Spill EAX before bailIn on x86

chakra-core · Apr 19, 2021 · 1e4632d · 1e4632d
1 parent d3ce892
commit 1e4632d
Showing 1 changed file with 12 additions and 0 deletions.
diff --git a/lib/Backend/LinearScan.cpp b/lib/Backend/LinearScan.cpp
@@ -3339,6 +3339,16 @@ LinearScan::KillImplicitRegs(IR::Instr *instr)
         return;
     }
 #endif
+#ifdef _M_IX86
+    if (instr->m_opcode == Js::OpCode::GeneratorBailInLabel)
+    {
+        this->SpillReg(this->bailIn->regs[0]);
+        this->tempRegs.Clear(this->bailIn->regs[0]);
+
+        this->RecordLoopUse(nullptr, this->bailIn->regs[0]);
+        return;
+    }
+#endif
 
     this->TrackInlineeArgLifetimes(instr);
 
@@ -5246,6 +5256,7 @@ void LinearScan::GeneratorBailIn::InsertRestoreSymbols(BailInInsertionPoint& ins
                 insertionPoint.instrInsertStackSym = instr;
             }
 
+#ifndef _M_IX86 // on x86 we spill EAX before BailIn and so this logic is unnecessary
             if (lifetime->reg == interpreterFrameRegOpnd->GetReg())
             {
                 // Ensure rax is restored last
@@ -5265,6 +5276,7 @@ void LinearScan::GeneratorBailIn::InsertRestoreSymbols(BailInInsertionPoint& ins
 
                 insertionPoint.raxRestoreInstr = instr;
             }
+#endif
 
             this->linearScan->RecordDef(lifetime, instr, 0);
         }