tree fffe0c7632558583b46e6a7b32b7f762a1aa1f3e
parent c1b79b3c594f1d5f7a22c60ffce7962ff4fbf8de
author Craig Topper <craig.topper@intel.com> 1553189938 +0000
committer Craig Topper <craig.topper@intel.com> 1553189938 +0000

[X86] Don't avoid folding multiple use sign extended 8-bit immediate into instructions under optsize.

Under optsize we try to avoid folding immediates into instructions under optsize. But if the immediate is 16-bits or 32 bits, but can be encoded as an 8-bit immediate we don't save enough from disabling the folding unless the immediate has enough uses to make up for the size of the move which is either 3 bytes or 5 bytes since there are no sign extended 8-bit moves. We would also save something if the immediate was a live out of the basic block and thus a move was unavoidable, but that would require a more advanced heuristic than just counting uses.

Note we only avoid folding multiple use immediates into the patterns that use X86ISD::ADD/SUB/XOR/OR/AND/CMP/ADC/SBB nodes and not the more common ISD::ADD/SUB/XOR/OR/AND nodes.

Differential Revision: https://reviews.llvm.org/D59522

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356688 91177308-0d34-0410-b5e6-96231b3b80d8