[builtins] Fix MathMaxMin on arm and arm64

src/arm/builtins-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 105 matching lines @@
   // tail call a stub
   __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
   ArrayConstructorStub stub(masm->isolate());
   __ TailCallStub(&stub);
 }
 
 
 // static
 void Builtins::Generate_MathMaxMin(MacroAssembler* masm, MathMaxMinKind kind) {
   // ----------- S t a t e -------------
-  //  -- r0                 : number of arguments
-  //  -- r1                 : function
-  //  -- cp                 : context
-  //  -- lr                 : return address
-  //  -- sp[(argc - n) * 8] : arg[n] (zero-based)
-  //  -- sp[(argc + 1) * 8] : receiver
+  //  -- r0                     : number of arguments
+  //  -- r1                     : function
+  //  -- cp                     : context
+  //  -- lr                     : return address
+  //  -- sp[(argc - n - 1) * 4] : arg[n] (zero based)
+  //  -- sp[argc * 4]           : receiver
   // -----------------------------------
   Condition const cc_done = (kind == MathMaxMinKind::kMin) ? mi : gt;
   Condition const cc_swap = (kind == MathMaxMinKind::kMin) ? gt : mi;
   Heap::RootListIndex const root_index =
       (kind == MathMaxMinKind::kMin) ? Heap::kInfinityValueRootIndex
                                      : Heap::kMinusInfinityValueRootIndex;
   DoubleRegister const reg = (kind == MathMaxMinKind::kMin) ? d2 : d1;
 
   // Load the accumulator with the default return value (either -Infinity or
   // +Infinity), with the tagged value in r5 and the double value in d1.
   __ LoadRoot(r5, root_index);
   __ vldr(d1, FieldMemOperand(r5, HeapNumber::kValueOffset));
 
-  // Remember how many slots to drop (including the receiver).
-  __ add(r4, r0, Operand(1));
-
   Label done_loop, loop;
+  __ mov(r4, r0);
   __ bind(&loop);
   {
     // Check if all parameters done.
-    __ sub(r0, r0, Operand(1), SetCC);
+    __ sub(r4, r4, Operand(1), SetCC);
     __ b(lt, &done_loop);
 
     // Load the next parameter tagged value into r2.
-    __ ldr(r2, MemOperand(sp, r0, LSL, kPointerSizeLog2));
+    __ ldr(r2, MemOperand(sp, r4, LSL, kPointerSizeLog2));
 
     // Load the double value of the parameter into d2, maybe converting the
     // parameter to a number first using the ToNumber builtin if necessary.
     Label convert, convert_smi, convert_number, done_convert;
     __ bind(&convert);
     __ JumpIfSmi(r2, &convert_smi);
     __ ldr(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
     __ JumpIfRoot(r3, Heap::kHeapNumberMapRootIndex, &convert_number);
     {
       // Parameter is not a Number, use the ToNumber builtin to convert it.
@@ skipping 48 matching lines @@
     __ b(&loop);
 
     // At least one side is NaN, which means that the result will be NaN too.
     __ bind(&compare_nan);
     __ LoadRoot(r5, Heap::kNanValueRootIndex);
     __ vldr(d1, FieldMemOperand(r5, HeapNumber::kValueOffset));
     __ b(&loop);
   }
 
   __ bind(&done_loop);
+  // Drop all slots, including the receiver.
+  __ add(r0, r0, Operand(1));
+  __ Drop(r0);
   __ mov(r0, r5);
-  __ Drop(r4);
   __ Ret();
 }
 
 // static
 void Builtins::Generate_NumberConstructor(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r0                     : number of arguments
   //  -- r1                     : constructor function
   //  -- lr                     : return address
   //  -- sp[(argc - n - 1) * 4] : arg[n] (zero based)
@@ skipping 2641 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM