diff options
Diffstat (limited to 'llvm/lib/Target/X86')
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index 1032137e8f6..329cdc0a53c 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -2025,8 +2025,7 @@ X86TargetLowering::getOptimalMemOpType(uint64_t Size, bool MemcpyStrSrc, MachineFunction &MF) const { const Function *F = MF.getFunction(); - if ((!IsMemset || ZeroMemset) && - !F->hasFnAttribute(Attribute::NoImplicitFloat)) { + if (!F->hasFnAttribute(Attribute::NoImplicitFloat)) { if (Size >= 16 && (!Subtarget.isUnalignedMem16Slow() || ((DstAlign == 0 || DstAlign >= 16) && @@ -2042,11 +2041,14 @@ X86TargetLowering::getOptimalMemOpType(uint64_t Size, return MVT::v4i32; if (Subtarget.hasSSE1()) return MVT::v4f32; - } else if (!MemcpyStrSrc && Size >= 8 && - !Subtarget.is64Bit() && - Subtarget.hasSSE2()) { + } else if ((!IsMemset || ZeroMemset) && !MemcpyStrSrc && Size >= 8 && + !Subtarget.is64Bit() && Subtarget.hasSSE2()) { // Do not use f64 to lower memcpy if source is string constant. It's // better to use i32 to avoid the loads. + // Also, do not use f64 to lower memset unless this is a memset of zeros. + // The gymnastics of splatting a byte value into an XMM register and then + // only using 8-byte stores (because this is a CPU with slow unaligned + // 16-byte accesses) makes that a loser. return MVT::f64; } } |
