Arm support for DoubleToIStub (truncating).

src/arm/macro-assembler-arm.h

Index: src/arm/macro-assembler-arm.h
diff --git a/src/arm/macro-assembler-arm.h b/src/arm/macro-assembler-arm.h
index 8b9fa2b22162bf0e1b1e1d8343bb3ebd1771fa10..021ba0e2593ae0bac836a7d698b4807957bc1e13 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -62,6 +62,14 @@ enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
 
 
+Register GetRegisterThatIsNotOneOf(Register reg1,
+                                   Register reg2 = no_reg,
+                                   Register reg3 = no_reg,
+                                   Register reg4 = no_reg,
+                                   Register reg5 = no_reg,
+                                   Register reg6 = no_reg);
+
+
 #ifdef DEBUG
 bool AreAliased(Register reg1,
                 Register reg2,
@@ -491,19 +499,6 @@ class MacroAssembler: public Assembler {
   void VmovLow(Register dst, DwVfpRegister src);
   void VmovLow(DwVfpRegister dst, Register src);
 
-  // Converts the smi or heap number in object to an int32 using the rules
-  // for ToInt32 as described in ECMAScript 9.5.: the value is truncated
-  // and brought into the range -2^31 .. +2^31 - 1.
-  void ConvertNumberToInt32(Register object,
-                            Register dst,
-                            Register heap_number_map,
-                            Register scratch1,
-                            Register scratch2,
-                            Register scratch3,
-                            DwVfpRegister double_scratch1,
-                            LowDwVfpRegister double_scratch2,
-                            Label* not_int32);
-
   // Loads the number from object into dst register.
   // If |object| is neither smi nor heap number, |not_number| is jumped to
   // with |object| still intact.
@@ -989,15 +984,33 @@ class MacroAssembler: public Assembler {
                      Label* exact);
 
   // Performs a truncating conversion of a floating point number as used by
+  // the JS bitwise operations. Goes to 'done' if it succeeds, otherwise falls
+  // through if result is saturated. On return 'result' either holds answer, or
+  // is clobbered on fall through.
+  void TryInlineTruncateDoubleToI(Register result,

[danno, 2013/08/16 12:18:19]

Perhaps make this a private member?

[rmcilroy_google, 2013/08/16 14:43:54]

I did this originally, but then needed to call the method from
test-code-stubs-arm.cc.  I could make a friend class for the test code to call,
but the test isn't currently a class itself.  Any thoughts?

[Benedikt Meurer, 2013/08/19 07:48:01]

If there's no easy way to make this private, you should at least add a comment
with reason why this is public.

[rmcilroy, 2013/08/19 12:35:24]

Done.

+                                  DwVfpRegister input,
+                                  Label* done);
+
+  // Performs a truncating conversion of a floating point number as used by
   // the JS bitwise operations. See ECMA-262 9.5: ToInt32.
-  // Double_scratch must be between d0 and d15.
-  // Exits with 'result' holding the answer and all other registers clobbered.
-  void ECMAToInt32(Register result,
-                   DwVfpRegister double_input,
-                   Register scratch,
-                   Register scratch_high,
-                   Register scratch_low,
-                   LowDwVfpRegister double_scratch);
+  // Exits with 'result' holding the answer.
+  void TruncateDoubleToI(Register result, DwVfpRegister double_input);
+
+  // Performs a truncating conversion of a floating point number located at the
+  // 'offset' from the address in 'input'. See ECMA-262 9.5: ToInt32.
+  // 'result' and 'input' must be different registers.  Exits with 'result'
+  // holding the answer.
+  void TruncateDoubleToI(Register result, Register input, int offset);

[danno, 2013/08/16 12:18:19]

Consider calling this TruncateHeapNumberToI like the ia32 version that Oli did
(I don't think that an offset is ever used that's not kPointerSize.

[rmcilroy, 2013/08/19 12:35:24]

Done.

+
+  // Converts the smi or heap number in object to an int32 using the rules
+  // for ToInt32 as described in ECMAScript 9.5.: the value is truncated
+  // and brought into the range -2^31 .. +2^31 - 1. 'result' and 'input' must be
+  // different registers.
+  void TruncateNumberToI(Register object,
+                         Register result,
+                         Register heap_number_map,
+                         Register scratch1,
+                         Label* not_int32);
 
   // Check whether d16-d31 are available on the CPU. The result is given by the
   // Z condition flag: Z==0 if d16-d31 available, Z==1 otherwise.