[PATCH] D50039: [LibCalls] Added nonnull atribute to libc function args

[Dávid Bolvanský via Phabricator via llvm-commits]

xbolva00 added a comment.

Calls which are not reorded in IR works ok, and transformation already works (memset, etc..)

int foo(char *s) {

  memset(s, 0, 10);
  if (!s) // eliminated
      abort();
  return l;

}

int foo(char *s) {

  int l = strlen(s);
  if (!s)
      abort();
  return l;

}

for strlen, we have IR:

; Function Attrs: nounwind
define dso_local i32 @foo(i8* readonly %s) local_unnamed_addr #0 {
entry:

  %tobool = icmp eq i8* %s, null
  br i1 %tobool, label %if.then, label %if.end

if.then:                                          ; preds = %entry

  tail call void @abort() #3
  unreachable

if.end:                                           ; preds = %entry

  %call = tail call i32 @strlen(i8* %s) #4
  ret i32 %call

}

; Function Attrs: argmemonly nounwind readonly
declare dso_local i32 @strlen(i8* nocapture nonnull) local_unnamed_addr #

Where should we work on above case? SCCP?


Repository:
  rL LLVM

https://reviews.llvm.org/D50039