gem5/src/arch/alpha/isa/decoder.isa
Brandon Potter a5802c823f syscall_emul: [patch 13/22] add system call retry capability
This changeset adds functionality that allows system calls to retry without
affecting thread context state such as the program counter or register values
for the associated thread context (when system calls return with a retry
fault).

This functionality is needed to solve problems with blocking system calls
in multi-process or multi-threaded simulations where information is passed
between processes/threads. Blocking system calls can cause deadlock because
the simulator itself is single threaded. There is only a single thread
servicing the event queue which can cause deadlock if the thread hits a
blocking system call instruction.

To illustrate the problem, consider two processes using the producer/consumer
sharing model. The processes can use file descriptors and the read and write
calls to pass information to one another. If the consumer calls the blocking
read system call before the producer has produced anything, the call will
block the event queue (while executing the system call instruction) and
deadlock the simulation.

The solution implemented in this changeset is to recognize that the system
calls will block and then generate a special retry fault. The fault will
be sent back up through the function call chain until it is exposed to the
cpu model's pipeline where the fault becomes visible. The fault will trigger
the cpu model to replay the instruction at a future tick where the call has
a chance to succeed without actually going into a blocking state.

In subsequent patches, we recognize that a syscall will block by calling a
non-blocking poll (from inside the system call implementation) and checking
for events. When events show up during the poll, it signifies that the call
would not have blocked and the syscall is allowed to proceed (calling an
underlying host system call if necessary). If no events are returned from the
poll, we generate the fault and try the instruction for the thread context
at a distant tick. Note that retrying every tick is not efficient.

As an aside, the simulator has some multi-threading support for the event
queue, but it is not used by default and needs work. Even if the event queue
was completely multi-threaded, meaning that there is a hardware thread on
the host servicing a single simulator thread contexts with a 1:1 mapping
between them, it's still possible to run into deadlock due to the event queue
barriers on quantum boundaries. The solution of replaying at a later tick
is the simplest solution and solves the problem generally.
2015-07-20 09:15:21 -05:00

1085 lines
45 KiB
C++

// -*- mode:c++ -*-
// Copyright (c) 2013 ARM Limited
// All rights reserved
//
// The license below extends only to copyright in the software and shall
// not be construed as granting a license to any other intellectual
// property including but not limited to intellectual property relating
// to a hardware implementation of the functionality of the software
// licensed hereunder. You may use the software subject to the license
// terms below provided that you ensure that this notice is replicated
// unmodified and in its entirety in all distributions of the software,
// modified or unmodified, in source code or in binary form.
//
// Copyright (c) 2003-2006 The Regents of The University of Michigan
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met: redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer;
// redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution;
// neither the name of the copyright holders nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Authors: Steve Reinhardt
////////////////////////////////////////////////////////////////////
//
// The actual decoder specification
//
decode OPCODE default Unknown::unknown() {
format LoadAddress {
0x08: lda({{ Ra = Rb + disp; }});
0x09: ldah({{ Ra = Rb + (disp << 16); }});
}
format LoadOrNop {
0x0a: ldbu({{ Ra_uq = Mem_ub; }});
0x0c: ldwu({{ Ra_uq = Mem_uw; }});
0x0b: ldq_u({{ Ra = Mem_uq; }}, ea_code = {{ EA = (Rb + disp) & ~7; }});
0x23: ldt({{ Fa = Mem_df; }});
0x2a: ldl_l({{ Ra_sl = Mem_sl; }}, mem_flags = LLSC);
0x2b: ldq_l({{ Ra_uq = Mem_uq; }}, mem_flags = LLSC);
}
format LoadOrPrefetch {
0x28: ldl({{ Ra_sl = Mem_sl; }});
0x29: ldq({{ Ra_uq = Mem_uq; }}, pf_flags = EVICT_NEXT);
// IsFloating flag on lds gets the prefetch to disassemble
// using f31 instead of r31... funcitonally it's unnecessary
0x22: lds({{ Fa_uq = s_to_t(Mem_ul); }},
pf_flags = PF_EXCLUSIVE, inst_flags = IsFloating);
}
format Store {
0x0e: stb({{ Mem_ub = Ra<7:0>; }});
0x0d: stw({{ Mem_uw = Ra<15:0>; }});
0x2c: stl({{ Mem_ul = Ra<31:0>; }});
0x2d: stq({{ Mem_uq = Ra_uq; }});
0x0f: stq_u({{ Mem_uq = Ra_uq; }}, {{ EA = (Rb + disp) & ~7; }});
0x26: sts({{ Mem_ul = t_to_s(Fa_uq); }});
0x27: stt({{ Mem_df = Fa; }});
}
format StoreCond {
0x2e: stl_c({{ Mem_ul = Ra<31:0>; }},
{{
uint64_t tmp = write_result;
// see stq_c
Ra = (tmp == 0 || tmp == 1) ? tmp : Ra;
if (tmp == 1) {
xc->setStCondFailures(0);
}
}}, mem_flags = LLSC, inst_flags = IsStoreConditional);
0x2f: stq_c({{ Mem_uq = Ra; }},
{{
uint64_t tmp = write_result;
// If the write operation returns 0 or 1, then
// this was a conventional store conditional,
// and the value indicates the success/failure
// of the operation. If another value is
// returned, then this was a Turbolaser
// mailbox access, and we don't update the
// result register at all.
Ra = (tmp == 0 || tmp == 1) ? tmp : Ra;
if (tmp == 1) {
// clear failure counter... this is
// non-architectural and for debugging
// only.
xc->setStCondFailures(0);
}
}}, mem_flags = LLSC, inst_flags = IsStoreConditional);
}
format IntegerOperate {
0x10: decode INTFUNC { // integer arithmetic operations
0x00: addl({{ Rc_sl = Ra_sl + Rb_or_imm_sl; }});
0x40: addlv({{
int32_t tmp = Ra_sl + Rb_or_imm_sl;
// signed overflow occurs when operands have same sign
// and sign of result does not match.
if (Ra_sl<31:> == Rb_or_imm_sl<31:> && tmp<31:> != Ra_sl<31:>)
fault = std::make_shared<IntegerOverflowFault>();
Rc_sl = tmp;
}});
0x02: s4addl({{ Rc_sl = (Ra_sl << 2) + Rb_or_imm_sl; }});
0x12: s8addl({{ Rc_sl = (Ra_sl << 3) + Rb_or_imm_sl; }});
0x20: addq({{ Rc = Ra + Rb_or_imm; }});
0x60: addqv({{
uint64_t tmp = Ra + Rb_or_imm;
// signed overflow occurs when operands have same sign
// and sign of result does not match.
if (Ra<63:> == Rb_or_imm<63:> && tmp<63:> != Ra<63:>)
fault = std::make_shared<IntegerOverflowFault>();
Rc = tmp;
}});
0x22: s4addq({{ Rc = (Ra << 2) + Rb_or_imm; }});
0x32: s8addq({{ Rc = (Ra << 3) + Rb_or_imm; }});
0x09: subl({{ Rc_sl = Ra_sl - Rb_or_imm_sl; }});
0x49: sublv({{
int32_t tmp = Ra_sl - Rb_or_imm_sl;
// signed overflow detection is same as for add,
// except we need to look at the *complemented*
// sign bit of the subtrahend (Rb), i.e., if the initial
// signs are the *same* then no overflow can occur
if (Ra_sl<31:> != Rb_or_imm_sl<31:> && tmp<31:> != Ra_sl<31:>)
fault = std::make_shared<IntegerOverflowFault>();
Rc_sl = tmp;
}});
0x0b: s4subl({{ Rc_sl = (Ra_sl << 2) - Rb_or_imm_sl; }});
0x1b: s8subl({{ Rc_sl = (Ra_sl << 3) - Rb_or_imm_sl; }});
0x29: subq({{ Rc = Ra - Rb_or_imm; }});
0x69: subqv({{
uint64_t tmp = Ra - Rb_or_imm;
// signed overflow detection is same as for add,
// except we need to look at the *complemented*
// sign bit of the subtrahend (Rb), i.e., if the initial
// signs are the *same* then no overflow can occur
if (Ra<63:> != Rb_or_imm<63:> && tmp<63:> != Ra<63:>)
fault = std::make_shared<IntegerOverflowFault>();
Rc = tmp;
}});
0x2b: s4subq({{ Rc = (Ra << 2) - Rb_or_imm; }});
0x3b: s8subq({{ Rc = (Ra << 3) - Rb_or_imm; }});
0x2d: cmpeq({{ Rc = (Ra == Rb_or_imm); }});
0x6d: cmple({{ Rc = (Ra_sq <= Rb_or_imm_sq); }});
0x4d: cmplt({{ Rc = (Ra_sq < Rb_or_imm_sq); }});
0x3d: cmpule({{ Rc = (Ra_uq <= Rb_or_imm_uq); }});
0x1d: cmpult({{ Rc = (Ra_uq < Rb_or_imm_uq); }});
0x0f: cmpbge({{
int hi = 7;
int lo = 0;
uint64_t tmp = 0;
for (int i = 0; i < 8; ++i) {
tmp |= (Ra_uq<hi:lo> >= Rb_or_imm_uq<hi:lo>) << i;
hi += 8;
lo += 8;
}
Rc = tmp;
}});
}
0x11: decode INTFUNC { // integer logical operations
0x00: and({{ Rc = Ra & Rb_or_imm; }});
0x08: bic({{ Rc = Ra & ~Rb_or_imm; }});
0x20: bis({{ Rc = Ra | Rb_or_imm; }});
0x28: ornot({{ Rc = Ra | ~Rb_or_imm; }});
0x40: xor({{ Rc = Ra ^ Rb_or_imm; }});
0x48: eqv({{ Rc = Ra ^ ~Rb_or_imm; }});
// conditional moves
0x14: cmovlbs({{ Rc = ((Ra & 1) == 1) ? Rb_or_imm : Rc; }});
0x16: cmovlbc({{ Rc = ((Ra & 1) == 0) ? Rb_or_imm : Rc; }});
0x24: cmoveq({{ Rc = (Ra == 0) ? Rb_or_imm : Rc; }});
0x26: cmovne({{ Rc = (Ra != 0) ? Rb_or_imm : Rc; }});
0x44: cmovlt({{ Rc = (Ra_sq < 0) ? Rb_or_imm : Rc; }});
0x46: cmovge({{ Rc = (Ra_sq >= 0) ? Rb_or_imm : Rc; }});
0x64: cmovle({{ Rc = (Ra_sq <= 0) ? Rb_or_imm : Rc; }});
0x66: cmovgt({{ Rc = (Ra_sq > 0) ? Rb_or_imm : Rc; }});
// For AMASK, RA must be R31.
0x61: decode RA {
31: amask({{ Rc = Rb_or_imm & ~ULL(0x17); }});
}
// For IMPLVER, RA must be R31 and the B operand
// must be the immediate value 1.
0x6c: decode RA {
31: decode IMM {
1: decode INTIMM {
// return EV5 for FullSystem and EV6 otherwise
1: implver({{ Rc = FullSystem ? 1 : 2 }});
}
}
}
// The mysterious 11.25...
0x25: WarnUnimpl::eleven25();
}
0x12: decode INTFUNC {
0x39: sll({{ Rc = Ra << Rb_or_imm<5:0>; }});
0x34: srl({{ Rc = Ra_uq >> Rb_or_imm<5:0>; }});
0x3c: sra({{ Rc = Ra_sq >> Rb_or_imm<5:0>; }});
0x02: mskbl({{ Rc = Ra & ~(mask( 8) << (Rb_or_imm<2:0> * 8)); }});
0x12: mskwl({{ Rc = Ra & ~(mask(16) << (Rb_or_imm<2:0> * 8)); }});
0x22: mskll({{ Rc = Ra & ~(mask(32) << (Rb_or_imm<2:0> * 8)); }});
0x32: mskql({{ Rc = Ra & ~(mask(64) << (Rb_or_imm<2:0> * 8)); }});
0x52: mskwh({{
int bv = Rb_or_imm<2:0>;
Rc = bv ? (Ra & ~(mask(16) >> (64 - 8 * bv))) : Ra;
}});
0x62: msklh({{
int bv = Rb_or_imm<2:0>;
Rc = bv ? (Ra & ~(mask(32) >> (64 - 8 * bv))) : Ra;
}});
0x72: mskqh({{
int bv = Rb_or_imm<2:0>;
Rc = bv ? (Ra & ~(mask(64) >> (64 - 8 * bv))) : Ra;
}});
0x06: extbl({{ Rc = (Ra_uq >> (Rb_or_imm<2:0> * 8))< 7:0>; }});
0x16: extwl({{ Rc = (Ra_uq >> (Rb_or_imm<2:0> * 8))<15:0>; }});
0x26: extll({{ Rc = (Ra_uq >> (Rb_or_imm<2:0> * 8))<31:0>; }});
0x36: extql({{ Rc = (Ra_uq >> (Rb_or_imm<2:0> * 8)); }});
0x5a: extwh({{
Rc = (Ra << (64 - (Rb_or_imm<2:0> * 8))<5:0>)<15:0>; }});
0x6a: extlh({{
Rc = (Ra << (64 - (Rb_or_imm<2:0> * 8))<5:0>)<31:0>; }});
0x7a: extqh({{
Rc = (Ra << (64 - (Rb_or_imm<2:0> * 8))<5:0>); }});
0x0b: insbl({{ Rc = Ra< 7:0> << (Rb_or_imm<2:0> * 8); }});
0x1b: inswl({{ Rc = Ra<15:0> << (Rb_or_imm<2:0> * 8); }});
0x2b: insll({{ Rc = Ra<31:0> << (Rb_or_imm<2:0> * 8); }});
0x3b: insql({{ Rc = Ra << (Rb_or_imm<2:0> * 8); }});
0x57: inswh({{
int bv = Rb_or_imm<2:0>;
Rc = bv ? (Ra_uq<15:0> >> (64 - 8 * bv)) : 0;
}});
0x67: inslh({{
int bv = Rb_or_imm<2:0>;
Rc = bv ? (Ra_uq<31:0> >> (64 - 8 * bv)) : 0;
}});
0x77: insqh({{
int bv = Rb_or_imm<2:0>;
Rc = bv ? (Ra_uq >> (64 - 8 * bv)) : 0;
}});
0x30: zap({{
uint64_t zapmask = 0;
for (int i = 0; i < 8; ++i) {
if (Rb_or_imm<i:>)
zapmask |= (mask(8) << (i * 8));
}
Rc = Ra & ~zapmask;
}});
0x31: zapnot({{
uint64_t zapmask = 0;
for (int i = 0; i < 8; ++i) {
if (!Rb_or_imm<i:>)
zapmask |= (mask(8) << (i * 8));
}
Rc = Ra & ~zapmask;
}});
}
0x13: decode INTFUNC { // integer multiplies
0x00: mull({{ Rc_sl = Ra_sl * Rb_or_imm_sl; }}, IntMultOp);
0x20: mulq({{ Rc = Ra * Rb_or_imm; }}, IntMultOp);
0x30: umulh({{
uint64_t hi, lo;
mul128(Ra, Rb_or_imm, hi, lo);
Rc = hi;
}}, IntMultOp);
0x40: mullv({{
// 32-bit multiply with trap on overflow
int64_t Rax = Ra_sl; // sign extended version of Ra_sl
int64_t Rbx = Rb_or_imm_sl;
int64_t tmp = Rax * Rbx;
// To avoid overflow, all the upper 32 bits must match
// the sign bit of the lower 32. We code this as
// checking the upper 33 bits for all 0s or all 1s.
uint64_t sign_bits = tmp<63:31>;
if (sign_bits != 0 && sign_bits != mask(33))
fault = std::make_shared<IntegerOverflowFault>();
Rc_sl = tmp<31:0>;
}}, IntMultOp);
0x60: mulqv({{
// 64-bit multiply with trap on overflow
uint64_t hi, lo;
mul128(Ra, Rb_or_imm, hi, lo);
// all the upper 64 bits must match the sign bit of
// the lower 64
if (!((hi == 0 && lo<63:> == 0) ||
(hi == mask(64) && lo<63:> == 1)))
fault = std::make_shared<IntegerOverflowFault>();
Rc = lo;
}}, IntMultOp);
}
0x1c: decode INTFUNC {
0x00: decode RA { 31: sextb({{ Rc_sb = Rb_or_imm< 7:0>; }}); }
0x01: decode RA { 31: sextw({{ Rc_sw = Rb_or_imm<15:0>; }}); }
0x30: ctpop({{
uint64_t count = 0;
for (int i = 0; Rb<63:i>; ++i) {
if (Rb<i:i> == 0x1)
++count;
}
Rc = count;
}}, IntAluOp);
0x31: perr({{
uint64_t temp = 0;
int hi = 7;
int lo = 0;
for (int i = 0; i < 8; ++i) {
uint8_t ra_ub = Ra_uq<hi:lo>;
uint8_t rb_ub = Rb_uq<hi:lo>;
temp += (ra_ub >= rb_ub) ?
(ra_ub - rb_ub) : (rb_ub - ra_ub);
hi += 8;
lo += 8;
}
Rc = temp;
}});
0x32: ctlz({{
uint64_t count = 0;
uint64_t temp = Rb;
if (temp<63:32>) temp >>= 32; else count += 32;
if (temp<31:16>) temp >>= 16; else count += 16;
if (temp<15:8>) temp >>= 8; else count += 8;
if (temp<7:4>) temp >>= 4; else count += 4;
if (temp<3:2>) temp >>= 2; else count += 2;
if (temp<1:1>) temp >>= 1; else count += 1;
if ((temp<0:0>) != 0x1) count += 1;
Rc = count;
}}, IntAluOp);
0x33: cttz({{
uint64_t count = 0;
uint64_t temp = Rb;
if (!(temp<31:0>)) { temp >>= 32; count += 32; }
if (!(temp<15:0>)) { temp >>= 16; count += 16; }
if (!(temp<7:0>)) { temp >>= 8; count += 8; }
if (!(temp<3:0>)) { temp >>= 4; count += 4; }
if (!(temp<1:0>)) { temp >>= 2; count += 2; }
if (!(temp<0:0> & ULL(0x1))) {
temp >>= 1; count += 1;
}
if (!(temp<0:0> & ULL(0x1))) count += 1;
Rc = count;
}}, IntAluOp);
0x34: unpkbw({{
Rc = (Rb_uq<7:0>
| (Rb_uq<15:8> << 16)
| (Rb_uq<23:16> << 32)
| (Rb_uq<31:24> << 48));
}}, IntAluOp);
0x35: unpkbl({{
Rc = (Rb_uq<7:0> | (Rb_uq<15:8> << 32));
}}, IntAluOp);
0x36: pkwb({{
Rc = (Rb_uq<7:0>
| (Rb_uq<23:16> << 8)
| (Rb_uq<39:32> << 16)
| (Rb_uq<55:48> << 24));
}}, IntAluOp);
0x37: pklb({{
Rc = (Rb_uq<7:0> | (Rb_uq<39:32> << 8));
}}, IntAluOp);
0x38: minsb8({{
uint64_t temp = 0;
int hi = 63;
int lo = 56;
for (int i = 7; i >= 0; --i) {
int8_t ra_sb = Ra_uq<hi:lo>;
int8_t rb_sb = Rb_uq<hi:lo>;
temp = ((temp << 8)
| ((ra_sb < rb_sb) ? Ra_uq<hi:lo>
: Rb_uq<hi:lo>));
hi -= 8;
lo -= 8;
}
Rc = temp;
}});
0x39: minsw4({{
uint64_t temp = 0;
int hi = 63;
int lo = 48;
for (int i = 3; i >= 0; --i) {
int16_t ra_sw = Ra_uq<hi:lo>;
int16_t rb_sw = Rb_uq<hi:lo>;
temp = ((temp << 16)
| ((ra_sw < rb_sw) ? Ra_uq<hi:lo>
: Rb_uq<hi:lo>));
hi -= 16;
lo -= 16;
}
Rc = temp;
}});
0x3a: minub8({{
uint64_t temp = 0;
int hi = 63;
int lo = 56;
for (int i = 7; i >= 0; --i) {
uint8_t ra_ub = Ra_uq<hi:lo>;
uint8_t rb_ub = Rb_uq<hi:lo>;
temp = ((temp << 8)
| ((ra_ub < rb_ub) ? Ra_uq<hi:lo>
: Rb_uq<hi:lo>));
hi -= 8;
lo -= 8;
}
Rc = temp;
}});
0x3b: minuw4({{
uint64_t temp = 0;
int hi = 63;
int lo = 48;
for (int i = 3; i >= 0; --i) {
uint16_t ra_sw = Ra_uq<hi:lo>;
uint16_t rb_sw = Rb_uq<hi:lo>;
temp = ((temp << 16)
| ((ra_sw < rb_sw) ? Ra_uq<hi:lo>
: Rb_uq<hi:lo>));
hi -= 16;
lo -= 16;
}
Rc = temp;
}});
0x3c: maxub8({{
uint64_t temp = 0;
int hi = 63;
int lo = 56;
for (int i = 7; i >= 0; --i) {
uint8_t ra_ub = Ra_uq<hi:lo>;
uint8_t rb_ub = Rb_uq<hi:lo>;
temp = ((temp << 8)
| ((ra_ub > rb_ub) ? Ra_uq<hi:lo>
: Rb_uq<hi:lo>));
hi -= 8;
lo -= 8;
}
Rc = temp;
}});
0x3d: maxuw4({{
uint64_t temp = 0;
int hi = 63;
int lo = 48;
for (int i = 3; i >= 0; --i) {
uint16_t ra_uw = Ra_uq<hi:lo>;
uint16_t rb_uw = Rb_uq<hi:lo>;
temp = ((temp << 16)
| ((ra_uw > rb_uw) ? Ra_uq<hi:lo>
: Rb_uq<hi:lo>));
hi -= 16;
lo -= 16;
}
Rc = temp;
}});
0x3e: maxsb8({{
uint64_t temp = 0;
int hi = 63;
int lo = 56;
for (int i = 7; i >= 0; --i) {
int8_t ra_sb = Ra_uq<hi:lo>;
int8_t rb_sb = Rb_uq<hi:lo>;
temp = ((temp << 8)
| ((ra_sb > rb_sb) ? Ra_uq<hi:lo>
: Rb_uq<hi:lo>));
hi -= 8;
lo -= 8;
}
Rc = temp;
}});
0x3f: maxsw4({{
uint64_t temp = 0;
int hi = 63;
int lo = 48;
for (int i = 3; i >= 0; --i) {
int16_t ra_sw = Ra_uq<hi:lo>;
int16_t rb_sw = Rb_uq<hi:lo>;
temp = ((temp << 16)
| ((ra_sw > rb_sw) ? Ra_uq<hi:lo>
: Rb_uq<hi:lo>));
hi -= 16;
lo -= 16;
}
Rc = temp;
}});
format BasicOperateWithNopCheck {
0x70: decode RB {
31: ftoit({{ Rc = Fa_uq; }}, FloatCvtOp);
}
0x78: decode RB {
31: ftois({{ Rc_sl = t_to_s(Fa_uq); }},
FloatCvtOp);
}
}
}
}
// Conditional branches.
format CondBranch {
0x39: beq({{ cond = (Ra == 0); }});
0x3d: bne({{ cond = (Ra != 0); }});
0x3e: bge({{ cond = (Ra_sq >= 0); }});
0x3f: bgt({{ cond = (Ra_sq > 0); }});
0x3b: ble({{ cond = (Ra_sq <= 0); }});
0x3a: blt({{ cond = (Ra_sq < 0); }});
0x38: blbc({{ cond = ((Ra & 1) == 0); }});
0x3c: blbs({{ cond = ((Ra & 1) == 1); }});
0x31: fbeq({{ cond = (Fa == 0); }});
0x35: fbne({{ cond = (Fa != 0); }});
0x36: fbge({{ cond = (Fa >= 0); }});
0x37: fbgt({{ cond = (Fa > 0); }});
0x33: fble({{ cond = (Fa <= 0); }});
0x32: fblt({{ cond = (Fa < 0); }});
}
// unconditional branches
format UncondBranch {
0x30: br();
0x34: bsr(IsCall);
}
// indirect branches
0x1a: decode JMPFUNC {
format Jump {
0: jmp();
1: jsr(IsCall);
2: ret(IsReturn);
3: jsr_coroutine(IsCall, IsReturn);
}
}
// Square root and integer-to-FP moves
0x14: decode FP_SHORTFUNC {
// Integer to FP register moves must have RB == 31
0x4: decode RB {
31: decode FP_FULLFUNC {
format BasicOperateWithNopCheck {
0x004: itofs({{ Fc_uq = s_to_t(Ra_ul); }}, FloatCvtOp);
0x024: itoft({{ Fc_uq = Ra_uq; }}, FloatCvtOp);
0x014: FailUnimpl::itoff(); // VAX-format conversion
}
}
}
// Square root instructions must have FA == 31
0xb: decode FA {
31: decode FP_TYPEFUNC {
format FloatingPointOperate {
#if SS_COMPATIBLE_FP
0x0b: sqrts({{
if (Fb < 0.0)
fault = std::make_shared<ArithmeticFault>();
Fc = sqrt(Fb);
}}, FloatSqrtOp);
#else
0x0b: sqrts({{
if (Fb_sf < 0.0)
fault = std::make_shared<ArithmeticFault>();
Fc_sf = sqrt(Fb_sf);
}}, FloatSqrtOp);
#endif
0x2b: sqrtt({{
if (Fb < 0.0)
fault = std::make_shared<ArithmeticFault>();
Fc = sqrt(Fb);
}}, FloatSqrtOp);
}
}
}
// VAX-format sqrtf and sqrtg are not implemented
0xa: FailUnimpl::sqrtfg();
}
// IEEE floating point
0x16: decode FP_SHORTFUNC_TOP2 {
// The top two bits of the short function code break this
// space into four groups: binary ops, compares, reserved, and
// conversions. See Table 4-12 of AHB. There are different
// special cases in these different groups, so we decode on
// these top two bits first just to select a decode strategy.
// Most of these instructions may have various trapping and
// rounding mode flags set; these are decoded in the
// FloatingPointDecode template used by the
// FloatingPointOperate format.
// add/sub/mul/div: just decode on the short function code
// and source type. All valid trapping and rounding modes apply.
0: decode FP_TRAPMODE {
// check for valid trapping modes here
0,1,5,7: decode FP_TYPEFUNC {
format FloatingPointOperate {
#if SS_COMPATIBLE_FP
0x00: adds({{ Fc = Fa + Fb; }});
0x01: subs({{ Fc = Fa - Fb; }});
0x02: muls({{ Fc = Fa * Fb; }}, FloatMultOp);
0x03: divs({{ Fc = Fa / Fb; }}, FloatDivOp);
#else
0x00: adds({{ Fc_sf = Fa_sf + Fb_sf; }});
0x01: subs({{ Fc_sf = Fa_sf - Fb_sf; }});
0x02: muls({{ Fc_sf = Fa_sf * Fb_sf; }}, FloatMultOp);
0x03: divs({{ Fc_sf = Fa_sf / Fb_sf; }}, FloatDivOp);
#endif
0x20: addt({{ Fc = Fa + Fb; }});
0x21: subt({{ Fc = Fa - Fb; }});
0x22: mult({{ Fc = Fa * Fb; }}, FloatMultOp);
0x23: divt({{ Fc = Fa / Fb; }}, FloatDivOp);
}
}
}
// Floating-point compare instructions must have the default
// rounding mode, and may use the default trapping mode or
// /SU. Both trapping modes are treated the same by M5; the
// only difference on the real hardware (as far a I can tell)
// is that without /SU you'd get an imprecise trap if you
// tried to compare a NaN with something else (instead of an
// "unordered" result).
1: decode FP_FULLFUNC {
format BasicOperateWithNopCheck {
0x0a5, 0x5a5: cmpteq({{ Fc = (Fa == Fb) ? 2.0 : 0.0; }},
FloatCmpOp);
0x0a7, 0x5a7: cmptle({{ Fc = (Fa <= Fb) ? 2.0 : 0.0; }},
FloatCmpOp);
0x0a6, 0x5a6: cmptlt({{ Fc = (Fa < Fb) ? 2.0 : 0.0; }},
FloatCmpOp);
0x0a4, 0x5a4: cmptun({{ // unordered
Fc = (!(Fa < Fb) && !(Fa == Fb) && !(Fa > Fb)) ? 2.0 : 0.0;
}}, FloatCmpOp);
}
}
// The FP-to-integer and integer-to-FP conversion insts
// require that FA be 31.
3: decode FA {
31: decode FP_TYPEFUNC {
format FloatingPointOperate {
0x2f: decode FP_ROUNDMODE {
format FPFixedRounding {
// "chopped" i.e. round toward zero
0: cvttq({{ Fc_sq = (int64_t)trunc(Fb); }},
Chopped);
// round to minus infinity
1: cvttq({{ Fc_sq = (int64_t)floor(Fb); }},
MinusInfinity);
}
default: cvttq({{ Fc_sq = (int64_t)nearbyint(Fb); }});
}
// The cvtts opcode is overloaded to be cvtst if the trap
// mode is 2 or 6 (which are not valid otherwise)
0x2c: decode FP_FULLFUNC {
format BasicOperateWithNopCheck {
// trap on denorm version "cvtst/s" is
// simulated same as cvtst
0x2ac, 0x6ac: cvtst({{ Fc = Fb_sf; }});
}
default: cvtts({{ Fc_sf = Fb; }});
}
// The trapping mode for integer-to-FP conversions
// must be /SUI or nothing; /U and /SU are not
// allowed. The full set of rounding modes are
// supported though.
0x3c: decode FP_TRAPMODE {
0,7: cvtqs({{ Fc_sf = Fb_sq; }});
}
0x3e: decode FP_TRAPMODE {
0,7: cvtqt({{ Fc = Fb_sq; }});
}
}
}
}
}
// misc FP operate
0x17: decode FP_FULLFUNC {
format BasicOperateWithNopCheck {
0x010: cvtlq({{
Fc_sl = (Fb_uq<63:62> << 30) | Fb_uq<58:29>;
}});
0x030: cvtql({{
Fc_uq = (Fb_uq<31:30> << 62) | (Fb_uq<29:0> << 29);
}});
// We treat the precise & imprecise trapping versions of
// cvtql identically.
0x130, 0x530: cvtqlv({{
// To avoid overflow, all the upper 32 bits must match
// the sign bit of the lower 32. We code this as
// checking the upper 33 bits for all 0s or all 1s.
uint64_t sign_bits = Fb_uq<63:31>;
if (sign_bits != 0 && sign_bits != mask(33))
fault = std::make_shared<IntegerOverflowFault>();
Fc_uq = (Fb_uq<31:30> << 62) | (Fb_uq<29:0> << 29);
}});
0x020: cpys({{ // copy sign
Fc_uq = (Fa_uq<63:> << 63) | Fb_uq<62:0>;
}});
0x021: cpysn({{ // copy sign negated
Fc_uq = (~Fa_uq<63:> << 63) | Fb_uq<62:0>;
}});
0x022: cpyse({{ // copy sign and exponent
Fc_uq = (Fa_uq<63:52> << 52) | Fb_uq<51:0>;
}});
0x02a: fcmoveq({{ Fc = (Fa == 0) ? Fb : Fc; }});
0x02b: fcmovne({{ Fc = (Fa != 0) ? Fb : Fc; }});
0x02c: fcmovlt({{ Fc = (Fa < 0) ? Fb : Fc; }});
0x02d: fcmovge({{ Fc = (Fa >= 0) ? Fb : Fc; }});
0x02e: fcmovle({{ Fc = (Fa <= 0) ? Fb : Fc; }});
0x02f: fcmovgt({{ Fc = (Fa > 0) ? Fb : Fc; }});
0x024: mt_fpcr({{ FPCR = Fa_uq; }}, IsIprAccess);
0x025: mf_fpcr({{ Fa_uq = FPCR; }}, IsIprAccess);
}
}
// miscellaneous mem-format ops
0x18: decode MEMFUNC {
format WarnUnimpl {
0x8000: fetch();
0xa000: fetch_m();
0xe800: ecb();
}
format MiscPrefetch {
0xf800: wh64({{ EA = Rb & ~ULL(63); }},
{{ ; }},
mem_flags = PREFETCH);
}
format BasicOperate {
0xc000: rpcc({{
/* Rb is a fake dependency so here is a fun way to get
* the parser to understand that.
*/
uint64_t unused_var M5_VAR_USED = Rb;
Ra = FullSystem ? xc->readMiscReg(IPR_CC) : curTick();
}}, IsUnverifiable);
// All of the barrier instructions below do nothing in
// their execute() methods (hence the empty code blocks).
// All of their functionality is hard-coded in the
// pipeline based on the flags IsSerializing,
// IsMemBarrier, and IsWriteBarrier. In the current
// detailed CPU model, the execute() function only gets
// called at fetch, so there's no way to generate pipeline
// behavior at any other stage. Once we go to an
// exec-in-exec CPU model we should be able to get rid of
// these flags and implement this behavior via the
// execute() methods.
// trapb is just a barrier on integer traps, where excb is
// a barrier on integer and FP traps. "EXCB is thus a
// superset of TRAPB." (Alpha ARM, Sec 4.11.4) We treat
// them the same though.
0x0000: trapb({{ }}, IsSerializing, IsSerializeBefore, No_OpClass);
0x0400: excb({{ }}, IsSerializing, IsSerializeBefore, No_OpClass);
0x4000: mb({{ }}, IsMemBarrier, MemReadOp);
0x4400: wmb({{ }}, IsWriteBarrier, MemWriteOp);
}
0xe000: decode FullSystemInt {
0: FailUnimpl::rc_se();
default: BasicOperate::rc({{
Ra = IntrFlag;
IntrFlag = 0;
}}, IsNonSpeculative, IsUnverifiable);
}
0xf000: decode FullSystemInt {
0: FailUnimpl::rs_se();
default: BasicOperate::rs({{
Ra = IntrFlag;
IntrFlag = 1;
}}, IsNonSpeculative, IsUnverifiable);
}
}
0x00: decode FullSystemInt {
0: decode PALFUNC {
format EmulatedCallPal {
0x00: halt ({{
exitSimLoop("halt instruction encountered");
}}, IsNonSpeculative);
0x83: callsys({{
xc->syscall(R0, &fault);
}}, IsSerializeAfter, IsNonSpeculative, IsSyscall);
// Read uniq reg into ABI return value register (r0)
0x9e: rduniq({{ R0 = Runiq; }}, IsIprAccess);
// Write uniq reg with value from ABI arg register (r16)
0x9f: wruniq({{ Runiq = R16; }}, IsIprAccess);
}
}
default: CallPal::call_pal({{
if (!palValid ||
(palPriv
&& xc->readMiscReg(IPR_ICM) != mode_kernel)) {
// invalid pal function code, or attempt to do privileged
// PAL call in non-kernel mode
fault = std::make_shared<UnimplementedOpcodeFault>();
} else {
// check to see if simulator wants to do something special
// on this PAL call (including maybe suppress it)
bool dopal = xc->simPalCheck(palFunc);
if (dopal) {
xc->setMiscReg(IPR_EXC_ADDR, NPC);
NPC = xc->readMiscReg(IPR_PAL_BASE) + palOffset;
}
}
}}, IsNonSpeculative);
}
0x1b: decode PALMODE {
0: OpcdecFault::hw_st_quad();
1: decode HW_LDST_QUAD {
format HwLoad {
0: hw_ld({{ EA = (Rb + disp) & ~3; }}, {{ Ra = Mem_ul; }},
L, IsSerializing, IsSerializeBefore);
1: hw_ld({{ EA = (Rb + disp) & ~7; }}, {{ Ra = Mem_uq; }},
Q, IsSerializing, IsSerializeBefore);
}
}
}
0x1f: decode PALMODE {
0: OpcdecFault::hw_st_cond();
format HwStore {
1: decode HW_LDST_COND {
0: decode HW_LDST_QUAD {
0: hw_st({{ EA = (Rb + disp) & ~3; }},
{{ Mem_ul = Ra<31:0>; }}, L, IsSerializing, IsSerializeBefore);
1: hw_st({{ EA = (Rb + disp) & ~7; }},
{{ Mem_uq = Ra_uq; }}, Q, IsSerializing, IsSerializeBefore);
}
1: FailUnimpl::hw_st_cond();
}
}
}
0x19: decode PALMODE {
0: OpcdecFault::hw_mfpr();
format HwMoveIPR {
1: hw_mfpr({{
int miscRegIndex = (ipr_index < MaxInternalProcRegs) ?
IprToMiscRegIndex[ipr_index] : -1;
if(miscRegIndex < 0 || !IprIsReadable(miscRegIndex) ||
miscRegIndex >= NumInternalProcRegs)
fault = std::make_shared<UnimplementedOpcodeFault>();
else
Ra = xc->readMiscReg(miscRegIndex);
}}, IsIprAccess);
}
}
0x1d: decode PALMODE {
0: OpcdecFault::hw_mtpr();
format HwMoveIPR {
1: hw_mtpr({{
int miscRegIndex = (ipr_index < MaxInternalProcRegs) ?
IprToMiscRegIndex[ipr_index] : -1;
if(miscRegIndex < 0 || !IprIsWritable(miscRegIndex) ||
miscRegIndex >= NumInternalProcRegs)
fault = std::make_shared<UnimplementedOpcodeFault>();
else
xc->setMiscReg(miscRegIndex, Ra);
if (traceData) { traceData->setData(Ra); }
}}, IsIprAccess);
}
}
0x1e: decode PALMODE {
0: OpcdecFault::hw_rei();
format BasicOperate {
1: hw_rei({{ xc->hwrei(); }}, IsSerializing, IsSerializeBefore);
}
}
format BasicOperate {
// M5 special opcodes use the reserved 0x01 opcode space
0x01: decode M5FUNC {
0x00: arm({{
PseudoInst::arm(xc->tcBase());
}}, IsNonSpeculative);
0x01: quiesce({{
// Don't sleep if (unmasked) interrupts are pending
Interrupts* interrupts =
xc->tcBase()->getCpuPtr()->getInterruptController(0);
if (interrupts->checkInterrupts(xc->tcBase())) {
PseudoInst::quiesceSkip(xc->tcBase());
} else {
PseudoInst::quiesce(xc->tcBase());
}
}}, IsNonSpeculative, IsQuiesce);
0x02: quiesceNs({{
PseudoInst::quiesceNs(xc->tcBase(), R16);
}}, IsNonSpeculative, IsQuiesce);
0x03: quiesceCycles({{
PseudoInst::quiesceCycles(xc->tcBase(), R16);
}}, IsNonSpeculative, IsQuiesce, IsUnverifiable);
0x04: quiesceTime({{
R0 = PseudoInst::quiesceTime(xc->tcBase());
}}, IsNonSpeculative, IsUnverifiable);
0x07: rpns({{
R0 = PseudoInst::rpns(xc->tcBase());
}}, IsNonSpeculative, IsUnverifiable);
0x09: wakeCPU({{
PseudoInst::wakeCPU(xc->tcBase(), R16);
}}, IsNonSpeculative, IsUnverifiable);
0x10: deprecated_ivlb({{
warn_once("Obsolete M5 ivlb instruction encountered.\n");
}});
0x11: deprecated_ivle({{
warn_once("Obsolete M5 ivlb instruction encountered.\n");
}});
0x20: deprecated_exit ({{
warn_once("deprecated M5 exit instruction encountered.\n");
PseudoInst::m5exit(xc->tcBase(), 0);
}}, No_OpClass, IsNonSpeculative);
0x21: m5exit({{
PseudoInst::m5exit(xc->tcBase(), R16);
}}, No_OpClass, IsNonSpeculative);
0x31: loadsymbol({{
PseudoInst::loadsymbol(xc->tcBase());
}}, No_OpClass, IsNonSpeculative);
0x30: initparam({{
Ra = PseudoInst::initParam(xc->tcBase(), R16, R17);
}});
0x40: resetstats({{
PseudoInst::resetstats(xc->tcBase(), R16, R17);
}}, IsNonSpeculative);
0x41: dumpstats({{
PseudoInst::dumpstats(xc->tcBase(), R16, R17);
}}, IsNonSpeculative);
0x42: dumpresetstats({{
PseudoInst::dumpresetstats(xc->tcBase(), R16, R17);
}}, IsNonSpeculative);
0x43: m5checkpoint({{
PseudoInst::m5checkpoint(xc->tcBase(), R16, R17);
}}, IsNonSpeculative);
0x50: m5readfile({{
R0 = PseudoInst::readfile(xc->tcBase(), R16, R17, R18);
}}, IsNonSpeculative);
0x51: m5break({{
PseudoInst::debugbreak(xc->tcBase());
}}, IsNonSpeculative);
0x52: m5switchcpu({{
PseudoInst::switchcpu(xc->tcBase());
}}, IsNonSpeculative);
0x53: m5addsymbol({{
PseudoInst::addsymbol(xc->tcBase(), R16, R17);
}}, IsNonSpeculative);
0x54: m5panic({{
panic("M5 panic instruction called at pc = %#x.", PC);
}}, IsNonSpeculative);
#define CPANN(lbl) CPA::cpa()->lbl(xc->tcBase())
0x55: decode RA {
0x00: m5a_old({{
panic("Deprecated M5 annotate instruction executed "
"at pc = %#x\n", PC);
}}, IsNonSpeculative);
0x01: m5a_bsm({{
CPANN(swSmBegin);
}}, IsNonSpeculative);
0x02: m5a_esm({{
CPANN(swSmEnd);
}}, IsNonSpeculative);
0x03: m5a_begin({{
CPANN(swExplictBegin);
}}, IsNonSpeculative);
0x04: m5a_end({{
CPANN(swEnd);
}}, IsNonSpeculative);
0x06: m5a_q({{
CPANN(swQ);
}}, IsNonSpeculative);
0x07: m5a_dq({{
CPANN(swDq);
}}, IsNonSpeculative);
0x08: m5a_wf({{
CPANN(swWf);
}}, IsNonSpeculative);
0x09: m5a_we({{
CPANN(swWe);
}}, IsNonSpeculative);
0x0C: m5a_sq({{
CPANN(swSq);
}}, IsNonSpeculative);
0x0D: m5a_aq({{
CPANN(swAq);
}}, IsNonSpeculative);
0x0E: m5a_pq({{
CPANN(swPq);
}}, IsNonSpeculative);
0x0F: m5a_l({{
CPANN(swLink);
}}, IsNonSpeculative);
0x10: m5a_identify({{
CPANN(swIdentify);
}}, IsNonSpeculative);
0x11: m5a_getid({{
R0 = CPANN(swGetId);
}}, IsNonSpeculative);
0x13: m5a_scl({{
CPANN(swSyscallLink);
}}, IsNonSpeculative);
0x14: m5a_rq({{
CPANN(swRq);
}}, IsNonSpeculative);
} // M5 Annotate Operations
#undef CPANN
0x56: m5reserved2({{
warn("M5 reserved opcode ignored");
}}, IsNonSpeculative);
0x57: m5reserved3({{
warn("M5 reserved opcode ignored");
}}, IsNonSpeculative);
0x58: m5reserved4({{
warn("M5 reserved opcode ignored");
}}, IsNonSpeculative);
0x59: m5reserved5({{
warn("M5 reserved opcode ignored");
}}, IsNonSpeculative);
}
}
}