ARM: Add instruction VFPCompareAndSetFlags to macro assembler

src/arm/macro-assembler-arm.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 501 matching lines @@
     strd(src1, src2, dst, cond);
   } else {
     MemOperand dst2(dst);
     dst2.set_offset(dst2.offset() + 4);
     str(src1, dst, cond);
     str(src2, dst2, cond);
   }
 }
 
 
-void MacroAssembler::ClearFPSCRBits(uint32_t bits_to_clear, Register scratch) {
-  vmrs(scratch);
-  bic(scratch, scratch, Operand(bits_to_clear));
-  vmsr(scratch);
+void MacroAssembler::ClearFPSCRBits(const uint32_t bits_to_clear,
+                                    const Register scratch,
+                                    const Condition cond) {
+  vmrs(scratch, cond);
+  bic(scratch, scratch, Operand(bits_to_clear), LeaveCC, cond);
+  vmsr(scratch, cond);
+}
+
+
+void MacroAssembler::VFPCompareAndSetFlags(const DwVfpRegister src1,

[Rodolph Perfetta, 2011/01/10 14:59:36]

If the flags are cleared the intent is to read them shortly after, so the case
where scratch is used sounds redundant with VFPCompareAndLoad.

[Søren Thygesen Gjesse, 2011/01/11 12:41:52]

Done.

+                                           const DwVfpRegister src2,
+                                           const Register scratch,
+                                           const Condition cond) {
+  // Clear the Invalid cumulative exception flags if a scratch register is
+  // supplied.
+  if (!scratch.is(no_reg)) {
+    ClearFPSCRBits(kVFPInvalidExceptionBit, scratch, cond);
+  }
+
+  // Compare and move FPSCR flags to the normal condition flags.
+  vcmp(src1, src2, cond);
+  vmrs(pc, cond);
+}
+
+void MacroAssembler::VFPCompareAndSetFlags(const DwVfpRegister src1,

[Rodolph Perfetta, 2011/01/10 14:59:36]

Ditto.

[Søren Thygesen Gjesse, 2011/01/11 12:41:52]

Done.

+                                           const double src2,
+                                           const Register scratch,
+                                           const Condition cond) {
+  // Clear the Invalid cumulative exception flags if a scratch register is
+  // supplied.
+  if (!scratch.is(no_reg)) {
+    ClearFPSCRBits(kVFPInvalidExceptionBit, scratch, cond);
+  }
+
+  // Compare and move FPSCR flags to the normal condition flags.
+  vcmp(src1, src2, cond);
+  vmrs(pc, cond);
+}
+
+
+void MacroAssembler::VFPCompareAndLoadFlags(const DwVfpRegister src1,
+                                            const DwVfpRegister src2,
+                                            const Register fpscr_flags,
+                                            const Condition cond) {
+  // Clear the Invalid cumulative exception flags (use fpscr_flags as scratch).
+  ClearFPSCRBits(kVFPInvalidExceptionBit, fpscr_flags);
+
+  // Compare and load FPSCR.
+  vcmp(src1, src2, cond);
+  vmrs(fpscr_flags);
+}
+
+void MacroAssembler::VFPCompareAndLoadFlags(const DwVfpRegister src1,
+                                            const double src2,
+                                            const Register fpscr_flags,
+                                            const Condition cond) {
+  // Clear the Invalid cumulative exception flags (use fpscr_flags as scratch).
+  ClearFPSCRBits(kVFPInvalidExceptionBit, fpscr_flags);
+
+  // Compare and load FPSCR.
+  vcmp(src1, src2, cond);
+  vmrs(fpscr_flags);
 }
 
 
 void MacroAssembler::EnterFrame(StackFrame::Type type) {
   // r0-r3: preserved
   stm(db_w, sp, cp.bit() | fp.bit() | lr.bit());
   mov(ip, Operand(Smi::FromInt(type)));
   push(ip);
   mov(ip, Operand(CodeObject()));
   push(ip);
@@ skipping 1616 matching lines @@
 
 void CodePatcher::Emit(Address addr) {
   masm()->emit(reinterpret_cast<Instr>(addr));
 }
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM