ARM: Fix context save/restore for VFP registers.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org//7217011
Patch from Martyn Capewell <m.m.capewell@googlemail.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8357 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/assembler-arm.h

@@ -303,6 +303,10 @@ const DwVfpRegister d13 = { 13 };
 const DwVfpRegister d14 = { 14 };
 const DwVfpRegister d15 = { 15 };
 
+// Aliases for double registers.
+const DwVfpRegister kFirstCalleeSavedDoubleReg = d8;
+const DwVfpRegister kLastCalleeSavedDoubleReg = d15;
+
 
 // Coprocessor register
 struct CRegister {

src/arm/code-stubs-arm.cc

@@ -3550,12 +3550,24 @@ void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
   // Save callee-saved registers (incl. cp and fp), sp, and lr
   __ stm(db_w, sp, kCalleeSaved | lr.bit());
 
+  if (CpuFeatures::IsSupported(VFP3)) {
+    CpuFeatures::Scope scope(VFP3);
+    // Save callee-saved vfp registers.
+    __ vstm(db_w, sp, kFirstCalleeSavedDoubleReg, kLastCalleeSavedDoubleReg);
+  }
+
   // Get address of argv, see stm above.
   // r0: code entry
   // r1: function
   // r2: receiver
   // r3: argc
-  __ ldr(r4, MemOperand(sp, (kNumCalleeSaved + 1) * kPointerSize));  // argv
+
+  // Setup argv in r4.
+  int offset_to_argv = (kNumCalleeSaved + 1) * kPointerSize;
+  if (CpuFeatures::IsSupported(VFP3)) {
+    offset_to_argv += kNumDoubleCalleeSaved * kDoubleSize;
+  }
+  __ ldr(r4, MemOperand(sp, offset_to_argv));
 
   // Push a frame with special values setup to mark it as an entry frame.
   // r0: code entry
@@ -3680,6 +3692,13 @@ void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
     __ mov(lr, Operand(pc));
   }
 #endif
+
+  if (CpuFeatures::IsSupported(VFP3)) {
+    CpuFeatures::Scope scope(VFP3);
+    // Restore callee-saved vfp registers.
+    __ vldm(ia_w, sp, kFirstCalleeSavedDoubleReg, kLastCalleeSavedDoubleReg);
+  }
+
   __ ldm(ia_w, sp, kCalleeSaved | pc.bit());
 }
 

src/arm/frames-arm.h

@@ -72,6 +72,9 @@ static const RegList kCalleeSaved =
 
 static const int kNumCalleeSaved = 7 + kR9Available;
 
+// Double registers d8 to d15 are callee-saved.
+static const int kNumDoubleCalleeSaved = 8;
+
 
 // Number of registers for which space is reserved in safepoints. Must be a
 // multiple of 8.