| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This PR fixes this situation:
(block $out
(local.set $x (struct.new X Y Z))
(struct.set $X 0 (local.get $x) (..br $out..)) ;; X' here has a br
)
(local.get $x)
=>
(block $out
(local.set $x (struct.new (..br $out..) Y Z))
)
(local.get $x)
We want to fold the struct.set into the struct.new, but the br is
a problem: if it executes then we skip the struct.set, and the last
local.get in fact reads the struct before the write. And, if we did this
optimization, we'd end up with the br on the struct.new, so it
would skip that instruction and even the local.set.
To fix this, we use the new API from #7039, which lets us query,
"is it ok to move the local.set to where the struct.set is?"
|
|
|
HeapStoreOptimization (#6882)
This just moves code out of OptimizeInstructions to the new pass. The existing
test is renamed and now runs the new pass instead. The new pass is run right
after each --optimize-instructions invocation, so it should not cause any
noticeable effects whatsoever, making this NFC.
The motivation here is that there is a bug in the pass, see the new testcase
added at the end, which shows the bug. It is not practical to fix that bug in
OptimizeInstructions since we need more than peephole optimizations to do
so. This PR moves the code to a new pass so we can fix it there properly,
later.
The new pass is named HeapStoreOptimization since the same infrastructure
we will need to fix the bug will also help dead store elimination and related
things.
|
