Evan Cheng 376642ed62 Some enhancements for memcpy / memset inline expansion. ... 1. Teach it to use overlapping unaligned load / store to copy / set the trailing bytes. e.g. On 86, use two pairs of movups / movaps for 17 - 31 byte copies. 2. Use f64 for memcpy / memset on targets where i64 is not legal but f64 is. e.g. x86 and ARM. 3. When memcpy from a constant string, do *not* replace the load with a constant if it's not possible to materialize an integer immediate with a single instruction (required a new target hook: TLI.isIntImmLegal()). 4. Use unaligned load / stores more aggressively if target hooks indicates they are "fast". 5. Update ARM target hooks to use unaligned load / stores. e.g. vld1.8 / vst1.8. Also increase the threshold to something reasonable (8 for memset, 4 pairs for memcpy). This significantly improves Dhrystone, up to 50% on ARM iOS devices. rdar://12760078 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169791 91177308-0d34-0410-b5e6-96231b3b80d8		2012-12-10 23:21:26 +00:00
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llvm	Some enhancements for memcpy / memset inline expansion.	2012-12-10 23:21:26 +00:00
llvm-c	Revert r169656.	2012-12-10 21:33:45 +00:00