VM: More compact code for pushing constant arguments on ia32/x64.

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
diff --git a/runtime/vm/intermediate_language_ia32.cc b/runtime/vm/intermediate_language_ia32.cc
index 62d8bef02cce1a8e1cb43ff90512e15ebc583680..63b6731238f5856574f540c3c726b33a2ff65bf9 100644
--- a/runtime/vm/intermediate_language_ia32.cc
+++ b/runtime/vm/intermediate_language_ia32.cc
@@ -151,14 +151,16 @@ LocationSummary* ConstantInstr::MakeLocationSummary(Zone* zone,
   const intptr_t kNumInputs = 0;
   return LocationSummary::Make(zone,
                                kNumInputs,
-                               Location::RequiresRegister(),
+                               Assembler::IsSafe(value())
+                                   ? Location::Constant(this)
+                                   : Location::RequiresRegister(),
                                LocationSummary::kNoCall);
 }
 
 
 void ConstantInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   // The register allocator drops constant definitions that have no uses.
-  if (!locs()->out(0).IsInvalid()) {
+  if (locs()->out(0).IsRegister()) {
     Register result = locs()->out(0).reg();
     __ LoadObjectSafely(result, value());
   }

[srdjan, 2015/09/30 17:00:20]

Maybe:

else {
  ASSERT(locs()->out(0).IsInvalid()) or constant ...
}

or similar

[Florian Schneider, 2015/10/01 09:16:31]

Done.