[PATCH] D60532: [X86] Teach foldMaskedShiftToScaledMask to look throw an any_extend from i32 to i64 between the and & shl

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
craig.topper added reviewers: spatel, RKSimon.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.
craig.topper updated this revision to Diff 194569.
craig.topper added a comment.

Upload the right patch. The other was partial


foldMaskedShiftToScaledMask tries to reorder and & shl to enable the shl to fold into an LEA. But if there is an any_extend between them it doesn't work.

This patch modifies the code to look through any_extend from i32 to i64 when the and mask only uses bits that weren't from the extended part.

This will prevent a regression from D60358 <https://reviews.llvm.org/D60358> caused by 64-bit SHL being narrowed to 32-bits when their upper bits aren't demanded.


https://reviews.llvm.org/D60532

Files:
  llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
  llvm/test/CodeGen/X86/fold-and-shift-x86_64.ll

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