commit 76b29b518dad5e719077a1066e242fa91f777a7c
author Craig Topper <craig.topper@gmail.com> Thu Sep 13 05:45:42 2012 +0000
committer Craig Topper <craig.topper@gmail.com> Thu Sep 13 05:45:42 2012 +0000
tree 4d4219f3a5859b42b605958219d94dfd631f3e5f
parent 7639f98c5fc903339bf50e574aee999d54340cdf

Add a new compression type to ModRM table that detects when the memory modRM byte represent 8 instructions and the reg modRM byte represents up to 64 instructions. Reduces modRM table from 43k entreis to 25k entries. Based on a patch from Manman Ren.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163774 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/X86DisassemblerTables.cpp

diff --git a/utils/TableGen/X86DisassemblerTables.cpp b/utils/TableGen/X86DisassemblerTables.cpp
index 8526621..468a1f8 100644
--- a/utils/TableGen/X86DisassemblerTables.cpp
+++ b/utils/TableGen/X86DisassemblerTables.cpp
@@ -209,6 +209,7 @@
   bool satisfiesOneEntry = true;
   bool satisfiesSplitRM = true;
   bool satisfiesSplitReg = true;
+  bool satisfiesSplitMisc = true;
 
   for (unsigned index = 0; index < 256; ++index) {
     if (decision.instructionIDs[index] != decision.instructionIDs[0])
@@ -228,7 +229,7 @@
 
     if (((index & 0xc0) != 0xc0) &&
        (decision.instructionIDs[index] != decision.instructionIDs[index&0x38]))
-      satisfiesSplitReg = false;
+      satisfiesSplitMisc = false;
   }
 
   if (satisfiesOneEntry)
@@ -237,9 +238,12 @@
   if (satisfiesSplitRM)
     return MODRM_SPLITRM;
 
-  if (satisfiesSplitReg)
+  if (satisfiesSplitReg && satisfiesSplitMisc)
     return MODRM_SPLITREG;
 
+  if (satisfiesSplitMisc)
+    return MODRM_SPLITMISC;
+
   return MODRM_FULL;
 }
 
@@ -332,6 +336,12 @@
       for (unsigned index = 0xc0; index < 256; index += 8)
         emitOneID(o1, i1, decision.instructionIDs[index], true);
       break;
+    case MODRM_SPLITMISC:
+      for (unsigned index = 0; index < 64; index += 8)
+        emitOneID(o1, i1, decision.instructionIDs[index], true);
+      for (unsigned index = 0xc0; index < 256; ++index)
+        emitOneID(o1, i1, decision.instructionIDs[index], true);
+      break;
     case MODRM_FULL:
       for (unsigned index = 0; index < 256; ++index)
         emitOneID(o1, i1, decision.instructionIDs[index], true);
@@ -361,6 +371,9 @@
     case MODRM_SPLITREG:
       sEntryNumber += 16;
       break;
+    case MODRM_SPLITMISC:
+      sEntryNumber += 8 + 64;
+      break;
     case MODRM_FULL:
       sEntryNumber += 256;
       break;