From c6d07ae1b5a66d111367517ea2763e18863d967f Mon Sep 17 00:00:00 2001
From: Stanislav Shwartsman <sshwarts@users.sourceforge.net>
Date: Tue, 20 Sep 2011 06:02:27 +0000
Subject: [PATCH] store modrm() for x87 in Ib() byte because x87 have no Ib()

---
 bochs/cpu/fetchdecode.cc   | 7 +++----
 bochs/cpu/fetchdecode64.cc | 7 +++----
 bochs/cpu/instr.h          | 6 +++---
 3 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/bochs/cpu/fetchdecode.cc b/bochs/cpu/fetchdecode.cc
index c750ccf77..ff05c8f9e 100644
--- a/bochs/cpu/fetchdecode.cc
+++ b/bochs/cpu/fetchdecode.cc
@@ -1362,6 +1362,7 @@ fetch_b1:
 #if BX_SUPPORT_FPU
   i->setVL(BX_NO_VL);
 #endif
+  i->modRMForm.Id = 0;
 
   unsigned index = b1 + (os_32 << 9); // *512
 
@@ -1457,13 +1458,12 @@ fetch_b1:
        vvv = nnn;
     i->setVvv(vvv);
 
+    i->setModRM(b2); /* for x87 */
+
     // MOVs with CRx and DRx always use register ops and ignore the mod field.
     if ((b1 & ~3) == 0x120)
       mod = 0xc0;
 
-    if ((b1 & 0xff8) == 0xd8)
-      i->setModRM(b2);
-
     if (mod == 0xc0) { // mod == 11b
       i->assertModC0();
       i->setRm(rm);
@@ -1737,7 +1737,6 @@ modrm_done:
     }
   }
 
-  i->modRMForm.Id = 0;
   unsigned imm_mode = attr & BxImmediate;
   if (imm_mode) {
     // make sure iptr was advanced after Ib(), Iw() and Id()
diff --git a/bochs/cpu/fetchdecode64.cc b/bochs/cpu/fetchdecode64.cc
index 09dc2f0ce..d08e54dad 100644
--- a/bochs/cpu/fetchdecode64.cc
+++ b/bochs/cpu/fetchdecode64.cc
@@ -1817,6 +1817,7 @@ fetch_b1:
 
   i->setB1(b1);
   i->setVL(BX_NO_VL);
+  i->modRMForm.Id = 0;
 
   unsigned index = b1+offset;
 
@@ -1918,13 +1919,12 @@ fetch_b1:
       vvv = nnn;
     i->setVvv(vvv);
 
+    i->setModRM(b2); /* for x87 */
+
     // MOVs with CRx and DRx always use register ops and ignore the mod field.
     if ((b1 & ~3) == 0x120)
       mod = 0xc0;
 
-    if ((b1 & 0xff8) == 0xd8)
-      i->setModRM(b2);
-
     if (mod == 0xc0) { // mod == 11b
       i->setRm(rm);
       i->assertModC0();
@@ -2147,7 +2147,6 @@ modrm_done:
     }
   }
 
-  i->modRMForm.Id = 0;
   unsigned imm_mode = attr & BxImmediate;
   if (imm_mode) {
     // make sure iptr was advanced after Ib(), Iw() and Id()
diff --git a/bochs/cpu/instr.h b/bochs/cpu/instr.h
index 5ea61eeaf..491407e6c 100644
--- a/bochs/cpu/instr.h
+++ b/bochs/cpu/instr.h
@@ -128,7 +128,6 @@ public:
 #define BX_INSTR_METADATA_BASE  4
 #define BX_INSTR_METADATA_INDEX 5
 #define BX_INSTR_METADATA_SCALE 6
-#define BX_INSTR_METADATA_MODRM 7 /* modrm for FPU only */
 #define BX_INSTR_METADATA_VVV   7
 
   // using 5-bit field for registers (16 regs in 64-bit, RIP, NIL)
@@ -184,10 +183,11 @@ public:
     metaData[BX_INSTR_METADATA_B1] = b1 & 0xff;
   }
   BX_CPP_INLINE void setModRM(unsigned modrm) {
-    metaData[BX_INSTR_METADATA_MODRM] = modrm;
+    // none of x87 instructions has immediate
+    modRMForm.Ib = modrm;
   }
   BX_CPP_INLINE unsigned modrm() const {
-    return metaData[BX_INSTR_METADATA_MODRM];
+    return modRMForm.Ib;
   }
   BX_CPP_INLINE void setNnn(unsigned nnn) {
     metaData[BX_INSTR_METADATA_NNN] = nnn;