Hi!
When we compute LABEL_NUSES from scratch, mark_all_labels doesn't call
mark_jump_label on DEBUG_INSNs:
if (NONDEBUG_INSN_P (insn))
mark_jump_label (PATTERN (insn), insn, 0);
and so doesn't increment LABEL_NUSES from references in DEBUG_INSNs.
But, when we call emit_copy_of_insn_after e.g. when duplicating some
DEBUG_INSNs, we call it even on those, which then results in LABEL_NUSES
differences and -fcompare-debug failures.
The following patch makes sure we don't call it on DEBUG_INSNs.
Bootstrapped/regtested on powerpc64le-linux, ok for trunk?
2022-04-20 Jakub Jelinek <ja...@redhat.com>
PR debug/105203
* emit-rtl.cc (emit_copy_of_insn_after): Don't call mark_jump_label
on DEBUG_INSNs.
* gfortran.dg/g77/pr105203.f: New test.
--- gcc/emit-rtl.cc.jj 2022-02-23 09:17:04.805125253 +0100
+++ gcc/emit-rtl.cc 2022-04-20 10:26:44.972198107 +0200
@@ -6440,7 +6440,8 @@ emit_copy_of_insn_after (rtx_insn *insn,
}
/* Update LABEL_NUSES. */
- mark_jump_label (PATTERN (new_rtx), new_rtx, 0);
+ if (NONDEBUG_INSN_P (insn))
+ mark_jump_label (PATTERN (new_rtx), new_rtx, 0);
INSN_LOCATION (new_rtx) = INSN_LOCATION (insn);
--- gcc/testsuite/gfortran.dg/g77/pr105203.f.jj 2022-04-20 10:29:44.830696254
+0200
+++ gcc/testsuite/gfortran.dg/g77/pr105203.f 2022-04-20 10:31:13.532463772
+0200
@@ -0,0 +1,20 @@
+C Test case for PR debug/105203
+C Origin: kmcca...@princeton.edu
+C
+C { dg-do compile }
+C { dg-options "-O2 -fcompare-debug -ftracer -w" }
+C { dg-additional-options "-fPIC" { target fpic } }
+ SUBROUTINE FOO (B)
+
+ 10 CALL BAR (A)
+ ASSIGN 20 TO M
+ IF (100.LT.A) GOTO 10
+ GOTO 40
+C
+ 20 IF (B.LT.ABS(A)) GOTO 10
+ ASSIGN 30 TO M
+ GOTO 40
+C
+ 30 ASSIGN 10 TO M
+ 40 GOTO M,(10,20,30)
+ END
Jakub
