ATOMIC_2] = "__llvm_memcpy_element_atomic_2";
+  Names[RTLIB::MEMCPY_ELEMENT_ATOMIC_4] = "__llvm_memcpy_element_atomic_4";
+  Names[RTLIB::MEMCPY_ELEMENT_ATOMIC_8] = "__llvm_memcpy_element_atomic_8";
+  Names[RTLIB::MEMCPY_ELEMENT_ATOMIC_16] = "__llvm_memcpy_element_atomic_16";
   Names[RTLIB::UNWIND_RESUME] = "_Unwind_Resume";
   Names[RTLIB::SYNC_VAL_COMPARE_AND_SWAP_1] = "__sync_val_compare_and_swap_1";
   Names[RTLIB::SYNC_VAL_COMPARE_AND_SWAP_2] = "__sync_val_compare_and_swap_2";
@@ -763,6 +768,24 @@ RTLIB::Libcall RTLIB::getSYNC(unsigned Opc, MVT VT) {
   return UNKNOWN_LIBCALL;
 }
 
+RTLIB::Libcall RTLIB::getMEMCPY_ELEMENT_ATOMIC(uint64_t ElementSize) {
+  switch (ElementSize) {
+  case 1:
+    return MEMCPY_ELEMENT_ATOMIC_1;
+  case 2:
+    return MEMCPY_ELEMENT_ATOMIC_2;
+  case 4:
+    return MEMCPY_ELEMENT_ATOMIC_4;
+  case 8:
+    return MEMCPY_ELEMENT_ATOMIC_8;
+  case 16:
+    return MEMCPY_ELEMENT_ATOMIC_16;
+  default:
+    return UNKNOWN_LIBCALL;
+  }
+
+}
+
 /// InitCmpLibcallCCs - Set default comparison libcall CC.
 ///
 static void InitCmpLibcallCCs(ISD::CondCode *CCs) {