Commit Graph

18 Commits

Author SHA1 Message Date
Philipp Tomsich 018e96f71f [RISCV] Add isel-patterns to optimize (a < 1) into blez (a <= 0)
The following code-sequence showed up in a testcase (isolated from
SPEC2017) for if-conversion and vectorization when searching for the
maximum in an array:
        addi    a2, zero, 1
        blt     a1, a2, .LBB0_5
which can be expressed as `bge zero,a1,.LBB0_5`/`blez a1,/LBB0_5`.

More generally, we want to express (a < 1) as (a <= 0).

This adds the required isel-pattern and updates the testcases.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D98449
2021-03-15 11:32:43 -07:00
Craig Topper 25c6b7ddd2 [RISCV] Add isel pattern to match X > -1 to bgez.
Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D97262
2021-02-25 07:42:22 -08:00
Craig Topper 7195aaa5a8 [RISCV] Add test case for missed opportunity use bgez for the canonical form X > -1. NFC 2021-02-23 00:33:23 -08:00
Dávid Bolvanský 0f14b2e6cb Revert "[BPI] Improve static heuristics for integer comparisons"
This reverts commit 50c743fa71. Patch will be split to smaller ones.
2020-08-17 20:44:33 +02:00
Dávid Bolvanský 50c743fa71 [BPI] Improve static heuristics for integer comparisons
Similarly as for pointers, even for integers a == b is usually false.

GCC also uses this heuristic.

Reviewed By: ebrevnov

Differential Revision: https://reviews.llvm.org/D85781
2020-08-13 19:54:27 +02:00
Dávid Bolvanský f9264995a6 Revert "[BPI] Improve static heuristics for integer comparisons"
This reverts commit 44587e2f7e. Sanitizer tests need to be updated.
2020-08-13 14:37:40 +02:00
Dávid Bolvanský 44587e2f7e [BPI] Improve static heuristics for integer comparisons
Similarly as for pointers, even for integers a == b is usually false.

GCC also uses this heuristic.

Reviewed By: ebrevnov

Differential Revision: https://reviews.llvm.org/D85781
2020-08-13 14:23:58 +02:00
Dávid Bolvanský a0485421d2 Revert "[BPI] Improve static heuristics for integer comparisons"
This reverts commit 385c9d673f.
2020-08-13 12:59:15 +02:00
Dávid Bolvanský 385c9d673f [BPI] Improve static heuristics for integer comparisons
Similarly as for pointers, even for integers a == b is usually false.

GCC also uses this heuristic.

Reviewed By: ebrevnov

Differential Revision: https://reviews.llvm.org/D85781
2020-08-13 12:45:40 +02:00
Alex Bradbury 5dabe03b41 [RISCV][NFC] Add nounwind attribute to functions missing it in test/CodeGen/RISCV
r360897 was incomplete, must have applied an old/wip patch. This is in preparation for emitting CFI directives.

llvm-svn: 361493
2019-05-23 12:43:13 +00:00
Alex Bradbury c0464d9271 [RISCV] Expand codegen -> compression sanity checks and move to a single file
The objdump tests interfere with update_llc_test_checks.py and can't be
automatically update them. Put the sanitify check for compression on the
codegen codepath into a separate file, and expand it to also include tests of
integer materialisation. This would catch changes such as those triggered by 
D41949.

llvm-svn: 330288
2018-04-18 20:17:29 +00:00
Sameer AbuAsal c1b0e66b58 [RISCV] Tablegen-driven Instruction Compression.
Summary:

    This patch implements a tablegen-driven Instruction Compression
    mechanism for generating RISCV compressed instructions
    (C Extension) from the expanded instruction form.

    This tablegen backend processes CompressPat declarations in a
    td file and generates all the compile-time and runtime checks
    required to validate the declarations, validate the input
    operands and generate correct instructions.

    The checks include validating register operands, immediate
    operands, fixed register operands and fixed immediate operands.

    Example:
      class CompressPat<dag input, dag output> {
        dag Input  = input;
        dag Output    = output;
        list<Predicate> Predicates = [];
      }

      let Predicates = [HasStdExtC] in {
      def : CompressPat<(ADD GPRNoX0:$rs1, GPRNoX0:$rs1, GPRNoX0:$rs2),
                        (C_ADD GPRNoX0:$rs1, GPRNoX0:$rs2)>;
      }

    The result is an auto-generated header file
    'RISCVGenCompressEmitter.inc' which exports two functions for
    compressing/uncompressing MCInst instructions, plus
    some helper functions:

      bool compressInst(MCInst& OutInst, const MCInst &MI,
                        const MCSubtargetInfo &STI,
                        MCContext &Context);

      bool uncompressInst(MCInst& OutInst, const MCInst &MI,
                          const MCRegisterInfo &MRI,
                          const MCSubtargetInfo &STI);

    The clients that include this auto-generated header file and
    invoke these functions can compress an instruction before emitting
    it, in the target-specific ASM or ELF streamer, or can uncompress
    an instruction before printing it, when the expanded instruction
    format aliases is favored.

    The following clients were added to implement compression\uncompression
    for RISCV:

    1) RISCVAsmParser::MatchAndEmitInstruction:
       Inserted a call to compressInst() to compresses instructions
       parsed by llvm-mc coming from an ASM input.
    2) RISCVAsmPrinter::EmitInstruction:
       Inserted a call to compressInst() to compress instructions that
       were lowered from Machine Instructions (MachineInstr).
    3) RVInstPrinter::printInst:
       Inserted a call to uncompressInst() to print the expanded
       version of the instruction instead of the compressed one (e.g,
       add s0, s0, a5 instead of c.add s0, a5) when -riscv-no-aliases
       is not passed.

This patch squashes D45119, D42780 and D41932. It was reviewed in  smaller patches by
asb, efriedma, apazos and mgrang.

Reviewers: asb, efriedma, apazos, llvm-commits, sabuasal

Reviewed By: sabuasal

Subscribers: mgorny, eraman, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, niosHD, kito-cheng, shiva0217, zzheng

Differential Revision: https://reviews.llvm.org/D45385

llvm-svn: 329455
2018-04-06 21:07:05 +00:00
Alex Bradbury 7d6aa1f7ae [RISCV] Implement frame pointer elimination
llvm-svn: 322839
2018-01-18 11:34:02 +00:00
Alex Bradbury e027c93ac2 [RISCV] Implement branch analysis
This is a prerequisite for the branch relaxation pass, and allows a number of
optimisation passes (e.g. BranchFolding and MachineBlockPlacement) to work.

Differential Revision: https://reviews.llvm.org/D40808

llvm-svn: 322222
2018-01-10 20:47:00 +00:00
Alex Bradbury 59136ffab1 [RISCV] Enable emission of alias instructions by default
This patch switches the default for -riscv-no-aliases to false
and updates all affected MC and CodeGen tests. As recommended in
D41071, MC tests use the canonical instructions and the CodeGen
tests use the aliases.

Additionally, for the f and d instructions with rounding mode,
the tests for the aliased versions are moved and tightened such
that they can actually detect if alias emission is enabled.
(see D40902 for context)

Differential Revision: https://reviews.llvm.org/D41225

Patch by Mario Werner.

llvm-svn: 320797
2017-12-15 09:47:01 +00:00
Alex Bradbury b014e3de52 [RISCV] Implement prolog and epilog insertion
As frame pointer elimination isn't implemented until a later patch and we make 
extensive use of update_llc_test_checks.py, this changes touches a lot of the 
RISC-V tests.

Differential Revision: https://reviews.llvm.org/D39849

llvm-svn: 320357
2017-12-11 12:34:11 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Alex Bradbury 74913e1c70 [RISCV] Codegen for conditional branches
A good portion of this patch is the extra functions that needed to be 
implemented to support the test case. e.g. storeRegToStackSlot, 
loadRegFromStackSlot, eliminateFrameIndex.

Setting ISD::BR_CC to Expand may appear non-obvious on an architecture with 
branch+cmp instructions. However, I found it much easier to deal with matching 
the expanded form.

I had to change simm13_lsb0 and simm21_lsb0 to inherit from the 
Operand<OtherVT> class rather than Operand<i32> in order to keep tablegen 
happy. This isn't a big deal, but it does seem a shame to lose the uniformity 
across immediate types when there's not an obvious benefit (I'm hoping a 
tablegen expert will educate me on what I'm missing here!).

Differential Revision: https://reviews.llvm.org/D29935

llvm-svn: 317690
2017-11-08 13:31:40 +00:00