[PPC][Hotspot] Aparently unrelated SharedRuntime::c_calling_convention call fails when implementing new intrinsics

[Gustavo Serra Scalet]

Hello Martin,

Thanks for explaining that! I'll perform these conversions on JDK8 and see how it goes.

> -----Original Message-----
> From: Doerr, Martin [mailto:martin.doerr at sap.com]
> Sent: segunda-feira, 10 de abril de 2017 06:46
> To: Gustavo Serra Scalet <gustavo.scalet at eldorado.org.br>; jdk8u-
> dev at openjdk.java.net; ppc-aix-port-dev at openjdk.java.net
> Subject: RE: [PPC][Hotspot] Aparently unrelated
> SharedRuntime::c_calling_convention call fails when implementing new
> intrinsics
> 
> Hi Gustavo,
> 
> before change "8086069: Adapt runtime calls to recent intrinsics to pass
> ints as long", it was required to convert int to long arguments for stub
> calls as well.
> 
> This could be done in library_call by:
>     Node* call = NULL;
>     if (CCallingConventionRequiresIntsAsLongs) {
>       Node* xlen_I2L = ConvI2L(xlen);
>       Node* ylen_I2L = ConvI2L(ylen);
>       Node* zlen_I2L = ConvI2L(zlen);
>       call = make_runtime_call(RC_LEAF|RC_NO_FP,
>                                OptoRuntime::multiplyToLen_Type(),
>                                stubAddr, stubName, TypePtr::BOTTOM,
>                                x_start, xlen_I2L XTOP, y_start, ylen_I2L
> XTOP, z_start, zlen_I2L XTOP);
>     }
>     else {
>       call = make_runtime_call(RC_LEAF|RC_NO_FP,
>                                OptoRuntime::multiplyToLen_Type(),
>                                stubAddr, stubName, TypePtr::BOTTOM,
>                                x_start, xlen, y_start, ylen, z_start,
> zlen);
>     }
> 
> In the current jdk9 code, stub calls are no longer performed according
> to the C calling convention (which requires int to long conversion on
> PPC64). The current stub code is designed to ignore the high 32 bits.
> Hence, the requirement for conversion only exists for real C calls, but
> no longer for stubs.
> 
> Best regards,
> Martin
> 
> 
> -----Original Message-----
> From: ppc-aix-port-dev [mailto:ppc-aix-port-dev-
> bounces at openjdk.java.net] On Behalf Of Gustavo Serra Scalet
> Sent: Freitag, 7. April 2017 16:15
> To: jdk8u-dev at openjdk.java.net; ppc-aix-port-dev at openjdk.java.net
> Subject: [PPC][Hotspot] Aparently unrelated
> SharedRuntime::c_calling_convention call fails when implementing new
> intrinsics
> 
> Hi,
> 
> We implemented the MulAdd intrinsic on PPC on JDK 9 and now we're
> backporting it to 8 but I'm facing an exception which I assume it's a
> bug elsewhere:
> # To suppress the following error report, specify this argument
> # after -XX: or in .hotspotrc:
> SuppressErrorAt=/sharedRuntime_ppc.cpp:737
> #
> # A fatal error has been detected by the Java Runtime Environment:
> #
> #  Internal Error (/home/gut/jdk8u-
> dev/hotspot/src/cpu/ppc/vm/sharedRuntime_ppc.cpp:737), pid=7631,
> tid=0x00003fff3454f1a0
> #  guarantee(i > 0 && sig_bt[i-1] == T_LONG) failed: argument of type
> (bt) should have been promoted to type (T_LONG,bt) for bt in {T_BOOLEAN,
> T_CHAR, T_BYTE, T_SHORT, T_INT}
> #
> # JRE version: OpenJDK Runtime Environment (8.0) (build 1.8.0-internal-
> debug-gut_2017_04_05_11_00-b00)
> # Java VM: OpenJDK 64-Bit Server VM (25.71-b00-debug mixed mode linux-
> ppc64 compressed oops)
> # Failed to write core dump. Core dumps have been disabled. To enable
> core dumping, try "ulimit -c unlimited" before starting Java again
> #
> # An error report file with more information is saved as:
> # /home/gut/hs/hotspot/src/cpu/ppc/vm/tst/hs_err_pid7631.log
> #
> # Compiler replay data is saved as:
> # /home/gut/hs/hotspot/src/cpu/ppc/vm/tst/replay_pid7631.log
> #
> # If you would like to submit a bug report, please visit:
> #   http://bugreport.java.com/bugreport/crash.jsp
> #
> Current thread is 70365327192480
> Dumping core ...
> Aborted
> 
> Please take a look at the diff[1] for the new muladd and a test case[2]
> in java, which has an argument to repeat the main loop. Setting it with
> a high value such as 1234 is enough to jit the code and run the
> intrinsic.
> 
> I also noticed that this check in
> hotspot/src/cpu/ppc/vm/sharedRuntime_ppc.cpp does not exist in JDK9 due
> to a changeset[3] that was not backported. But that didn't stop X64
> MulAdd intrinsics to work as it is. As I implemented one with the same
> interface, I don't understand why it's happening now...
> 
> Thanks in advance
> 
> [1] https://gist.github.com/gut/3d5f7984ef3114113b224853867bc906#file-
> add-muladd-ppc-diff
> [2] https://gist.github.com/gut/3d5f7984ef3114113b224853867bc906#file-
> testmuladd-java
> [3] http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/d7f63963925f#l3.7