Summary:
SI_ELSE is lowered into two parts:
s_or_saveexec_b64 dst, src (at the start of the basic block)
s_xor_b64 exec, exec, dst (at the end of the basic block)
The idea is that dst contains the exec mask of the preceding IF block. It can
happen that SIWholeQuadMode decides to switch from WQM to Exact mode inside
the basic block that contains SI_ELSE, in which case it introduces an instruction
s_and_b64 exec, exec, s[...]
which masks out bits that can correspond to both the IF and the ELSE paths.
So the resulting sequence must be:
s_or_savexec_b64 dst, src
s_and_b64 exec, exec, s[...] <-- added by SIWholeQuadMode
s_and_b64 dst, dst, exec <-- added by SILowerControlFlow
s_xor_b64 exec, exec, dst
Whether to add the additional s_and_b64 dst, dst, exec is currently determined
via the ExecModified tracking. With this change, it is instead determined by
an additional flag on SI_ELSE which is set by SIWholeQuadMode.
Finally: It also occured to me that an alternative approach for the long run
is for SILowerControlFlow to unconditionally emit
s_or_saveexec_b64 dst, src
...
s_and_b64 dst, dst, exec
s_xor_b64 exec, exec, dst
and have a pass that detects and cleans up the "redundant AND with exec"
pattern where possible. This could be useful anyway, because we also add
instructions
s_and_b64 vcc, exec, vcc
before s_cbranch_scc (in moveToALU), and those are often redundant. I have
some pending changes to how KILL is lowered that could also benefit from
such a cleanup pass.
In any case, this current patch could help in the short term with the whole
ExecModified business.
Reviewers: tstellarAMD, arsenm
Subscribers: arsenm, llvm-commits, kzhuravl
Differential Revision: https://reviews.llvm.org/D22846
llvm-svn: 276972
Only if the value is negative or positive is what matters,
so use a constant that doesn't require an instruction to
materialize.
These should really just emit the write exec directly,
but for stick with the kill pseudo-terminator.
llvm-svn: 275988
This is to help moveSILowerControlFlow to before regalloc.
There are a couple of tradeoffs with this. The complete CFG
is visible to more passes, the loop body avoids an extra copy of m0,
vcc isn't required, and immediate offsets can be shrunk into s_movk_i32.
The disadvantage is the register allocator doesn't understand that
the single lane's vector is dead within the loop body, so an extra
register is used to outlive the loop block when expanding the
VGPR -> m0 loop. This also now results in worse waitcnt insertion
before the loop instead of after for pending operations at the point
of the indexing, but that should be fixed by future improvements to
cross block waitcnt insertion.
v_movreld_b32's operands are now modeled more correctly since vdst
is not a true output. This is kind of a hack to treat vdst as a
use operand. Extra checking is required in the verifier since
I can't seem to get tablegen to emit an implicit operand for a
virtual register.
llvm-svn: 275934
Summary:
Previously, constant index insertelements would be turned into SI_INDIRECT_DST,
which is bound to prevent some optimization opportunities. Worse, it mislead
the heuristic that decides whether immediates should be lowered to S_MOV_B32
or V_MOV_B32 in a way that resulted in unnecessary v_readfirstlanes.
Reviewers: arsenm, tstellarAMD
Subscribers: arsenm, kzhuravl, llvm-commits
Differential Revision: http://reviews.llvm.org/D22217
llvm-svn: 275160
Summary:
The isGlobalLoad() query was returning true for constant address space loads
with memory types less than 32-bits, which is wrong. This logic has been
replaced with PatFrag in the TableGen files, to provide the same functionality.
Reviewers: arsenm
Subscribers: arsenm, kzhuravl, llvm-commits
Differential Revision: http://reviews.llvm.org/D21696
llvm-svn: 274521
Split AMDGPUSubtarget into amdgcn/r600 specific subclasses.
This removes most of the static_casting of the basic codegen
classes everywhere, and tries to restrict the features
visible on the wrong target.
llvm-svn: 273652
The main sin this was committing was using terminator
instructions in the middle of the block, and then
not updating the block successors / predecessors.
Split the blocks up to avoid this and introduce new
pseudo instructions for branches taken with exec masking.
Also use a pseudo instead of emitting s_endpgm and erasing
it in the special case of a non-void return.
llvm-svn: 273467
This should select to s_trap, but that requires
additonal work to setup and enable the trap handler.
For now emit s_endpgm so bugpoint stops getting stuck
on the unsupported call to abort.
Emit a warning that this will only terminate the wave and
not really trap.
llvm-svn: 273062
Summary:
We now use a standard fixup type applying the pc-relative address of
constant address space variables, and we have the GlobalAddress lowering
code add the required 4 byte offset to the global address rather than
doing it as part of the fixup.
This refactoring will make it easier to use the same code for global
address space variables and also simplifies the code.
Re-commit this after fixing a bug where we were trying to use a
reference to a Triple object that had already been destroyed.
Reviewers: arsenm, kzhuravl
Subscribers: arsenm, kzhuravl, llvm-commits
Differential Revision: http://reviews.llvm.org/D21154
llvm-svn: 272705
Summary:
We now use a standard fixup type applying the pc-relative address of
constant address space variables, and we have the GlobalAddress lowering
code add the required 4 byte offset to the global address rather than
doing it as part of the fixup.
This refactoring will make it easier to use the same code for global
address space variables and also simplifies the code.
Reviewers: arsenm, kzhuravl
Subscribers: arsenm, kzhuravl, llvm-commits
Differential Revision: http://reviews.llvm.org/D21154
llvm-svn: 272675
This was using extract_subreg sub0 to extract the low register
of the result instead of sub0_sub1, producing an invalid copy.
There doesn't seem to be a way to use the compound subreg indices
in tablegen since those are generated, so manually select it.
llvm-svn: 272344
Another step for unification llvm assembler/disassembler with sp3.
Besides, CodeGen output is a bit improved, thus changes in CodeGen tests.
Assembler/Disassembler tests updated/added.
Differential Revision: http://reviews.llvm.org/D20796
llvm-svn: 271900
Remove broken patterns matching it. This was matching the
unsafe math pattern and expanding the fix for the buggy instruction
from the pattern. The problems are also on CI. Remove the workarounds
and only use fract with unsafe math or from the intrinsic.
llvm-svn: 271078
Some custom Operands and AsmOperandClasses moved to proper place.
No functional changes.
Differential Revision: http://reviews.llvm.org/D20012
llvm-svn: 268780
Added support for sendmsg(MSG[, OP[, STREAM_ID]]) syntax
in s_sendmsg and s_sendmsghalt instructions.
The syntax matches the SP3 assembler/disassembler rules.
That is why implicit inputs (like M0 and EXEC) are not printed
to disassembly output anymore.
sendmsg(...) allows only known message types and attributes,
even if literals are used instead of symbolic names.
However, raw literal (without "sendmsg") still can be used,
and that allows for any 16-bit value.
Tests updated/added.
Differential Revision: http://reviews.llvm.org/D19596
llvm-svn: 268762
Added support of TTMP quads.
Reworked M0 exclusion machinery for SMRD and similar instructions
to enable usage of TTMP registers in those instructions as destinations.
Tests added.
Differential Revision: http://reviews.llvm.org/D19342
llvm-svn: 267733
Summary:
So it appears that to guarantee some of the ordering requirements of a GLSL
memoryBarrier() executed in the shader, we need to emit an s_waitcnt.
(We can't use an s_barrier, because memoryBarrier() may appear anywhere in
the shader, in particular it may appear in non-uniform control flow.)
Reviewers: arsenm, mareko, tstellarAMD
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D19203
llvm-svn: 267729
Support for SDWA instructions for VOP1 and VOP2 encoding.
Not done yet:
- converters for support optional operands and modifiers
- VOPC
- sext() modifier
- intrinsics
- VOP2b (see vop_dpp.s)
- V_MAC_F32 (see vop_dpp.s)
Differential Revision: http://reviews.llvm.org/D19360
llvm-svn: 267553
Summary:
This intrinsic returns true if the current thread belongs to a live pixel
and false if it belongs to a pixel that we are executing only for derivative
computation. It will be used by Mesa to implement gl_HelperInvocation.
Note that for pixels that are killed during the shader, this implementation
also returns true, but it doesn't matter because those pixels are always
disabled in the EXEC mask.
This unearthed a corner case in the instruction verifier, which complained
about a v_cndmask 0, 1, exec, exec<imp-use> instruction. That's stupid but
correct code, so make the verifier accept it as such.
Reviewers: arsenm, tstellarAMD
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D19191
llvm-svn: 267102
Summary:
This property is used to mark an intrinsic that only writes to memory, but
neither reads from memory nor has other side effects.
An example where this is useful is the llvm.amdgcn.buffer.store.format.*
intrinsic, which corresponds to a store instruction that goes through a special
buffer descriptor rather than through a plain pointer.
With this property, the intrinsic should still be handled as having side
effects at the LLVM IR level, but machine scheduling can make smarter
decisions.
Reviewers: tstellarAMD, arsenm, joker.eph, reames
Subscribers: arsenm, llvm-commits
Differential Revision: http://reviews.llvm.org/D18291
llvm-svn: 266826
