[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] x86emul: fold SReg PUSH/POP cases
Now that segment registers are numbered naturally this can be easily done to achieve some code size reduction. Also consistently use X86EMUL_OKAY in the code being touched. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> --- a/xen/arch/x86/x86_emulate/x86_emulate.c +++ b/xen/arch/x86/x86_emulate/x86_emulate.c @@ -2670,51 +2670,40 @@ x86_emulate( break; case 0x06: /* push %%es */ - src.val = x86_seg_es; - push_seg: - generate_exception_if(mode_64bit() && !ext, EXC_UD); + case 0x0e: /* push %%cs */ + case 0x16: /* push %%ss */ + case 0x1e: /* push %%ds */ + generate_exception_if(mode_64bit(), EXC_UD); + /* fall through */ + case X86EMUL_OPC(0x0f, 0xa0): /* push %%fs */ + case X86EMUL_OPC(0x0f, 0xa8): /* push %%gs */ fail_if(ops->read_segment == NULL); - if ( (rc = ops->read_segment(src.val, &sreg, ctxt)) != 0 ) + if ( (rc = ops->read_segment((b >> 3) & 7, &sreg, + ctxt)) != X86EMUL_OKAY ) goto done; src.val = sreg.sel; goto push; case 0x07: /* pop %%es */ - src.val = x86_seg_es; - pop_seg: - generate_exception_if(mode_64bit() && !ext, EXC_UD); + case 0x17: /* pop %%ss */ + case 0x1f: /* pop %%ds */ + generate_exception_if(mode_64bit(), EXC_UD); + /* fall through */ + case X86EMUL_OPC(0x0f, 0xa1): /* pop %%fs */ + case X86EMUL_OPC(0x0f, 0xa9): /* pop %%gs */ fail_if(ops->write_segment == NULL); /* 64-bit mode: POP defaults to a 64-bit operand. */ if ( mode_64bit() && (op_bytes == 4) ) op_bytes = 8; - if ( (rc = read_ulong(x86_seg_ss, sp_post_inc(op_bytes), - &dst.val, op_bytes, ctxt, ops)) != 0 || - (rc = load_seg(src.val, dst.val, 0, NULL, ctxt, ops)) != 0 ) + if ( (rc = read_ulong(x86_seg_ss, sp_post_inc(op_bytes), &dst.val, + op_bytes, ctxt, ops)) != X86EMUL_OKAY || + (rc = load_seg((b >> 3) & 7, dst.val, 0, NULL, ctxt, + ops)) != X86EMUL_OKAY ) goto done; - if ( src.val == x86_seg_ss ) + if ( b == 0x07 ) ctxt->retire.mov_ss = true; break; - case 0x0e: /* push %%cs */ - src.val = x86_seg_cs; - goto push_seg; - - case 0x16: /* push %%ss */ - src.val = x86_seg_ss; - goto push_seg; - - case 0x17: /* pop %%ss */ - src.val = x86_seg_ss; - goto pop_seg; - - case 0x1e: /* push %%ds */ - src.val = x86_seg_ds; - goto push_seg; - - case 0x1f: /* pop %%ds */ - src.val = x86_seg_ds; - goto pop_seg; - case 0x27: /* daa */ case 0x2f: /* das */ { uint8_t al = _regs.eax; @@ -5042,14 +5031,6 @@ x86_emulate( dst.val = test_cc(b, _regs.eflags); break; - case X86EMUL_OPC(0x0f, 0xa0): /* push %%fs */ - src.val = x86_seg_fs; - goto push_seg; - - case X86EMUL_OPC(0x0f, 0xa1): /* pop %%fs */ - src.val = x86_seg_fs; - goto pop_seg; - case X86EMUL_OPC(0x0f, 0xa2): /* cpuid */ { unsigned int eax = _regs.eax, ebx = _regs.ebx; unsigned int ecx = _regs.ecx, edx = _regs.edx; @@ -5107,14 +5088,6 @@ x86_emulate( break; } - case X86EMUL_OPC(0x0f, 0xa8): /* push %%gs */ - src.val = x86_seg_gs; - goto push_seg; - - case X86EMUL_OPC(0x0f, 0xa9): /* pop %%gs */ - src.val = x86_seg_gs; - goto pop_seg; - case X86EMUL_OPC(0x0f, 0xab): bts: /* bts */ emulate_2op_SrcV_nobyte("bts", src, dst, _regs.eflags); break; Attachment:
x86emul-fold-SReg-push-pop.patch _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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