[v8-dev] ARM: Optimize truncating division and fix sim

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 8f1c9c090dfbdf6e1de38ed34c1f028a2efbe8b0..6bd5ebf23b1e320f818fb3cddd06f85d1fd67a41 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -1413,7 +1413,11 @@ void LCodeGen::DoDivI(LDivI* instr) {
   }
 
   // Check for (kMinInt / -1).
-  if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
+  if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow) &&
+      (!CpuFeatures::IsSupported(SUDIV) ||
+       !instr->hydrogen()->CheckFlag(HValue::kAllUsesTruncatingToInt32))) {
+    // We don't need to check for overflow when truncating with sdiv
+    // support because, on ARM, sdiv kMinInt, -1 -> kMinInt.
     Label left_not_min_int;
     __ cmp(left, Operand(kMinInt));
     __ b(ne, &left_not_min_int);