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authorMin Kyu Jeong <minkyu.jeong@arm.com>2010-08-23 11:18:40 -0500
committerMin Kyu Jeong <minkyu.jeong@arm.com>2010-08-23 11:18:40 -0500
commit5f91ec3f4618dad8d36efbf8b5a5112a1ce0d1b7 (patch)
tree3984b0d3f3328901bf8c999b9d01162943fb328d
parent7acf67971cca761efec79a0a0ac453b1115387a9 (diff)
downloadgem5-5f91ec3f4618dad8d36efbf8b5a5112a1ce0d1b7.tar.xz
ARM/O3: store the result of the predicate evaluation in DynInst or Threadstate.
THis allows the CPU to handle predicated-false instructions accordingly. This particular patch makes loads that are predicated-false to be sent straight to the commit stage directly, not waiting for return of the data that was never requested since it was predicated-false.
-rw-r--r--src/arch/arm/isa/templates/mem.isa21
-rw-r--r--src/arch/arm/isa/templates/pred.isa2
-rw-r--r--src/cpu/base_dyn_inst.hh13
-rw-r--r--src/cpu/base_dyn_inst_impl.hh1
-rw-r--r--src/cpu/o3/lsq_unit_impl.hh18
-rw-r--r--src/cpu/simple/base.hh3
-rw-r--r--src/cpu/simple_thread.hh13
-rw-r--r--src/cpu/thread_context.hh5
8 files changed, 71 insertions, 5 deletions
diff --git a/src/arch/arm/isa/templates/mem.isa b/src/arch/arm/isa/templates/mem.isa
index ea66ce2a6..5431777b2 100644
--- a/src/arch/arm/isa/templates/mem.isa
+++ b/src/arch/arm/isa/templates/mem.isa
@@ -69,6 +69,8 @@ def template SwapExecute {{
if (fault == NoFault) {
%(op_wb)s;
}
+ } else {
+ xc->setPredicate(false);
}
if (fault == NoFault && machInst.itstateMask != 0) {
@@ -103,6 +105,8 @@ def template SwapInitiateAcc {{
if (fault == NoFault) {
%(op_wb)s;
}
+ } else {
+ xc->setPredicate(false);
}
if (fault == NoFault && machInst.itstateMask != 0) {
@@ -164,6 +168,8 @@ def template LoadExecute {{
if (fault == NoFault) {
%(op_wb)s;
}
+ } else {
+ xc->setPredicate(false);
}
if (fault == NoFault && machInst.itstateMask != 0) {
@@ -200,6 +206,8 @@ def template StoreExecute {{
if (fault == NoFault) {
%(op_wb)s;
}
+ } else {
+ xc->setPredicate(false);
}
if (fault == NoFault && machInst.itstateMask != 0) {
@@ -242,6 +250,8 @@ def template StoreExExecute {{
if (fault == NoFault) {
%(op_wb)s;
}
+ } else {
+ xc->setPredicate(false);
}
if (fault == NoFault && machInst.itstateMask != 0) {
@@ -279,6 +289,8 @@ def template StoreExInitiateAcc {{
if (fault == NoFault) {
%(op_wb)s;
}
+ } else {
+ xc->setPredicate(false);
}
if (fault == NoFault && machInst.itstateMask != 0) {
@@ -316,6 +328,8 @@ def template StoreInitiateAcc {{
if (fault == NoFault) {
%(op_wb)s;
}
+ } else {
+ xc->setPredicate(false);
}
if (fault == NoFault && machInst.itstateMask != 0) {
@@ -342,8 +356,11 @@ def template LoadInitiateAcc {{
if (fault == NoFault) {
fault = xc->read(EA, (uint%(mem_acc_size)d_t &)Mem, memAccessFlags);
}
- } else if (fault == NoFault && machInst.itstateMask != 0) {
- xc->setMiscReg(MISCREG_ITSTATE, machInst.newItstate);
+ } else {
+ xc->setPredicate(false);
+ if (fault == NoFault && machInst.itstateMask != 0) {
+ xc->setMiscReg(MISCREG_ITSTATE, machInst.newItstate);
+ }
}
return fault;
diff --git a/src/arch/arm/isa/templates/pred.isa b/src/arch/arm/isa/templates/pred.isa
index 7a5b92760..1029cfaee 100644
--- a/src/arch/arm/isa/templates/pred.isa
+++ b/src/arch/arm/isa/templates/pred.isa
@@ -142,6 +142,8 @@ def template PredOpExecute {{
{
%(op_wb)s;
}
+ } else {
+ xc->setPredicate(false);
}
if (fault == NoFault && machInst.itstateMask != 0) {
diff --git a/src/cpu/base_dyn_inst.hh b/src/cpu/base_dyn_inst.hh
index 6ea00dd3d..a992664d0 100644
--- a/src/cpu/base_dyn_inst.hh
+++ b/src/cpu/base_dyn_inst.hh
@@ -246,6 +246,9 @@ class BaseDynInst : public FastAlloc, public RefCounted
/** Micro PC of this instruction. */
Addr microPC;
+ /** Did this instruction execute, or is it predicated false */
+ bool predicate;
+
protected:
/** Next non-speculative PC. It is not filled in at fetch, but rather
* once the target of the branch is truly known (either decode or
@@ -794,6 +797,16 @@ class BaseDynInst : public FastAlloc, public RefCounted
nextMicroPC = val;
}
+ bool readPredicate()
+ {
+ return predicate;
+ }
+
+ void setPredicate(bool val)
+ {
+ predicate = val;
+ }
+
/** Sets the ASID. */
void setASID(short addr_space_id) { asid = addr_space_id; }
diff --git a/src/cpu/base_dyn_inst_impl.hh b/src/cpu/base_dyn_inst_impl.hh
index 70c91ceda..7425431db 100644
--- a/src/cpu/base_dyn_inst_impl.hh
+++ b/src/cpu/base_dyn_inst_impl.hh
@@ -154,6 +154,7 @@ BaseDynInst<Impl>::initVars()
eaCalcDone = false;
memOpDone = false;
+ predicate = true;
lqIdx = -1;
sqIdx = -1;
diff --git a/src/cpu/o3/lsq_unit_impl.hh b/src/cpu/o3/lsq_unit_impl.hh
index fcc57ab09..dddfb7e1b 100644
--- a/src/cpu/o3/lsq_unit_impl.hh
+++ b/src/cpu/o3/lsq_unit_impl.hh
@@ -1,4 +1,16 @@
/*
+ * Copyright (c) 2010 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) 2004-2005 The Regents of The University of Michigan
* All rights reserved.
*
@@ -439,9 +451,9 @@ LSQUnit<Impl>::executeLoad(DynInstPtr &inst)
load_fault = inst->initiateAcc();
- // If the instruction faulted, then we need to send it along to commit
- // without the instruction completing.
- if (load_fault != NoFault) {
+ // If the instruction faulted or predicated false, then we need to send it
+ // along to commit without the instruction completing.
+ if (load_fault != NoFault || inst->readPredicate() == false) {
// Send this instruction to commit, also make sure iew stage
// realizes there is activity.
// Mark it as executed unless it is an uncached load that
diff --git a/src/cpu/simple/base.hh b/src/cpu/simple/base.hh
index 1265a1f2f..90cb81c0c 100644
--- a/src/cpu/simple/base.hh
+++ b/src/cpu/simple/base.hh
@@ -287,12 +287,15 @@ class BaseSimpleCPU : public BaseCPU
uint64_t readNextPC() { return thread->readNextPC(); }
uint64_t readNextMicroPC() { return thread->readNextMicroPC(); }
uint64_t readNextNPC() { return thread->readNextNPC(); }
+ bool readPredicate() { return thread->readPredicate(); }
void setPC(uint64_t val) { thread->setPC(val); }
void setMicroPC(uint64_t val) { thread->setMicroPC(val); }
void setNextPC(uint64_t val) { thread->setNextPC(val); }
void setNextMicroPC(uint64_t val) { thread->setNextMicroPC(val); }
void setNextNPC(uint64_t val) { thread->setNextNPC(val); }
+ void setPredicate(bool val)
+ { return thread->setPredicate(val); }
MiscReg readMiscRegNoEffect(int misc_reg)
{
diff --git a/src/cpu/simple_thread.hh b/src/cpu/simple_thread.hh
index bc8588041..dcd933ffc 100644
--- a/src/cpu/simple_thread.hh
+++ b/src/cpu/simple_thread.hh
@@ -128,6 +128,9 @@ class SimpleThread : public ThreadState
*/
Addr nextNPC;
+ /** Did this instruction execute or is it predicated false */
+ bool predicate;
+
public:
// pointer to CPU associated with this SimpleThread
BaseCPU *cpu;
@@ -371,6 +374,16 @@ class SimpleThread : public ThreadState
#endif
}
+ bool readPredicate()
+ {
+ return predicate;
+ }
+
+ void setPredicate(bool val)
+ {
+ predicate = val;
+ }
+
MiscReg
readMiscRegNoEffect(int misc_reg, ThreadID tid = 0)
{
diff --git a/src/cpu/thread_context.hh b/src/cpu/thread_context.hh
index 78ecdacf2..7f6d258ab 100644
--- a/src/cpu/thread_context.hh
+++ b/src/cpu/thread_context.hh
@@ -404,6 +404,11 @@ class ProxyThreadContext : public ThreadContext
void setNextMicroPC(uint64_t val) { actualTC->setNextMicroPC(val); }
+ bool readPredicate() { return actualTC->readPredicate(); }
+
+ void setPredicate(bool val)
+ { actualTC->setPredicate(val); }
+
MiscReg readMiscRegNoEffect(int misc_reg)
{ return actualTC->readMiscRegNoEffect(misc_reg); }