# Pin: W65816FrameLowering::orderFrameObjects lays a large frame out with
# its most-used objects nearest S.  A slot more than 0xFF bytes above S is
# out of `off,s` reach, so every access to it goes through the $F6 frame
# pointer (`sty $fa ; ldy #off ; lda [$f6],y ; ldy $fa`, 18 cycles against
# 5).  In creation order the 2-byte scalar below sat on top of the 300-byte
# array it was created before; by access density (direct accesses, 8x per
# loop level, per byte) it now sits at S+1 and the array, reached only
# through the address ADDframe builds, goes on top.
#
# pha_pinned: an object accessed past its end is the PHA-bracket idiom
# (W65816ImgCalleeSave saves IMG8..15 with `pha ; lda dp ; sta slot+2,s ;
# pla`), whose +2 holds only stack-relative: through $F6, which the PHA does
# not move, it addresses the neighbour.  Such objects stay nearest S however
# rarely they are used.  The first cut sorted runtime snprintf's IMG8 save
# slot out of reach: `format` restored IMG8 from its neighbour and fprintf
# wrote nothing (the smoke test's GS/OS fflush check).
#
# RUN: llc -mtriple=w65816 -run-pass=prologepilog -o - %s | FileCheck %s
# RUN: env W65816_DISABLE_FRAME_ORDER=1 llc -mtriple=w65816 -run-pass=prologepilog -o - %s | FileCheck %s --check-prefix=CREATION
--- |
  target triple = "w65816"
  define void @hot_near() { ret void }
  define void @pha_pinned() { ret void }
...
---
# CHECK-LABEL: name: hot_near
# CHECK-NOT:   DPIndLongY 246
# CHECK:       STA_StackRel 1
# CHECK-NOT:   DPIndLongY 246
# CHECK:       LDA_StackRel 1
# CREATION-LABEL: name: hot_near
# CREATION:    STA_DPIndLongY 246
name: hot_near
tracksRegLiveness: false
stack:
  - { id: 0, size: 2, alignment: 1 }
  - { id: 1, size: 300, alignment: 1 }
body: |
  bb.0:
    $a = ADDframe %stack.1, 0
    STAfi $a, %stack.0, 0, implicit-def $a
    $a = LDAi16imm 0
    $a = LDAfi %stack.0, 0
    RTL
...
---
# CHECK-LABEL: name: pha_pinned
# CHECK:       PHA
# CHECK-NEXT:  LDA_DP 192
# CHECK-NEXT:  STA_StackRel 3
# CHECK-NEXT:  PLA
# The array's 20 loop accesses outweigh the save slot's one (by density),
# which alone would sort the slot above the array, out of reach.
name: pha_pinned
tracksRegLiveness: false
stack:
  - { id: 0, size: 2, alignment: 1 }
  - { id: 1, size: 300, alignment: 1 }
body: |
  bb.0:
    successors: %bb.1
    PHA implicit $a
    LDA_DP 192, implicit-def $a
    STAfi $a, %stack.0, 2, implicit-def $a
    PLA implicit-def $a
  bb.1:
    successors: %bb.1, %bb.2
    $a = LDAfi %stack.1, 0
    $a = LDAfi %stack.1, 2
    $a = LDAfi %stack.1, 4
    $a = LDAfi %stack.1, 6
    $a = LDAfi %stack.1, 8
    $a = LDAfi %stack.1, 10
    $a = LDAfi %stack.1, 12
    $a = LDAfi %stack.1, 14
    $a = LDAfi %stack.1, 16
    $a = LDAfi %stack.1, 18
    $a = LDAfi %stack.1, 20
    $a = LDAfi %stack.1, 22
    $a = LDAfi %stack.1, 24
    $a = LDAfi %stack.1, 26
    $a = LDAfi %stack.1, 28
    $a = LDAfi %stack.1, 30
    $a = LDAfi %stack.1, 32
    $a = LDAfi %stack.1, 34
    $a = LDAfi %stack.1, 36
    $a = LDAfi %stack.1, 38
    CMPi16imm $a, 0, implicit-def $p
    BNE %bb.1, implicit $p
  bb.2:
    RTL
...