RFR: 8335367: [s390] Add support for load immediate on condition instructions. [v2]

[Lutz Schmidt]

On Thu, 28 Nov 2024 07:11:52 GMT, Manjunath S Matti. <duke at openjdk.org> wrote:

>> Add support for load immediate on condition instructions.
>
> Manjunath S Matti. has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update src/hotspot/cpu/s390/assembler_s390.hpp
>   
>   Update the comments as suggested by Amit Kumar
>   
>   Co-authored-by: Amit Kumar <amitlocham09 at icloud.com>

Changes requested by lucy (Reviewer).

src/hotspot/cpu/s390/assembler_s390.hpp line 996:

> 994: #define BCTR_ZOPC   (unsigned  int)(6 << 8)
> 995: #define BCTG_ZOPC   (unsigned  long)(227L << 40 | 70)
> 996: #define BCTGR_ZOPC  (unsigned int)(0xb946 << 16)

Please align as above. Nice catch, btw.

src/hotspot/cpu/s390/assembler_s390.hpp line 2074:

> 2072: 
> 2073:   // load halfword immediate on condition
> 2074:   inline void z_lochi(Register r1, int64_t i2, branch_condition m3);   // load immediate r1[32-63] = i2_simm16   ; int32 <- int16

Please align as above.

src/hotspot/cpu/s390/macroAssembler_s390.cpp line 3291:

> 3289:   bind(L_failure);
> 3290: 
> 3291:   z_lghi(r_result, 1);

This lghi deserves a conversion to locghi. Furthermore, without checking for feature availability, the code will require z13 or newer. Is that intended?

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

PR Review: https://git.openjdk.org/jdk/pull/22058#pullrequestreview-2469266277
PR Review Comment: https://git.openjdk.org/jdk/pull/22058#discussion_r1863077698
PR Review Comment: https://git.openjdk.org/jdk/pull/22058#discussion_r1863079413
PR Review Comment: https://git.openjdk.org/jdk/pull/22058#discussion_r1863088997