================
@@ -281,23 +279,19 @@ entry:
define void @store_trunc_add_from_64bits(ptr %src, ptr %dst) {
; CHECK-LABEL: store_trunc_add_from_64bits:
; CHECK: ; %bb.0: ; %entry
-; CHECK-NEXT: sub sp, sp, #16
-; CHECK-NEXT: .cfi_def_cfa_offset 16
; CHECK-NEXT: ldr s0, [x0]
; CHECK-NEXT: add x9, x0, #4
; CHECK-NEXT: Lloh0:
; CHECK-NEXT: adrp x8, lCPI7_0@PAGE
; CHECK-NEXT: Lloh1:
; CHECK-NEXT: ldr d1, [x8, lCPI7_0@PAGEOFF]
+; CHECK-NEXT: add x8, x1, #1
; CHECK-NEXT: ld1.h { v0 }[2], [x9]
+; CHECK-NEXT: add x9, x1, #2
; CHECK-NEXT: add.4h v0, v0, v1
-; CHECK-NEXT: xtn.8b v1, v0
-; CHECK-NEXT: umov.h w8, v0[2]
-; CHECK-NEXT: str s1, [sp, #12]
-; CHECK-NEXT: ldrh w9, [sp, #12]
----------------
efriedma-quic wrote:
Spent a little time looking at why the default code is so horrible; the primary
issue is actually the way the legalizer (GenWidenVectorStores) is trying to
lower the operation into an i16 store followed by an i8 store. It ends up
generating a bitcast from v4i8 to v2i16, and the default handling for that is
completely terrible (it doesn't know how to use a shuffle, so it goes through a
stack temporary).
Maybe worth looking into improving the bitcast situation if you're going to
continue looking at very narrow vector types.
https://github.com/llvm/llvm-project/pull/78637
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
