From 2b054aca2584046eb9957a3254d9a3fa0fb63b07 Mon Sep 17 00:00:00 2001
From: jdh8d <jdh8d@git.zephyr-software.com>
Date: Thu, 1 Mar 2018 18:09:54 +0000
Subject: [PATCH] Removed bea engine from lots of inclue places and link steps,
changed verbose mode for zipr to false, added very-verbose mode for zipr.
fixed a few zipr bugs related to non-existant fallthroughs, etc.
---
include/zipr_impl.h | 15 ++++-
src/zipr.cpp | 133 +++++++++++++++++++++++++++++---------------
2 files changed, 100 insertions(+), 48 deletions(-)
diff --git a/include/zipr_impl.h b/include/zipr_impl.h
index 44824fd..e90fa9b 100644
--- a/include/zipr_impl.h
+++ b/include/zipr_impl.h
@@ -52,7 +52,8 @@ class ZiprImpl_t : public Zipr_t
m_callbacks("callbacks"),
m_objcopy("objcopy", "/usr/bin/objcopy"),
m_replop("replop", false),
- m_verbose("verbose", true),
+ m_verbose("verbose", false),
+ m_vverbose("very_verbose", false),
m_apply_nop("apply_nop", false),
m_add_sections("add-sections", false),
m_bss_opts("bss-opts", true),
@@ -343,6 +344,16 @@ class ZiprImpl_t : public Zipr_t
// exist by adding direct jump instructions where necessary to eliminate multiple fallthroughs.
void FixMultipleFallthroughs();
+ // zipr assumes that jumps (jcc and jmp) are either 2 or 5 byte.
+ // sometimes they include a prefix to help the branch predictor
+ // remove unneeded prefixes to meet zipr assumptions.
+ void FixTwoByteWithPrefix();
+
+ // zipr also has internal assumptions about conditional branches having targets/fallthrougsh.
+ // patch any instructions with null fallthrougsh and targtes a halt instruction
+ void FixNoFallthroughs();
+
+
/*
* DetermineWorstCaseInsnSize
@@ -491,7 +502,7 @@ class ZiprImpl_t : public Zipr_t
// Options
ZiprOptions_t m_zipr_options;
ZiprStringOption_t m_output_filename, m_callbacks, m_objcopy;
- ZiprBooleanOption_t m_replop, m_verbose, m_apply_nop, m_add_sections, m_bss_opts;
+ ZiprBooleanOption_t m_replop, m_verbose, m_vverbose, m_apply_nop, m_add_sections, m_bss_opts;
ZiprIntegerOption_t m_variant, m_architecture, m_seed;
ZiprStringOption_t m_dollop_map_filename;
diff --git a/src/zipr.cpp b/src/zipr.cpp
index ec5f9f9..1ad2a1f 100644
--- a/src/zipr.cpp
+++ b/src/zipr.cpp
@@ -186,6 +186,7 @@ ZiprOptionsNamespace_t *ZiprImpl_t::RegisterOptions(ZiprOptionsNamespace_t *glob
global->AddOption(&m_variant);
global->AddOption(&m_verbose);
+ global->AddOption(&m_vverbose);
global->AddOption(&m_apply_nop);
global->AddOption(&m_add_sections);
global->AddOption(&m_bss_opts);
@@ -226,8 +227,11 @@ void ZiprImpl_t::CreateBinaryFile()
cout << "Seeded the random number generator with " << m_seed << "." << endl;
+ FixTwoByteWithPrefix(); // have to do this before multi-fallthrough in case it creaates some.
+ FixNoFallthroughs(); // have to do this before multi-fallthrough in case it creaates some.
FixMultipleFallthroughs();
+
// create ranges, including extra range that's def. big enough.
FindFreeRanges(m_output_filename);
@@ -2024,7 +2028,7 @@ void ZiprImpl_t::PlaceDollops()
to_place = pq_entry.first;
from_address = pq_entry.second;
- if (m_verbose)
+ if (m_vverbose)
cout << "Original starting address: " << std::hex
<< to_place->front()->Instruction()->GetAddress()->GetVirtualOffset()
<< endl;
@@ -2193,7 +2197,7 @@ void ZiprImpl_t::PlaceDollops()
//cout << "Adjusting cur_addr to " << std::hex << cur_addr << " at A." << endl;
has_fallthrough = (to_place->FallthroughDollop() != NULL);
- if (m_verbose)
+ if (m_vverbose)
{
cout << "Placing " << std::dec << to_place->GetSize() << " dollop in "
<< std::dec << (placement.GetEnd() - placement.GetStart())
@@ -2369,26 +2373,8 @@ void ZiprImpl_t::PlaceDollops()
) < Utils::TRAMPOLINE_SIZE
));
- if (m_verbose)
+ if (m_vverbose)
{
-#if 0
- cout << "de_and_fallthrough_fit : "
- << de_and_fallthrough_fit << endl
- << "last_de_fits : "
- << last_de_fits << endl
- << "fits_entirely : "
- << fits_entirely << endl
- << "all_fallthroughs_fit : "
- << all_fallthroughs_fit << endl
- << "initial_placement_abuts_pin : "
- << initial_placement_abuts_pin << endl
- << "initial_placement_abuts_fallthrough: "
- << initial_placement_abuts_fallthrough << endl
- << "initial_placement_abuts_pin : "
- << initial_placement_abuts_pin << endl
- << "disallowed_override : "
- << disallowed_override << endl;
-#else
struct custom_bool : numpunct<char>
{
protected:
@@ -2411,7 +2397,6 @@ void ZiprImpl_t::PlaceDollops()
<< initial_placement_abuts_pin << ", "
<< disallowed_override << noboolalpha << endl;
-#endif
}
if ((de_and_fallthrough_fit ||
@@ -2421,8 +2406,7 @@ void ZiprImpl_t::PlaceDollops()
initial_placement_abuts_pin ||
all_fallthroughs_fit) && !disallowed_override)
{
-#if 1
- if (m_verbose) {
+ if (m_vverbose) {
/*DISASM d;
Disassemble(dollop_entry->Instruction(),d);
*/
@@ -2430,14 +2414,13 @@ void ZiprImpl_t::PlaceDollops()
cout << std::hex << dollop_entry->Instruction()->GetBaseID()
<< ":" << d.getDisassembly()/*.CompleteInstr*/ << endl;
}
-#endif
dollop_entry->Place(cur_addr);
cur_addr+=DetermineWorstCaseDollopEntrySize(dollop_entry,
false);
//cout << "Adjusting cur_addr to " << std::hex << cur_addr << " at B." << endl;
if (dollop_entry->TargetDollop())
{
- if (m_verbose)
+ if (m_vverbose)
cout << "Adding " << std::hex << dollop_entry->TargetDollop()
<< " to placement queue." << endl;
placement_queue.insert(pair<Dollop_t*, RangeAddress_t>(
@@ -2470,7 +2453,7 @@ void ZiprImpl_t::PlaceDollops()
if (am_coalescing)
m_stats->truncated_dollops_during_coalesce++;
- if (m_verbose)
+ if (m_vverbose)
cout << "Split a "
<< ((am_coalescing) ? "coalesced " : " ")
<< "dollop because it didn't fit. Fallthrough to "
@@ -2577,7 +2560,7 @@ void ZiprImpl_t::PlaceDollops()
* smaller than the first instruction fallthrough
* in the fallthrough dollop and the trampoline size.
*/
- if (m_verbose)
+ if (m_vverbose)
cout << "Determining whether to coalesce: "
<< "Remaining: " << std::dec << remaining_size
<< " vs Needed: " << std::dec
@@ -2607,12 +2590,10 @@ void ZiprImpl_t::PlaceDollops()
to_place->push_back(patch_de);
to_place->FallthroughPatched(true);
- if (m_verbose)
+ if (m_vverbose)
cout << "Not coalescing"
- << string((fallthrough->IsPlaced()) ?
- " because fallthrough is placed" : "")
- << string((!allowed_coalescing) ?
- " because I am not allowed" : "")
+ << string((fallthrough->IsPlaced()) ? " because fallthrough is placed" : "")
+ << string((!allowed_coalescing) ? " because I am not allowed" : "")
<< "; Added jump (via " << std::hex << patch_de
<< " at " << std::hex << patch_de->Place() << ") "
<< "to fallthrough dollop (" << std::hex
@@ -2637,7 +2618,7 @@ void ZiprImpl_t::PlaceDollops()
}
else
{
- if (m_verbose)
+ if (m_vverbose)
cout << "Coalescing fallthrough dollop." << endl;
to_place->WasCoalesced(true);
/*
@@ -2658,7 +2639,7 @@ void ZiprImpl_t::PlaceDollops()
/*
* Reserve the range that we just used.
*/
- if (m_verbose)
+ if (m_vverbose)
cout << "Reserving " << std::hex << placement.GetStart()
<< ", " << std::hex << cur_addr << "." << endl;
memory_space.SplitFreeRange(Range_t(placement.GetStart(), cur_addr));
@@ -3344,7 +3325,14 @@ RangeAddress_t ZiprImpl_t::PlopDollopEntryWithTarget(
* is the last of the dollop.
*/
if (!fallthrough_de)
- fallthrough_de = entry->MemberOfDollop()->FallthroughDollop()->front();
+ {
+ if(entry->MemberOfDollop()->FallthroughDollop())
+ fallthrough_de = entry->MemberOfDollop()->FallthroughDollop()->front();
+ else
+ // even a cond branch may have a null fallthrough, account for that here
+ // by plopping nothing
+ return ret;
+ }
assert(fallthrough_de && fallthrough_de->IsPlaced());
@@ -3793,15 +3781,6 @@ int find_magic_segment_index(ELFIO::elfio *elfiop)
{
ELFIO::segment* seg = elfiop->segments[i];
assert(seg);
-#if 0
- if( (seg->get_flags() & PF_X) == 0 )
- continue;
- if( (seg->get_flags() & PF_R) == 0)
- continue;
- last_seg=seg;
- last_seg_index=i;
- break;
-#else
if(seg->get_type() != PT_LOAD)
continue;
if(last_seg && (last_seg->get_virtual_address() + last_seg->get_memory_size()) > (seg->get_virtual_address() + seg->get_memory_size()))
@@ -3810,7 +3789,6 @@ int find_magic_segment_index(ELFIO::elfio *elfiop)
continue;
last_seg=seg;
last_seg_index=i;
-#endif
}
cout<<"Found magic Seg #"<<std::dec<<last_seg_index<<" has file offset "<<last_seg->get_offset()<<endl;
return last_seg_index;
@@ -4214,6 +4192,69 @@ void ZiprImpl_t::UpdateScoops()
+void ZiprImpl_t::FixNoFallthroughs()
+{
+ Instruction_t *hlt=addNewAssembly(m_firp, NULL, "hlt");
+ hlt->SetFallthrough(hlt);
+
+ for(const auto insn : m_firp->GetInstructions())
+ {
+ if(insn==hlt) continue;
+
+ if(insn->GetFallthrough()==NULL)
+ {
+ const auto d=DecodedInstruction_t(insn);
+ if(d.isConditionalBranch())
+ insn->SetFallthrough(hlt);
+ }
+ if(insn->GetTarget()==NULL)
+ {
+ const auto d=DecodedInstruction_t(insn);
+ if(d.isBranch() && !d.isReturn() && d.hasOperand(0) && d.getOperand(0).isConstant())
+ insn->SetTarget(hlt);
+ }
+
+ }
+
+
+}
+
+void ZiprImpl_t::FixTwoByteWithPrefix()
+{
+ for(const auto insn : m_firp->GetInstructions())
+ {
+ const auto d=DecodedInstruction_t(insn);
+ if(!d.isBranch()) continue;
+ if(d.isReturn()) continue;
+ if(d.getOperands().size()!=1) continue;
+ if(!d.getOperand(0).isConstant()) continue;
+
+ auto done=false;
+ while (!done)
+ {
+ char b=insn->GetDataBits()[0];
+ switch(b)
+ {
+
+ case (char)0x2e:
+ case (char)0x3e:
+ case (char)0x64:
+ case (char)0x65:
+ {
+ // remove prefix
+ insn->SetDataBits(insn->GetDataBits().erase(0,1));
+ break;
+ }
+ default:
+ done=1;
+ break;
+ }
+ }
+
+ }
+}
+
+
void ZiprImpl_t::FixMultipleFallthroughs()
{
int count=0;
--
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