forked from OSchip/llvm-project
5d66f2b0af
Change D60691 caused some knock-on failures that weren't caught by the existing tests. Firstly, selecting a CPU that should have had a restricted FPU (e.g. `-mcpu=cortex-m4`, which should have 16 d-regs and no double precision) could give the unrestricted version, because `ARM::getFPUFeatures` returned a list of features including subtracted ones (here `-fp64`,`-d32`), but `ARMTargetInfo::initFeatureMap` threw away all the ones that didn't start with `+`. Secondly, the preprocessor macros didn't reliably match the actual compilation settings: for example, `-mfpu=softvfp` could still set `__ARM_FP` as if hardware FP was available, because the list of features on the cc1 command line would include things like `+vfp4`,`-vfp4d16` and clang didn't realise that one of those cancelled out the other. I've fixed both of these issues by rewriting `ARM::getFPUFeatures` so that it returns a list that enables every FP-related feature compatible with the selected FPU and disables every feature not compatible, which is more verbose but means clang doesn't have to understand the dependency relationships between the backend features. Meanwhile, `ARMTargetInfo::handleTargetFeatures` is testing for all the various forms of the FP feature names, so that it won't miss cases where it should have set `HW_FP` to feed into feature test macros. That in turn caused an ordering problem when handling `-mcpu=foo+bar` together with `-mfpu=something_that_turns_off_bar`. To fix that, I've arranged that the `+bar` suffixes on the end of `-mcpu` and `-march` cause feature names to be put into a separate vector which is concatenated after the output of `getFPUFeatures`. Another side effect of all this is to fix a bug where `clang -target armv8-eabi` by itself would fail to set `__ARM_FEATURE_FMA`, even though `armv8` (aka Arm v8-A) implies FP-Armv8 which has FMA. That was because `HW_FP` was being set to a value including only the `FPARMV8` bit, but that feature test macro was testing only the `VFP4FPU` bit. Now `HW_FP` ends up with all the bits set, so it gives the right answer. Changes to tests included in this patch: * `arm-target-features.c`: I had to change basically all the expected results. (The Cortex-M4 test in there should function as a regression test for the accidental double-precision bug.) * `arm-mfpu.c`, `armv8.1m.main.c`: switched to using `CHECK-DAG` everywhere so that those tests are no longer sensitive to the order of cc1 feature options on the command line. * `arm-acle-6.5.c`: been updated to expect the right answer to that FMA test. * `Preprocessor/arm-target-features.c`: added a regression test for the `mfpu=softvfp` issue. Reviewers: SjoerdMeijer, dmgreen, ostannard, samparker, JamesNagurne Reviewed By: ostannard Subscribers: srhines, javed.absar, kristof.beyls, hiraditya, cfe-commits, llvm-commits Tags: #clang, #llvm Differential Revision: https://reviews.llvm.org/D62998 llvm-svn: 362791 |
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