V4: clean-up target specific register definitions and stack usage

All constants referring to registers and all constants and functions
that do platform specific things with the stack, are all modev into a
separate file. Information about how a specific platform register is
used by the ABI is also extended and is now captured in the RegisterInfo
class. Usage of this information will be extended in subsequent patches.

This also fix ARM register usage:
- Correct fp register for Thumb mode.
- Only push registers that have to be saved and will actually be used
  from the stack (i.e. do not push r0-r3 in the function prelude).

Change-Id: Ia372505ade8f2648595c7aec1d281955392f34a1
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 9 insertions, 59 deletions

diff --git a/src/qml/jit/qv4assembler.cpp b/src/qml/jit/qv4assembler.cpp
index f090e7d506..7ce682490d 100644
--- a/src/qml/jit/qv4assembler.cpp
+++ b/src/qml/jit/qv4assembler.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the QtQml module of the Qt Toolkit.
@@ -91,58 +91,6 @@ QV4::ExecutableAllocator::ChunkOfPages *CompilationUnit::chunkForFunction(int fu
     return handle->chunk();
 }
 
-
-
-/* Platform/Calling convention/Architecture specific section */
-
-#if CPU(X86_64)
-#  if OS(LINUX) || OS(MAC_OS_X)
-static const Assembler::RegisterID calleeSavedRegisters[] = {
-    JSC::X86Registers::ebx,
-    JSC::X86Registers::r12, // LocalsRegister
-    JSC::X86Registers::r13,
-    JSC::X86Registers::r14, // ContextRegister
-    JSC::X86Registers::r15
-};
-#  elif OS(WINDOWS)
-static const Assembler::RegisterID calleeSavedRegisters[] = {
-    JSC::X86Registers::ebx,
-    JSC::X86Registers::esi,
-    JSC::X86Registers::edi,
-    JSC::X86Registers::r12, // LocalsRegister
-    JSC::X86Registers::r13,
-    JSC::X86Registers::r14, // ContextRegister
-    JSC::X86Registers::r15
-};
-#  endif
-#endif
-
-#if CPU(X86)
-static const Assembler::RegisterID calleeSavedRegisters[] = {
-    JSC::X86Registers::ebx, // temporary register
-    JSC::X86Registers::esi, // ContextRegister
-    JSC::X86Registers::edi  // LocalsRegister
-};
-#endif
-
-#if CPU(ARM)
-static const Assembler::RegisterID calleeSavedRegisters[] = {
-    JSC::ARMRegisters::r11,
-    JSC::ARMRegisters::r10,
-    JSC::ARMRegisters::r9,
-    JSC::ARMRegisters::r8,
-    JSC::ARMRegisters::r7,
-    JSC::ARMRegisters::r6,
-    JSC::ARMRegisters::r5,
-    JSC::ARMRegisters::r4
-};
-#endif
-
-const int Assembler::calleeSavedRegisterCount = sizeof(calleeSavedRegisters) / sizeof(calleeSavedRegisters[0]);
-
-/* End of platform/calling convention/architecture specific section */
-
-
 const Assembler::VoidType Assembler::Void;
 
 Assembler::Assembler(InstructionSelection *isel, IR::Function* function, QV4::ExecutableAllocator *executableAllocator,
@@ -295,7 +243,7 @@ void Assembler::storeValue(QV4::Primitive value, IR::Expr *destination)
 
 void Assembler::enterStandardStackFrame()
 {
-    platformEnterStandardStackFrame();
+    platformEnterStandardStackFrame(this);
 
     // ### FIXME: Handle through calleeSavedRegisters mechanism
     // or eliminate StackFrameRegister altogether.
@@ -306,16 +254,18 @@ void Assembler::enterStandardStackFrame()
 
     subPtr(TrustedImm32(frameSize), StackPointerRegister);
 
-    for (int i = 0; i < calleeSavedRegisterCount; ++i)
-        storePtr(calleeSavedRegisters[i], Address(StackFrameRegister, -(i + 1) * sizeof(void*)));
+    const RegisterInformation &calleeSavedRegisters = getCalleeSavedRegisters();
+    for (int i = 0; i < calleeSavedRegisterCount(); ++i)
+        storePtr(calleeSavedRegisters[i].reg<RegisterID>(), Address(StackFrameRegister, -(i + 1) * sizeof(void*)));
 
 }
 
 void Assembler::leaveStandardStackFrame()
 {
     // restore the callee saved registers
-    for (int i = calleeSavedRegisterCount - 1; i >= 0; --i)
-        loadPtr(Address(StackFrameRegister, -(i + 1) * sizeof(void*)), calleeSavedRegisters[i]);
+    const RegisterInformation &calleeSavedRegisters = getCalleeSavedRegisters();
+    for (int i = calleeSavedRegisterCount() - 1; i >= 0; --i)
+        loadPtr(Address(StackFrameRegister, -(i + 1) * sizeof(void*)), calleeSavedRegisters[i].reg<RegisterID>());
 
     int frameSize = _stackLayout.calculateStackFrameSize();
     // Work around bug in ARMv7Assembler.h where add32(imm, sp, sp) doesn't
@@ -328,7 +278,7 @@ void Assembler::leaveStandardStackFrame()
 #endif
 
     pop(StackFrameRegister);
-    platformLeaveStandardStackFrame();
+    platformLeaveStandardStackFrame(this);
 }