efriedma added inline comments.
================
Comment at: clang/include/clang/Basic/arm_sve.td:1050
def SVCOMPACT : SInst<"svcompact[_{d}]", "dPd", "ilUiUlfd",
MergeNone, "aarch64_sve_compact">;
-// SVDUP_LANE (to land in D78750)
+def SVDUP_LANE : SInst<"svdup_lane[_{d}]", "ddL", "csilUcUsUiUlhfd",
MergeNone, "aarch64_sve_tbl">; // Implemented using tbl
def SVDUPQ_LANE : SInst<"svdupq_lane[_{d}]", "ddn", "csilUcUsUiUlhfd",
MergeNone, "aarch64_sve_dupq_lane">;
----------------
"Implemented using tbl" isn't really a helpful comment.
I guess you're doing it this way so the lane doesn't have to be a constant?
(And then I guess you can optimize it in the backend.)
================
Comment at: clang/lib/CodeGen/CGBuiltin.cpp:8047
+ Value *PFalse = Constant::getNullValue(PTrue->getType());
+ Value *Sel = Builder.CreateSelect(CmpNE, PTrue, PFalse);
+ return EmitSVEPredicateCast(Sel, cast<llvm::ScalableVectorType>(Ty));
----------------
The select might not be the best approach. I mean, it's semantically correct,
but the backend currently doesn't know how to lower a select like that. And
even if it did, it's probably better to avoid generating it for now.
Maybe this should use whilelo directly, since that's what the backend would
eventually use anyway.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D79357/new/
https://reviews.llvm.org/D79357
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
