⚠️ split B ISA extension into individual sub-extensions #1044
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The RISC-V "bit manipulation" (
B
) ISA extensions consists of three individual sub-extensions. This PR splits the core'sB
extension so users can specify which sub-extension they really need (improving hardware efficiency).Zba
: shifted-add bit manipulation instructions; enabled viaRISCV_ISA_Zba
Zbb
: basic bit manipulation instructions; enabled viaRISCV_ISA_Zbb
Zbs
: single-bit bit manipulation instructions; enabled viaRISCV_ISA_Zbs
Hence,
B
=Zba
+Zbb
+Zbs
.