On 06/08/2011 03:39 AM, Richard Earnshaw wrote: > On 08/06/11 03:14, Janis Johnson wrote: >> On 06/07/2011 06:25 PM, Mike Stump wrote: >>> On Jun 7, 2011, at 4:24 PM, Janis Johnson wrote: >>>> On 06/07/2011 02:07 PM, Joseph S. Myers wrote: >>>>> On Tue, 7 Jun 2011, Janis Johnson wrote: >>>>> >>>>>> Several tests in gcc.target/arm use dg-options with -mcpu=xxxx, which >>>>>> causes compiler warnings or errors when the multilib flags include >>>>>> -march=yyyy. This patch causes those tests to be skipped. It also >>>>>> prevents gcc.target/arm/20090811-1.c from running with multilibs that >>>>>> would override -mcpu or -mfloat-abi options specified for the test. >>>>> >>>>> I think you should allow compatible -march options - for example, if >>>>> dg-options has -mcpu=cortex-a8, allow -march=armv7-a but disallow all >>>>> other -march options. >>>>> >>>> Is this one OK? >>> >>> Not sure if the arm people want to review this or would rather I review >>> it... >>> >>> Let's give the arm folks a couple days to comment, if no objections, Ok. >>> >>> A point of warning, eventually, you'll discover that when a compiler >>> defaults to the argument you want to skip, that you'll needs slightly more >>> power to skip them. darwin ran into this with things like -m64, and >>> eventually had to do something like lp64. configure options like >>> --with-cpu=arm9 are the sort that can change the default. >> >> Yes, I hope to hear from ARM people. >> >> On ARM, the default from --with-cpu= is overridden by -march at >> compile so it's not a problem for this particular set of tests. >> As I said originally, this set is the tip of the iceberg and they >> get more difficult. >> >> Janis >> >> > > > I'm worried by this whole approach of command-line checking. It works, > just about, for testsuite variations set with target_list, but it won't > work with options used to configure the compiler (eg --with-mode=thumb, > or --with-cpu=...). Perhaps a better approach would be a new dg- test > that built a trivial file with all the options and disabled the test if > that test failed for any reason. Something like: > > dg-target-compatible (target, <compile|link>, additional-opts) > > The test is only performed if target matches the current target. > > I'm not sure if this is something that can be easily cached (well, it > might be possible if you could index off additional-opts and the default > opts), so it might be that this test has to be re-run every time there > is a test that needs it. > > R.
There's a similar functionality now with effective targets that end with "_ok"; they test with options that would be added with a later directive. The problem is that they can't be specific enough for what the test is looking for; arm_neon_fp16_ok, for example, currently passes when the multilib options include -mfpu=neon, which overrides the options provided by dg-options, and that leads to problems. I think that a test that requires a specific option should provide that option, but be skipped if multilib options include a conflict. This includes -mcpu, -mfpu, -march, -mfloat-abi, -mbig-endian, and possibly more. Those options override the defaults for the configuration, so we shouldn't have to worry about the defaults. The big question is whether such a test should be run for all multilibs that might possibly pass the test, or only for default and for mulitlibs that provide the same options. There are a lot of arm tests that use -march but pass for a great many other -march options. In most cases they use -march with the value for which the problem was reported. Should those tests be run for all multilibs, with the multilib options overriding the "defaults" for the test from dg-options, or should they be skipped multilibs that use other values? The answer might depend on the individual test; maybe some should be run for a large number of multilib options to find problems with specific ones, while others can be limited to run just once or a few times. Janis
