[jdk18] RFR: 8278489: Preserve result in native wrapper with +UseHeavyMonitors

[David Holmes]

On Mon, 13 Dec 2021 20:54:55 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

> Testing observed a few failures after JDK-8276901. The reason for the failures is in the native-wrappers, in the +UseHeavyMonitors paths, we don't preserve the result register after the native call.
> 
> Testing:
>  - [x] java/awt/color, sun/java2d/cmm tests (x86_32, x86_64 x -UseHeavyMonitors, +UseHeavyMonitors)
>  - [ ] tier1 (x86_32, x86_64 x -UseHeavyMonitors, +UseHeavyMonitors)

Not a review as not my area but saw some nits with the adjusted code.

David

src/hotspot/cpu/x86/sharedRuntime_x86_32.cpp line 1867:

> 1865:     }
> 1866: 
> 1867:     // Must save rax, if if it is live now because cmpxchg must use it

Existing typo: if if

src/hotspot/cpu/x86/sharedRuntime_x86_32.cpp line 1870:

> 1868:      if (ret_type != T_FLOAT && ret_type != T_DOUBLE && ret_type != T_VOID) {
> 1869:        save_native_result(masm, ret_type, stack_slots);
> 1870:      }

Indentation looks wrong

src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp line 2069:

> 2067:     }
> 2068: 
> 2069:     // Must save rax if if it is live now because cmpxchg must use it

existing typo: if if

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PR: https://git.openjdk.java.net/jdk18/pull/16