X86: Fix argument register indexing.

Code was assuming that all argument registers followed in order from ArgumentReg0. There is now an ArgumentReg array which is indexed to find the right index. There is a constant, NumArgumentRegs, which can be used to protect against using an invalid ArgumentReg.

--HG--
extra : convert_revision : f448a3ca4d6adc3fc3323562870f70eec05a8a1f

1 files changed, 4 insertions, 2 deletions

diff --git a/src/cpu/o3/sparc/cpu_impl.hh b/src/cpu/o3/sparc/cpu_impl.hh
index 2e398577e..068057fc0 100644
--- a/src/cpu/o3/sparc/cpu_impl.hh
+++ b/src/cpu/o3/sparc/cpu_impl.hh
@@ -270,8 +270,9 @@ template <class Impl>
 TheISA::IntReg
 SparcO3CPU<Impl>::getSyscallArg(int i, int tid)
 {
+    assert(i < TheISA::NumArgumentRegs);
     TheISA::IntReg idx = TheISA::flattenIntIndex(this->tcBase(tid),
-            SparcISA::ArgumentReg0 + i);
+            SparcISA::ArgumentReg[i]);
     TheISA::IntReg val = this->readArchIntReg(idx, tid);
     if (bits(this->readMiscRegNoEffect(SparcISA::MISCREG_PSTATE, tid), 3, 3))
         val = bits(val, 31, 0);
@@ -282,8 +283,9 @@ template <class Impl>
 void
 SparcO3CPU<Impl>::setSyscallArg(int i, TheISA::IntReg val, int tid)
 {
+    assert(i < TheISA::NumArgumentRegs);
     TheISA::IntReg idx = TheISA::flattenIntIndex(this->tcBase(tid),
-            SparcISA::ArgumentReg0 + i);
+            SparcISA::ArgumentReg[i]);
     this->setArchIntReg(idx, val, tid);
 }