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| author | Alexey Volkov <avolkov.intel@gmail.com> | 2014-05-20 08:55:50 +0000 |
|---|---|---|
| committer | Alexey Volkov <avolkov.intel@gmail.com> | 2014-05-20 08:55:50 +0000 |
| commit | 0d0bab5168239afddcc6a4fbcc73b101b570f563 (patch) | |
| tree | 2b1c12e5abd648345f55aa87864a772354782836 /lib/Target/X86/X86InstrInfo.cpp | |
| parent | 6f242c93ec57db744194ae3052fa59db71716ffe (diff) | |
| download | llvm-0d0bab5168239afddcc6a4fbcc73b101b570f563.tar.gz llvm-0d0bab5168239afddcc6a4fbcc73b101b570f563.tar.bz2 llvm-0d0bab5168239afddcc6a4fbcc73b101b570f563.tar.xz | |
[X86] Tune LEA usage for Silvermont
According to Intel Software Optimization Manual on Silvermont in some cases LEA
is better to be replaced with ADD instructions:
"The rule of thumb for ADDs and LEAs is that it is justified to use LEA
with a valid index and/or displacement for non-destructive destination purposes
(especially useful for stack offset cases), or to use a SCALE.
Otherwise, ADD(s) are preferable."
Differential Revision: http://reviews.llvm.org/D3826
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209198 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/X86InstrInfo.cpp')
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.cpp | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp index 6a2854790d..efb5c70c81 100644 --- a/lib/Target/X86/X86InstrInfo.cpp +++ b/lib/Target/X86/X86InstrInfo.cpp @@ -1728,12 +1728,8 @@ X86InstrInfo::isReallyTriviallyReMaterializable(const MachineInstr *MI, return true; } -/// isSafeToClobberEFLAGS - Return true if it's safe insert an instruction that -/// would clobber the EFLAGS condition register. Note the result may be -/// conservative. If it cannot definitely determine the safety after visiting -/// a few instructions in each direction it assumes it's not safe. -static bool isSafeToClobberEFLAGS(MachineBasicBlock &MBB, - MachineBasicBlock::iterator I) { +bool X86InstrInfo::isSafeToClobberEFLAGS(MachineBasicBlock &MBB, + MachineBasicBlock::iterator I) const { MachineBasicBlock::iterator E = MBB.end(); // For compile time consideration, if we are not able to determine the |