Version 5.2.361.24 (cherry-pick)

src/crankshaft/x87/lithium-codegen-x87.cc

Index: src/crankshaft/x87/lithium-codegen-x87.cc
diff --git a/src/crankshaft/x87/lithium-codegen-x87.cc b/src/crankshaft/x87/lithium-codegen-x87.cc
index 62690376f57372fd3b9c4d93ba334efcf1dd23ed..641a87af193b37e000c41b0eff94a5d0c5f59645 100644
--- a/src/crankshaft/x87/lithium-codegen-x87.cc
+++ b/src/crankshaft/x87/lithium-codegen-x87.cc
@@ -3356,8 +3356,19 @@ void LCodeGen::DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr) {
   DeoptimizeIf(not_equal, instr, Deoptimizer::kNotAHeapNumber);
 
   Label slow, allocated, done;
-  Register tmp = input_reg.is(eax) ? ecx : eax;
-  Register tmp2 = tmp.is(ecx) ? edx : input_reg.is(ecx) ? edx : ecx;
+  uint32_t available_regs = eax.bit() | ecx.bit() | edx.bit() | ebx.bit();
+  available_regs &= ~input_reg.bit();
+  if (instr->context()->IsRegister()) {
+    // Make sure that the context isn't overwritten in the AllocateHeapNumber
+    // macro below.
+    available_regs &= ~ToRegister(instr->context()).bit();
+  }
+
+  Register tmp =
+      Register::from_code(base::bits::CountTrailingZeros32(available_regs));
+  available_regs &= ~tmp.bit();
+  Register tmp2 =
+      Register::from_code(base::bits::CountTrailingZeros32(available_regs));
 
   // Preserve the value of all registers.
   PushSafepointRegistersScope scope(this);