diff options
| author | Anton Korobeynikov <asl@math.spbu.ru> | 2009-11-24 00:44:37 +0000 |
|---|---|---|
| committer | Anton Korobeynikov <asl@math.spbu.ru> | 2009-11-24 00:44:37 +0000 |
| commit | 5cdc3a949af0cef7f2163f8a7acbf3049c226321 (patch) | |
| tree | 6cbd9b033b162075d09d6815be1c15f65f1bd468 /lib/Target/ARM/ARMSubtarget.cpp | |
| parent | 6935efcb667bcd4dd3a00bbd420461e1fadba73a (diff) | |
Materialize global addresses via movt/movw pair, this is always better
than doing the same via constpool:
1. Load from constpool costs 3 cycles on A9, movt/movw pair - just 2.
2. Load from constpool might stall up to 300 cycles due to cache miss.
3. Movt/movw does not use load/store unit.
4. Less constpool entries => better compiler performance.
This is only enabled on ELF systems, since darwin does not have needed
relocations (yet).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89720 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/ARM/ARMSubtarget.cpp')
| -rw-r--r-- | lib/Target/ARM/ARMSubtarget.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/lib/Target/ARM/ARMSubtarget.cpp b/lib/Target/ARM/ARMSubtarget.cpp index 432ed78c19..d6b072b6c2 100644 --- a/lib/Target/ARM/ARMSubtarget.cpp +++ b/lib/Target/ARM/ARMSubtarget.cpp @@ -27,6 +27,10 @@ UseNEONFP("arm-use-neon-fp", cl::desc("Use NEON for single-precision FP"), cl::init(false), cl::Hidden); +static cl::opt<bool> +UseMOVT("arm-use-movt", + cl::init(true), cl::Hidden); + ARMSubtarget::ARMSubtarget(const std::string &TT, const std::string &FS, bool isT) : ARMArchVersion(V4T) @@ -36,6 +40,7 @@ ARMSubtarget::ARMSubtarget(const std::string &TT, const std::string &FS, , ThumbMode(Thumb1) , PostRAScheduler(false) , IsR9Reserved(ReserveR9) + , UseMovt(UseMOVT) , stackAlignment(4) , CPUString("generic") , TargetType(isELF) // Default to ELF unless otherwise specified. |