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authorGabe Black <gblack@eecs.umich.edu>2011-02-13 17:40:07 -0800
committerGabe Black <gblack@eecs.umich.edu>2011-02-13 17:40:07 -0800
commitf036fd97481081afce7f757231ab69ba212f7f2a (patch)
tree34dc558f4264e932d6019f680fad511eb32b8e99 /src/cpu/o3/fetch_impl.hh
parent7c763b34c9fc69a4e13a8f74df0f981fdf71f221 (diff)
downloadgem5-f036fd97481081afce7f757231ab69ba212f7f2a.tar.xz
O3: Fetch from the microcode ROM when needed.
Diffstat (limited to 'src/cpu/o3/fetch_impl.hh')
-rw-r--r--src/cpu/o3/fetch_impl.hh17
1 files changed, 12 insertions, 5 deletions
diff --git a/src/cpu/o3/fetch_impl.hh b/src/cpu/o3/fetch_impl.hh
index 2e4e4819e..d2cde496e 100644
--- a/src/cpu/o3/fetch_impl.hh
+++ b/src/cpu/o3/fetch_impl.hh
@@ -1070,6 +1070,8 @@ DefaultFetch<Impl>::fetch(bool &status_change)
Addr pcOffset = fetchOffset[tid];
Addr fetchAddr = (thisPC.instAddr() + pcOffset) & BaseCPU::PCMask;
+ bool inRom = isRomMicroPC(thisPC.microPC());
+
// If returning from the delay of a cache miss, then update the status
// to running, otherwise do the cache access. Possibly move this up
// to tick() function.
@@ -1083,7 +1085,7 @@ DefaultFetch<Impl>::fetch(bool &status_change)
Addr block_PC = icacheBlockAlignPC(fetchAddr);
// Unless buffer already got the block, fetch it from icache.
- if (!cacheDataValid[tid] || block_PC != cacheDataPC[tid]) {
+ if (!(cacheDataValid[tid] && block_PC == cacheDataPC[tid]) && !inRom) {
DPRINTF(Fetch, "[tid:%i]: Attempting to translate and read "
"instruction, starting at PC %s.\n", tid, thisPC);
@@ -1155,7 +1157,7 @@ DefaultFetch<Impl>::fetch(bool &status_change)
!predictedBranch) {
// If we need to process more memory, do it now.
- if (!curMacroop && !predecoder.extMachInstReady()) {
+ if (!(curMacroop || inRom) && !predecoder.extMachInstReady()) {
if (ISA_HAS_DELAY_SLOT && pcOffset == 0) {
// Walk past any annulled delay slot instructions.
Addr pcAddr = thisPC.instAddr() & BaseCPU::PCMask;
@@ -1181,7 +1183,7 @@ DefaultFetch<Impl>::fetch(bool &status_change)
// Extract as many instructions and/or microops as we can from
// the memory we've processed so far.
do {
- if (!curMacroop) {
+ if (!(curMacroop || inRom)) {
if (predecoder.extMachInstReady()) {
ExtMachInst extMachInst;
@@ -1202,8 +1204,13 @@ DefaultFetch<Impl>::fetch(bool &status_change)
break;
}
}
- if (curMacroop) {
- staticInst = curMacroop->fetchMicroop(thisPC.microPC());
+ if (curMacroop || inRom) {
+ if (inRom) {
+ staticInst = cpu->microcodeRom.fetchMicroop(
+ thisPC.microPC(), curMacroop);
+ } else {
+ staticInst = curMacroop->fetchMicroop(thisPC.microPC());
+ }
if (staticInst->isLastMicroop()) {
curMacroop = NULL;
pcOffset = 0;