[v8-dev] ARM: Improve double to integer truncation on ARM.

src/arm/macro-assembler-arm.h

Index: src/arm/macro-assembler-arm.h
===================================================================
--- src/arm/macro-assembler-arm.h	(revision 13104)
+++ src/arm/macro-assembler-arm.h	(working copy)
@@ -959,6 +959,14 @@
                       DwVfpRegister double_scratch,
                       Label *not_int32);
 
+  // Try to convert a double to a signed 32-bit integer. If the double value
+  // can be exactly represented as an integer the code jump to 'done' and
+  // 'result' contains the integer value. Otherwise the code fall trough.

[ulan, 2012/12/05 15:43:15]

Minor nit: should be ", the code jumps" and ", the code falls through".

+  void TryFastDoubleToInt32(Register result,
+                            DwVfpRegister double_input,
+                            DwVfpRegister double_scratch,
+                            Label* done);
+
   // Truncates a double using a specific rounding mode, and writes the value
   // to the result register.
   // Clears the z flag (ne condition) if an overflow occurs.
@@ -989,7 +997,7 @@
   // Exits with 'result' holding the answer and all other registers clobbered.
   void EmitECMATruncate(Register result,
                         DwVfpRegister double_input,
-                        SwVfpRegister single_scratch,
+                        DwVfpRegister double_scratch,
                         Register scratch,
                         Register scratch2,
                         Register scratch3);