[PATCH] D75124: [AVR] Fix private label prefix

[Ayke via Phabricator via llvm-commits]

aykevl created this revision.
aykevl added a reviewer: dylanmckay.
aykevl added a project: LLVM.
Herald added subscribers: Jim, hiraditya.

This is a small pet peeve from me. This change makes sure the AVR backend uses the correct private label prefix (.L) so that private labels are hidden in avr-objdump.

Example code:

  define i8 @foo(i1 %cond) {    
    br i1 %cond, label %then, label %else    
  then:    
    ret i8 3    
  else:    
    ret i8 5    
  }    

When compiling this:

  llc -march=avr -filetype=obj -o test.o test.ll

and then dumping it:

  avr-objdump -d test.o

You would previously get an ugly temporary label:

  
  00000000 <foo>:    
     0:        81 70       andi       r24, 0x01    ; 1    
     2:        80 30       cpi        r24, 0x00    ; 0    
     4:        f9 f3       breq       .-2          ; 0x4 <foo+0x4>    
     6:        83 e0       ldi        r24, 0x03    ; 3    
     8:        08 95       ret    
  
  0000000a <LBB0_2>:    
     a:        85 e0       ldi        r24, 0x05    ; 5    
     c:        08 95       ret    


This patch fixes that, the output is now:

  
  00000000 <foo>:    
     0:        81 70       andi       r24, 0x01    ; 1    
     2:        80 30       cpi        r24, 0x00    ; 0    
     4:        01 f0       breq       .+0          ; 0x6 <foo+0x6>    
     6:        83 e0       ldi        r24, 0x03    ; 3    
     8:        08 95       ret    
     a:        85 e0       ldi        r24, 0x05    ; 5    
     c:        08 95       ret    

Note that as you can see the breq operand is different. However it is still the same after linking:

  4:        11 f0       breq       .+4


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D75124

Files:
  llvm/lib/Target/AVR/MCTargetDesc/AVRMCAsmInfo.cpp
  llvm/test/CodeGen/AVR/branch-relaxation-long.ll
  llvm/test/CodeGen/AVR/branch-relaxation.ll
  llvm/test/CodeGen/AVR/ctlz.ll
  llvm/test/CodeGen/AVR/cttz.ll
  llvm/test/CodeGen/AVR/integration/blink.ll
  llvm/test/CodeGen/AVR/rot.ll
  llvm/test/CodeGen/AVR/smul-with-overflow.ll
  llvm/test/CodeGen/AVR/umul-with-overflow.ll

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