GlobalISel: translate @llvm.va_start intrinsic.

Because we need to preserve the memory access being performed we need a
separate instruction to represent this.

llvm-svn: 294492

3 files changed, 15 insertions, 0 deletions

diff --git a/llvm/include/llvm/Target/GenericOpcodes.td b/llvm/include/llvm/Target/GenericOpcodes.td
index d3b2835d1bd..6352a6990f2 100644
--- a/llvm/include/llvm/Target/GenericOpcodes.td
+++ b/llvm/include/llvm/Target/GenericOpcodes.td
@@ -91,6 +91,13 @@ def G_FCONSTANT : Instruction {
   let hasSideEffects = 0;
 }
 
+def G_VASTART : Instruction {
+  let OutOperandList = (outs);
+  let InOperandList = (ins type0:$list);
+  let hasSideEffects = 0;
+  let mayStore = 1;
+}
+
 //------------------------------------------------------------------------------
 // Binary ops.
 //------------------------------------------------------------------------------
diff --git a/llvm/include/llvm/Target/TargetLowering.h b/llvm/include/llvm/Target/TargetLowering.h
index bc98673e029..68696763fca 100644
--- a/llvm/include/llvm/Target/TargetLowering.h
+++ b/llvm/include/llvm/Target/TargetLowering.h
@@ -987,6 +987,11 @@ public:
     return GatherAllAliasesMaxDepth;
   }
 
+  /// Returns the size of the platform's va_list object.
+  virtual unsigned getVaListSizeInBits(const DataLayout &DL) const {
+    return getPointerTy(DL).getSizeInBits();
+  }
+
   /// \brief Get maximum # of store operations permitted for llvm.memset
   ///
   /// This function returns the maximum number of store operations permitted
diff --git a/llvm/include/llvm/Target/TargetOpcodes.def b/llvm/include/llvm/Target/TargetOpcodes.def
index 290e3ff78f0..a0d6a6309dc 100644
--- a/llvm/include/llvm/Target/TargetOpcodes.def
+++ b/llvm/include/llvm/Target/TargetOpcodes.def
@@ -280,6 +280,9 @@ HANDLE_TARGET_OPCODE(G_CONSTANT)
 /// Generic floating constant.
 HANDLE_TARGET_OPCODE(G_FCONSTANT)
 
+/// Generic va_start instruction. Stores to its one pointer operand.
+HANDLE_TARGET_OPCODE(G_VASTART)
+
 // Generic sign extend
 HANDLE_TARGET_OPCODE(G_SEXT)