Move RegStackify after coalescing and teach it to use LiveIntervals instead
of depending on SSA form. This avoids a problem where a register in a COPY
instruction is stackified and then subsequently coalesced with a register
that is not stackified.
This also puts it after the scheduler, which allows us to simplify the
EXPR_STACK constraint, as we no longer have instructions being reordered
after stackification and before coloring.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256402 91177308-0d34-0410-b5e6-96231b3b80d8
WebAssembly is currently using labels to end scopes, so for example a
loop scope looks like this:
BB0_0:
loop BB0_1
...
BB0_1:
with BB0_0 being the label of the first block not in the loop. This
requires that the label be printed even when it's only reachable via
fallthrough. To arrange this, insert a no-op LOOP_END instruction in
such cases at the end of the loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253901 91177308-0d34-0410-b5e6-96231b3b80d8
Always starting blocks at the top of their containing loops works, but creates
unnecessarily deep nesting because it makes all blocks in a loop overlap.
Refine the BLOCK placement algorithm to start blocks at nearest common
dominating points instead, which significantly shrinks them and reduces
overlapping.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253876 91177308-0d34-0410-b5e6-96231b3b80d8
This pass implements a simple algorithm for conversion from CFG to
wasm's structured control flow. It doesn't yet handle multiple-entry
loops; that will be added in a future patch.
It also adds initial support for switch statements.
Differential Revision: http://reviews.llvm.org/D12735
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247818 91177308-0d34-0410-b5e6-96231b3b80d8
