[MIPS] Initial support for MIPS architecture.

llvm/lib/Target/Mips/MipsNaClHeaders.cpp

Index: llvm/lib/Target/Mips/MipsNaClHeaders.cpp
===================================================================
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+++ b/llvm/lib/Target/Mips/MipsNaClHeaders.cpp
@@ -0,0 +1,146 @@
+//===-- MipsNaClHeaders.cpp - Print SFI headers to an Mips .s file -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the initial header string needed
+// for the Native Client target in Mips assembly.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/raw_ostream.h"
+#include "MipsNaClRewritePass.h"
+#include <string>
+
+using namespace llvm;
+
+void EmitMipsSFIHeaders(raw_ostream &O) {
+  O << " # ========================================\n";
+  O << "# Branch: " << FlagSfiBranch << "\n";
+  O << "# Stack: " << FlagSfiStack << "\n";
+  O << "# Store: " << FlagSfiStore << "\n";
+  O << "# Data: " << FlagSfiData << "\n";
+
+  O << " # ========================================\n";
+  // NOTE: this macro does bundle alignment as follows
+  //       if current bundle pos is X emit pX data items of value "val"
+  // NOTE: that pos will be one of: 0,4,8,12
+  //
+  O <<
+    "\t.macro sfi_long_based_on_pos p0 p1 p2 p3 val\n"
+    "\t.set pos, (. - XmagicX) % 16\n"
+    "\t.fill  (((\\p3<<12)|(\\p2<<8)|(\\p1<<4)|\\p0)>>pos) & 15, 4, \\val\n"
+    "\t.endm\n"
+    "\n\n";
+
+  O <<
+    "\t.macro sfi_nop_if_at_bundle_end\n"
+    "\tsfi_long_based_on_pos 0 0 0 1 0x00000000\n"
+    "\t.endm\n"
+      "\n\n";
+
+  O <<
+    "\t.macro sfi_nops_to_force_slot3\n"
+    "\tsfi_long_based_on_pos 3 2 1 0 0x00000000\n"
+    "\t.endm\n"
+    "\n\n";
+
+  O <<
+    "\t.macro sfi_nops_to_force_slot2\n"
+    "\tsfi_long_based_on_pos 2 1 0 3 0x00000000\n"
+    "\t.endm\n"
+    "\n\n";
+
+  O <<
+    "\t.macro sfi_nops_to_force_slot1\n"
+    "\tsfi_long_based_on_pos 1 0 3 2 0x00000000\n"
+    "\t.endm\n"
+    "\n\n";
+
+  O << " # ========================================\n";
+  if (FlagSfiZeroMask) {
+    // This mode sets all mask to zero which makes them into nops
+    // this is useful for linking this code against non-sandboxed code
+    // for debugging purposes
+    O <<
+      "\t.macro sfi_data_mask reg1 reg2 maskreg\n"
+      "\tand \\reg1, \\reg1, \\reg1\n"
+      "\t.endm\n"
+      "\n\n";
+
+    O <<
+      "\t.macro sfi_code_mask reg1 reg2 maskreg\n"
+      "\tand \\reg1, \\reg1, \\reg1\n"
+      "\t.endm\n"
+      "\n\n";
+
+  } else {
+    O <<
+      "\t.macro sfi_data_mask reg1 reg2 maskreg\n"
+      "\tand \\reg1, \\reg2, \\maskreg\n"
+      "\t.endm\n"
+      "\n\n";
+
+    O <<
+      "\t.macro sfi_code_mask reg1 reg2 maskreg\n"
+      "\tand \\reg1, \\reg2, \\maskreg\n"
+      "\t.endm\n"
+      "\n\n";
+  }
+
+  O << " # ========================================\n";
+  if (FlagSfiBranch) {
+    O <<
+      "\t.macro sfi_call_preamble\n"
+      "\tsfi_nops_to_force_slot2\n"
+      "\t.endm\n"
+      "\n\n";
+
+    O <<
+      "\t.macro sfi_return_preamble reg1 reg2 maskreg\n"
+      "\tsfi_nop_if_at_bundle_end\n"
+      "\tsfi_code_mask \\reg1, \\reg2, \\maskreg\n"
+      "\t.endm\n"
+      "\n\n";
+
+    // This is used just before "jr"
+    O <<
+      "\t.macro sfi_indirect_jump_preamble reg1 reg2 maskreg\n"
+      "\tsfi_nop_if_at_bundle_end\n"
+      "\tsfi_code_mask \\reg1, \\reg2, \\maskreg\n"
+      "\t.endm\n"
+      "\n\n";
+
+    // This is used just before "jalr"
+    O <<
+      "\t.macro sfi_indirect_call_preamble reg1 reg2 maskreg\n"
+      "\tsfi_nops_to_force_slot1\n"
+      "\tsfi_code_mask \\reg1, \\reg2, \\maskreg\n"
+      "\t.endm\n"
+      "\n\n";
+
+  }
+
+  if (FlagSfiStore) {
+    O << " # ========================================\n";
+
+    O <<
+      "\t.macro sfi_load_store_preamble reg1 reg2 maskreg\n"
+      "\tsfi_nop_if_at_bundle_end\n"
+      "\tsfi_data_mask \\reg1, \\reg2 , \\maskreg\n"
+      "\t.endm\n"
+      "\n\n";
+  } else {
+    O <<
+      "\t.macro sfi_load_store_preamble reg1 reg2 maskreg\n"
+      "\t.endm\n"
+      "\n\n";
+  }
+
+  O << " # ========================================\n";
+  O << "\t.text\n";
+}