[PATCH] D92097: [RISCV] Basic jump table lowering

[Jessica Clarke via Phabricator via llvm-commits]

jrtc27 added inline comments.


================
Comment at: llvm/lib/Target/RISCV/RISCVExpandPseudoInsts.cpp:126
 
-  BuildMI(NewMBB, DL, TII->get(RISCV::AUIPC), DestReg)
-      .addDisp(Symbol, 0, FlagsHi);
+  if (Symbol.isJTI()) {
+    BuildMI(NewMBB, DL, TII->get(RISCV::AUIPC), DestReg)
----------------
nand wrote:
> jrtc27 wrote:
> > Why is it that expandAuipcInstPair needs to handle this specially but there's no corresponding logic for medlow's plain LUI/ADDI?
> Based on my understanding, `addDisp` seems to be a generic method that produces an operand with an arbitrary offset from some reference, however it doesn't seem like offsets into jump tables are supported. Since the offset is always 0, the jump table index is handled separately. I might be wrong though.
Right, then surely the correct fix is to add an MO_JumpTableIndex case to addDisp that calls addJumpTableIndex?


Repository:
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  https://reviews.llvm.org/D92097/new/

https://reviews.llvm.org/D92097