The 16-bit immediate operand of s_waitcnt_depctr / s_wait_alu has some
unused bits. Previously codegen would set these bits to 1, but setting
them to 0 matches the SP3 assembler behaviour better, which in turn
means that we can print them using the human readable SP3 syntax:
s_wait_alu 0xfffd ; unused bits set to 1
s_wait_alu 0xff9d ; unused bits set to 0
s_wait_alu depctr_va_vcc(0) ; unused bits set to 0, human readable
Note that the set of unused bits changed between GFX10.1 and GFX10.3.
This patch includes:
1. fma_mix inst takes fp16 type as input, but place the operand in
vgpr32. Update selector to insert vgpr32 for true16 mode if necessary.
2. fma_mix inst returns fp16 type as output, but place the vdst in
vgpr32. Create a fma_mix_t16 pesudo inst for isel pattern, and lower it
to mix_lo/hi in the mc lowering pass.
These stop isel from emitting illegal `vgpr32 = COPY vgpr16` and improve
code quality
Recent upstream trends have moved away from explicitly using `-verify-machineinstrs`, as it's already covered by the expensive checks. This PR removes almost all `-verify-machineinstrs` from tests in `llvm/test/CodeGen/AMDGPU/*.ll`, leaving only those tests where its removal currently causes failures.
Added a srl pattern for true16 flow. Changing right shift 16bit to a
reg_sequence
`srl vgpr32, 16 -> reg_sequence (vgpr32.hi16, 0)`
and finally it's lowered to two COPY
`vdst.lo16 = COPY vsrc.hi16`
`vdst.hi16 = COPY 0`
The benefits of this transform is allowing the following pass to
optimize out these copy.
MSG_DEALLOC_VGPRS slows down very small waveslot limited kernels. It's
been identified this message is only really needed for VGPR limited
kernels. A kernel becomes VGPR limited if a total number of VGPRs per
SIMD / number of used VGPRs is more than a number of wave slots.
For targets that support xnack replay feature (gfx8+), the
multi-dword scalar loads shouldn't clobber any register that
holds the src address. The constrained version of the scalar
loads have the early clobber flag attached to the dst operand
to restrict RA from re-allocating any of the src regs for its
dst operand.
This reverts commit adaff46d087799072438dd744b038e6fd50a2d78.
Drop the -O3 checks from default-attributes.hip. I don't know why they
are different on some bots but reverting this is far too disruptive.
Removing it from the codegen pipeline induces a lot of test churn
because llc is no longer optimizing out implicit arguments to kernels.
Mostly mechanical, but there are some creative test updates. I preferred
to take the changes as-is in tests where the ABI isn't relevant. In
cases where it's more relevant, or the optimize out logic was too
ingrained in the test, I pre-run the optimization. Some cases manually
add attributes to disable inputs.
Similar to 806761a7629df268c8aed49657aeccffa6bca449.
For IR files without a target triple, -mtriple= specifies the full
target triple while -march= merely sets the architecture part of the
default target triple, leaving a target triple which may not make sense,
e.g. amdgpu-apple-darwin.
Therefore, -march= is error-prone and not recommended for tests without
a target triple. The issue has been benign as we recognize
$unknown-apple-darwin as ELF instead of rejecting it outrightly.
This patch changes AMDGPU tests to not rely on the default
OS/environment components. Tests that need fixes are not changed:
```
LLVM :: CodeGen/AMDGPU/fabs.f64.ll
LLVM :: CodeGen/AMDGPU/fabs.ll
LLVM :: CodeGen/AMDGPU/floor.ll
LLVM :: CodeGen/AMDGPU/fneg-fabs.f64.ll
LLVM :: CodeGen/AMDGPU/fneg-fabs.ll
LLVM :: CodeGen/AMDGPU/r600-infinite-loop-bug-while-reorganizing-vector.ll
LLVM :: CodeGen/AMDGPU/schedule-if-2.ll
```
Make codegen emit correctly rounded sqrt by default.
Emit the fast but only kind of fast expansion in AMDGPUCodeGenPrepare
based on !fpmath, like the fdiv case. Hack around visitation ordering
problems from AMDGPUCodeGenPrepare using forward iteration instead of
a well behaved combiner.
https://reviews.llvm.org/D158129
Introducing rsq contract flags is wrong, and also requires some level
of approximate functions. AMDGPUCodeGenPrepare already should handle
the f32 cases with appropriate flags, and I don't see how new
situations to handle would arise during legalization (other than cases
involving the rcp intrinsic, which instcombine tries to
handle). AMDGPUCodeGenPrepare does need to learn better handling of
rcp/rsq for f64 though, which we never bothered to handle well.
Removes another obstacle to correctly lowering sqrt.
https://reviews.llvm.org/D158099
These inherited the fast math checks from f32, but the manual suggests
these should be accurate enough for unconditional use. The definition
of correctly rounded is 0.5ulp, but the manual says "0.51ulp". I've
been a bit nervous about changing this as the OpenCL conformance test
does not cover half. Brute force produces identical values compared to
a reference host implementation for all values.
The previous implementation was incorrect, and based off incorrect
instruction definitions. Unfortunately we can't match natural
addressing in a lot of cases due to the shift/scale applied in
getelementptrs. This relies on reducing the 64-bit shift to 32-bits.
This will likely introduce catastrophic performance regressions on
older subtargets, but should be correct. A follow up change will
remove the old fp32-denormals subtarget features, and switch to using
the new denormal-fp-math/denormal-fp-math-f32 attributes. Frontends
should be making sure to add the denormal-fp-math-f32 attribute when
appropriate to avoid performance regressions.
Summary:
The accuracy limit to use rcp is adjusted to 1.0 ulp from 2.5 ulp.
Also, afn instead of arcp is used to allow inaccurate rcp to be used.
Reviewers:
arsenm
Differential Revision: https://reviews.llvm.org/D73588
Summary: This patch originated from D46562 and is a proper subset, with some issues addressed.
Reviewers: spatel, hfinkel, wristow, arsenm
Reviewed By: spatel
Subscribers: wdng, nhaehnle
Differential Revision: https://reviews.llvm.org/D47954
llvm-svn: 334862
Currently the default C calling convention functions are treated
the same as compute kernels. Make this explicit so the default
calling convention can be changed to a non-kernel.
Converted with perl -pi -e 's/define void/define amdgpu_kernel void/'
on the relevant test directories (and undoing in one place that actually
wanted a non-kernel).
llvm-svn: 298444
This switches to the workaround that HSA defaults to
for the mesa path.
This should be applied to the 4.0 branch.
Patch by Vedran Miletić <vedran@miletic.net>
llvm-svn: 292982