From ee63e441588e3ddbda87e8267c1fd014cfe28d8d Mon Sep 17 00:00:00 2001
From: Sean Stangl <sstangl@mozilla.com>
Date: Thu, 9 Jan 2014 15:32:51 -0800
Subject: [PATCH] Bug 958672 - Remove argslot from MCall LIR. r=h4writer

---
 js/src/jit/LIR-Common.h | 28 ++++++----------------------
 js/src/jit/Lowering.cpp | 21 +++++++++------------
 2 files changed, 15 insertions(+), 34 deletions(-)

diff --git a/js/src/jit/LIR-Common.h b/js/src/jit/LIR-Common.h
index 73cd2c323a6..2852041e0f5 100644
--- a/js/src/jit/LIR-Common.h
+++ b/js/src/jit/LIR-Common.h
@@ -1004,17 +1004,9 @@ class LStackArgV : public LInstructionHelper<0, BOX_PIECES, 0>
 template <size_t Defs, size_t Operands, size_t Temps>
 class LJSCallInstructionHelper : public LCallInstructionHelper<Defs, Operands, Temps>
 {
-    // Slot below which %esp should be adjusted to make the call.
-    // Zero for a function without arguments.
-    uint32_t argslot_;
-
   public:
-    LJSCallInstructionHelper(uint32_t argslot)
-      : argslot_(argslot)
-    { }
-
     uint32_t argslot() const {
-        return argslot_;
+        return mir()->numStackArgs();
     }
     MCall *mir() const {
         return this->mir_->toCall();
@@ -1039,8 +1031,6 @@ class LJSCallInstructionHelper : public LCallInstructionHelper<Defs, Operands, T
     uint32_t numActualArgs() const {
         return mir()->numActualArgs();
     }
-
-    typedef LJSCallInstructionHelper<Defs, Operands, Temps> JSCallHelper;
 };
 
 // Generates a polymorphic callsite, wherein the function being called is
@@ -1050,9 +1040,8 @@ class LCallGeneric : public LJSCallInstructionHelper<BOX_PIECES, 1, 2>
   public:
     LIR_HEADER(CallGeneric)
 
-    LCallGeneric(const LAllocation &func, uint32_t argslot,
-                 const LDefinition &nargsreg, const LDefinition &tmpobjreg)
-      : JSCallHelper(argslot)
+    LCallGeneric(const LAllocation &func, const LDefinition &nargsreg,
+                 const LDefinition &tmpobjreg)
     {
         setOperand(0, func);
         setTemp(0, nargsreg);
@@ -1076,8 +1065,7 @@ class LCallKnown : public LJSCallInstructionHelper<BOX_PIECES, 1, 1>
   public:
     LIR_HEADER(CallKnown)
 
-    LCallKnown(const LAllocation &func, uint32_t argslot, const LDefinition &tmpobjreg)
-      : JSCallHelper(argslot)
+    LCallKnown(const LAllocation &func, const LDefinition &tmpobjreg)
     {
         setOperand(0, func);
         setTemp(0, tmpobjreg);
@@ -1097,10 +1085,8 @@ class LCallNative : public LJSCallInstructionHelper<BOX_PIECES, 0, 4>
   public:
     LIR_HEADER(CallNative)
 
-    LCallNative(uint32_t argslot,
-                const LDefinition &argContext, const LDefinition &argUintN,
+    LCallNative(const LDefinition &argContext, const LDefinition &argUintN,
                 const LDefinition &argVp, const LDefinition &tmpreg)
-      : JSCallHelper(argslot)
     {
         // Registers used for callWithABI().
         setTemp(0, argContext);
@@ -1131,10 +1117,8 @@ class LCallDOMNative : public LJSCallInstructionHelper<BOX_PIECES, 0, 4>
   public:
     LIR_HEADER(CallDOMNative)
 
-    LCallDOMNative(uint32_t argslot,
-                   const LDefinition &argJSContext, const LDefinition &argObj,
+    LCallDOMNative(const LDefinition &argJSContext, const LDefinition &argObj,
                    const LDefinition &argPrivate, const LDefinition &argArgs)
-      : JSCallHelper(argslot)
     {
         setTemp(0, argJSContext);
         setTemp(1, argObj);
diff --git a/js/src/jit/Lowering.cpp b/js/src/jit/Lowering.cpp
index ee4daa5dc35..72918f63363 100644
--- a/js/src/jit/Lowering.cpp
+++ b/js/src/jit/Lowering.cpp
@@ -404,7 +404,6 @@ LIRGenerator::visitCall(MCall *call)
         return false;
 
     // Height of the current argument vector.
-    uint32_t argslot = call->numStackArgs();
     JSFunction *target = call->getSingleTarget();
 
     // Call DOM functions.
@@ -416,10 +415,9 @@ LIRGenerator::visitCall(MCall *call)
         GetTempRegForIntArg(2, 0, &privReg);
         mozilla::DebugOnly<bool> ok = GetTempRegForIntArg(3, 0, &argsReg);
         MOZ_ASSERT(ok, "How can we not have four temp registers?");
-        LCallDOMNative *lir = new(alloc()) LCallDOMNative(argslot, tempFixed(cxReg),
-                                                          tempFixed(objReg), tempFixed(privReg),
-                                                          tempFixed(argsReg));
-        return (defineReturn(lir, call) && assignSafepoint(lir, call));
+        LCallDOMNative *lir = new(alloc()) LCallDOMNative(tempFixed(cxReg), tempFixed(objReg),
+                                                          tempFixed(privReg), tempFixed(argsReg));
+        return defineReturn(lir, call) && assignSafepoint(lir, call);
     }
 
     // Call known functions.
@@ -435,21 +433,20 @@ LIRGenerator::visitCall(MCall *call)
             mozilla::DebugOnly<bool> ok = GetTempRegForIntArg(3, 0, &tmpReg);
             MOZ_ASSERT(ok, "How can we not have four temp registers?");
 
-            LCallNative *lir = new(alloc()) LCallNative(argslot, tempFixed(cxReg),
-                                                        tempFixed(numReg),
-                                                        tempFixed(vpReg),
-                                                        tempFixed(tmpReg));
+            LCallNative *lir = new(alloc()) LCallNative(tempFixed(cxReg), tempFixed(numReg),
+                                                        tempFixed(vpReg), tempFixed(tmpReg));
             return (defineReturn(lir, call) && assignSafepoint(lir, call));
         }
 
         LCallKnown *lir = new(alloc()) LCallKnown(useFixed(call->getFunction(), CallTempReg0),
-                                                  argslot, tempFixed(CallTempReg2));
-        return (defineReturn(lir, call) && assignSafepoint(lir, call));
+                                                  tempFixed(CallTempReg2));
+        return defineReturn(lir, call) && assignSafepoint(lir, call);
     }
 
     // Call anything, using the most generic code.
     LCallGeneric *lir = new(alloc()) LCallGeneric(useFixed(call->getFunction(), CallTempReg0),
-        argslot, tempFixed(ArgumentsRectifierReg), tempFixed(CallTempReg2));
+                                                  tempFixed(ArgumentsRectifierReg),
+                                                  tempFixed(CallTempReg2));
     return defineReturn(lir, call) && assignSafepoint(lir, call);
 }