bolt/test/X86/shrinkwrapping-pop-order.s

   1 ## This test reproduces a POP reordering issue in shrink wrapping where we would
   2 ## incorrectly put a store after a load (instead of before) when having multiple
   3 ## insertions at the same point. Check that the order is correct in this test.
   4
   5 # REQUIRES: system-linux
   6
   7 # RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %s -o %t.o
   8 # RUN: link_fdata %s %t.o %t.fdata
   9 # RUN: llvm-strip --strip-unneeded %t.o
  10 # RUN: %clang %cflags %t.o -o %t.exe -Wl,-q -nostdlib
  11 # RUN: llvm-bolt %t.exe -o %t.out --data %t.fdata --frame-opt=all --lite=0 \
  12 # RUN:           --print-fop 2>&1 | FileCheck %s
  13
  14   .globl _start
  15 _start:
  16     .cfi_startproc
  17 # FDATA: 0 [unknown] 0 1 _start 0 0 6
  18     je a
  19 b:  jne _start
  20 # FDATA: 1 _start #b# 1 _start #c# 0 3
  21
  22 c:
  23   push  %rbx
  24   push  %rbp
  25   pop   %rbp
  26   pop   %rbx
  27
  28 ## This basic block is treated as having 0 execution count.
  29 ## push and pop will be sinked into this block.
  30 a:
  31     ud2
  32     .cfi_endproc
  33
  34
  35 ## Check shrink wrapping results:
  36 # CHECK: BOLT-INFO: Shrink wrapping moved 0 spills inserting load/stores and 2 spills inserting push/pops
  37 # CHECK: BOLT-INFO: Shrink wrapping reduced 6 store executions (28.6% total instructions executed, 100.0% store instructions)
  38 # CHECK: BOLT-INFO: Shrink wrapping failed at reducing 0 store executions (0.0% total instructions executed, 0.0% store instructions)
  39
  40 ## Check that order is correct
  41 # CHECK:      Binary Function "_start" after frame-optimizer
  42 # Pushes are ordered according to their reg number and come first
  43 # CHECK:      pushq   %rbp
  44 # CHECK:      pushq   %rbx
  45 ## Pops are ordered according to their dominance relation and come last
  46 # CHECK:      popq    %rbx
  47 # CHECK:      popq    %rbp