RFR: 8259619: C1: 3-arg StubAssembler::call_RT stack-use condition is incorrect [v2]

[Vladimir Kozlov]

On Tue, 12 Jan 2021 12:47:11 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> SonarCould instance reports this code smell in c1_Runtime_x86.cpp: Identical sub-expressions on both sides of operator "||"
>> 
>> int StubAssembler::call_RT(Register oop_result1, Register metadata_result, address entry, Register arg1, Register arg2, Register arg3) {
>> #ifdef _LP64
>>   // if there is any conflict use the stack
>>   if (arg1 == c_rarg2 || arg1 == c_rarg3 ||
>>       arg2 == c_rarg1 || arg1 == c_rarg3 ||
>>       arg3 == c_rarg1 || arg1 == c_rarg2) { <---- HERE
>>     push(arg3);
>>     push(arg2);
>>     push(arg1);
>>     pop(c_rarg1);
>>     pop(c_rarg2);
>>     pop(c_rarg3);
>>   } else {
>>     mov(c_rarg1, arg1);
>>     mov(c_rarg2, arg2);
>>     mov(c_rarg3, arg3);
>>   }
>> 
>> It seems obvious that the right column in the condition should have been `arg1`, `arg2`, `arg3`.
>> 
>> Additional testing:
>>  - [x] Linux x86_64 `tier1`
>
> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Also fix AArch64

Good.

-------------

Marked as reviewed by kvn (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/2048