Commit Graph

13 Commits

Author SHA1 Message Date
Eric Wang d8a2d3f7d4 [NFC][Regalloc] Introduce the RegAllocPriorityAdvisorAnalysis
This patch introduces the priority analysis and the priority advisor,
the default implementation, and the scaffolding for introducing the
other implementations of the advisor.

Reviewed By: mtrofin

Differential Revision: https://reviews.llvm.org/D132835
2022-09-08 07:50:03 -07:00
Matthias Gehre af3758d678 Fix remaining test failures for "[llvm/CodeGen] Enable the ExpandLargeDivRem pass for X86, Arm and AArch64" 2022-09-06 16:38:43 +01:00
Luís Marques 260a641068 [RISCV] Pre-RA expand pseudos pass
Expand load address pseudo-instructions earlier (pre-ra) to allow follow-up
patches to fold the addi of PseudoLLA instructions into the immediate
operand of load/store instructions.

Differential Revision: https://reviews.llvm.org/D123264
2022-07-31 23:19:00 +02:00
Craig Topper 8cc483099a [RISCV] Teach RISCVCodeGenPrepare to optimize (i64 (and (zext/sext (i32 X), C1)))
If X is known positive by a dominating condition, we can fill in
ones into the upper bits of C1 if that would allow it to become an
simm12 allowing the use of ANDI.

This pattern often occurs in unrolled loops where the induction
variable has been widened.

To get the best benefit from this, I had to move the pass above
ConstantHoisting which is in addIRPasses. Otherwise the AND constant
is often hoisted away from the AND.

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D129888
2022-07-17 11:00:56 -07:00
Craig Topper 1a8468ba61 [RISCV] Add a RISCV specific CodeGenPrepare pass.
Initial optimization is to convert (i64 (zext (i32 X))) to
(i64 (sext (i32 X))) if the dominating condition for the basic block
guaranteed the sign bit of X is zero.

This frequently occurs in loop preheaders where a signed induction
variable that can never be negative has been widened. There will be
a dominating check that the 32-bit trip count isn't negative or zero.
The check here is not restricted to that specific case though.

A i32->i64 sext is cheaper than zext on RV64 without the Zba
extension. Later optimizations can often remove the sext from the
preheader basic block because the dominating block also needs a sext to
evaluate the greater than 0 check.

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D129732
2022-07-14 10:20:59 -07:00
Rahman Lavaee 3aa249329f Revert "[Propeller] Promote functions with propeller profiles to .text.hot."
This reverts commit 4d8d2580c5.
2022-05-26 18:45:40 -07:00
Rahman Lavaee 4d8d2580c5 [Propeller] Promote functions with propeller profiles to .text.hot.
Today, text section prefixes (none, .unlikely, .hot, and .unkown) are determined based on PGO profile. However, Propeller may deem a function hot when PGO doesn't. Besides, when `-Wl,-keep-text-section-prefix=true` Propeller cannot enforce a global section ordering as the linker can only reorder sections within each output section (.text, .text.hot, .text.unlikely).

This patch promotes all functions with Propeller profiles (functions listed in the basic-block-sections profile) to .text.hot. The feature is hidden behind the flag `--bbsections-guided-section-prefix` which defaults to `true`.

The new implementation refactors the parsing of basic block sections profile into a new `BasicBlockSectionsProfileReader` analysis pass. This allows us to use the information earlier in `CodeGenPrepare` in order to set the functions text prefix. `BasicBlockSectionsProfileReader` will be used both by `BasicBlockSections` pass and `CodeGenPrepare`.

Differential Revision: https://reviews.llvm.org/D122930
2022-05-26 16:23:21 -07:00
Chen Zheng d79275238f [MachineSink] replace MachineLoop with MachineCycle
reapply 62a9b36fcf and fix module build
failue:
1: remove MachineCycleInfoWrapperPass in MachinePassRegistry.def
   MachineCycleInfoWrapperPass is a anylysis pass, should not be there.
2: move the definition for MachineCycleInfoPrinterPass to cpp file.

Otherwise, there are module conflicit for MachineCycleInfoWrapperPass
in MachinePassRegistry.def and MachineCycleAnalysis.h after
62a9b36fcf.

MachineCycle can handle irreducible loop. Natural loop
analysis (MachineLoop) can not return correct loop depth if
the loop is irreducible loop. And MachineSink is sensitive
to the loop depth, see MachineSinking::isProfitableToSinkTo().

This patch tries to use MachineCycle so that we can handle
irreducible loop better.

Reviewed By: sameerds, MatzeB

Differential Revision: https://reviews.llvm.org/D123995
2022-05-26 06:45:23 -04:00
Lewis Revill 29a5a7c6d4 [RISCV] Add pre-emit pass to make more instructions compressible
When optimizing for size, this pass searches for instructions that are
prevented from being compressed by one of the following:

1. The use of a single uncompressed register.
2. A base register + offset where the offset is too large to be
   compressed and the base register may or may not already be compressed.

In the first case, if there is a compressed register available, then the
uncompressed register is copied to the compressed register and its uses
replaced. This is only done if there are enough uses that code size
would be improved.

In the second case, if a compressed register is available, then the
original base register is copied and adjusted such that:

new_base_register = base_register + adjustment
base_register + large_offset = new_base_register + small_offset

and the uses of the base register are replaced with the new base
register. Again this is only done if there are enough uses for code size
to be improved.

This pass was authored by Lewis Revill, with large offset optimization
added by Craig Blackmore.

Differential Revision: https://reviews.llvm.org/D92105
2022-05-25 09:25:02 +01:00
Chen Zheng 80c4910f3d Revert "[MachineSink] replace MachineLoop with MachineCycle"
This reverts commit 62a9b36fcf.
Cause build failure on lldb incremental buildbot:
https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/43994/changes
2022-05-24 22:43:37 -04:00
Chen Zheng 62a9b36fcf [MachineSink] replace MachineLoop with MachineCycle
MachineCycle can handle irreducible loop. Natural loop
analysis (MachineLoop) can not return correct loop depth if
the loop is irreducible loop. And MachineSink is sensitive
to the loop depth, see MachineSinking::isProfitableToSinkTo().

This patch tries to use MachineCycle so that we can handle
irreducible loop better.

Reviewed By: sameerds, MatzeB

Differential Revision: https://reviews.llvm.org/D123995
2022-05-24 01:16:19 -04:00
wangpc 4ff5e8184c [RISCV] Enable MachineOutliner by default under -Oz for RISCV
Enable default outlining when the function has the minsize attribute.

`addr-label.ll` crashed after enabling this, so a barrier is added before
instruction selection as a workaround.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D122213
2022-05-06 17:37:45 +08:00
Craig Topper 7cd78da8da [RISCV] Add tests showing the optimization pipeline for O0 and O3.
Other targets like ARM, AArch64, and X86 have similar tests.

Reviewed By: asb

Differential Revision: https://reviews.llvm.org/D120840
2022-03-09 21:42:09 -08:00