Commit Graph

17 Commits

Author SHA1 Message Date
Craig Topper 98d4adc2d1 [RISCV] Add custom isel to select (and (srl X, C1), C2) and (and (shl X, C1), C2)
Replace some existing isel patterns that are covered by the new
code. SLLIUWPat has been removed in favor of folding its root case
into the new code. The other uses in isel patterns for shXadd.uw
have been switched to using hardcoded AND masks.

This is based on the original version of D49585 from ARM. The final
version of that was made a DAG combine, but I've chosen to keep it
as custom isel. I'm not convinced DAG combine is as good with
shift pairs as it is with and+shift. I saw some issues optimizing
the shifts created by vscale lowering if an and isn't created for
from a shift pair.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D106230
2021-07-20 08:53:55 -07:00
Craig Topper 00c1cc867f [RISCV] Add more i32 srem/sdiv with power of 2 constant tests. NFC
Add a small power 2 srem test to match existing sdiv test. Add
larger power of 2 test to both.

The larger constant test shows materialization of a constant
for an AND in the RV64 code. We should be using W shift instructions
to match the RV32 code.
2021-07-18 00:21:14 -07:00
Craig Topper 1e670dc7d7 [RISCV] Use DIVUW/REMUW/DIVW instructions for i8/i16/i32 udiv/urem/sdiv when LHS is constant.
We don't really have optimizations for division with a constant
LHS. If we don't use a W instruction we end up needing to sign
or zero extend the RHS to use the 64-bit instruction.

I had to sign_extend i32 constants on the LHS instead of using
any_extend which becomes zero_extend. If we don't do this, constants
that were originally negative become harder to materialize. I think
this problem exists for more of our W instruction cases. For example
(i32 (shl -1, X)), but we don't have lit tests. I'll work on that
as a follow up.

I also left a FIXME for enabling W instruction for RHS constants
under -Oz.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D105769
2021-07-13 10:33:57 -07:00
Craig Topper 99b8c46828 [RISCV] Restore non-constant srem test I accidentally deleted. NFC 2021-07-10 18:02:13 -07:00
Craig Topper 86109fa9e8 [RISCV] Add test cases for div/rem with constant left hand side. NFC
Some of these would produce better code if we used W instructions,
but constant LHS currently prevents that.
2021-07-10 17:22:40 -07:00
Craig Topper 420bd5ee8e [RISCV] Use ComputeNumSignBits/MaskedValueIsZero in RISCVDAGToDAGISel::selectSExti32/selectZExti32.
This helps us select W instructions in more cases. Most of the
affected tests have had the sign_extend_inreg or AND folded into
sextload/zextload.

Differential Revision: https://reviews.llvm.org/D104079
2021-06-10 19:06:45 -07:00
Craig Topper 16fb1c7aae [RISCV] Add i8/i16 test cases to div.ll and i8/i16/i64 to rem.ll. NFC
This improves our coverage of these operations and shows that we
use really large constants for division by constant on i8/i16
especially on RV64. The issue is that BuildSDIV/BuildUDIV are
limited to legal types so we have to promote to i64 before it
kicks in. At that point we've lost the range information for the
original type.
2021-02-04 16:46:23 -08:00
Michael Munday e28b6a60bc [RISCV][NFC] Regenerate RISCV CodeGen tests
Regenerated using:

./llvm/utils/update_llc_test_checks.py -u llvm/test/CodeGen/RISCV/*.ll

This has added comments to spill-related instructions and added @plt to
some symbols.

Differential Revision: https://reviews.llvm.org/D92841
2020-12-09 19:42:49 +00:00
Alex Bradbury 61aa940074 [RISCV] Introduce codegen patterns for RV64M-only instructions
As discussed on llvm-dev
<http://lists.llvm.org/pipermail/llvm-dev/2018-December/128497.html>, we have
to be careful when trying to select the *w RV64M instructions. i32 is not a
legal type for RV64 in the RISC-V backend, so operations have been promoted by
the time they reach instruction selection. Information about whether the
operation was originally a 32-bit operations has been lost, and it's easy to
write incorrect patterns.

Similarly to the variable 32-bit shifts, a DAG combine on ANY_EXTEND will
produce a SIGN_EXTEND if this is likely to result in sdiv/udiv/urem being
selected (and so save instructions to sext/zext the input operands).

Differential Revision: https://reviews.llvm.org/D53230

llvm-svn: 350993
2019-01-12 07:43:06 +00:00
Shiva Chen d58bd8dc4a [RISCV] Expand function call to "call" pseudoinstruction
To do this:
1. Change GlobalAddress SDNode to TargetGlobalAddress to avoid legalizer
   split the symbol.

2. Change ExternalSymbol SDNode to TargetExternalSymbol to avoid legalizer
   split the symbol.

3. Let PseudoCALL match direct call with target operand TargetGlobalAddress
   and TargetExternalSymbol.

Differential Revision: https://reviews.llvm.org/D44885

llvm-svn: 330827
2018-04-25 14:19:12 +00:00
Alex Bradbury 921383828e [RISCV] Codegen support for the standard RV32M instruction set extension
llvm-svn: 322843
2018-01-18 12:36:38 +00:00
Alex Bradbury 7d6aa1f7ae [RISCV] Implement frame pointer elimination
llvm-svn: 322839
2018-01-18 11:34:02 +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
Alex Bradbury 660bcceccf [RISCV] Support lowering FrameIndex
Introduces the AddrFI "addressing mode", which is necessary simply because 
it's not possible to write a pattern that directly matches a frameindex.

Ensure callee-saved registers are accessed relative to the stackpointer. This
is necessary as callee-saved register spills are performed before the frame
pointer is set.

Move HexagonDAGToDAGISel::isOrEquivalentToAdd to SelectionDAGISel, so we can 
make use of it in the RISC-V backend.

Differential Revision: https://reviews.llvm.org/D39848

llvm-svn: 320353
2017-12-11 11:53:54 +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 ffc435e9c7 [RISCV] Support and tests for a variety of additional LLVM IR constructs
Previous patches primarily ensured that codegen was possible for the standard
RISC-V instructions. However, there are a number of IR inputs that wouldn't be
appropriately lowered. This patch both adds test cases and supports lowering
for a number of these cases:
* Improved sext/zext/trunc support
* Support for setcc variants that don't map directly to RISC-V instructions
* Lowering mul, and hence support for external symbols
* addc, adde, subc, sube
* mulhs, srem, mulhu, urem, udiv, sdiv
* {srl,sra,shl}_parts
* brind
* br_jt
* bswap, ctlz, cttz, ctpop
* rotl, rotr
* BlockAddress operands

Differential Revision: https://reviews.llvm.org/D29938

llvm-svn: 318737
2017-11-21 08:11:03 +00:00