Commit 75066cd4ea ("x86emul: fix {,i}mul and {,i}div") can be had with
less code: Simply do the destination register override depending on
DstEax being in effect (the four other ModRM.reg encoded operations of
these two opcodes all use DstMem).
Signed-off-by: Jan Beulich <jbeul...@suse.com>
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -4084,6 +4084,8 @@ x86_emulate(
break;
case 0xf6 ... 0xf7: /* Grp3 */
+ if ( (d & DstMask) == DstEax )
+ dst.reg = (unsigned long *)&_regs.eax;
switch ( modrm_reg & 7 )
{
unsigned long u[2], v;
@@ -4098,7 +4100,6 @@ x86_emulate(
emulate_1op("neg", dst, _regs.eflags);
break;
case 4: /* mul */
- dst.reg = (unsigned long *)&_regs.eax;
_regs.eflags &= ~(EFLG_OF|EFLG_CF);
switch ( dst.bytes )
{
@@ -4136,7 +4137,6 @@ x86_emulate(
}
break;
case 5: /* imul */
- dst.reg = (unsigned long *)&_regs.eax;
imul:
_regs.eflags &= ~(EFLG_OF|EFLG_CF);
switch ( dst.bytes )
@@ -4178,7 +4178,6 @@ x86_emulate(
}
break;
case 6: /* div */
- dst.reg = (unsigned long *)&_regs.eax;
switch ( src.bytes )
{
case 1:
@@ -4224,7 +4223,6 @@ x86_emulate(
}
break;
case 7: /* idiv */
- dst.reg = (unsigned long *)&_regs.eax;
switch ( src.bytes )
{
case 1:
x86emul: simplify {,i}{mul,div} fix
Commit 75066cd4ea ("x86emul: fix {,i}mul and {,i}div") can be had with
less code: Simply do the destination register override depending on
DstEax being in effect (the four other ModRM.reg encoded operations of
these two opcodes all use DstMem).
Signed-off-by: Jan Beulich <jbeul...@suse.com>
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -4084,6 +4084,8 @@ x86_emulate(
break;
case 0xf6 ... 0xf7: /* Grp3 */
+ if ( (d & DstMask) == DstEax )
+ dst.reg = (unsigned long *)&_regs.eax;
switch ( modrm_reg & 7 )
{
unsigned long u[2], v;
@@ -4098,7 +4100,6 @@ x86_emulate(
emulate_1op("neg", dst, _regs.eflags);
break;
case 4: /* mul */
- dst.reg = (unsigned long *)&_regs.eax;
_regs.eflags &= ~(EFLG_OF|EFLG_CF);
switch ( dst.bytes )
{
@@ -4136,7 +4137,6 @@ x86_emulate(
}
break;
case 5: /* imul */
- dst.reg = (unsigned long *)&_regs.eax;
imul:
_regs.eflags &= ~(EFLG_OF|EFLG_CF);
switch ( dst.bytes )
@@ -4178,7 +4178,6 @@ x86_emulate(
}
break;
case 6: /* div */
- dst.reg = (unsigned long *)&_regs.eax;
switch ( src.bytes )
{
case 1:
@@ -4224,7 +4223,6 @@ x86_emulate(
}
break;
case 7: /* idiv */
- dst.reg = (unsigned long *)&_regs.eax;
switch ( src.bytes )
{
case 1:
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