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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2 3/6] x86emul: simplify FPU destination operand handling
Consolidate the copying of ea to dst: There's no need to set the type
to OP_MEM, and instead the load cases setting it to OP_NONE allows the
copying to be done just once per major opcode.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
v2: Re-base over changes to patch 1.
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -3663,6 +3663,7 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
+ dst = ea;
switch ( modrm_reg & 7 )
{
case 0: /* fld m32fp */
@@ -3670,18 +3671,15 @@ x86_emulate(
4, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("flds", src.val);
+ dst.type = OP_NONE;
break;
case 2: /* fstp m32fp */
- ea.bytes = 4;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fsts", dst.val);
+ dst.bytes = 4;
break;
case 3: /* fstp m32fp */
- ea.bytes = 4;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fstps", dst.val);
+ dst.bytes = 4;
break;
case 4: /* fldenv - TODO */
goto cannot_emulate;
@@ -3690,14 +3688,13 @@ x86_emulate(
2, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("fldcw", src.val);
+ dst.type = OP_NONE;
break;
case 6: /* fnstenv - TODO */
goto cannot_emulate;
case 7: /* fnstcw m2byte */
- ea.bytes = 2;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fnstcw", dst.val);
+ dst.bytes = 2;
break;
default:
generate_exception(EXC_UD);
@@ -3777,6 +3774,7 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
+ dst = ea;
switch ( modrm_reg & 7 )
{
case 0: /* fild m32i */
@@ -3784,37 +3782,31 @@ x86_emulate(
4, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("fildl", src.val);
+ dst.type = OP_NONE;
break;
case 1: /* fisttp m32i */
host_and_vcpu_must_have(sse3);
- ea.bytes = 4;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fisttpl", dst.val);
+ dst.bytes = 4;
break;
case 2: /* fist m32i */
- ea.bytes = 4;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fistl", dst.val);
+ dst.bytes = 4;
break;
case 3: /* fistp m32i */
- ea.bytes = 4;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fistpl", dst.val);
+ dst.bytes = 4;
break;
case 5: /* fld m80fp */
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);
+ dst.type = OP_NONE;
break;
case 7: /* fstp m80fp */
- ea.bytes = 10;
- dst.type = OP_MEM;
- dst = ea;
emulate_fpu_insn_memdst("fstpt", dst.val);
+ dst.bytes = 10;
break;
default:
generate_exception(EXC_UD);
@@ -3885,6 +3877,7 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
+ dst = ea;
switch ( modrm_reg & 7 )
{
case 0: /* fld m64fp */;
@@ -3892,34 +3885,27 @@ x86_emulate(
8, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("fldl", src.val);
+ dst.type = OP_NONE;
break;
case 1: /* fisttp m64i */
host_and_vcpu_must_have(sse3);
- ea.bytes = 8;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fisttpll", dst.val);
+ dst.bytes = 8;
break;
case 2: /* fst m64fp */
- ea.bytes = 8;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fstl", dst.val);
+ dst.bytes = 8;
break;
case 3: /* fstp m64fp */
- ea.bytes = 8;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fstpl", dst.val);
+ dst.bytes = 8;
break;
case 4: /* frstor - TODO */
case 6: /* fnsave - TODO */
goto cannot_emulate;
case 7: /* fnstsw m2byte */
- ea.bytes = 2;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fnstsw", dst.val);
+ dst.bytes = 2;
break;
default:
generate_exception(EXC_UD);
@@ -3997,6 +3983,7 @@ x86_emulate(
break;
default:
generate_exception_if(ea.type != OP_MEM, EXC_UD);
+ dst = ea;
switch ( modrm_reg & 7 )
{
case 0: /* fild m16i */
@@ -4004,49 +3991,42 @@ x86_emulate(
2, ctxt)) != X86EMUL_OKAY )
goto done;
emulate_fpu_insn_memsrc("filds", src.val);
+ dst.type = OP_NONE;
break;
case 1: /* fisttp m16i */
host_and_vcpu_must_have(sse3);
- ea.bytes = 2;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fisttps", dst.val);
+ dst.bytes = 2;
break;
case 2: /* fist m16i */
- ea.bytes = 2;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fists", dst.val);
+ dst.bytes = 2;
break;
case 3: /* fistp m16i */
- ea.bytes = 2;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fistps", dst.val);
+ dst.bytes = 2;
break;
case 4: /* fbld m80dec */
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);
+ dst.type = OP_NONE;
break;
case 5: /* fild m64i */
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);
+ dst.type = OP_NONE;
break;
case 6: /* fbstp packed bcd */
- ea.bytes = 10;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fbstp", dst.val);
+ dst.bytes = 10;
break;
case 7: /* fistp m64i */
- ea.bytes = 8;
- dst = ea;
- dst.type = OP_MEM;
emulate_fpu_insn_memdst("fistpll", dst.val);
+ dst.bytes = 8;
break;
}
}
Attachment:
x86emul-FPU-simplify-dst.patch _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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