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X86: Don't use "#if FULL_SYSTEM" in the X86 ISA description.

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The decoder now checks the value of FULL_SYSTEM in a switch statement to
decide whether to return a real syscall instruction or one that triggers
syscall emulation (or a panic in FS mode). The switch statement should devolve
into an if, and also should be optimized out since it's based on constant
input.
This commit is contained in:
Gabe Black 2011-09-19 02:53:37 -07:00
parent 10c2e37f60
commit 7701c5b1ec
2 changed files with 22 additions and 28 deletions
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20
src/arch/x86/isa/decoder/one_byte_opcodes.isa
View file

@ -394,19 +394,15 @@
default: Inst::RET_FAR();
}
0x4: int3();
#if FULL_SYSTEM
0x5: int_Ib();
#else
// Really only the LSB matters, but the predecoder will sign
// extend it, and there's no easy way to specify only checking
// the first byte.
0x5: decode IMMEDIATE {
-0x80:
SyscallInst::int80('xc->syscall(Rax)',
IsSyscall, IsNonSpeculative, IsSerializeAfter);
default: int_Ib();
0x5: decode FULL_SYSTEM default int_Ib() {
0: decode IMMEDIATE {
// Really only the LSB matters, but the predecoder
// will sign extend it, and there's no easy way to
// specify only checking the first byte.
-0x80: SyscallInst::int80('xc->syscall(Rax)',
IsSyscall, IsNonSpeculative, IsSerializeAfter);
}
}
#endif
0x6: decode MODE_SUBMODE {
0x0: Inst::UD2();
default: into();

30
src/arch/x86/isa/decoder/two_byte_opcodes.isa
View file

@ -216,18 +216,17 @@
default: Inst::UD2();
}
}
#if FULL_SYSTEM
0x05: decode MODE_MODE {
0x0: decode MODE_SUBMODE {
0x0: Inst::SYSCALL_64();
0x1: Inst::SYSCALL_COMPAT();
0x05: decode FULL_SYSTEM {
0: SyscallInst::syscall('xc->syscall(Rax)',
IsSyscall, IsNonSpeculative, IsSerializeAfter);
default: decode MODE_MODE {
0x0: decode MODE_SUBMODE {
0x0: Inst::SYSCALL_64();
0x1: Inst::SYSCALL_COMPAT();
}
0x1: Inst::SYSCALL_LEGACY();
}
0x1: Inst::SYSCALL_LEGACY();
}
#else
0x05: SyscallInst::syscall('xc->syscall(Rax)',
IsSyscall, IsNonSpeculative, IsSerializeAfter);
#endif
0x06: Inst::CLTS();
0x07: decode MODE_SUBMODE {
0x0: decode OPSIZE {
@ -399,12 +398,11 @@
0x1: Inst::RDTSC();
0x2: Inst::RDMSR();
0x3: rdpmc();
#if FULL_SYSTEM
0x4: sysenter();
#else
0x4: SyscallInst::sysenter('xc->syscall(Rax)',
IsSyscall, IsNonSpeculative, IsSerializeAfter);
#endif
0x4: decode FULL_SYSTEM {
0: SyscallInst::sysenter('xc->syscall(Rax)',
IsSyscall, IsNonSpeculative, IsSerializeAfter);
default: sysenter();
}
0x5: sysexit();
0x6: Inst::UD2();
0x7: getsec();