arch,cpu: Add vector predicate registers

Latest-gen. vector/SIMD extensions, including the Arm Scalable Vector
Extension (SVE), introduce the notion of a predicate register file.
This changeset adds this feature across architectures and CPU models.

Change-Id: Iebcadbad89c0a582ff8b1b70de353305db603946
Signed-off-by: Giacomo Gabrielli <giacomo.gabrielli@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13715
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

2 files changed, 57 insertions, 2 deletions

diff --git a/src/cpu/checker/cpu.hh b/src/cpu/checker/cpu.hh
index 4468689bd..9d6061ad8 100644
--- a/src/cpu/checker/cpu.hh
+++ b/src/cpu/checker/cpu.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2016 ARM Limited
+ * Copyright (c) 2011, 2016-2017 ARM Limited
  * Copyright (c) 2013 Advanced Micro Devices, Inc.
  * All rights reserved
  *
@@ -304,6 +304,22 @@ class CheckerCPU : public BaseCPU, public ExecContext
         return thread->readVecElem(reg);
     }
 
+    const VecPredRegContainer&
+    readVecPredRegOperand(const StaticInst *si, int idx) const override
+    {
+        const RegId& reg = si->srcRegIdx(idx);
+        assert(reg.isVecPredReg());
+        return thread->readVecPredReg(reg);
+    }
+
+    VecPredRegContainer&
+    getWritableVecPredRegOperand(const StaticInst *si, int idx) override
+    {
+        const RegId& reg = si->destRegIdx(idx);
+        assert(reg.isVecPredReg());
+        return thread->getWritableVecPredReg(reg);
+    }
+
     CCReg
     readCCRegOperand(const StaticInst *si, int idx) override
     {
@@ -336,6 +352,14 @@ class CheckerCPU : public BaseCPU, public ExecContext
                                InstResult::ResultType::VecElem));
     }
 
+    template<typename T>
+    void
+    setVecPredResult(T&& t)
+    {
+        result.push(InstResult(std::forward<T>(t),
+                               InstResult::ResultType::VecPredReg));
+    }
+
     void
     setIntRegOperand(const StaticInst *si, int idx, RegVal val) override
     {
@@ -383,6 +407,15 @@ class CheckerCPU : public BaseCPU, public ExecContext
         setVecElemResult(val);
     }
 
+    void setVecPredRegOperand(const StaticInst *si, int idx,
+                              const VecPredRegContainer& val) override
+    {
+        const RegId& reg = si->destRegIdx(idx);
+        assert(reg.isVecPredReg());
+        thread->setVecPredReg(reg, val);
+        setVecPredResult(val);
+    }
+
     bool readPredicate() const override { return thread->readPredicate(); }
 
     void
diff --git a/src/cpu/checker/thread_context.hh b/src/cpu/checker/thread_context.hh
index b5a2079ea..8ce5a740d 100644
--- a/src/cpu/checker/thread_context.hh
+++ b/src/cpu/checker/thread_context.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011-2012, 2016 ARM Limited
+ * Copyright (c) 2011-2012, 2016-2018 ARM Limited
  * Copyright (c) 2013 Advanced Micro Devices, Inc.
  * All rights reserved
  *
@@ -263,6 +263,12 @@ class CheckerThreadContext : public ThreadContext
     const VecElem& readVecElem(const RegId& reg) const
     { return actualTC->readVecElem(reg); }
 
+    const VecPredRegContainer& readVecPredReg(const RegId& reg) const override
+    { return actualTC->readVecPredReg(reg); }
+
+    VecPredRegContainer& getWritableVecPredReg(const RegId& reg) override
+    { return actualTC->getWritableVecPredReg(reg); }
+
     CCReg readCCReg(int reg_idx)
     { return actualTC->readCCReg(reg_idx); }
 
@@ -295,6 +301,13 @@ class CheckerThreadContext : public ThreadContext
     }
 
     void
+    setVecPredReg(const RegId& reg, const VecPredRegContainer& val)
+    {
+        actualTC->setVecPredReg(reg, val);
+        checkerTC->setVecPredReg(reg, val);
+    }
+
+    void
     setCCReg(int reg_idx, CCReg val)
     {
         actualTC->setCCReg(reg_idx, val);
@@ -428,6 +441,15 @@ class CheckerThreadContext : public ThreadContext
                         const ElemIndex& elem_idx, const VecElem& val)
     { actualTC->setVecElemFlat(idx, elem_idx, val); }
 
+    const VecPredRegContainer& readVecPredRegFlat(int idx) const override
+    { return actualTC->readVecPredRegFlat(idx); }
+
+    VecPredRegContainer& getWritableVecPredRegFlat(int idx) override
+    { return actualTC->getWritableVecPredRegFlat(idx); }
+
+    void setVecPredRegFlat(int idx, const VecPredRegContainer& val) override
+    { actualTC->setVecPredRegFlat(idx, val); }
+
     CCReg readCCRegFlat(int idx)
     { return actualTC->readCCRegFlat(idx); }