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
This is a followup change to add v7ve support to clang for gcc
compatibility. Please see r294661.
Patch by Manoj Gupta.
Differential Revision: https://reviews.llvm.org/D29773
llvm-svn: 294662
Summary:
According to the ACLE spec, "__ARM_FEATURE_FMA is defined to 1 if
the hardware floating-point architecture supports fused floating-point
multiply-accumulate".
This changes clang's behaviour from emitting this macro for v7-A and v7-R
cores to only emitting it when the target has VFPv4 (and therefore support
for the floating point multiply-accumulate instruction).
Fixes PR27216
Reviewers: t.p.northover, rengolin
Subscribers: aemerson, rengolin, cfe-commits
Differential Revision: http://reviews.llvm.org/D18963
llvm-svn: 267869
The logic for parsing FP capabilities to set __ARM_FP was mistakenly removing
the Half-Precision capability when handling fp-only-sp resulting in a value
of 0x4. Section 6.5.1 of ACLE states that for such FP architectures the value
should be 0x6
llvm-svn: 250888
The ACLE (ARM C Language Extensions) 2.0 allows the __fp16 type to be
used as a functon argument or return type (ACLE 1.1 did not).
The current public release of the AAPCS (2.09) states that __fp16 values
should be converted to single-precision before being passed or returned,
but AAPCS 2.10 (to be released shortly) changes this, so that they are
passed in the least-significant 16 bits of either a GPR (for base AAPCS)
or a single-precision register (for AAPCS-VFP). This does not change how
arguments are passed if they get passed on the stack.
This patch brings clang up to compliance with the latest versions of
both of these specs.
We can now set the __ARM_FP16_ARGS ACLE predefine, and we have always
been able to set the __ARM_FP16_FORMAT_IEEE predefine (we do not support
the alternative format).
llvm-svn: 246764
Original commit message:
[ARM] Allow passing/returning of __fp16 arguments
The ACLE (ARM C Language Extensions) 2.0 allows the __fp16 type to be
used as a functon argument or return type (ACLE 1.1 did not).
The current public release of the AAPCS (2.09) states that __fp16 values
should be converted to single-precision before being passed or returned,
but AAPCS 2.10 (to be released shortly) changes this, so that they are
passed in the least-significant 16 bits of either a GPR (for base AAPCS)
or a single-precision register (for AAPCS-VFP). This does not change how
arguments are passed if they get passed on the stack.
This patch brings clang up to compliance with the latest versions of
both of these specs.
We can now set the __ARM_FP16_ARGS ACLE predefine, and we have always
been able to set the __ARM_FP16_FORMAT_IEEE predefine (we do not support
the alternative format).
llvm-svn: 246760
The ACLE (ARM C Language Extensions) 2.0 allows the __fp16 type to be
used as a functon argument or return type (ACLE 1.1 did not).
The current public release of the AAPCS (2.09) states that __fp16 values
should be converted to single-precision before being passed or returned,
but AAPCS 2.10 (to be released shortly) changes this, so that they are
passed in the least-significant 16 bits of either a GPR (for base AAPCS)
or a single-precision register (for AAPCS-VFP). This does not change how
arguments are passed if they get passed on the stack.
This patch brings clang up to compliance with the latest versions of
both of these specs.
We can now set the __ARM_FP16_ARGS ACLE predefine, and we have always
been able to set the __ARM_FP16_FORMAT_IEEE predefine (we do not support
the alternative format).
llvm-svn: 246755
The ARM ACLE describes the values as hex constants rather than numeric
constants; follow suit. Address post-commit review comments from Jon Roelofs.
llvm-svn: 218009
Extend ARM ACLE support (Section 6.5.1) for AArch32. Define __ARM_FP if
hardware floating point support is available as per the value defined by the
ACLE.
llvm-svn: 217957
Simon Tatham