Commit Graph

3 Commits

Author SHA1 Message Date
Sheng 314155eb8f [TableGen][VarLenCodeEmitterGen] Improve the error message
This gives a approximate error location. Although not very
accurate, it suffices to debug.

Reviewed By: myhsu

Differential Revision: https://reviews.llvm.org/D119684
2022-02-16 12:56:18 +08:00
Min-Yih Hsu b99365a7f4 [TableGen] Add a new `encoder` directive into VarLenCodeEmitterGen
The new encoder directive can be used to specify custom encoder for a
single operand or slice. This is different from the EncoderMethod field
within an Operand, which affects every operands in the target.

In addition, this patch also changes the function signature of the
encoder method -- a new argument, InsertPost, is added to both the
default one (i.e. getMachineValue) and the custom one. This argument
provides the bit position where the operand will eventually be inserted.

Differential Revision: https://reviews.llvm.org/D119100
2022-02-14 20:41:15 -08:00
Min-Yih Hsu 31f9519d48 [TableGen][CodeEmitter] Introducing the VarLenCodeEmitterGen infrastructure
Full write up:
https://gist.github.com/mshockwave/66e98d099256deefc062633909bb7b5b

The existing CodeEmitterGen infrastructure is unable to generate encoder
function for ISAs with variable-length instructions. This patch
introduces a new infrastructure to support variable-length instruction
encoding, including a new TableGen syntax for writing instruction
encoding directives and a new TableGen backend component,
VarLenCodeEmitterGen, built on top of CodeEmitterGen.

Differential Revision: https://reviews.llvm.org/D115128
2022-02-11 09:31:11 -08:00