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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2 2/6] x86emul: simplify FPU source operand handling
Consistently use ea instead of src for passing the memory address to
->read(). This eliminates the need to copy ea to src, resulting in a
couple of hundred bytes smaller binary size.
In addition for opcode DE we can leverage SrcMem16 to eliminate a call
of the ->read() hook. At the same time drop the stray Mov attributes
from D8, DA, DC, and DE: They're meaningful for memory writes only.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -159,10 +159,10 @@ static const opcode_desc_t opcode_table[
ByteOp|DstMem|SrcImplicit|ModRM, DstMem|SrcImplicit|ModRM,
DstImplicit|SrcImmByte, DstImplicit|SrcImmByte, ImplicitOps, ImplicitOps,
/* 0xD8 - 0xDF */
- ImplicitOps|ModRM|Mov, ImplicitOps|ModRM|Mov,
- ImplicitOps|ModRM|Mov, ImplicitOps|ModRM|Mov,
- ImplicitOps|ModRM|Mov, ImplicitOps|ModRM|Mov,
- ImplicitOps|ModRM|Mov, ImplicitOps|ModRM|Mov,
+ ImplicitOps|ModRM, ImplicitOps|ModRM|Mov,
+ ImplicitOps|ModRM, ImplicitOps|ModRM|Mov,
+ ImplicitOps|ModRM, ImplicitOps|ModRM|Mov,
+ DstImplicit|SrcMem16|ModRM, ImplicitOps|ModRM|Mov,
/* 0xE0 - 0xE7 */
DstImplicit|SrcImmByte, DstImplicit|SrcImmByte,
DstImplicit|SrcImmByte, DstImplicit|SrcImmByte,
@@ -3589,10 +3589,8 @@ x86_emulate(
break;
default:
ASSERT(ea.type == OP_MEM);
- ea.bytes = 4;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off, &src.val,
- src.bytes, ctxt)) != 0 )
+ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
+ 4, ctxt)) != X86EMUL_OKAY )
goto done;
switch ( modrm_reg & 7 )
{
@@ -3668,10 +3666,8 @@ x86_emulate(
switch ( modrm_reg & 7 )
{
case 0: /* fld m32fp */
- ea.bytes = 4;
- src = ea;
if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
- src.bytes, ctxt)) != 0 )
+ 4, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("flds", src.val);
break;
@@ -3690,10 +3686,8 @@ x86_emulate(
case 4: /* fldenv - TODO */
goto cannot_emulate;
case 5: /* fldcw m2byte */
- ea.bytes = 2;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off, &src.val,
- src.bytes, ctxt)) != 0 )
+ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
+ 2, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("fldcw", src.val);
break;
@@ -3727,10 +3721,8 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
- ea.bytes = 4;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off, &src.val,
- src.bytes, ctxt)) != 0 )
+ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
+ 4, ctxt)) != X86EMUL_OKAY )
goto done;
switch ( modrm_reg & 7 )
{
@@ -3788,10 +3780,8 @@ x86_emulate(
switch ( modrm_reg & 7 )
{
case 0: /* fild m32i */
- ea.bytes = 4;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off, &src.val,
- src.bytes, ctxt)) != 0 )
+ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
+ 4, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("fildl", src.val);
break;
@@ -3815,10 +3805,8 @@ x86_emulate(
emulate_fpu_insn_memdst("fistpl", dst.val);
break;
case 5: /* fld m80fp */
- ea.bytes = 10;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off,
- &src.val, src.bytes, ctxt)) != 0 )
+ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
+ 10, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("fldt", src.val);
break;
@@ -3850,10 +3838,8 @@ x86_emulate(
break;
default:
ASSERT(ea.type == OP_MEM);
- ea.bytes = 8;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off, &src.val,
- src.bytes, ctxt)) != 0 )
+ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
+ 8, ctxt)) != X86EMUL_OKAY )
goto done;
switch ( modrm_reg & 7 )
{
@@ -3902,10 +3888,8 @@ x86_emulate(
switch ( modrm_reg & 7 )
{
case 0: /* fld m64fp */;
- ea.bytes = 8;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off, &src.val,
- src.bytes, ctxt)) != 0 )
+ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
+ 8, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("fldl", src.val);
break;
@@ -3959,11 +3943,6 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
- ea.bytes = 2;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off, &src.val,
- src.bytes, ctxt)) != 0 )
- goto done;
switch ( modrm_reg & 7 )
{
case 0: /* fiadd m16i */
@@ -4021,10 +4000,8 @@ x86_emulate(
switch ( modrm_reg & 7 )
{
case 0: /* fild m16i */
- ea.bytes = 2;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off, &src.val,
- src.bytes, ctxt)) != 0 )
+ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
+ 2, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("filds", src.val);
break;
@@ -4048,18 +4025,14 @@ x86_emulate(
emulate_fpu_insn_memdst("fistps", dst.val);
break;
case 4: /* fbld m80dec */
- ea.bytes = 10;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off,
- &src.val, src.bytes, ctxt)) != 0 )
+ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
+ 10, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("fbld", src.val);
break;
case 5: /* fild m64i */
- ea.bytes = 8;
- src = ea;
- if ( (rc = ops->read(src.mem.seg, src.mem.off, &src.val,
- src.bytes, ctxt)) != 0 )
+ if ( (rc = ops->read(ea.mem.seg, ea.mem.off, &src.val,
+ 8, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("fildll", src.val);
break;
Attachment:
x86emul-FPU-simplify-src.patch _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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