Bug 912264 - Reset OSI-regs flags before the implicit interrupt check. r=

js/src/jit/CodeGenerator.cpp

@@ -881,6 +881,14 @@ class OutOfLineInterruptCheckImplicit : public OutOfLineCodeBase<CodeGenerator>
 bool
 CodeGenerator::visitOutOfLineInterruptCheckImplicit(OutOfLineInterruptCheckImplicit *ool)
 {
+#ifdef CHECK_OSIPOINT_REGISTERS
+    // This is path is entered from the patched back-edge of the loop. This
+    // means that the JitAtivation flags used for checking the validity of the
+    // OSI points are not reseted by the path generated by generateBody, so we
+    // have to reset it here.
+    resetOsiPointRegs(ool->lir->safepoint());
+#endif
+
     LInstructionIterator iter = ool->block->begin();
     for (; iter != ool->block->end(); iter++) {
         if (iter->isLabel()) {
@@ -2766,17 +2774,8 @@ CodeGenerator::generateBody()
             }
 
 #ifdef CHECK_OSIPOINT_REGISTERS
-            if (iter->safepoint() && shouldVerifyOsiPointRegs(iter->safepoint())) {
+            if (iter->safepoint())
-                // Set checkRegs to 0. If we perform a VM call, the instruction
+                resetOsiPointRegs(iter->safepoint());
-                // will set it to 1.
-                GeneralRegisterSet allRegs(GeneralRegisterSet::All());
-                Register scratch = allRegs.takeAny();
-                masm.push(scratch);
-                masm.loadJitActivation(scratch);
-                Address checkRegs(scratch, JitActivation::offsetOfCheckRegs());
-                masm.store32(Imm32(0), checkRegs);
-                masm.pop(scratch);
-            }
 #endif
 
             if (!callTraceLIR(i, *iter))

js/src/jit/shared/CodeGenerator-shared.cpp

@@ -591,6 +591,23 @@ CodeGeneratorShared::shouldVerifyOsiPointRegs(LSafepoint *safepoint)
 
     return true;
 }
+
+void
+CodeGeneratorShared::resetOsiPointRegs(LSafepoint *safepoint)
+{
+    if (!shouldVerifyOsiPointRegs(safepoint))
+        return;
+
+    // Set checkRegs to 0. If we perform a VM call, the instruction
+    // will set it to 1.
+    GeneralRegisterSet allRegs(GeneralRegisterSet::All());
+    Register scratch = allRegs.takeAny();
+    masm.push(scratch);
+    masm.loadJitActivation(scratch);
+    Address checkRegs(scratch, JitActivation::offsetOfCheckRegs());
+    masm.store32(Imm32(0), checkRegs);
+    masm.pop(scratch);
+}
 #endif
 
 // Before doing any call to Cpp, you should ensure that volatile

js/src/jit/shared/CodeGenerator-shared.h

@@ -200,6 +200,7 @@ class CodeGeneratorShared : public LInstructionVisitor
     }
 
 #ifdef CHECK_OSIPOINT_REGISTERS
+    void resetOsiPointRegs(LSafepoint *safepoint);
     bool shouldVerifyOsiPointRegs(LSafepoint *safepoint);
     void verifyOsiPointRegs(LSafepoint *safepoint);
 #endif