[JBS] {New} (JDK-8170430) x86 pow() stub from Intel libm is inconsistent with pow() from fdlib

[Deshpande, Vivek R]

Hi Martin

With the current solution with -InlineIntrinsics it does not go to either SharedRuntime function or Libm based function when its interpreted and goes to SharedRuntime function with C1 and C2.
So removing this line 
  if (!InlineIntrinsics) return NULL; // Generate a vanilla entry
from generate_math_entry() seems a correct way, so that with with -InlineIntrinsics option it will always go to SharedRuntime function.

Vladimir, could you please let me know if this sounds ok to you.

Regards,
Vivek
-----Original Message-----
From: hotspot-compiler-dev [mailto:hotspot-compiler-dev-bounces at openjdk.java.net] On Behalf Of Doerr, Martin
Sent: Thursday, December 01, 2016 10:07 AM
To: Andrew Haley; hotspot-compiler-dev at openjdk.java.net
Subject: RE: [JBS] {New} (JDK-8170430) x86 pow() stub from Intel libm is inconsistent with pow() from fdlib

Hi Andrew,

sounds like a good idea.

At least, the following functions should by in sync:
Interpreter: TemplateInterpreterGenerator::generate_math_entry
C1: LIRGenerator::do_MathIntrinsic
C2: LibraryCallKit::inline_math_native

I think it would be nice to have tables in shared code which translate the respective MethodKind or vmIntrinsics to the function pointers of the SharedRuntime functions.
I don't like all function calls to get replicated for all platforms.

E.g. generate_math_entry could handle platform specific intrinsics first. If none is available, it could just call the SharedRuntime function retrieved from the shared table.

I believe generate_math_entry should never return 0 because that would mean ending up in StrictMath while C1 and C2 use the SharedRuntime functions. Right?

Best regards,
Martin


-----Original Message-----
From: hotspot-compiler-dev [mailto:hotspot-compiler-dev-bounces at openjdk.java.net] On Behalf Of Andrew Haley
Sent: Donnerstag, 1. Dezember 2016 10:15
To: hotspot-compiler-dev at openjdk.java.net
Subject: Re: [JBS] {New} (JDK-8170430) x86 pow() stub from Intel libm is inconsistent with pow() from fdlib

I think we should fix up the interpreter and all JITs to call the common routines.  It's not hard, and it will fix non-monotonic behaviour.

Andrew.