This patch allows SimplifyDemandedBits to call SimplifyMultipleUseDemandedBits in cases where the source operand has other uses, enabling us to peek through the shifted value if we don't demand all the bits/elts.
This helps with several of the regressions from D125836
If the LHS/RHS selection operands can be cheaply concatenated back together then replace 2 x 128-bit selection nodes with 1 x 256-bit node
Addresses the regression introduced in the bug fix from rGd5af6a38082b39ae520a328e44dc29ebcb036bb2
REAPPLIED with for bug identified in rGea8fb3b60196
Since D61806, DAGCombiner has folded subvector_extract(bitcast(..)) to
bitcast(subvector_extract(..)), which would place a bitcast between a
subvector_extract and the operation that could be converted to a high
neon instruction (like smull2). This adds better matching for the
subvector_extract, through the tablegen extract_high PatFrags to
optionally skip the bitcast under little ending, still matchings an
extract of the high half of the input vector.
I didn't update the extract_high of a duplicate patterns, as the
ComplexPattern need names operands. I did add a extract_high_dup_v8i16
PatFrag to abstract away the common code, which can be extended in a
future patch.
Differential Revision: https://reviews.llvm.org/D126782
GCC and Clang/LLVM will support `_Float16` on X86 in C/C++, following
the latest X86 psABI. (https://gitlab.com/x86-psABIs)
_Float16 arithmetic will be performed using native half-precision. If
native arithmetic instructions are not available, it will be performed
at a higher precision (currently always float) and then truncated down
to _Float16 immediately after each single arithmetic operation.
Reviewed By: LuoYuanke
Differential Revision: https://reviews.llvm.org/D107082
As a follow up to D126686, this does the same fold for floating point
add and shuffle. In this case it is limited to reassoc either x[0]+x[1]
or x[1]+x[0] for both result[0] and results[1].
Differential Revision: https://reviews.llvm.org/D127087
1. When checking if a candidate contains a CFI instruction, actually
iterate over all of the instructions, instead of stopping halfway
through.
2. Make sure copied CFI directives refer to the correct instruction.
Fixes https://github.com/llvm/llvm-project/issues/55842
Differential Revision: https://reviews.llvm.org/D126930
We need a preheader and a single latch, but we don't need a dedicated
exit.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D127513
Our optimization pass checks for loop simplify form, before doing
the transform. The loops here aren't in loop simplify form because
the exit block has two predecessors.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D127451
The encoding of COMPUTE_TMPRING_SIZE.WAVESIZE and
SPI_TMPRING_SIZE.WAVESIZE has changed in GFX11: it is now in units
of 64 dwords instead of 256 dwords, and the field has been widened
from 13 bits to 15 bits.
Depends on D126989
Reviewed By: rampitec, arsenm, #amdgpu
Differential Revision: https://reviews.llvm.org/D127248
In the same spirit as D73543 and in reply to https://reviews.llvm.org/D126768#3549920 this patch is adding support for `__builtin_memset_inline`.
The idea is to get support from the compiler to easily write efficient memory function implementations.
This patch could be split in two:
- one for the LLVM part adding the `llvm.memset.inline.*` intrinsics.
- and another one for the Clang part providing the instrinsic as a builtin.
Differential Revision: https://reviews.llvm.org/D126903
Fixes a regression on D127115 - splitting was creating extract_subvector(bitcast(build_vector())) patterns which prevented the build vectors being split before being bitcast to vXi16 types, resulting in various issues with further folding of the (now legal) build vectors
We already have patterns for matching fadd(select(..., -0.0)),
but an upcoming patch will lead to patterns using +0.0 as the
identity instead of -0.0. I'm adding support for these patterns
now to avoid any regressions for MVE.
Differential Revision: https://reviews.llvm.org/D127275
D125887 changed the ctlz/cttz despeculation transform to insert
a freeze for the introduced branch on zero. While this does fix
the "branch on poison" issue, we may still get in trouble if we
pick a different value for the branch and for the ctz argument
(i.e. non-zero for the branch, but zero for the ctz). To avoid
this, we should use the same frozen value in both positions.
This does cause a regression in RISCV codegen by introducing an
additional sext. The DAG looks like this:
t0: ch = EntryToken
t2: i64,ch = CopyFromReg t0, Register:i64 %3
t4: i64 = AssertSext t2, ValueType:ch:i32
t23: i64 = freeze t4
t9: ch = CopyToReg t0, Register:i64 %0, t23
t16: ch = CopyToReg t0, Register:i64 %4, Constant:i64<32>
t18: ch = TokenFactor t9, t16
t25: i64 = sign_extend_inreg t23, ValueType:ch:i32
t24: i64 = setcc t25, Constant:i64<0>, seteq:ch
t28: i64 = and t24, Constant:i64<1>
t19: ch = brcond t18, t28, BasicBlock:ch<cond.end 0x8311f68>
t21: ch = br t19, BasicBlock:ch<cond.false 0x8311e80>
I don't see a really obvious way to improve this, as we can't push
the freeze past the AssertSext (which may produce poison).
Differential Revision: https://reviews.llvm.org/D126638
Add new intrinsic and codegen support for the s_sendmsg_rtn_b32 and
s_sendmsg_rtn_b64 instructions.
Differential Revision: https://reviews.llvm.org/D127315
In GFX10 dlc controlled L1 cache bypass. In GFX11 it has been repurposed
to control MALL NOALLOC, and glc controls L1 as well as L0 cache bypass.
Update the documentation and SIMemoryLegalizer accordingly. Set dlc for
nontemporal and volatile accesses.
Differential Revision: https://reviews.llvm.org/D127405
The patch is a replacement of D125199. PseudoReadVL with vtype has worry for
computing same vtypes of VLEFF/VLSEGFF in two different places, DAGToDAG and
InsertVSETVLI. VLEFF/VLSEGFF MI with VL output still could provide the vtype of
VLEFF/VLSEGFF to the users of its VL.
The patch names the new pseudo as original VLEFF/VLSEGFF name suffixed "_VL" and
expand them in RISCVInsertVSETVLI pass.
This patch also reverts commit 4537aae0d57e17c217c192d8977012ba475b130c,
"[RISCV] Make PseudoReadVL have the vtypes of the corresponding VLEFF/VLSEGFF.".
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D126794
For an addition with simm14 and simm15 immediates with 2 or 3 trailing bits,
we can use a shXadd instruction and an addi to do the addition.
This patch teaches RISCVMergeBaseOffset to see through this pattern.
I don't think the sh1add case occurs because we use two addis for that,
but I implemented it for completeness.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D127376
Changes for GFX11:
- Clauses may not mix instructions of different types, and there are
more types. For example image instructions with and without a sampler
are now different types.
- The max size of a clause is explicitly documented as 63 instructions.
Previously it was implicitly assumed to be 64. This is such a tiny
difference that it does not seem worth making it conditional on the
subtarget.
- It can be beneficial to clause stores as well as loads.
Differential Revision: https://reviews.llvm.org/D127391
Nic Curtis done the experiments to prove it is faster than a
separate mul and add.
Fixes: SWDEV-332806
Differential Revision: https://reviews.llvm.org/D127253
- VOP3 and SDWA forms of V_CMPX were not handled
- Hazard only exists if the compare defines EXEC (i.e. V_CMPX)
forwarded to the permlane.
Differential Revision: https://reviews.llvm.org/D127344
This was assuming the vector types were MVTs, but they don't have to be.
Note that the concrete output of the test isn't very useful, since it's
dominated by nonsensical calling convention lowering for the weird types.
Differential Revision: https://reviews.llvm.org/D126505
In order to make sure the stack point is right through the EH region,
we also need to restore stack pointer from the frame pointer if we
don't preserve stack space within prologue/epilogue for outgoing variables,
normally it's just checking the variable sized object is present or not
is enough, but we also don't preserve that at prologue/epilogue when
have vector objects in stack.
Example to show what happened:
```
try {
sp adjust for outgoing args. // 1. Sp changed.
func_call // 2. Exception raised
sp restore // Oh, not restored
} catch {
// 3. And now we are here.
}
// 4. Prepare to return!, restore return address from stack, but...sp is wrong.
// 5. Screw up!
```
Reviewed By: rogfer01
Differential Revision: https://reviews.llvm.org/D126861
This should fix a number of shuffle regressions in D127115 where the re-ordered combines mean we fail to fold a EXTRACT_VECTOR_ELT/INSERT_VECTOR_ELT sequence into a BUILD_VECTOR if we extract from more than one vector source.
The generic legalizer framework is still used to reduce the problem
to scalar multiplication with the bit size a multiple of 32.
Generating optimal code sequences for big integer multiplication is
somewhat tricky and has a number of target-specific intricacies:
- The target has V_MAD_U64_U32 instructions that multiply two 32-bit
factors and add a 64-bit accumulator. Most partial products should
use this instruction.
- The accumulator is mapped to consecutive 32-bit GPRs, and partial-
product multiply-adds can feed the accumulator into each other
directly. (The register allocator's support for that is somewhat
limited, but that only matters for 128-bit integers and larger.)
- OTOH, on some hardware, V_MAD_U64_U32 requires the accumulator
to be stored in an even-aligned pair of GPRs. To avoid excessive
register copies, it makes sense to compute odd partial products
separately from even partial products (where a partial product
src0[j0] * src1[j1] is "odd" if j0 + j1 is odd) and add both
halves together as a final step.
- We can combine G_MUL+G_ADD into a single cascade of multiply-adds.
- The target can keep many carry-bits in flight simultaneously, so
combining carries using G_UADDE is preferable over G_ZEXT + G_ADD.
- Not addressed by this patch: When the factors are sign-extended,
the V_MAD_I64_I32 instruction (signed version!) can be used.
It is difficult to address these points generically:
1) Finding matching pairs of G_MUL and G_UMULH to find a wide
multiply is expensive. We could add a G_UMUL_LOHI generic instruction
and conditionally use that in the generic legalizer, but by itself
this wouldn't allow us to use the accumulation capability of
V_MAD_U64_U32. One could attempt to find matching G_ADD + G_UADDE
post-legalization, but this is also expensive.
2) Similarly, making sense of the legalization outcome of a wide
pre-legalization G_MUL+G_ADD pair is extremely expensive.
3) How could the generic legalizer possibly deal with the
particular idiosyncracy of "odd" vs. "even" partial products.
All this points in the direction of directly emitting an ideal code
sequence during legalization, but the generic legalizer should not
be burdened with such overly target-specific concerns. Hence, a
custom legalization.
Note that the implemented approach is different from that used by
SelectionDAG because narrowing of scalars works differently in
general. SelectionDAG iteratively cuts wide scalars into low and
high halves until a legal size is reached. By contrast, GlobalISel
does the narrowing in a single shot, which should be better for
compile-time and for the quality of the generated code.
This patch leaves three gaps open:
1. When the factors are uniform, we should execute the multiplication on
the SALU. Register bank mapping already ensures this.
However, the resulting code sequence is not optimal because it doesn't
fully use the carry-in capabilities of S_ADDC_U32. (V_MAD_U64_U32
doesn't have a carry-in.) It is very difficult to fix this after the
fact, so we should really use a different legalization sequence in
this case. Unfortunately, we don't have a divergence analysis and so
cannot make that choice.
(This only matters for 128-bit integers and larger.)
2. Avoid unnecessary multiplies when sources are known to be zero- or
sign-extended. The challenge is that the legalizer does not currently
have access to GISelKnownBits.
3. When the G_MUL is followed by a G_ADD, we should consider combining
the two instructions into a single multiply-add sequence, to utilize
the accumulator of V_MAD_U64_U32 fully. (Unless the multiply has
multiple uses and the implied duplication of the multiply is an
overall negative). However, this is also not true when the factors
are uniform: in that case, it is generally better to *not* combine
the two operations, so that the multiply can be done on the SALU.
Again, we don't have a divergence analysis available and so cannot
make an informed choice.
Differential Revision: https://reviews.llvm.org/D124844
This matches what we do in IR. For the RISC-V test case, this allows
us to use -8 for the AND mask instead of materializing a constant in a register.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D127335
