X86 table-generator and disassembler support for the AVX

instruction set.  This code adds support for the VEX prefix
and for the YMM registers accessible on AVX-enabled
architectures.  Instruction table support that enables AVX
instructions for the disassembler is in an upcoming patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127644 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 319 insertions, 42 deletions

diff --git a/lib/Target/X86/Disassembler/X86Disassembler.cpp b/lib/Target/X86/Disassembler/X86Disassembler.cpp
index f7777561b6..d8a105e7e9 100644
--- a/lib/Target/X86/Disassembler/X86Disassembler.cpp
+++ b/lib/Target/X86/Disassembler/X86Disassembler.cpp
@@ -409,6 +409,7 @@ static bool translateRM(MCInst &mcInst, const OperandSpecifier &operand,
   case TYPE_XMM32:
   case TYPE_XMM64:
   case TYPE_XMM128:
+  case TYPE_XMM256:
   case TYPE_DEBUGREG:
   case TYPE_CONTROLREG:
     return translateRMRegister(mcInst, insn);
@@ -418,6 +419,7 @@ static bool translateRM(MCInst &mcInst, const OperandSpecifier &operand,
   case TYPE_M32:
   case TYPE_M64:
   case TYPE_M128:
+  case TYPE_M256:
   case TYPE_M512:
   case TYPE_Mv:
   case TYPE_M32FP:
@@ -500,6 +502,9 @@ static bool translateOperand(MCInst &mcInst, const OperandSpecifier &operand,
   case ENCODING_Rv:
     translateRegister(mcInst, insn.opcodeRegister);
     return false;
+  case ENCODING_VVVV:
+    translateRegister(mcInst, insn.vvvv);
+    return false;
   case ENCODING_DUP:
     return translateOperand(mcInst,
                             insn.spec->operands[operand.type - TYPE_DUP0],
diff --git a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c
index a9d28c965a..06300a6868 100644
--- a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c
+++ b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c
@@ -368,29 +368,109 @@ static int readPrefixes(struct InternalInstruction* insn) {
     if (isPrefix)
       dbgprintf(insn, "Found prefix 0x%hhx", byte);
   }
+    
+  insn->vexSize = 0;
   
-  if (insn->mode == MODE_64BIT) {
-    if ((byte & 0xf0) == 0x40) {
-      uint8_t opcodeByte;
+  if (byte == 0xc4) {
+    uint8_t byte1;
       
-      if (lookAtByte(insn, &opcodeByte) || ((opcodeByte & 0xf0) == 0x40)) {
-        dbgprintf(insn, "Redundant REX prefix");
-        return -1;
+    if (lookAtByte(insn, &byte1)) {
+      dbgprintf(insn, "Couldn't read second byte of VEX");
+      return -1;
+    }
+    
+    if (insn->mode == MODE_64BIT || byte1 & 0x8) {
+      insn->vexSize = 3;
+      insn->necessaryPrefixLocation = insn->readerCursor - 1;
+    }
+    else {
+      unconsumeByte(insn);
+      insn->necessaryPrefixLocation = insn->readerCursor - 1;
+    }
+    
+    if (insn->vexSize == 3) {
+      insn->vexPrefix[0] = byte;
+      consumeByte(insn, &insn->vexPrefix[1]);
+      consumeByte(insn, &insn->vexPrefix[2]);
+
+      /* We simulate the REX prefix for simplicity's sake */
+    
+      insn->rexPrefix = 0x40 
+                      | (wFromVEX3of3(insn->vexPrefix[2]) << 3)
+                      | (rFromVEX2of3(insn->vexPrefix[1]) << 2)
+                      | (xFromVEX2of3(insn->vexPrefix[1]) << 1)
+                      | (bFromVEX2of3(insn->vexPrefix[1]) << 0);
+    
+      switch (ppFromVEX3of3(insn->vexPrefix[2]))
+      {
+      default:
+        break;
+      case VEX_PREFIX_66:
+        hasOpSize = TRUE;      
+        break;
       }
+    
+      dbgprintf(insn, "Found VEX prefix 0x%hhx 0x%hhx 0x%hhx", insn->vexPrefix[0], insn->vexPrefix[1], insn->vexPrefix[2]);
+    }
+  }
+  else if (byte == 0xc5) {
+    uint8_t byte1;
+    
+    if (lookAtByte(insn, &byte1)) {
+      dbgprintf(insn, "Couldn't read second byte of VEX");
+      return -1;
+    }
       
-      insn->rexPrefix = byte;
-      insn->necessaryPrefixLocation = insn->readerCursor - 2;
-      
-      dbgprintf(insn, "Found REX prefix 0x%hhx", byte);
-    } else {                
+    if (insn->mode == MODE_64BIT || byte1 & 0x8) {
+      insn->vexSize = 2;
+    }
+    else {
+      unconsumeByte(insn);
+    }
+    
+    if (insn->vexSize == 2) {
+      insn->vexPrefix[0] = byte;
+      consumeByte(insn, &insn->vexPrefix[1]);
+        
+      insn->rexPrefix = 0x40 
+                      | (rFromVEX2of2(insn->vexPrefix[1]) << 2);
+        
+      switch (ppFromVEX2of2(insn->vexPrefix[1]))
+      {
+      default:
+        break;
+      case VEX_PREFIX_66:
+        hasOpSize = TRUE;      
+        break;
+      }
+         
+      dbgprintf(insn, "Found VEX prefix 0x%hhx 0x%hhx", insn->vexPrefix[0], insn->vexPrefix[1]);
+    }
+  }
+  else {
+    if (insn->mode == MODE_64BIT) {
+      if ((byte & 0xf0) == 0x40) {
+        uint8_t opcodeByte;
+          
+        if (lookAtByte(insn, &opcodeByte) || ((opcodeByte & 0xf0) == 0x40)) {
+          dbgprintf(insn, "Redundant REX prefix");
+          return -1;
+        }
+          
+        insn->rexPrefix = byte;
+        insn->necessaryPrefixLocation = insn->readerCursor - 2;
+          
+        dbgprintf(insn, "Found REX prefix 0x%hhx", byte);
+      } else {                
+        unconsumeByte(insn);
+        insn->necessaryPrefixLocation = insn->readerCursor - 1;
+      }
+    } else {
       unconsumeByte(insn);
       insn->necessaryPrefixLocation = insn->readerCursor - 1;
     }
-  } else {
-    unconsumeByte(insn);
-    insn->necessaryPrefixLocation = insn->readerCursor - 1;
   }
-  
+
   if (insn->mode == MODE_16BIT) {
     insn->registerSize       = (hasOpSize ? 4 : 2);
     insn->addressSize        = (hasAdSize ? 4 : 2);
@@ -438,6 +518,39 @@ static int readOpcode(struct InternalInstruction* insn) {
   dbgprintf(insn, "readOpcode()");
   
   insn->opcodeType = ONEBYTE;
+    
+  if (insn->vexSize == 3)
+  {
+    switch (mmmmmFromVEX2of3(insn->vexPrefix[1]))
+    {
+    default:
+      dbgprintf(insn, "Unhandled m-mmmm field for instruction (0x%hhx)", mmmmmFromVEX2of3(insn->vexPrefix[1]));
+      return -1;      
+    case 0:
+      break;
+    case VEX_LOB_0F:
+      insn->twoByteEscape = 0x0f;
+      insn->opcodeType = TWOBYTE;
+      return consumeByte(insn, &insn->opcode);
+    case VEX_LOB_0F38:
+      insn->twoByteEscape = 0x0f;
+      insn->threeByteEscape = 0x38;
+      insn->opcodeType = THREEBYTE_38;
+      return consumeByte(insn, &insn->opcode);
+    case VEX_LOB_0F3A:    
+      insn->twoByteEscape = 0x0f;
+      insn->threeByteEscape = 0x3a;
+      insn->opcodeType = THREEBYTE_3A;
+      return consumeByte(insn, &insn->opcode);
+    }
+  }
+  else if (insn->vexSize == 2)
+  {
+    insn->twoByteEscape = 0x0f;
+    insn->opcodeType = TWOBYTE;
+    return consumeByte(insn, &insn->opcode);
+  }
+    
   if (consumeByte(insn, &current))
     return -1;
   
@@ -600,20 +713,64 @@ static int getID(struct InternalInstruction* insn) {
   dbgprintf(insn, "getID()");
     
   attrMask = ATTR_NONE;
-  
+
   if (insn->mode == MODE_64BIT)
     attrMask |= ATTR_64BIT;
-  
-  if (insn->rexPrefix & 0x08)
-    attrMask |= ATTR_REXW;
-  
-  if (isPrefixAtLocation(insn, 0x66, insn->necessaryPrefixLocation))
-    attrMask |= ATTR_OPSIZE;
-  else if (isPrefixAtLocation(insn, 0xf3, insn->necessaryPrefixLocation))
-    attrMask |= ATTR_XS;
-  else if (isPrefixAtLocation(insn, 0xf2, insn->necessaryPrefixLocation))
-    attrMask |= ATTR_XD;
-  
+    
+  if (insn->vexSize) {
+    attrMask |= ATTR_VEX;
+
+    if (insn->vexSize == 3) {
+      switch (ppFromVEX3of3(insn->vexPrefix[2])) {
+      case VEX_PREFIX_66:
+        attrMask |= ATTR_OPSIZE;    
+        break;
+      case VEX_PREFIX_F3:
+        attrMask |= ATTR_XS;
+        break;
+      case VEX_PREFIX_F2:
+        attrMask |= ATTR_XD;
+        break;
+      }
+    
+      if (wFromVEX3of3(insn->vexPrefix[2]))
+        attrMask |= ATTR_REXW;
+      if (lFromVEX3of3(insn->vexPrefix[2]))
+        attrMask |= ATTR_VEXL;
+    }
+    else if (insn->vexSize == 2) {
+      switch (ppFromVEX2of2(insn->vexPrefix[1])) {
+      case VEX_PREFIX_66:
+        attrMask |= ATTR_OPSIZE;    
+        break;
+      case VEX_PREFIX_F3:
+        attrMask |= ATTR_XS;
+        break;
+      case VEX_PREFIX_F2:
+        attrMask |= ATTR_XD;
+        break;
+      }
+    
+      if (lFromVEX2of2(insn->vexPrefix[1]))
+        attrMask |= ATTR_VEXL;
+    }
+    else {
+      return -1;
+    }
+  }
+  else {
+    if (insn->rexPrefix & 0x08)
+      attrMask |= ATTR_REXW;
+  
+    if (isPrefixAtLocation(insn, 0x66, insn->necessaryPrefixLocation))
+      attrMask |= ATTR_OPSIZE;
+    else if (isPrefixAtLocation(insn, 0xf3, insn->necessaryPrefixLocation))
+      attrMask |= ATTR_XS;
+    else if (isPrefixAtLocation(insn, 0xf2, insn->necessaryPrefixLocation))
+      attrMask |= ATTR_XD;
+    
+  }
+
   if (getIDWithAttrMask(&instructionID, insn, attrMask))
     return -1;
   
@@ -1012,6 +1169,8 @@ static int readModRM(struct InternalInstruction* insn) {
       return prefix##_EAX + index;                        \
     case TYPE_R64:                                        \
       return prefix##_RAX + index;                        \
+    case TYPE_XMM256:                                     \
+      return prefix##_YMM0 + index;                       \
     case TYPE_XMM128:                                     \
     case TYPE_XMM64:                                      \
     case TYPE_XMM32:                                      \
@@ -1073,6 +1232,14 @@ static int fixupReg(struct InternalInstruction *insn,
   default:
     debug("Expected a REG or R/M encoding in fixupReg");
     return -1;
+  case ENCODING_VVVV:
+    insn->vvvv = (Reg)fixupRegValue(insn,
+                                    (OperandType)op->type,
+                                    insn->vvvv,
+                                    &valid);
+    if (!valid)
+      return -1;
+    break;
   case ENCODING_REG:
     insn->reg = (Reg)fixupRegValue(insn,
                                    (OperandType)op->type,
@@ -1237,6 +1404,27 @@ static int readImmediate(struct InternalInstruction* insn, uint8_t size) {
 }
 
 /*
+ * readVVVV - Consumes an immediate operand from an instruction, given the
+ *   desired operand size.
+ *
+ * @param insn  - The instruction whose operand is to be read.
+ * @return      - 0 if the immediate was successfully consumed; nonzero
+ *                otherwise.
+ */
+static int readVVVV(struct InternalInstruction* insn) {
+  dbgprintf(insn, "readVVVV()");
+        
+  if (insn->vexSize == 3)
+    insn->vvvv = vvvvFromVEX3of3(insn->vexPrefix[2]);
+  else if (insn->vexSize == 2)
+    insn->vvvv = vvvvFromVEX2of2(insn->vexPrefix[1]);
+  else
+    return -1;
+
+  return 0;
+}
+
+/*
  * readOperands - Consults the specifier for an instruction and consumes all
  *   operands for that instruction, interpreting them as it goes.
  *
@@ -1317,6 +1505,13 @@ static int readOperands(struct InternalInstruction* insn) {
     case ENCODING_I:
       if (readOpcodeModifier(insn))
         return -1;
+      break;
+    case ENCODING_VVVV:
+      if (readVVVV(insn))
+        return -1;
+      if (fixupReg(insn, &insn->spec->operands[index]))
+        return -1;
+      break;
     case ENCODING_DUP:
       break;
     default:
diff --git a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h
index d0dc8b56ae..d4a88d765d 100644
--- a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h
+++ b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h
@@ -34,16 +34,30 @@ extern "C" {
 /*
  * Accessor functions for various fields of an Intel instruction
  */
-#define modFromModRM(modRM)  ((modRM & 0xc0) >> 6)
-#define regFromModRM(modRM)  ((modRM & 0x38) >> 3)
-#define rmFromModRM(modRM)   (modRM & 0x7)
-#define scaleFromSIB(sib)    ((sib & 0xc0) >> 6)
-#define indexFromSIB(sib)    ((sib & 0x38) >> 3)
-#define baseFromSIB(sib)     (sib & 0x7)
-#define wFromREX(rex)        ((rex & 0x8) >> 3)
-#define rFromREX(rex)        ((rex & 0x4) >> 2)
-#define xFromREX(rex)        ((rex & 0x2) >> 1)
-#define bFromREX(rex)        (rex & 0x1)
+#define modFromModRM(modRM)  (((modRM) & 0xc0) >> 6)
+#define regFromModRM(modRM)  (((modRM) & 0x38) >> 3)
+#define rmFromModRM(modRM)   ((modRM) & 0x7)
+#define scaleFromSIB(sib)    (((sib) & 0xc0) >> 6)
+#define indexFromSIB(sib)    (((sib) & 0x38) >> 3)
+#define baseFromSIB(sib)     ((sib) & 0x7)
+#define wFromREX(rex)        (((rex) & 0x8) >> 3)
+#define rFromREX(rex)        (((rex) & 0x4) >> 2)
+#define xFromREX(rex)        (((rex) & 0x2) >> 1)
+#define bFromREX(rex)        ((rex) & 0x1)
+    
+#define rFromVEX2of3(vex)       (((~(vex)) & 0x80) >> 7)
+#define xFromVEX2of3(vex)       (((~(vex)) & 0x40) >> 6)
+#define bFromVEX2of3(vex)       (((~(vex)) & 0x20) >> 5)
+#define mmmmmFromVEX2of3(vex)   ((vex) & 0x1f)
+#define wFromVEX3of3(vex)       (((vex) & 0x80) >> 7)
+#define vvvvFromVEX3of3(vex)    (((~(vex)) & 0x78) >> 3)
+#define lFromVEX3of3(vex)       (((vex) & 0x4) >> 2)
+#define ppFromVEX3of3(vex)      ((vex) & 0x3)
+
+#define rFromVEX2of2(vex)       (((~(vex)) & 0x80) >> 7)
+#define vvvvFromVEX2of2(vex)    (((~(vex)) & 0x78) >> 3)
+#define lFromVEX2of2(vex)       (((vex) & 0x4) >> 2)
+#define ppFromVEX2of2(vex)      ((vex) & 0x3)
 
 /*
  * These enums represent Intel registers for use by the decoder.
@@ -206,7 +220,25 @@ extern "C" {
   ENTRY(XMM13)    \
   ENTRY(XMM14)    \
   ENTRY(XMM15)
-  
+
+#define REGS_YMM  \
+  ENTRY(YMM0)     \
+  ENTRY(YMM1)     \
+  ENTRY(YMM2)     \
+  ENTRY(YMM3)     \
+  ENTRY(YMM4)     \
+  ENTRY(YMM5)     \
+  ENTRY(YMM6)     \
+  ENTRY(YMM7)     \
+  ENTRY(YMM8)     \
+  ENTRY(YMM9)     \
+  ENTRY(YMM10)    \
+  ENTRY(YMM11)    \
+  ENTRY(YMM12)    \
+  ENTRY(YMM13)    \
+  ENTRY(YMM14)    \
+  ENTRY(YMM15)
+    
 #define REGS_SEGMENT \
   ENTRY(ES)          \
   ENTRY(CS)          \
@@ -252,6 +284,7 @@ extern "C" {
   REGS_64BIT          \
   REGS_MMX            \
   REGS_XMM            \
+  REGS_YMM            \
   REGS_SEGMENT        \
   REGS_DEBUG          \
   REGS_CONTROL        \
@@ -332,6 +365,27 @@ typedef enum {
   SEG_OVERRIDE_GS,
   SEG_OVERRIDE_max
 } SegmentOverride;
+    
+/*
+ * VEXLeadingOpcodeByte - Possible values for the VEX.m-mmmm field
+ */
+
+typedef enum {
+  VEX_LOB_0F = 0x1,
+  VEX_LOB_0F38 = 0x2,
+  VEX_LOB_0F3A = 0x3
+} VEXLeadingOpcodeByte;
+
+/*
+ * VEXPrefixCode - Possible values for the VEX.pp field
+ */
+
+typedef enum {
+  VEX_PREFIX_NONE = 0x0,
+  VEX_PREFIX_66 = 0x1,
+  VEX_PREFIX_F3 = 0x2,
+  VEX_PREFIX_F2 = 0x3
+} VEXPrefixCode;
 
 typedef uint8_t BOOL;
 
@@ -389,10 +443,12 @@ struct InternalInstruction {
   uint8_t prefixPresent[0x100];
   /* contains the location (for use with the reader) of the prefix byte */
   uint64_t prefixLocations[0x100];
+  /* The value of the VEX prefix, if present */
+  uint8_t vexPrefix[3];
+  /* The length of the VEX prefix (0 if not present) */
+  uint8_t vexSize;
   /* The value of the REX prefix, if present */
   uint8_t rexPrefix;
-  /* The location of the REX prefix */
-  uint64_t rexLocation;
   /* The location where a mandatory prefix would have to be (i.e., right before
      the opcode, or right before the REX prefix if one is present) */
   uint64_t necessaryPrefixLocation;
@@ -428,6 +484,10 @@ struct InternalInstruction {
   /* state for additional bytes, consumed during operand decode.  Pattern:
      consumed___ indicates that the byte was already consumed and does not
      need to be consumed again */
+
+  /* The VEX.vvvv field, which contains a thrid register operand for some AVX
+     instructions */
+  Reg                           vvvv;
   
   /* The ModR/M byte, which contains most register operands and some portion of
      all memory operands */
diff --git a/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h b/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h
index 1425b86ba5..bc35be80c8 100644
--- a/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h
+++ b/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h
@@ -49,7 +49,9 @@
   ENUM_ENTRY(ATTR_XS,     0x02) \
   ENUM_ENTRY(ATTR_XD,     0x04) \
   ENUM_ENTRY(ATTR_REXW,   0x08) \
-  ENUM_ENTRY(ATTR_OPSIZE, 0x10)
+  ENUM_ENTRY(ATTR_OPSIZE, 0x10) \
+  ENUM_ENTRY(ATTR_VEX,    0x20) \
+  ENUM_ENTRY(ATTR_VEXL,   0x40)
 
 #define ENUM_ENTRY(n, v) n = v,
 enum attributeBits {
@@ -87,7 +89,20 @@ enum attributeBits {
                                         "IC_64BIT_REXW_XS")                    \
   ENUM_ENTRY(IC_64BIT_REXW_OPSIZE,  7,  "The Dynamic Duo!  Prefer over all "   \
                                         "else because this changes most "      \
-                                        "operands' meaning")
+                                        "operands' meaning")                   \
+  ENUM_ENTRY(IC_VEX,                1,  "requires a VEX prefix")               \
+  ENUM_ENTRY(IC_VEX_XS,             2,  "requires VEX and the XS prefix")      \
+  ENUM_ENTRY(IC_VEX_XD,             2,  "requires VEX and the XD prefix")      \
+  ENUM_ENTRY(IC_VEX_OPSIZE,         2,  "requires VEX and the OpSize prefix")  \
+  ENUM_ENTRY(IC_VEX_W,              3,  "requires VEX and the W prefix")       \
+  ENUM_ENTRY(IC_VEX_W_XS,           4,  "requires VEX, W, and XS prefix")      \
+  ENUM_ENTRY(IC_VEX_W_XD,           4,  "requires VEX, W, and XD prefix")      \
+  ENUM_ENTRY(IC_VEX_W_OPSIZE,       4,  "requires VEX, W, and OpSize")         \
+  ENUM_ENTRY(IC_VEX_L,              3,  "requires VEX and the L prefix")       \
+  ENUM_ENTRY(IC_VEX_L_XS,           4,  "requires VEX and the L and XS prefix")\
+  ENUM_ENTRY(IC_VEX_L_XD,           4,  "requires VEX and the L and XS prefix")\
+  ENUM_ENTRY(IC_VEX_L_OPSIZE,       4,  "requires VEX, L, and OpSize")
+
 
 #define ENUM_ENTRY(n, r, d) n,    
 typedef enum {
@@ -183,6 +198,7 @@ struct ContextDecision {
   ENUM_ENTRY(ENCODING_NONE,   "")                                              \
   ENUM_ENTRY(ENCODING_REG,    "Register operand in ModR/M byte.")              \
   ENUM_ENTRY(ENCODING_RM,     "R/M operand in ModR/M byte.")                   \
+  ENUM_ENTRY(ENCODING_VVVV,   "Register operand in VEX.vvvv byte.")            \
   ENUM_ENTRY(ENCODING_CB,     "1-byte code offset (possible new CS value)")    \
   ENUM_ENTRY(ENCODING_CW,     "2-byte")                                        \
   ENUM_ENTRY(ENCODING_CD,     "4-byte")                                        \
@@ -278,6 +294,7 @@ struct ContextDecision {
   ENUM_ENTRY(TYPE_XMM32,      "4-byte XMM register or memory operand")         \
   ENUM_ENTRY(TYPE_XMM64,      "8-byte")                                        \
   ENUM_ENTRY(TYPE_XMM128,     "16-byte")                                       \
+  ENUM_ENTRY(TYPE_XMM256,     "32-byte")                                       \
   ENUM_ENTRY(TYPE_XMM0,       "Implicit use of XMM0")                          \
   ENUM_ENTRY(TYPE_SEGMENTREG, "Segment register operand")                      \
   ENUM_ENTRY(TYPE_DEBUGREG,   "Debug register operand")                        \