Committed. This test fails for mmix for (almost) the same reason it would fail for e.g. mipsel-elf: the end-condition of the loop tests against a register set to a constant, and that register is (one of) the "unexpected IV" moved out of the loop "without introducing a new temporary register" and making the dump contain more than one "Decided", causing a non-matching loop2 dump. The test should probably have been restricted to just the original target for which a problem was observed to be fixed.
gcc/testsuite: * gcc.dg/loop-8.c: Skip for mmix. --- gcc/gcc/testsuite/gcc.dg/loop-8.c.orig Mon Jan 13 22:30:47 2020 +++ gcc/gcc/testsuite/gcc.dg/loop-8.c Sat Aug 1 03:07:52 2020 @@ -1,6 +1,6 @@ /* { dg-do compile } */ /* { dg-options "-O1 -fdump-rtl-loop2_invariant" } */ -/* { dg-skip-if "unexpected IV" { "hppa*-*-* mips*-*-* visium-*-* powerpc*-*-* riscv*-*-*" } } */ +/* { dg-skip-if "unexpected IV" { "hppa*-*-* mips*-*-* visium-*-* powerpc*-*-* riscv*-*-* mmix-*-*" } } */ /* Load immediate on condition is available from z13 on and prevents moving the load out of the loop, so always run this test with -march=zEC12 that does not have load immediate on condition. */