[llvm] [AArch64][SVE] Fold ADD+CNTB to INCB and DECB (PR #118280)

[David Sherwood via llvm-commits]

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@@ -271,9 +271,9 @@ define void @str_with_off_15(ptr %ptr) {
 define void @str_with_off_15mulvl(ptr %ptr) {
 ; CHECK-LABEL: str_with_off_15mulvl:
 ; CHECK:       // %bb.0:
+; CHECK-NEXT:    incb x0, all, mul #15
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david-arm wrote:

I think this is the same as addvl, right? The optimisation guides state incb is only fast for mul immediates 1,2 and 4. Might be good for now to restrict incb to those cases?

https://github.com/llvm/llvm-project/pull/118280