With -Og we do no constant propagation after folding all remaining
builtins which is a problem when RTL expansion issues errors
such as those for function calls to functions with the error
attribute.
Fixed as follows, bootstrap and regtest pending on
x86_64-unknown-linux-gnu.
Richard.
2013-06-24 Richard Biener <rguent...@suse.de>
PR middle-end/56977
* passes.c (init_optimization_passes): Move pass_fold_builtins
and pass_dce earlier with -Og.
* gcc.dg/pr56977.c: New testcase.
Index: gcc/passes.c
===================================================================
*** gcc/passes.c (revision 200367)
--- gcc/passes.c (working copy)
*************** init_optimization_passes (void)
*** 1536,1550 ****
/* Perform simple scalar cleanup which is constant/copy propagation. */
NEXT_PASS (pass_ccp);
NEXT_PASS (pass_object_sizes);
/* Copy propagation also copy-propagates constants, this is necessary
! to forward object-size results properly. */
NEXT_PASS (pass_copy_prop);
NEXT_PASS (pass_asan);
NEXT_PASS (pass_tsan);
NEXT_PASS (pass_rename_ssa_copies);
- NEXT_PASS (pass_dce);
- /* Fold remaining builtins. */
- NEXT_PASS (pass_fold_builtins);
/* ??? We do want some kind of loop invariant motion, but we possibly
need to adjust LIM to be more friendly towards preserving accurate
debug information here. */
--- 1536,1550 ----
/* Perform simple scalar cleanup which is constant/copy propagation. */
NEXT_PASS (pass_ccp);
NEXT_PASS (pass_object_sizes);
+ /* Fold remaining builtins. */
+ NEXT_PASS (pass_fold_builtins);
/* Copy propagation also copy-propagates constants, this is necessary
! to forward object-size and builtin folding results properly. */
NEXT_PASS (pass_copy_prop);
+ NEXT_PASS (pass_dce);
NEXT_PASS (pass_asan);
NEXT_PASS (pass_tsan);
NEXT_PASS (pass_rename_ssa_copies);
/* ??? We do want some kind of loop invariant motion, but we possibly
need to adjust LIM to be more friendly towards preserving accurate
debug information here. */
Index: gcc/testsuite/gcc.dg/pr56977.c
===================================================================
*** gcc/testsuite/gcc.dg/pr56977.c (revision 0)
--- gcc/testsuite/gcc.dg/pr56977.c (working copy)
***************
*** 0 ****
--- 1,10 ----
+ /* { dg-do compile } */
+ /* { dg-options "-Og" } */
+
+ __attribute__((__error__("error"))) void error ();
+
+ void f (int i) {
+ if (__builtin_constant_p (i)) {
+ error ();
+ }
+ }
