ART: Change temporaries to positive names

Changes compiler temporaries to have positive names. The numbering now
puts them above the code VRs (locals + ins, in that order). The patch also
introduces APIs to query the number of temporaries, locals and ins.

The compiler temp infrastructure suffered from several issues
which are also addressed by this patch:
-There is no longer a queue of compiler temps. This would be polluted
with Method* when post opts were called multiple times.
-Sanity checks have been added to allow requesting of temps from BE
and to prevent temps after frame is committed.
-None of the structures holding temps can overflow because they are
allocated to allow holding maximum temps. Thus temps can be requested
by BE with no problem.
-Since the queue of compiler temps is no longer maintained, it is no
longer possible to refer to a temp that has invalid ssa (because it
was requested before ssa was run).
-The BE can now request temps after all ME allocations and it is guaranteed
to actually receive them.
-ME temps are now treated like normal VRs in all cases with no special
handling. Only the BE temps are handled specially because there are no
references to them from MIRs.
-Deprecated and removed several fields in CompilationUnit that saved
register information and updated callsites to call the new interface from
MIRGraph.

Change-Id: Ia8b1fec9384a1a83017800a59e5b0498dfb2698c
Signed-off-by: Razvan A Lupusoru <razvan.a.lupusoru@intel.com>
Signed-off-by: Udayan Banerji <udayan.banerji@intel.com>

1 files changed, 13 insertions, 17 deletions

diff --git a/compiler/dex/vreg_analysis.cc b/compiler/dex/vreg_analysis.cc
index 0d8a6f8793..bdfab130c0 100644
--- a/compiler/dex/vreg_analysis.cc
+++ b/compiler/dex/vreg_analysis.cc
@@ -401,7 +401,7 @@ bool MIRGraph::InferTypeAndSize(BasicBlock* bb, MIR* mir, bool changed) {
   return changed;
 }
 
-static const char* storage_name[] = {" Frame ", "PhysReg", " Spill "};
+static const char* storage_name[] = {" Frame ", "PhysReg", " CompilerTemp "};
 
 void MIRGraph::DumpRegLocTable(RegLocation* table, int count) {
   for (int i = 0; i < count; i++) {
@@ -421,7 +421,9 @@ static const RegLocation fresh_loc = {kLocDalvikFrame, 0, 0, 0, 0, 0, 0, 0, 0,
                                       RegStorage(), INVALID_SREG, INVALID_SREG};
 
 void MIRGraph::InitRegLocations() {
-  /* Allocate the location map */
+  // Allocate the location map. We also include the maximum possible temps because
+  // the temp allocation initializes reg location as well (in order to deal with
+  // case when it will be called after this pass).
   int max_regs = GetNumSSARegs() + GetMaxPossibleCompilerTemps();
   RegLocation* loc = static_cast<RegLocation*>(arena_->Alloc(max_regs * sizeof(*loc),
                                                              kArenaAllocRegAlloc));
@@ -432,22 +434,18 @@ void MIRGraph::InitRegLocations() {
     loc[i].wide = false;
   }
 
-  /* Patch up the locations for the compiler temps */
-  GrowableArray<CompilerTemp*>::Iterator iter(&compiler_temps_);
-  for (CompilerTemp* ct = iter.Next(); ct != NULL; ct = iter.Next()) {
-    loc[ct->s_reg_low].location = kLocCompilerTemp;
-    loc[ct->s_reg_low].defined = true;
-  }
-
   /* Treat Method* as a normal reference */
-  loc[GetMethodSReg()].ref = true;
+  int method_sreg = GetMethodSReg();
+  loc[method_sreg].ref = true;
+  loc[method_sreg].location = kLocCompilerTemp;
+  loc[method_sreg].defined = true;
 
   reg_location_ = loc;
 
-  int num_regs = cu_->num_dalvik_registers;
+  int num_regs = GetNumOfCodeVRs();
 
   /* Add types of incoming arguments based on signature */
-  int num_ins = cu_->num_ins;
+  int num_ins = GetNumOfInVRs();
   if (num_ins > 0) {
     int s_reg = num_regs - num_ins;
     if ((cu_->access_flags & kAccStatic) == 0) {
@@ -502,11 +500,9 @@ void MIRGraph::InitRegLocations() {
  */
 void MIRGraph::RemapRegLocations() {
   for (int i = 0; i < GetNumSSARegs(); i++) {
-    if (reg_location_[i].location != kLocCompilerTemp) {
-      int orig_sreg = reg_location_[i].s_reg_low;
-      reg_location_[i].orig_sreg = orig_sreg;
-      reg_location_[i].s_reg_low = SRegToVReg(orig_sreg);
-    }
+    int orig_sreg = reg_location_[i].s_reg_low;
+    reg_location_[i].orig_sreg = orig_sreg;
+    reg_location_[i].s_reg_low = SRegToVReg(orig_sreg);
   }
 }