177 Commits

Author SHA1 Message Date
Craig Topper
a64998be99 [RISCV] Share VTYPE encoding code between the assembler and the CustomInserter for adding VSETVLI before vector instructions
This merges the SEW and LMUL enums that each used into singles enums in RISCVBaseInfo.h. The patch also adds a new encoding helper to take SEW, LMUL, tail agnostic, mask agnostic and turn it into a vtype immediate.

I also stopped storing the Encoding in the VTYPE operand in the assembler. It is easy to calculate when adding the operand which should only happen once per instruction.

Differential Revision: https://reviews.llvm.org/D92813
2020-12-08 16:04:20 -08:00
Craig Topper
5c819eb389 [RISCV] Form GORCI from (or (rotl/rotr X, Bitwidth/2), X).
A rotate by half the bitwidth swaps the bottom and top half which is the same as one of the MSB GREVI stage.

We have to do this as a special combine because we prefer to keep (rotl/rotr X, BitWidth/2) as a rotate rather than a single stage GREVI.

Differential Revision: https://reviews.llvm.org/D92286
2020-12-07 10:28:04 -08:00
Craig Topper
5baef6353e [RISCV] Initial infrastructure for code generation of the RISC-V V-extension
The companion RFC (http://lists.llvm.org/pipermail/llvm-dev/2020-October/145850.html) gives lots of details on the overall strategy, but we summarize it here:

LLVM IR involving vector types is going to be selected using pseudo instructions (only MachineInstr). These pseudo instructions contain dummy operands to represent the vector type being operated and the vector length for the operation.
These two dummy operands, as set by instruction selection, will be used by the custom inserter to prepend every operation with an appropriate vsetvli instruction that ensures the vector architecture is properly configured for the operation. Not in this patch: later passes will remove the redundant vsetvli instructions.
Register classes of tuples of vector registers are used to represent vector register groups (LMUL > 1).
Those pseudos are eventually lowered into the actual instructions when emitting the MCInsts.
About the patch:

Because there is a bit of initial infrastructure required, this is the minimal patch that allows us to select instructions for 3 LLVM IR instructions: load, add and store vectors of integers. LLVM IR operations have "whole-vector" semantics (as in they generate values for all the elements).

Later patches will extend the information represented in TableGen.

Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Evandro Menezes <evandro.menezes@sifive.com>
Co-Authored-by: Craig Topper <craig.topper@sifive.com>

Differential Revision: https://reviews.llvm.org/D89449
2020-12-04 11:39:30 -08:00
Craig Topper
3fcdf9ca78 [RISCV] Rename FPCCToExtend->FPOpToExpand and FPOpToExtend->FPOpToExpand. NFC
These are used to call setOperationAction/setCondCodeAction with
the Expand action so it seems that Expand is a better name than
Extend.
2020-12-03 16:00:49 -08:00
Craig Topper
a18d5e3e9f [RISCV] Merge FMV_H_X_RV32/FMV_H_X_RV64 into a single opcode. Same with FMV_X_ANYEXTH_RV32/RV64
Rather than having a different opcode for RV32 and RV64. Let's just say the integer type is XLenVT and use a single opcode for both modes.

Differential Revision: https://reviews.llvm.org/D92538
2020-12-03 11:12:40 -08:00
Craig Topper
e52a91e156 [RISCV] Add f16 to isFMAFasterThanFMulAndFAdd now that the Zfh extension is supported 2020-12-02 20:31:43 -08:00
Hsiangkai Wang
f7bc7c2981 [RISCV] Support Zfh half-precision floating-point extension.
Support "Zfh" extension according to
https://github.com/riscv/riscv-isa-manual/blob/zfh/src/zfh.tex

Differential Revision: https://reviews.llvm.org/D90738
2020-12-03 09:16:33 +08:00
Craig Topper
bfc4f29f46 [RISCV] Combine (GORCI (GORCI x, C2), C1) -> (GORCI x, C1|C2).
Unlike GREVI, GORCI stages can't be undone, but they are
redundant if done more than once.

Differential Revision: https://reviews.llvm.org/D92295
2020-11-30 08:42:46 -08:00
Craig Topper
76d1026b59 [RISCV] Custom legalize bswap/bitreverse to GREVI with Zbp extension to enable them to combine with other GREVI instructions
This enables bswap/bitreverse to combine with other GREVI patterns or each other without needing to add more special cases to the DAG combine or new DAG combines.

I've also enabled the existing GREVI combine for GREVIW so that it can pick up the i32 bswap/bitreverse on RV64 after they've been type legalized to GREVIW.

Differential Revision: https://reviews.llvm.org/D92253
2020-11-30 08:30:40 -08:00
Craig Topper
cbbd7021f1 [RISCV] Only combine (or (GREVI x, shamt), x) -> GORCI if shamt is a power of 2.
GORCI performs an OR between each stage. So we need to ensure only
one stage is active before doing this combine.

Initial attempts at finding a test case for this failed due to
the order things get combined. It's most likely that we'll form
one stage of GREVI then combine to GORCI before the two stages of
GREVI are able to be formed and combined with each other to form
a multi stage GREVI.

Differential Revision: https://reviews.llvm.org/D92289
2020-11-30 08:10:39 -08:00
Craig Topper
8709d9d872 [RISCV] Replace getSimpleValueType() with getValueType() in DAG combines to prevent asserts with weird types. 2020-11-27 12:49:12 -08:00
Craig Topper
ed95cafbc5 [RISCV] Add an implementation of isFMAFasterThanFMulAndFAdd
Start with an assumption that FMA is faster than Fmul+FAdd. If thats not true
on some particular implementation we can add a tuning parameter in the future.

I've update the fmuladd test cases and added new test cases for fast math flag
based contraction.

Differential Revision: https://reviews.llvm.org/D91987
2020-11-25 15:07:34 -08:00
Craig Topper
751b0d970e [RISCV] Make SMIN/SMAX/UMIN/UMAX legal with Zbb extension.
This is the logically correct thing to do. But it generates worse
code for i32 umin/umax on the rv64 due to type legalize requesting
zext even though the arguments are sext. Maybe we can teach type
legalizer to use sext for umin/umax for RISCV.

It's also producing possibly worse code on i64 on RV32 since we
still end up with selects that become branches. But this seems
like something we could improve in type legalization or DAG combine.

Hopefully this makes D92095 work for RISCV with Zbb.
2020-11-25 12:48:43 -08:00
Craig Topper
c26e8697d7 [RISCV] Custom type legalize i32 fshl/fshr on RV64 with Zbt.
This adds custom opcodes for FSLW/FSRW so we can type legalize
fshl/fshr without needing to match a sign_extend_inreg.

I've used the operand order from fshl/fshr to make the isel
pattern similar to the non-W form. It was also hard to decide
another order since the register instruction has the shift amount
as the second operand, but the immediate instruction has it as
the third operand.

Differential Revision: https://reviews.llvm.org/D91479
2020-11-25 10:01:47 -08:00
Luís Marques
a8dc2110cd [RISCV] Add GHC calling convention
This is a special calling convention to be used by the GHC compiler.

Patch by Andreas Schwab (schwab)

Differential Revision: https://reviews.llvm.org/D89788
2020-11-24 22:35:23 +00:00
Luís Marques
e4d9380245 Revert "[RISCV] Add GHC calling convention"
This reverts commit f8317bb256be2cd8ed81ebc567f0fa626b645f63 due to lack of
proper attribution.
2020-11-24 22:34:20 +00:00
Luís Marques
f8317bb256 [RISCV] Add GHC calling convention
This is a special calling convention to be used by the GHC compiler.

Differential Revision: https://reviews.llvm.org/D89788
2020-11-24 21:56:28 +00:00
Fraser Cormack
ca1f2f2716 [RISCV] Combine GREVI sequences
This combine step performs the following type of transformation:

    rev.p a0, a0   # grevi a0, a0, 0b01
    rev2.n a0, a0  # grevi a0, a0, 0b10
    -->
    rev.n a0, a0   # grevi a0, a0, 0b11

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D91877
2020-11-24 12:07:13 +00:00
Craig Topper
84b8222705 [RISCV] Use separate Lo and Hi MemOperands when expanding BuildPairF64Pseudo and SplitF64Pseudo.
We generate two 4 byte loads or two stores as part of the expansion.
Previously the MemOperand was set the same for both to cover the
full 8 bytes. Now we set a separate 4 byte mem operand for each
with a 4 byte offset for the high part.
2020-11-22 00:46:12 -08:00
Craig Topper
6a1d8b91ed [RISCV] Custom type legalize i32 bswap/bitreverse to GREVIW on RV64 with Zbp extension
Previously we required a sra to pattern match these properly in isel. If the consumer didn't need the result sign extended we'll have an srl instead of sra and fail to match.

This patch switches to custom legalizing to GREVIW using portions of D91259.

Differential Revision: https://reviews.llvm.org/D91457
2020-11-20 10:41:01 -08:00
Craig Topper
78767b7f8e [RISCV] Add RISCVISD::ROLW/RORW use those for custom legalizing i32 rotl/rotr on RV64IZbb.
This should result in better utilization of RORIW since we
don't need to look for a SIGN_EXTEND_INREG that may not exist.

Also remove rotl/rotr isel matching to GREVI and just prefer RORI.
This is to keep consistency so we don't have to match ROLW/RORW
to GREVIW as well. I imagine RORI/RORIW performance will be the
same or better than GREVI.

Differential Revision: https://reviews.llvm.org/D91449
2020-11-20 10:25:47 -08:00
Fraser Cormack
1ac9b54831 [RISCV] Lower GREVI and GORCI as custom nodes
This moves the recognition of GREVI and GORCI from TableGen patterns
into a DAGCombine. This is done primarily to match "deeper" patterns in
the future, like (grevi (grevi x, 1) 2) -> (grevi x, 3).

TableGen is not best suited to matching patterns such as these as the compile
time of the DAG matchers quickly gets out of hand due to the expansion of
commutative permutations.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D91259
2020-11-19 18:11:42 +00:00
Fraser Cormack
fe9dc2e54a [RISCV] Use a macro to simplify getTargetNodeName
Similar to the X86 and AMDGPU targets, this uses a macro to cut down on
repetitive and error-prone code when converting RISCVISD node names to
strings in getTargetNodeName.

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D91414
2020-11-16 09:33:47 +00:00
Craig Topper
637f19c36b [RISCV] Remove traces of Glue from RISCVISD::SELECT_CC
We were creating RISCVISD::SELECT_CC nodes with Glue output that was never being used, and the tablegen SDNode had the SDNPInGlue flag instead of the SDNPOutGlue flag.

Since we don't seem to need the Glue just get rid of it from both places.

Differential Revision: https://reviews.llvm.org/D91199
2020-11-11 09:30:48 -08:00
Craig Topper
5d3fd3df94 [RISCV] Make ctlz/cttz cheap to speculatively execute so CodeGenPrepare won't insert a zero check.
Add additional isel patterns for ctzw/clzw instructions.

Differential Revision: https://reviews.llvm.org/D91040
2020-11-09 10:13:45 -08:00
Craig Topper
4265cbaa34 [RISCV] Make SIGN_EXTEND_INREG from i8/i16 legal when Zbb extension is enabled.
This produces better code for sign extend to i64 on RV32 target.

Differential Revision: https://reviews.llvm.org/D91023
2020-11-09 10:13:45 -08:00
Craig Topper
ce5f4f22e9 [RISCV] Use the 'si' lib call for (double (fp_to_sint/uint i32 X)) when F extension is enabled.
D80526 added custom lowering to pick the si lib call on RV64, but this custom handling is only enabled when the F and D extension are both disabled. This prevents the si library call from being used for double when F is enabled but D is not.

This patch changes the behavior so we always enable the Custom hook on RV64 and decide in ReplaceNodeResults if we should emit a libcall based on whether the FP type should be softened or not.

Differential Revision: https://reviews.llvm.org/D90817
2020-11-05 10:46:45 -08:00
Craig Topper
ce1270fc7e [RISCV] Remove shadow register list passed to AllocateReg when allocating FP registers for calling convention
The _F and _D registers are already sub/super registers. When one gets allocated all its aliases are already marked as allocated. We don't need to explicitly shadow it too.

I believe shadow is for calling conventions like 64-bit Windows on X86 where have rules like this

CCIfType<[i32], CCAssignToRegWithShadow<[ECX , EDX , R8D , R9D ],
                                         [XMM0, XMM1, XMM2, XMM3]>>

For that calling convention the argument number determines which register is used regardless of how many scalars or vectors came before it.

Removing this removes a question I had in D90738.

Differential Revision: https://reviews.llvm.org/D90801
2020-11-05 09:49:42 -08:00
Simon Pilgrim
36920d5f9d [RISCV] Avoid std::pair<> in FPReg StringSwitch to avoid MSVC compile failures. NFCI.
As discussed on D90322, some MSVC builds are failing with is_trivially_copyable static asserts (see D86126) - we can avoid this by not using the std::pair<unsigned,unsigned> which held both the FP+DP Registers, just handle the FP register and convert to DP on the fly.
2020-11-02 11:30:57 +00:00
Craig Topper
a76cd10fcd [RISCV] Use 'unsigned' instead of Register in getRegForInlineAsmConstraint. NFC
The return value of this interface still uses an 'unsigned' on all
targets. So we convert Register back to unsigned at the end.

I'm hoping this will prevent the issue that caused the revert of
D90322.
2020-11-01 10:16:52 -08:00
Craig Topper
6915c76e10 [RISCV] Don't use DCI.CombineTo to replace a single result. NFCI
Just return the new node, which is the standard practice.

I also noticed what appeared to be an unnecessary attempt at
creating an ANY_EXTEND where the type should already be correct.
I replace with an assert to verify the type.

Differential Revision: https://reviews.llvm.org/D90444
2020-10-30 10:46:32 -07:00
Craig Topper
74b078294f [RISCV] Improve worklist management in the DAG combine for SLLW/SRLW/SRAW
This combine makes two calls to SimplifyDemandedBits, one for the LHS and one
for the RHS. If the LHS call returns true, we don't make the RHS call. When
SimplifyDemandedBits makes a change, it will add the nodes around the change to
the DAG combiner worklist. If the simplification happens on the first recursion
step, the N will get added to the worklist. But if the simplification happens
deeper in the recursion, then N will not be revisited until the next time the
DAG combiner runs.

This patch explicitly addes N to the worklist anytime a Simplification is made.
Without this we might miss additional simplifications on the LHS or never
simplify the RHS. Special care also needs to be taken to not add N if it has
been CSEd by the simplification. There are similar examples in DAGCombiner and
the X86 target, but I don't have a test for it for RISC-V. I've also returned
SDValue(N, 0) instead of SDValue() so DAGCombiner knows a change was made and
will update its Statistic variable.

The test here was constructed so that 2 simplifications happen to the LHS.
Without this fix one happens in the post type legalization DAG combine and the
other happens after LegalizeDAG. This prevents the RHS from ever being
simplified causing the left and right shift to clear the upper 32 bits of the
RHS to be left behind.

Differential Revision: https://reviews.llvm.org/D90339
2020-10-29 14:52:53 -07:00
StephenFan
a96921afa7 [RISCV] eliminate the repetition declare of SDLoc DL
Differential revision: https://reviews.llvm.org/D85002
2020-08-03 10:24:30 +08:00
Yuanfang Chen
ca1e69a675 [NFC] remove unused includes of SelectionDAGISel.h 2020-07-20 10:43:29 -07:00
lewis-revill
c9c955ada8 [RISCV] Add matching of codegen patterns to RISCV Bit Manipulation Zbt asm instructions
This patch provides optimization of bit manipulation operations by
enabling the +experimental-b target feature.
It adds matching of single block patterns of instructions to specific
bit-manip instructions from the ternary subset (zbt subextension) of the
experimental B extension of RISC-V.
It adds also the correspondent codegen tests.

This patch is based on Claire Wolf's proposal for the bit manipulation
extension of RISCV:
https://github.com/riscv/riscv-bitmanip/blob/master/bitmanip-0.92.pdf

Differential Revision: https://reviews.llvm.org/D79875
2020-07-15 12:19:34 +01:00
lewis-revill
6144f0a1e5 [RISCV] Add matching of codegen patterns to RISCV Bit Manipulation Zbbp asm instructions
This patch provides optimization of bit manipulation operations by
enabling the +experimental-b target feature.
It adds matching of single block patterns of instructions to specific
bit-manip instructions belonging to both the permutation and the base
subsets of the experimental B extension of RISC-V.
It adds also the correspondent codegen tests.

This patch is based on Claire Wolf's proposal for the bit manipulation
extension of RISCV:
https://github.com/riscv/riscv-bitmanip/blob/master/bitmanip-0.92.pdf

Differential Revision: https://reviews.llvm.org/D79873
2020-07-15 12:19:34 +01:00
lewis-revill
31b52b4345 [RISCV] Add matching of codegen patterns to RISCV Bit Manipulation Zbp asm instructions
This patch provides optimization of bit manipulation operations by
enabling the +experimental-b target feature.
It adds matching of single block patterns of instructions to specific
bit-manip instructions from the permutation subset (zbp subextension) of
the experimental B extension of RISC-V.
It adds also the correspondent codegen tests.

This patch is based on Claire Wolf's proposal for the bit manipulation
extension of RISCV:
https://github.com/riscv/riscv-bitmanip/blob/master/bitmanip-0.92.pdf

Differential Revision: https://reviews.llvm.org/D79871
2020-07-15 12:19:34 +01:00
lewis-revill
e2692f0ee7 [RISCV] Add matching of codegen patterns to RISCV Bit Manipulation Zbb asm instructions
This patch provides optimization of bit manipulation operations by
enabling the +experimental-b target feature.
It adds matching of single block patterns of instructions to specific
bit-manip instructions from the base subset (zbb subextension) of the
experimental B extension of RISC-V.
It adds also the correspondent codegen tests.

This patch is based on Claire Wolf's proposal for the bit manipulation
extension of RISCV:
https://github.com/riscv/riscv-bitmanip/blob/master/bitmanip-0.92.pdf

Differential Revision: https://reviews.llvm.org/D79870
2020-07-15 12:19:34 +01:00
Ben Shi
cb82de2960 [RISCV] Optimize multiplication by constant
... to shift/add or shift/sub.

Do not enable it on riscv32 with the M extension where decomposeMulByConstant
may not be an optimization.

Reviewed By: luismarques, MaskRay

Differential Revision: https://reviews.llvm.org/D82660
2020-07-07 18:50:24 -07:00
Sam Elliott
7dc892661e [RISCV] Implement Hooks to avoid chaining SELECT
Summary:
This implements two hooks that attempt to avoid control flow for RISC-V. RISC-V
will lower SELECTs into control flow, which is not a great idea.

The hook `hasMultipleConditionRegisters()` turns off the following
DAGCombiner folds:
    select(C0|C1, x, y) <=> select(C0, x, select(C1, x, y))
    select(C0&C1, x, y) <=> select(C0, select(C1, x, y), y)

The second hook `setJumpIsExpensive` controls a flag that has a similar purpose
and is used in CodeGenPrepare and the SelectionDAGBuilder.

Both of these have the effect of ensuring more logic is done before fewer jumps.

Note: with the `B` extension, we may be able to lower select into a conditional
move instruction, so at some point these hooks will need to be guarded based on
enabled extensions.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D79268
2020-07-01 11:56:31 +01:00
Matt Arsenault
08649f0a9d RISCV: Don't store function in RISCVMachineFunctionInfo
Targets should not depend on the MachineFunction state during the
MachineFunctionInfo construction.
2020-06-30 16:08:51 -04:00
Guillaume Chatelet
2e7bba693e [Alignment][NFC] Use Align for TargetCallingConv::OrigAlign
This patch replaces D69249.

This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Differential Revision: https://reviews.llvm.org/D82307
2020-06-25 13:21:22 +00:00
Kamlesh Kumar
7622ea5835 [RISCV64] Emit correct lib call for fp(float/double) to ui/si
Since i32 is not legal in riscv64,
it always promoted to i64 before emitting lib call and
for conversions like float/double to int and float/double to unsigned int
wrong lib call was emitted. This commit fix it using custom lowering.

Differential Revision: https://reviews.llvm.org/D80526
2020-06-18 19:34:16 +05:30
Guillaume Chatelet
1778564f91 [Alignment][NFC] Migrate the rest of backends
Summary: This is a followup on D81196

Reviewers: courbet

Subscribers: arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81278
2020-06-08 07:17:20 +00:00
Ben Shi
4b6f0ea66c [RISCV] Fix a typo in RISCVISelLowering.cpp
The 9th parameter of "static bool CC_RISCV(...)" is isFixed, not isRet.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D81333
2020-06-06 18:41:00 -07:00
Zequan Wu
80e107ccd0 Add NoMerge MIFlag to avoid MIR branch folding
Let the codegen recognized the nomerge attribute and disable branch folding when the attribute is given

Differential Revision: https://reviews.llvm.org/D79537
2020-05-29 12:31:06 -07:00
Craig Topper
d1119980e5 [SelectionDAG] Use Align/MaybeAlign for ConstantPoolSDNode.
This patch stores the alignment for ConstantPoolSDNode as an
Align and updates the getConstantPool interface to take a MaybeAlign.

Removing getAlignment() will be done as a follow up.

Differential Revision: https://reviews.llvm.org/D79436
2020-05-08 16:04:11 -07:00
Craig Topper
113f37a1f9 [CallSite removal][TargetLowering] Replace ImmutableCallSite with CallBase
Differential Revision: https://reviews.llvm.org/D77995
2020-04-13 13:50:15 -07:00
Matt Arsenault
84aa58cbe2 CodeGen: Use Register in TargetLowering 2020-04-08 12:10:58 -04:00
Guillaume Chatelet
bdf77209b9 [Alignment][NFC] Use Align version of getMachineMemOperand
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: jyknight, sdardis, nemanjai, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, jfb, PkmX, jocewei, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77059
2020-03-30 15:46:27 +00:00