llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-11 10:31:40 +00:00

History

Dan Gohman 4b35f83b91 Teach LoopSimplify how to merge multiple loop exits into a single exit,

when one of them can be converted to a trivial icmp and conditional
branch.

This addresses what is essentially a phase ordering problem.
SimplifyCFG knows how to do this transformation, but it doesn't do so
if the primary block has any instructions in it other than an icmp and
a branch. In the given testcase, the block contains other instructions,
however they are loop-invariant and can be hoisted. SimplifyCFG doesn't
have LoopInfo though, so it can't hoist them. And, it's important that
the blocks be merged before LoopRotation, as it doesn't support
multiple-exit loops.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74396 91177308-0d34-0410-b5e6-96231b3b80d8

2009-06-27 21:30:38 +00:00

Analysis

Eliminate a layer of indirection in LoopInfo and MachineLoopInfo.

2009-06-27 21:22:48 +00:00