[llvm-dev] Update control flow graph when splitting a machine basic block?
Friedman, Eli via llvm-dev
llvm-dev at lists.llvm.org
Fri Nov 10 11:02:50 PST 2017
On 11/10/2017 4:33 AM, 章明 via llvm-dev wrote:
> Hi, there!
> There are situations where a machine basic block has to be split into
> two machine basic blocks, e.g., to place a constant pool entry or to
> fix a conditional branch so that its target is within its range
The right way to update the CFG very much depends on how you're
> However, it doesn't appear to be straightforward how the control flow
> graph should be updated when a machine basic block is split,
> especially when the split point is between two branches.In this case,
> in order to determine the successors of each of the two machine basic
> block, one needs to know the target of each terminator. If we ignore
> indirect branches whose targets are not known at compile-time, I
> wonder whether something like the following is viable or not:
Your pseudo-code looks similar to ARMBaseInstrInfo::analyzeBranch.
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