13 Commits

Author SHA1 Message Date
Yingwei Zheng
ab12bba0aa
[CGP] Drop poison-generating flags after hoisting (#90382)
See the following case:
```
define i8 @src1(i8 %x) {
entry:
  %cmp = icmp eq i8 %x, -1
  br i1 %cmp, label %exit, label %if.then

if.then:
  %inc = add nuw nsw i8 %x, 1
  br label %exit

exit:
  %retval = phi i8 [ %inc, %if.then ], [ -1, %entry ]
  ret i8 %retval
}

define i8 @tgt1(i8 %x) {
entry:
  %inc = add nuw nsw i8 %x, 1
  %0 = icmp eq i8 %inc, 0
  br i1 %0, label %exit, label %if.then

if.then:                                          ; preds = %entry
  br label %exit

exit:                                             ; preds = %if.then, %entry
  %retval = phi i8 [ %inc, %if.then ], [ -1, %entry ]
  ret i8 %retval
}
```
`optimizeBranch` converts `icmp eq X, -1` into cmp to zero on RISC-V and
hoists the add into the entry block. Poison-generating flags should be
dropped as they don't still hold.

Proof: https://alive2.llvm.org/ce/z/sP7mvK
Fixes https://github.com/llvm/llvm-project/issues/90380
2024-04-29 15:51:49 +08:00
Alex Bradbury
1c8410a67d
[CodeGenPrepare] Preserve flags (such as nsw/nuw) in SinkCast (#89904)
As demonstrated in the test change, when deciding to sink a trunc we
were losing its flags. This patch moves to cloning the original
instruction instead.
2024-04-25 15:05:07 +01:00
Alex Bradbury
2554a85c03 [CodeGenPrepare][test] Add test for sinking of truncs demonstrating nsw/nuw are dropped
SinkCast creates a new cast with the same type and inputs, which drops
the nsw/nuw flags.

Reviewed as part of <https://github.com/llvm/llvm-project/pull/89904>
but split out so I can land the test separately.
2024-04-25 15:01:55 +01:00
Yingwei Zheng
38a44bdc93
[CodeGenPrepare] Reverse the canonicalization of isInf/isNanOrInf (#81572)
In commit
2b582440c1,
we canonicalize the isInf/isNanOrInf idiom into fabs+fcmp for better
analysis/codegen (See also the discussion in
https://github.com/llvm/llvm-project/pull/76338).

This patch reverses the fabs+fcmp to `is.fpclass`. If the `is.fpclass`
is not supported by the target, it will be expanded by TLI.

Fixes the regression introduced by
2b582440c1
and
https://github.com/llvm/llvm-project/pull/80414#issuecomment-1936374206.
2024-03-18 18:27:45 +08:00
Nick Anderson
f1ec0d12bb
Port CodeGenPrepare to new pass manager (and BasicBlockSectionsProfil… (#77182)
Port CodeGenPrepare to new pass manager and dependency
BasicBlockSectionsProfileReader
Fixes: #75380

Co-authored-by: Krishna-13-cyber <84722531+Krishna-13-cyber@users.noreply.github.com>
2024-01-09 13:32:59 +07:00
Simon Pilgrim
7648371c25 Revert 4d7c5ad58467502fcbc433591edff40d8a4d697d "[NewPM] Update CodeGenPreparePass reference in CodeGenPassBuilder (#77054)"
Revert e0c554ad87d18dcbfcb9b6485d0da800ae1338d1 "Port CodeGenPrepare to new pass manager (and BasicBlockSectionsProfil… (#75380)"

Revert #75380 and #77054 as they were breaking EXPENSIVE_CHECKS buildbots: https://lab.llvm.org/buildbot/#/builders/104
2024-01-05 12:28:10 +00:00
Nick Anderson
e0c554ad87
Port CodeGenPrepare to new pass manager (and BasicBlockSectionsProfil… (#75380)
Port CodeGenPrepare to new pass manager and dependency
BasicBlockSectionsProfileReader
Fixes: #64560

Co-authored-by: Krishna-13-cyber <84722531+Krishna-13-cyber@users.noreply.github.com>
2024-01-05 13:47:56 +07:00
Tobias Hieta
f84bac329b
[NFC][Py Reformat] Reformat lit.local.cfg python files in llvm
This is a follow-up to b71edfaa4ec3c998aadb35255ce2f60bba2940b0
since I forgot the lit.local.cfg files in that one.

Reformatting is done with `black`.

If you end up having problems merging this commit because you
have made changes to a python file, the best way to handle that
is to run git checkout --ours <yourfile> and then reformat it
with black.

If you run into any problems, post to discourse about it and
we will try to help.

RFC Thread below:

https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style

Reviewed By: barannikov88, kwk

Differential Revision: https://reviews.llvm.org/D150762
2023-05-17 17:03:15 +02:00
Jake Egan
08533f8b86 Revert "[CGP] Add generic TargetLowering::shouldAlignPointerArgs() implementation"
These commits are causing a test-suite build failure on AIX. Revert for now for time to investigate.
https://lab.llvm.org/buildbot/#/builders/214/builds/5779/steps/9/logs/stdio

This reverts commit bd87a2449da0c82e63cebdf9c131c54a5472e3a7 and 4c72266830ffa332ebb7cf1d3bbd6c56d001fa0f.
2023-02-14 15:20:06 -05:00
Alex Richardson
bd87a2449d [CGP] Add generic TargetLowering::shouldAlignPointerArgs() implementation
This function was added for ARM targets, but aligning global/stack pointer
arguments passed to memcpy/memmove/memset can improve code size and
performance for all targets that don't have fast unaligned accesses.
This adds a generic implementation that adjusts the alignment to pointer
size if unaligned accesses are slow.
Review D134168 suggests that this significantly improves performance on
synthetic benchmarks such as Dhrystone on RV32 as it avoids memcpy() calls.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D134282
2023-02-09 10:11:40 +00:00
Matt Arsenault
d9e51e7552 CodeGenPrepare: Convert most tests to opaque pointers
NVPTX/dont-introduce-addrspacecast.ll required manually removing a check for
a bitcast.

AArch64/combine-address-mode.ll required rerunning update_test_checks

Mips required some manual updates due to a CHECK-NEXT coming after a
deleted bitcast.

ARM/sink-addrmode.ll needed one small manual fix.

Excludes one X86 function which needs more attention.
2022-11-28 09:21:59 -05:00
Alex Bradbury
c44c1e9d3e [RISCV] Implement isMaskAndCmp0FoldingBeneficial hook
This hook is currently only used by CodeGenPrepare, which will sink *and
duplicate* an 'and' into a block that has an 'icmp 0' user of it if the
hook returns true.

This hook is less useful for RISC-V than for targets like AArch64 that
have a TBZ (test bit and branch if zero instruction), but may still be
profitable if Zbs is available and a BEXTI can be selected.

Conservatively, we return false even if Zbs is enabled for any masks
that fit in the ANDI immediate because it's possible the only use is a
branch on the result, and ANDI+BNEZ => BEXTI+BNEZ isn't a profitable
transformation.

Differential Revision: https://reviews.llvm.org/D131492
2022-09-13 18:54:00 +01:00
Fraser Cormack
eabf11f9ea [CodeGenPrepare] Avoid a scalable-vector crash in ctlz/cttz
This patch fixes a crash when despeculating ctlz/cttz intrinsics with
scalable-vector types. It is not safe to speculatively get the size of
the vector type in bits in case the vector type is not a fixed-length type. As
it happens this isn't required as vector types are skipped anyway.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D112141
2021-10-20 16:45:55 +01:00