Fixes bugs in arm and mips intrinsifier.

runtime/vm/intermediate_language_mips.cc

Index: runtime/vm/intermediate_language_mips.cc
===================================================================
--- runtime/vm/intermediate_language_mips.cc	(revision 24410)
+++ runtime/vm/intermediate_language_mips.cc	(working copy)
@@ -3037,13 +3037,18 @@
 
 
 LocationSummary* MathSqrtInstr::MakeLocationSummary() const {
-  UNIMPLEMENTED();
-  return NULL;
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* summary =
+      new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  summary->set_in(0, Location::RequiresFpuRegister());
+  summary->set_out(Location::RequiresFpuRegister());
+  return summary;
 }
 
 
 void MathSqrtInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  UNIMPLEMENTED();
+  __ sqrtd(locs()->out().fpu_reg(), locs()->in(0).fpu_reg());
 }
 
 
@@ -3113,13 +3118,26 @@
 
 
 LocationSummary* DoubleToSmiInstr::MakeLocationSummary() const {
-  UNIMPLEMENTED();
-  return NULL;
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* result = new LocationSummary(
+      kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  result->set_in(0, Location::RequiresFpuRegister());
+  result->set_out(Location::RequiresRegister());
+  return result;
 }
 
 
 void DoubleToSmiInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  UNIMPLEMENTED();
+  Label* deopt = compiler->AddDeoptStub(deopt_id(), kDeoptDoubleToSmi);
+  Register result = locs()->out().reg();
+  DRegister value = locs()->in(0).fpu_reg();
+  __ cvtwd(STMP1, value);
+  __ mfc1(result, STMP1);
+
+  // Check for overflow and that it fits into Smi.
+  __ BranchUnsignedLess(result, 0xC0000000, deopt);

[regis, 2013/06/25 17:05:16]

Why not BranchSignedLess?
Don't we check for < 0xC0000000 (a negative number)? For example, 0x0 would be
ok to tag (no deopt).
Also, shouldn't we check for >= 0x40000000, signed as well?

[zra, 2013/06/25 17:34:30]

Whoops. BranchSignedLess isn't the same as MI on ARM or NEGATIVE on ia32 because
it uses the slt instruction rather than a subtraction. I missed the subtlety in
this code on the first pass, and just assumed I got the signedness of the
comparison wrong. Changing to a subtraction fixes things.

+  __ SmiTag(result);
 }