[PATCH] D122212: [RISCV] Add alias to pack/packw

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

In D122212#3418598 <https://reviews.llvm.org/D122212#3418598>, @Miss_Grape wrote:

> In D122212#3399915 <https://reviews.llvm.org/D122212#3399915>, @craig.topper wrote:
>
>> The correct fix is to change the predicate here to include Zbkb
>>
>>   let Predicates = [HasStdExtZbbOrZbp, IsRV32] in {                                
>>   def ZEXT_H_RV32 : RVBUnary<0b0000100, 0b00000, 0b100, OPC_OP, "zext.h">,         
>>                     Sched<[WriteIALU, ReadIALU]>;                                  
>>   } // Predicates = [HasStdExtZbbOrZbp, IsRV32]                                    
>>                                                                                    
>>   let Predicates = [HasStdExtZbbOrZbp, IsRV64] in {                                
>>   def ZEXT_H_RV64 : RVBUnary<0b0000100, 0b00000, 0b100, OPC_OP_32, "zext.h">,      
>>                     Sched<[WriteIALU, ReadIALU]>;                                  
>>   } // Predicates = [HasStdExtZbbOrZbp, IsRV64] 
>
> Can you send me the Bitmap manual you read, I read the riscv-crypto-spec-scalar-v1.0.1.pdf , and zext.h does not belong to zbkb
> zbkb Instruction：
> F22605625: image.png <https://reviews.llvm.org/F22605625>

The zext.h encoding is a subset of the pack encodings. We need to have consistent behavior in when we use the two instruction representations. Otherwise disassembling with Zba and Zbkb both enabled becomes ambiguous.


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  https://reviews.llvm.org/D122212/new/

https://reviews.llvm.org/D122212