[llvm-commits] [llvm] r103128 - in /llvm/trunk: lib/Target/X86/Disassembler/X86Disassembler.cpp tools/llvm-mc/Disassembler.cpp

[Sean Callanan]

Author: spyffe
Date: Wed May  5 17:47:27 2010
New Revision: 103128

URL: http://llvm.org/viewvc/llvm-project?rev=103128&view=rev
Log:
Fixed a sign-extension bug in the X86 disassembler
that was causing PC-relative branch targets to be
evaluated incorrectly.  Also added support for
checking operand values to the llvm-mc tester.

Modified:
    llvm/trunk/lib/Target/X86/Disassembler/X86Disassembler.cpp
    llvm/trunk/tools/llvm-mc/Disassembler.cpp

Modified: llvm/trunk/lib/Target/X86/Disassembler/X86Disassembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/Disassembler/X86Disassembler.cpp?rev=103128&r1=103127&r2=103128&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/Disassembler/X86Disassembler.cpp (original)
+++ llvm/trunk/lib/Target/X86/Disassembler/X86Disassembler.cpp Wed May  5 17:47:27 2010
@@ -155,7 +155,57 @@
 ///
 /// @param mcInst       - The MCInst to append to.
 /// @param immediate    - The immediate value to append.
-static void translateImmediate(MCInst &mcInst, uint64_t immediate) {
+/// @param operand      - The operand, as stored in the descriptor table.
+/// @param insn         - The internal instruction.
+static void translateImmediate(MCInst &mcInst, 
+                               uint64_t immediate, 
+                               OperandSpecifier &operand,
+                               InternalInstruction &insn) {
+  // Sign-extend the immediate if necessary.
+
+  OperandType type = operand.type;
+
+  if (type == TYPE_RELv) {
+    switch (insn.displacementSize) {
+    default:
+      break;
+    case 8:
+      type = TYPE_MOFFS8;
+      break;
+    case 16:
+      type = TYPE_MOFFS16;
+      break;
+    case 32:
+      type = TYPE_MOFFS32;
+      break;
+    case 64:
+      type = TYPE_MOFFS64;
+      break;
+    }
+  }
+
+  switch (type) {
+  case TYPE_MOFFS8:
+  case TYPE_REL8:
+    if(immediate & 0x80)
+      immediate |= ~(0xffull);
+    break;
+  case TYPE_MOFFS16:
+    if(immediate & 0x8000)
+      immediate |= ~(0xffffull);
+    break;
+  case TYPE_MOFFS32:
+  case TYPE_REL32:
+  case TYPE_REL64:
+    if(immediate & 0x80000000)
+      immediate |= ~(0xffffffffull);
+    break;
+  case TYPE_MOFFS64:
+  default:
+    // operand is 64 bits wide.  Do nothing.
+    break;
+  }
+    
   mcInst.addOperand(MCOperand::CreateImm(immediate));
 }
 
@@ -447,8 +497,10 @@
   case ENCODING_IO:
   case ENCODING_Iv:
   case ENCODING_Ia:
-    translateImmediate(mcInst, 
-                       insn.immediates[insn.numImmediatesTranslated++]);
+    translateImmediate(mcInst,
+                       insn.immediates[insn.numImmediatesTranslated++],
+                       operand,
+                       insn);
     return false;
   case ENCODING_RB:
   case ENCODING_RW:

Modified: llvm/trunk/tools/llvm-mc/Disassembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-mc/Disassembler.cpp?rev=103128&r1=103127&r2=103128&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-mc/Disassembler.cpp (original)
+++ llvm/trunk/tools/llvm-mc/Disassembler.cpp Wed May  5 17:47:27 2010
@@ -342,6 +342,8 @@
                       operand, 
                       verboseEvaluator, 
                       &disassembler);
+      
+    outs() << "=" << evaluatedResult;
     
     outs() << " ";
   }