Commit Graph

225 Commits

Author SHA1 Message Date
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 f8317bb256 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
Kamlesh Kumar aabc24acf0 [RISCV] Support llvm.thread.pointer
Fixes https://bugs.llvm.org/show_bug.cgi?id=45303 (clang crashed on __builtin_thread_pointer)

Reviewed By: lenary, MaskRay, luismarques

Differential Revision: https://reviews.llvm.org/D76828
2020-03-27 17:30:12 -07:00
Roger Ferrer Ibanez 3c24aee7ee [RISCV] Select +0.0 immediate using fmv.{w,d}.x / fcvt.d.w
Floating point positive zero can be selected using fmv.w.x / fmv.d.x /
fcvt.d.w and the zero source register.

Differential Revision: https://reviews.llvm.org/D75729
2020-03-20 09:42:24 +00:00
Andrew Wei 4ca753f4e3 [RISCV] Implement mayBeEmittedAsTailCall for tail call optimization
Implement TargetLowering callback mayBeEmittedAsTailCall for riscv in CodeGenPrepare,
which will duplicate return instructions to enable tailcall optimization.

Differential Revision: https://reviews.llvm.org/D73699
2020-02-18 23:56:42 +08:00
Craig Topper eeb63944e4 [LegalizeTypes][ARM][AArch64][PowerPC][RISCV][X86] Use BUILD_PAIR to return expanded integer results from ReplaceNodeResults instead of just returning two results.
Remove code from LegalizeTypes that allowed this to work.

We were already using BUILD_PAIR for this in some places so this
standardizes on a single way to do this.
2020-02-08 09:52:31 -08:00
Guillaume Chatelet 333f2ad8b8 [Alignment][NFC] Use Align for getMemcpy/Memmove/Memset
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: arsenm, dschuff, jyknight, 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, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73885
2020-02-03 17:13:19 +01:00
Zakk Chen 0cb274de39 [RISCV] Support ABI checking with per function target-features
1. if users don't specific -mattr, the default target-feature come
from IR attribute.
2. fixed bug and re-land this patch

Reviewers: lenary, asb

Reviewed By: lenary

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70837
2020-01-22 08:12:28 -08:00
Zakk Chen cef838e65f Revert "[RISCV] Support ABI checking with per function target-features"
This reverts commit 7bc58a779a.
It breaks EXPENSIVE_CHECKS on Windows
2020-01-16 18:01:07 -08:00
Zakk Chen 7bc58a779a [RISCV] Support ABI checking with per function target-features
if users don't specific -mattr, the default target-feature come
from IR attribute.

Reviewers: lenary, asb

Reviewed By: lenary, asb

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70837
2020-01-15 04:35:01 -08:00
Zakk Chen 3bc2860e92 Revert "[RISCV] Support ABI checking with per function target-features"
This reverts commit 109e4d12ed.
2020-01-15 04:32:57 -08:00
Zakk Chen 109e4d12ed [RISCV] Support ABI checking with per function target-features
if users don't specific -mattr, the default target-feature come
from IR attribute.
2020-01-15 02:30:43 -08:00
Matt Arsenault 255cc5a760 CodeGen: Use LLT instead of EVT in getRegisterByName
Only PPC seems to be using it, and only checks some simple cases and
doesn't distinguish between FP. Just switch to using LLT to simplify
use from GlobalISel.
2020-01-09 17:37:52 -05:00
Reid Kleckner 9c2b72821b Move tail call disabling code to target independent code
When the "disable-tail-calls" attribute was added, checks were added for
it in various backends. Now this code has proliferated, and it is
something the target is responsible for checking. Move that
responsibility back to the ISels (fast, global, and SD).

There's no major functionality change, except for targets that never
implemented this check.

This LLVM attribute was originally added in
d9699bc7bd (2015).

Reviewers: echristo, MaskRay

Differential Revision: https://reviews.llvm.org/D72118
2020-01-03 11:27:41 -08:00
Reid Kleckner 5d986953c8 [IR] Split out target specific intrinsic enums into separate headers
This has two main effects:
- Optimizes debug info size by saving 221.86 MB of obj file size in a
  Windows optimized+debug build of 'all'. This is 3.03% of 7,332.7MB of
  object file size.
- Incremental step towards decoupling target intrinsics.

The enums are still compact, so adding and removing a single
target-specific intrinsic will trigger a rebuild of all of LLVM.
Assigning distinct target id spaces is potential future work.

Part of PR34259

Reviewers: efriedma, echristo, MaskRay

Reviewed By: echristo, MaskRay

Differential Revision: https://reviews.llvm.org/D71320
2019-12-11 18:02:14 -08:00
James Clarke da7b129b1b [RISCV] Don't force Local Exec TLS for non-PIC
Summary:
Forcing Local Exec TLS requires the use of copy relocations. Copy
relocations need special handling in the runtime linker when being used
against TLS symbols, which is present in glibc, but not in FreeBSD nor
musl, and so cannot be relied upon. Moreover, copy relocations are a
hack that embed the size of an object in the ABI when it otherwise
wouldn't be, and break protected symbols (which are expected to be DSO
local), whilst also wasting space, thus they should be avoided whenever
possible. As discussed in D70398, RISC-V should move away from forcing
Local Exec, and instead use Initial Exec like other targets, with
possible linker relaxation to follow. The RISC-V GCC maintainers also
intend to adopt this more-conventional behaviour (see
https://github.com/riscv/riscv-elf-psabi-doc/issues/122).

Reviewers: asb, MaskRay

Reviewed By: MaskRay

Subscribers: emaste, krytarowski, hiraditya, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, llvm-commits, bsdjhb

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70649
2019-12-03 22:04:54 +00:00
Luís Marques 51b4b17eb7 [RISCV] Implement the TargetLowering::getRegisterByName hook
Summary: The hook should work for any RISC-V register. Non-allocatable registers
do not need to be reserved, for the remaining the hook will only succeed
if you pass clang the -ffixed-xX flag. This builds upon D67185, which
currently only allows reserving GPRs.

Reviewers: asb, lenary

Reviewed By: lenary

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69130
2019-11-04 11:23:54 +00:00
Sam Elliott 7214f7a79f [RISCV] Lower llvm.trap and llvm.debugtrap
Summary:
Until this commit, these have lowered to a call to abort().

`llvm.trap()` now lowers to `unimp`, which should trap on all systems.

`llvm.debugtrap()` now lowers to `ebreak`, which is exactly what this
instruction is for.

Reviewers: asb, luismarques

Reviewed By: asb

Subscribers: hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, pzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69390
2019-10-28 09:54:33 +00:00
Luís Marques 1baa50396d [RISCV] Add support for half-precision floats
Complete fp16 support by ensuring that load extension / truncate store
operations are properly expanded.

Reviewers: asb, lenary
Reviewed By: lenary
Differential Revision: https://reviews.llvm.org/D69246
2019-10-25 14:02:02 +01:00
Simon Cook aed9d6d64a [RISCV] Add support for -ffixed-xX flags
This adds support for reserving GPRs such that the compiler will not
choose a register for register allocation. The implementation follows
the same design as for AArch64; each reserved register becomes a target
feature and used for getting the reserved registers for a given
MachineFunction. The backend checks that it does not need to write to
any reserved register; if it does a relevant error is generated.

Differential Revision: https://reviews.llvm.org/D67185
2019-10-22 21:25:01 +01:00
Shiva Chen 078bec6c48 [RISCV] Support fast calling convention
LLVM may annotate the function with fastcc if there has only one caller
and there're no other caller out of the module and the function is not
naked or contain variable arguments.

The fastcc functions could pass the arguments by the caller saved registers.

Differential Revision: https://reviews.llvm.org/D68559

llvm-svn: 374857
2019-10-15 02:04:29 +00:00
Luis Marques aae97bfd0c [RISCV] Rename FPRs and use Register arithmetic
The new names for FPRs ensure that the Register values within the same class are
enumerated consecutively (the order is determined by the `LessRecordRegister`
function object). Where there were tables mapping between 32- and 64-bit FPRs
(and vice versa) this patch replaces them with Register arithmetic. The
enumeration order between different register classes is expected to continue to
be arbitrary, although it does impact the conversion from the (overloaded) asm
FPR names to Register values, and therefore might require updates to the target
if the sorting algorithm is changed. Static asserts were added to ensure that
changes to the ordering that would impact the current implementation are
detected.

Differential Revision: https://reviews.llvm.org/D67423

llvm-svn: 373096
2019-09-27 15:49:10 +00:00
Guillaume Chatelet 18f805a7ea [Alignment][NFC] Remove unneeded llvm:: scoping on Align types
llvm-svn: 373081
2019-09-27 12:54:21 +00:00
Luis Marques 2d0cd6cac8 [RISCV] Fix static analysis issues
Unlikely to be problematic but still worth fixing.

Differential Revision: https://reviews.llvm.org/D67640

llvm-svn: 372391
2019-09-20 13:48:02 +00:00
Guillaume Chatelet ad1cea0dda [Alignment][NFC] Use Align with TargetLowering::setPrefFunctionAlignment
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: nemanjai, javed.absar, hiraditya, kbarton, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, s.egerton, pzheng, ychen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67267

llvm-svn: 371212
2019-09-06 15:03:49 +00:00
Guillaume Chatelet 4fc3ad9e13 [Alignment][NFC] Use Align with TargetLowering::setMinFunctionAlignment
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, javed.absar, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, s.egerton, pzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67229

llvm-svn: 371200
2019-09-06 12:48:34 +00:00
Guillaume Chatelet aff45e4b23 [LLVM][Alignment] Make functions using log of alignment explicit
Summary:
This patch renames functions that takes or returns alignment as log2, this patch will help with the transition to llvm::Align.
The renaming makes it explicit that we deal with log(alignment) instead of a power of two alignment.
A few renames uncovered dubious assignments:

 - `MirParser`/`MirPrinter` was expecting powers of two but `MachineFunction` and `MachineBasicBlock` were using deal with log2(align). This patch fixes it and updates the documentation.
 - `MachineBlockPlacement` exposes two flags (`align-all-blocks` and `align-all-nofallthru-blocks`) supposedly interpreted as power of two alignments, internally these values are interpreted as log2(align). This patch updates the documentation,
 - `MachineFunctionexposes` exposes `align-all-functions` also interpreted as power of two alignment, internally this value is interpreted as log2(align). This patch updates the documentation,

Reviewers: lattner, thegameg, courbet

Subscribers: dschuff, arsenm, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, Jim, s.egerton, llvm-commits, courbet

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65945

llvm-svn: 371045
2019-09-05 10:00:22 +00:00
Jim Lin b77aa1d248 [RISCV] Enable tail call opt for variadic function
Summary: Tail call opt can treat variadic function call the same as normal function call

Reviewers: mgrang, asb, lenary, lewis-revill

Reviewed By: lenary

Subscribers: luismarques, pzheng, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66278

llvm-svn: 370835
2019-09-04 02:03:36 +00:00
Shiva Chen b39876d8cd [RISCV] Avoid generating AssertZext for LP64 ABI when lowering floating LibCall
The patch fixed the issue that RV64 didn't clear the upper bits
when return complex floating value with lp64 ABI.

float _Complex
complex_add(float _Complex a, float _Complex b)
{
   return a + b;
}

RealResult = zero_extend(RealA + RealB)
ImageResult = ImageA + ImageB
Return (RealResult | (ImageResult << 32))

The patch introduces shouldExtendTypeInLibCall target hook to suppress
the AssertZext generation when lowering floating LibCall.

Thanks to Eli's comments from the Bugzilla
https://bugs.llvm.org/show_bug.cgi?id=42820

Differential Revision: https://reviews.llvm.org/D65497

llvm-svn: 370275
2019-08-28 23:40:37 +00:00
Benjamin Kramer dc5f805d31 Do a sweep of symbol internalization. NFC.
llvm-svn: 369803
2019-08-23 19:59:23 +00:00
Luis Marques fa06e95898 [RISCV] Convert registers from unsigned to Register
Only in public interfaces that have not yet been converted should there remain
registers with unsigned type.

Differential Revision: https://reviews.llvm.org/D66252

llvm-svn: 369114
2019-08-16 14:27:50 +00:00
Lewis Revill 7abf863f76 [RISCV] Lower inline asm constraint A for RISC-V
This allows arguments with the constraint A to be lowered to input nodes
for RISC-V, which implies a memory address stored in a register.

This patch adds the minimal amount of code required to get operands with
the right constraints to compile.

https://reviews.llvm.org/D54296

llvm-svn: 369095
2019-08-16 10:28:34 +00:00
Daniel Sanders 3836874dbb [risc-v] Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM
Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Depends on D65919

Reviewers: lenary

Subscribers: jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision for full review was: https://reviews.llvm.org/D65962

llvm-svn: 368629
2019-08-12 22:41:02 +00:00
Sam Elliott fee242aed4 [RISCV] Fix ICE in isDesirableToCommuteWithShift
Summary:
Ana Pazos reported a bug where we were not checking that an APInt would
fit into 64-bits before calling `getSExtValue()`. This caused asserts when
compiling large constants, such as i128s, as happens when compiling compiler-rt.

This patch adds a testcase and makes the callback less error-prone.

Reviewers: apazos, asb, luismarques

Reviewed By: luismarques

Subscribers: hiraditya, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66081

llvm-svn: 368572
2019-08-12 13:51:00 +00:00
Sam Elliott 856d5c5817 [RISCV] Allow ABI Names in Inline Assembly Constraints
Summary:
Clang will replace references to registers using ABI names in inline
assembly constraints with references to architecture names, but other
frontends do not. LLVM uses the regular assembly parser to parse inline asm,
so inline assembly strings can contain references to registers using their
ABI names.

This patch adds support for parsing constraints using either the ABI name or
the architectural register name. This means we do not need to implement the
ABI name replacement code in every single frontend, especially those like
Rust which are a very thin shim on top of LLVM IR's inline asm, and that
constraints can more closely match the assembly strings they refer to.

Reviewers: asb, simoncook

Reviewed By: simoncook

Subscribers: hiraditya, rbar, johnrusso, JDevlieghere, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65947

llvm-svn: 368303
2019-08-08 14:59:16 +00:00
Shiva Chen b12056bd33 [RISCV] Custom legalize i32 operations for RV64 to reduce signed extensions
Differential Revision: https://reviews.llvm.org/D65434

llvm-svn: 367960
2019-08-06 00:24:00 +00:00
Guillaume Chatelet c97a3d15d2 [LLVM][Alignment] Introduce Alignment Type
Summary:
This is patch is part of a serie 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, jfb, jakehehrlich

Reviewed By: jfb

Subscribers: wuzish, jholewinski, arsenm, dschuff, nemanjai, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65514

llvm-svn: 367828
2019-08-05 11:02:05 +00:00
Bill Wendling 41a2847a9a Emit diagnostic if an inline asm constraint requires an immediate
Summary:
An inline asm call can result in an immediate after inlining. Therefore emit a
diagnostic here if constraint requires an immediate but one isn't supplied.

Reviewers: joerg, mgorny, efriedma, rsmith

Reviewed By: joerg

Subscribers: asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, s.egerton, MaskRay, jyknight, dylanmckay, javed.absar, fedor.sergeev, jrtc27, Jim, krytarowski, eraman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60942

llvm-svn: 367750
2019-08-03 05:52:47 +00:00
Sam Elliott 9e6b2e1605 [RISCV] Support 'f' Inline Assembly Constraint
Summary:
This adds the 'f' inline assembly constraint, as supported by GCC. An
'f'-constrained operand is passed in a floating point register. Exactly
which kind of floating-point register (32-bit or 64-bit) is decided
based on the operand type and the available standard extensions (-f and
-d, respectively).

This patch adds support in both the clang frontend, and LLVM itself.

Reviewers: asb, lewis-revill

Reviewed By: asb

Subscribers: hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D65500

llvm-svn: 367403
2019-07-31 09:45:55 +00:00
Simon Cook 8d7ec4d644 [RISCV] Add support for lowering floating point inlineasm clobbers
This adds the required extension to RISC-V's getRegForInlineAsmConstraint
in order to be able to correctly distringuish between the 32 and 64-bit
floating point registers when the generic fX name appears in inlineasm
clobber contraints. It also adds a check to validate that callee saved
floating point registers are only saved in this case when a hard-float
ABI is selected.

Differential Revision: https://reviews.llvm.org/D64751

llvm-svn: 367397
2019-07-31 09:07:21 +00:00
Alex Bradbury b8d352a08b [RISCV] Reset NoPHIS MachineFunctionProperty in emitSelectPseudo
We insered PHIS were there were none before, so the property must be
reset. This error was found on an EXPENSIVE_CHECKS build.

llvm-svn: 366412
2019-07-18 07:52:41 +00:00
Sam Elliott 114d2db49b [RISCV] Fix ICE in isDesirableToCommuteWithShift
Summary:
There was an error being thrown from isDesirableToCommuteWithShift in
some tests. This was tracked down to the method being called before
legalisation, with an extended value type, not a machine value type.

In the case I diagnosed, the error was only hit with an instruction sequence
involving `i24`s in the add and shift. `i24` is not a Machine ValueType, it is
instead an Extended ValueType which was causing the issue.

I have added a test to cover this case, and fixed the error in the callback.

Reviewers: asb, luismarques

Reviewed By: asb

Subscribers: hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64425

llvm-svn: 365511
2019-07-09 16:24:16 +00:00
Alex Bradbury 0b9addb8c0 [RISCV] Specify registers used in DWARF exception handling
Defines RISCV registers for getExceptionPointerRegister() and
getExceptionSelectorRegister().

Differential Revision: https://reviews.llvm.org/D63411
Patch by Edward Jones.
Modified by Alex Bradbury to add CHECK lines to exception-pointer-register.ll.

llvm-svn: 365301
2019-07-08 09:16:47 +00:00
Sam Elliott b2c9eed0d7 [RISCV] Support @llvm.readcyclecounter() Intrinsic
On RISC-V, the `cycle` CSR holds a 64-bit count of the number of clock
cycles executed by the core, from an arbitrary point in the past. This
matches the intended semantics of `@llvm.readcyclecounter()`, which we
currently leave to the default lowering (to the constant 0).

With this patch, we will now correctly lower this intrinsic to the
intended semantics, using the user-space instruction `rdcycle`. On
64-bit targets, we can directly lower to this instruction.

On 32-bit targets, we need to do more, as `rdcycle` only returns the low
32-bits of the `cycle` CSR. In this case, we perform a custom lowering,
based on the PowerPC lowering, using `rdcycleh` to obtain the high
32-bits of the `cycle` CSR. This custom lowering inserts a new basic
block which detects overflow in the high 32-bits of the `cycle` CSR
during reading (because multiple instructions are required to read). The
emitted assembly matches the suggested assembly in the RISC-V
specification.

Differential Revision: https://reviews.llvm.org/D64125

llvm-svn: 365201
2019-07-05 12:35:21 +00:00
Lewis Revill 39263ac5d1 [RISCV] Add lowering of global TLS addresses
This patch adds lowering for global TLS addresses for the TLS models of
InitialExec, GlobalDynamic, LocalExec and LocalDynamic.

LocalExec support required using a 4-operand add instruction, which uses
the fourth operand to express a relocation on the symbol. The necessary
fixup is emitted when the instruction is emitted.

Differential Revision: https://reviews.llvm.org/D55305

llvm-svn: 363771
2019-06-19 08:40:59 +00:00
Sam Elliott 9f155bc6e5 [RISCV] Prevent re-ordering some adds after shifts
Summary:
DAGCombine will normally turn a `(shl (add x, c1), c2)` into `(add (shl x, c2), c1 << c2)`, where `c1` and `c2` are constants. This can be prevented by a callback in TargetLowering.

On RISC-V, materialising the constant `c1 << c2` can be more expensive than materialising `c1`, because materialising the former may take more instructions, and may use a register, where materialising the latter would not.

This patch implements the hook in RISCVTargetLowering to prevent this transform, in the cases where:
- `c1` fits into the immediate field in an `addi` instruction.
- `c1` takes fewer instructions to materialise than `c1 << c2`.

In future, DAGCombine could do the check to see whether `c1` fits into an add immediate, which might simplify more targets hooks than just RISC-V.

Reviewers: asb, luismarques, efriedma

Reviewed By: asb

Subscribers: xbolva00, lebedev.ri, craig.topper, lewis-revill, Jim, hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62857

llvm-svn: 363736
2019-06-18 20:38:08 +00:00
Lewis Revill 74c8364954 [RISCV] Lower calls through PLT
This patch adds support for generating calls through the procedure
linkage table where required for a given ExternalSymbol or GlobalAddress
callee.

Differential Revision: https://reviews.llvm.org/D55304

llvm-svn: 363686
2019-06-18 14:29:45 +00:00
Lewis Revill a5240361dd [RISCV] Add lowering of addressing sequences for PIC
This patch allows lowering of PIC addresses by using PC-relative
addressing for DSO-local symbols and accessing the address through the
global offset table for non-DSO-local symbols.

Differential Revision: https://reviews.llvm.org/D55303

llvm-svn: 363058
2019-06-11 12:57:47 +00:00
Lewis Revill 28a5cadb3a [RISCV] Lower inline asm constraints I, J & K for RISC-V
This validates and lowers arguments to inline asm nodes which have the
constraints I, J & K, with the following semantics (equivalent to GCC):

I: Any 12-bit signed immediate.
J: Immediate integer zero only.
K: Any 5-bit unsigned immediate.

Differential Revision: https://reviews.llvm.org/D54093

llvm-svn: 363054
2019-06-11 12:42:13 +00:00
Sam Elliott f720647ddd [RISCV] Support Bit-Preserving FP in F/D Extensions
Summary:
This allows some integer bitwise operations to instead be performed by
hardware fp instructions. This is correct because the RISC-V spec
requires the F and D extensions to use the IEEE-754 standard
representation, and fp register loads and stores to be bit-preserving.

This is tested against the soft-float ABI, but with hardware float
extensions enabled, so that the tests also ensure the optimisation also
fires in this case.

Reviewers: asb, luismarques

Reviewed By: asb

Subscribers: hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62900

llvm-svn: 362790
2019-06-07 12:20:14 +00:00
Luis Marques 20d2424016 [RISCV] Custom lower SHL_PARTS, SRA_PARTS, SRL_PARTS
When not optimizing for minimum size (-Oz) we custom lower wide shifts
(SHL_PARTS, SRA_PARTS, SRL_PARTS) instead of expanding to a libcall.

Differential Revision: https://reviews.llvm.org/D59477

llvm-svn: 358498
2019-04-16 14:38:32 +00:00
Lewis Revill 24a74096a4 Test commit: Remove double variable assignment
llvm-svn: 357601
2019-04-03 15:54:30 +00:00
Alex Bradbury 44668ae7c7 [RISCV] Attach VK_RISCV_CALL to symbols upon creation
This patch replaces the addition of VK_RISCV_CALL in RISCVMCCodeEmitter by
creating the RISCVMCExpr when tail/call are parsed, or in the codegen case
when the callee symbols are created.

This required adding a new CallSymbol operand to allow only adding
VK_RISCV_CALL to tail/call instructions.

This patch will allow further expansion of parsing and codegen to easily
include PLT symbols which must generate the R_RISCV_CALL_PLT relocation.

Differential Revision: https://reviews.llvm.org/D55560
Patch by Lewis Revill.

llvm-svn: 357396
2019-04-01 14:53:17 +00:00
Alex Bradbury da20f5ca74 [RISCV] Generate address sequences suitable for mcmodel=medium
This patch adds an implementation of a PC-relative addressing sequence to be
used when -mcmodel=medium is specified. With absolute addressing, a 'medium'
codemodel may cause addresses to be out of range. This is because while
'medium' implies a 2 GiB addressing range, this 2 GiB can be at any offset as
opposed to 'small', which implies the first 2 GiB only.

Note that LLVM/Clang currently specifies code models differently to GCC, where
small and medium imply the same functionality as GCC's medlow and medany
respectively.

Differential Revision: https://reviews.llvm.org/D54143
Patch by Lewis Revill.

llvm-svn: 357393
2019-04-01 14:42:56 +00:00