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reg-notes.def: Fix up description of REG_NOALIAS

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The description of the REG_NOALIAS note in reg-notes.def isn't quite
right. It describes it as being attached to call insns, but it is
instead attached to a move insn receiving the return value from a call.

This can be seen by looking at the code in calls.cc:expand_call which
attaches the note:

  emit_move_insn (temp, valreg);

  /* The return value from a malloc-like function cannot alias
     anything else.  */
  last = get_last_insn ();
  add_reg_note (last, REG_NOALIAS, temp);

gcc/ChangeLog:

	* reg-notes.def (NOALIAS): Correct comment.
This commit is contained in:
Alex Coplan 2023-10-12 17:49:20 +01:00
parent d8c3ace898
commit f150717bd9
1 changed files with 3 additions and 2 deletions
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gcc/reg-notes.def
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@ -96,8 +96,9 @@ REG_NOTE (DEP_CONTROL)
to extract the actual value. */
REG_NOTE (BR_PROB)
/* Attached to a call insn; indicates that the call is malloc-like and
that the pointer returned cannot alias anything else. */
/* Attached to a move insn which receives the result of a call; indicates that
the call is malloc-like and that the pointer returned cannot alias anything
else. */
REG_NOTE (NOALIAS)
/* REG_BR_PRED is attached to JUMP_INSNs. It contains