diff options
| -rw-r--r-- | src/ir/effects.h | 3 | ||||
| -rw-r--r-- | src/passes/CodeFolding.cpp | 14 | ||||
| -rw-r--r-- | test/passes/code-folding.txt | 57 | ||||
| -rw-r--r-- | test/passes/code-folding.wast | 62 |
4 files changed, 134 insertions, 2 deletions
diff --git a/src/ir/effects.h b/src/ir/effects.h index 98911d451..b6eafae27 100644 --- a/src/ir/effects.h +++ b/src/ir/effects.h @@ -62,6 +62,9 @@ struct EffectAnalyzer : public PostWalker<EffectAnalyzer> { bool hasSideEffects() { return hasGlobalSideEffects() || localsWritten.size() > 0 || branches || implicitTrap; } bool hasAnything() { return branches || calls || accessesLocal() || readsMemory || writesMemory || accessesGlobal() || implicitTrap || isAtomic; } + // check if we break to anything external from ourselves + bool hasExternalBreakTargets() { return !breakNames.empty(); } + // checks if these effects would invalidate another set (e.g., if we write, we invalidate someone that reads, they can't be moved past us) bool invalidates(EffectAnalyzer& other) { if (branches || other.branches diff --git a/src/passes/CodeFolding.cpp b/src/passes/CodeFolding.cpp index 415cf38de..afcd3515c 100644 --- a/src/passes/CodeFolding.cpp +++ b/src/passes/CodeFolding.cpp @@ -61,6 +61,7 @@ #include "wasm-builder.h" #include "ir/utils.h" #include "ir/branch-utils.h" +#include "ir/effects.h" #include "ir/label-utils.h" namespace wasm { @@ -474,9 +475,18 @@ private: }; // let's see if we can merge deeper than num, to num + 1 auto next = tails; - // remove tails that are too short + // remove tails that are too short, or that we hit an item we can't handle next.erase(std::remove_if(next.begin(), next.end(), [&](Tail& tail) { - return effectiveSize(tail) < num + 1; + if (effectiveSize(tail) < num + 1) return true; + auto* newItem = getItem(tail, num); + // ignore tails that break to outside blocks. we want to move code to + // the very outermost position, so such code cannot be moved + // TODO: this should not be a problem in *non*-terminating tails, + // but double-verify that + if (EffectAnalyzer(getPassOptions(), newItem).hasExternalBreakTargets()) { + return true; + } + return false; }), next.end()); // if we have enough to investigate, do so if (next.size() >= 2) { diff --git a/test/passes/code-folding.txt b/test/passes/code-folding.txt index 031f93b91..e11999ac8 100644 --- a/test/passes/code-folding.txt +++ b/test/passes/code-folding.txt @@ -49,4 +49,61 @@ (f32.const 0) ) ) + (func $break-target-outside-of-return-merged-code (; 4 ;) (type $1) + (block $label$A + (if + (unreachable) + (block $block + (block $block0 + (block $label$B + (if + (unreachable) + (br_table $label$A $label$B + (unreachable) + ) + ) + ) + (return) + ) + ) + (block $block2 + (block $label$C + (if + (unreachable) + (br_table $label$A $label$C + (unreachable) + ) + ) + ) + (return) + ) + ) + ) + ) + (func $break-target-inside-all-good (; 5 ;) (type $1) + (block $folding-inner0 + (block $label$A + (if + (unreachable) + (block $block + (block $block4 + (br $folding-inner0) + ) + ) + (block $block6 + (br $folding-inner0) + ) + ) + ) + ) + (block $label$B + (if + (unreachable) + (br_table $label$B $label$B + (unreachable) + ) + ) + ) + (return) + ) ) diff --git a/test/passes/code-folding.wast b/test/passes/code-folding.wast index 32a32b28b..2064f2db6 100644 --- a/test/passes/code-folding.wast +++ b/test/passes/code-folding.wast @@ -52,5 +52,67 @@ ) ) ) + (func $break-target-outside-of-return-merged-code + (block $label$A + (if + (unreachable) + (block + (block + (block $label$B + (if + (unreachable) + (br_table $label$A $label$B + (unreachable) + ) + ) + ) + (return) + ) + ) + (block + (block $label$C + (if + (unreachable) + (br_table $label$A $label$C ;; this all looks mergeable, but $label$A is outside + (unreachable) + ) + ) + ) + (return) + ) + ) + ) + ) + (func $break-target-inside-all-good + (block $label$A + (if + (unreachable) + (block + (block + (block $label$B + (if + (unreachable) + (br_table $label$B $label$B + (unreachable) + ) + ) + ) + (return) + ) + ) + (block + (block $label$C + (if + (unreachable) + (br_table $label$C $label$C ;; this all looks mergeable, and is, B ~~ C + (unreachable) + ) + ) + ) + (return) + ) + ) + ) + ) ) |