[PATCH] Add a shrink-wrapping pass to improve the placement of prologue and epilogue.
kparzysz at codeaurora.org
Thu Apr 23 06:29:49 PDT 2015
I have a patch that does this for Hexagon. It's implemented as a part of PEI, specifically in HexagonFrameLowering::insertPrologue.
The problem with multiple prologs is that this can increase code size, plus it's a lot harder to identify the set of registers that need to be saved in each prolog. You don't want to be saving more registers than you need.
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