add support for alignment attributes on load/store instructions

llvm-svn: 36301

1 files changed, 27 insertions, 5 deletions

diff --git a/llvm/lib/Bytecode/Writer/Writer.cpp b/llvm/lib/Bytecode/Writer/Writer.cpp
index 4688e69ef2f..1dd0dc923a5 100644
--- a/llvm/lib/Bytecode/Writer/Writer.cpp
+++ b/llvm/lib/Bytecode/Writer/Writer.cpp
@@ -616,7 +616,7 @@ void BytecodeWriter::outputInstruction(const Instruction &I) {
   unsigned Opcode = I.getOpcode();
   unsigned NumOperands = I.getNumOperands();
 
-  // Encode 'tail call' as 61, 'volatile load' as 62, and 'volatile store' as
+  // Encode 'tail call' as 61
   // 63.
   if (const CallInst *CI = dyn_cast<CallInst>(&I)) {
     if (CI->getCallingConv() == CallingConv::C) {
@@ -632,10 +632,6 @@ void BytecodeWriter::outputInstruction(const Instruction &I) {
     } else {
       Opcode = 58;      // Call escape sequence.
     }
-  } else if (isa<LoadInst>(I) && cast<LoadInst>(I).isVolatile()) {
-    Opcode = 62;
-  } else if (isa<StoreInst>(I) && cast<StoreInst>(I).isVolatile()) {
-    Opcode = 63;
   }
 
   // Figure out which type to encode with the instruction.  Typically we want
@@ -744,6 +740,32 @@ void BytecodeWriter::outputInstruction(const Instruction &I) {
     } else if (isa<InvokeInst>(I)) {
       // Invoke escape seq has at least 4 operands to encode.
       ++NumOperands;
+    } else if (const LoadInst *LI = dyn_cast<LoadInst>(&I)) {
+      // Encode attributed load as opcode 62
+      // We need to encode the attributes of the load instruction as the second
+      // operand. Its not really a slot, but we don't want to break the 
+      // instruction format for these instructions.
+      if (LI->getAlignment() || LI->isVolatile()) {
+        NumOperands = 2;
+        Slots[1] = ((Log2_32(LI->getAlignment())+1)<<1) + 
+                    (LI->isVolatile() ? 1 : 0);
+        if (Slots[1] > MaxOpSlot) 
+          MaxOpSlot = Slots[1];
+        Opcode = 62;
+      }
+    } else if (const StoreInst *SI = dyn_cast<StoreInst>(&I)) {
+      // Encode attributed store as opcode 63
+      // We need to encode the attributes of the store instruction as the third
+      // operand. Its not really a slot, but we don't want to break the 
+      // instruction format for these instructions.
+      if (SI->getAlignment() || SI->isVolatile()) {
+        NumOperands = 3;
+        Slots[2] = ((Log2_32(SI->getAlignment())+1)<<1) + 
+                    (SI->isVolatile() ? 1 : 0);
+        if (Slots[2] > MaxOpSlot) 
+          MaxOpSlot = Slots[2];
+        Opcode = 63;
+      }
     }
 
     // Decide which instruction encoding to use.  This is determined primarily