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| author | Amara Emerson <amara@apple.com> | 2022-07-26 01:27:44 -0700 |
|---|---|---|
| committer | Amara Emerson <amara@apple.com> | 2022-07-27 10:51:16 -0700 |
| commit | 19cdd1908b173a0a4bdf29a18c689729fc3497ac (patch) | |
| tree | afe3d8dd0d13f17a9b6fac89eaea46823eb8668c /llvm/lib/CodeGen/MachineRegisterInfo.cpp | |
| parent | 24301569f080d60f644d7a69496596cbd65079ce (diff) | |
| download | llvm-19cdd1908b173a0a4bdf29a18c689729fc3497ac.zip llvm-19cdd1908b173a0a4bdf29a18c689729fc3497ac.tar.gz llvm-19cdd1908b173a0a4bdf29a18c689729fc3497ac.tar.bz2 | |
[AArch64][GlobalISel] Add heuristics for localizing G_CONSTANT.
This adds similar heuristics to G_GLOBAL_VALUE, querying the cost of
materializing a specific constant in code size. Doing so prevents us from
sinking constants which require multiple instructions to generate into
use blocks.
Code size savings on CTMark -Os:
Program size.__text
before after diff
ClamAV/clamscan 381940.00 382052.00 0.0%
lencod/lencod 428408.00 428428.00 0.0%
SPASS/SPASS 411868.00 411876.00 0.0%
kimwitu++/kc 449944.00 449944.00 0.0%
Bullet/bullet 463588.00 463556.00 -0.0%
sqlite3/sqlite3 284696.00 284668.00 -0.0%
consumer-typeset/consumer-typeset 414492.00 414424.00 -0.0%
7zip/7zip-benchmark 595244.00 594972.00 -0.0%
mafft/pairlocalalign 247512.00 247368.00 -0.1%
tramp3d-v4/tramp3d-v4 372884.00 372044.00 -0.2%
Geomean difference -0.0%
Differential Revision: https://reviews.llvm.org/D130554
Diffstat (limited to 'llvm/lib/CodeGen/MachineRegisterInfo.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/MachineRegisterInfo.cpp | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/MachineRegisterInfo.cpp b/llvm/lib/CodeGen/MachineRegisterInfo.cpp index 511bb80..dc109cd 100644 --- a/llvm/lib/CodeGen/MachineRegisterInfo.cpp +++ b/llvm/lib/CodeGen/MachineRegisterInfo.cpp @@ -420,6 +420,16 @@ bool MachineRegisterInfo::hasOneNonDBGUser(Register RegNo) const { return hasSingleElement(use_nodbg_instructions(RegNo)); } +bool MachineRegisterInfo::hasAtMostUserInstrs(Register Reg, + unsigned MaxUsers) const { + unsigned NumUsers = 0; + auto UI = use_instr_nodbg_begin(Reg), UE = use_instr_nodbg_end(); + for (; UI != UE && NumUsers < MaxUsers; ++UI) + NumUsers++; + // If we haven't reached the end yet then there are more than MaxUses users. + return UI == UE; +} + /// clearKillFlags - Iterate over all the uses of the given register and /// clear the kill flag from the MachineOperand. This function is used by /// optimization passes which extend register lifetimes and need only |