| Message ID | 0f785cef9fcf40b5a54e2e2950083caa50d9bdce.1492506999.git.segher@kernel.crashing.org |
|---|---|
| State | New |
| Headers | show |
On Tue, Apr 18, 2017 at 09:30:19AM +0000, Segher Boessenkool wrote: > In split_live_ranges_for_shrink_wrap IRA also splits regs that are > only used in debug insns, leading to -fcompare-debug failures. > > Bootstrapped and tested on powerpc64-linux {-m32,-m64}. This happens > on at least GCC 5, so not a regression; but it is trivial and obvious, > is it okay for trunk anyway? I think the first question here is if it is beneficial to replace the regs in DEBUG_INSNs or not. If it is beneficial, then it of course has to be changed such that it never does newreg = ira_create_new_reg (dest); just because it sees DEBUG_INSN uses, but otherwise it should do what it does now. So one option is e.g. to split that loop into two, one doing analysis, i.e. that newreg = ira_create_new_reg (dest);, but not validate_change (uin, DF_REF_REAL_LOC (use), newreg, true); and this loop would also ignore DEBUG_INSN_P. And the other loop, with the same content, just without that newreg = ... and with the validate_change, as whole guarded with if (newreg), replacing stuff on all insns. Or another way to write this is have the loop as currently is, with if (DEBUG_INSN_P (uin) && (!newreg || debug_insns_seen_p)) { debug_insns_seen_p = true; continue; } and then another loop done only if (debug_insns_seen_p && newreg) that would only adjust DEBUG_INSNs. Jakub
diff --git a/gcc/ira.c b/gcc/ira.c index 7079573..1f760fe 100644 --- a/gcc/ira.c +++ b/gcc/ira.c @@ -4999,6 +4999,9 @@ split_live_ranges_for_shrink_wrap (void) rtx_insn *uin = DF_REF_INSN (use); next = DF_REF_NEXT_REG (use); + if (DEBUG_INSN_P (uin)) + continue; + basic_block ubb = BLOCK_FOR_INSN (uin); if (ubb == call_dom || dominated_by_p (CDI_DOMINATORS, ubb, call_dom))
In split_live_ranges_for_shrink_wrap IRA also splits regs that are only used in debug insns, leading to -fcompare-debug failures. Bootstrapped and tested on powerpc64-linux {-m32,-m64}. This happens on at least GCC 5, so not a regression; but it is trivial and obvious, is it okay for trunk anyway? Segher 2017-04-18 Segher Boessenkool <segher@kernel.crashing.org> PR rtl-optimization/80429 * ira.c (split_live_ranges_for_shrink_wrap): Skip DEBUG_INSNs. --- gcc/ira.c | 3 +++ 1 file changed, 3 insertions(+)